12 Infection

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Contents

Objectives

When you have completed this unit you should be able to:

Preventing infection

12-1 What is infection?

Infection is the invasion of the body by organisms such as bacteria, viruses, fungi, spirochaetes and protozoa. This may result in disease by causing inflammation, abnormal growth, damage or death of tissues. In contrast, colonisation is simply the growth of organisms on a body surface, such as the skin, gut or airways, without the invasion of tissues.

12-2 How does the body prevent infection?

The immune system, which helps protect the body against infection, can be divided into 4 different parts:

  1. Antibodies (immunoglobulins), such as IgG, IgA and IgM, which damage organisms and attract phagocytic cells.
  2. Lymphocytes that produce antibodies and kill organisms.
  3. Phagocytic cells, such as macrophages and polymorphs, that ingest and, thereby, kill organisms.
  4. Complement. This is a group of proteins that help antibodies to damage organisms and attract phagocytic cells.

These different parts of the immune system all function together to destroy invading organisms and, thereby, protect the infant from infection.

12-3 Is infection common in newborn infants?

Yes. Newborn infants often become infected as the risk of infection in the newborn infant is much higher than in older children or adults. Infection is important as it is one of the commonest causes of death in infants during the first few months of life. Infection is particularly common and dangerous in preterm infants.

Infection is an important cause of death in young infants.

12-4 Why do newborn infants often become infected?

Infection is common in newborn infants because their immune system is immature. The following deficiencies in the immune system make newborn infants susceptible to infection:

  1. The antibodies IgA and IgM are too big to cross the placenta from the mother. The fetus and newborn infant, therefore, do not have maternal IgA and IgM to protect them from infection. However, during the first 6 months of life the infant gradually produces its own IgA and IgM.
  2. The antibody IgG does cross the placenta but most only crosses in the last weeks of pregnancy. Preterm infants, therefore, have very little IgG. After birth the infant starts to produce its own IgG as the amount of maternal IgG decreases.
  3. Both term and preterm infants have lymphocytes. However, these lymphocytes are immature and, therefore, do not function well. A mature lymphocyte needs previous contact with a specific organism before it is able to recognise and kill it. The function of lymphocytes improves as the infant gets older.
  4. The concentration of complement in the blood is low in newborn infants, especially if born preterm.
  5. The phagocytic cells are present in both term and preterm infants but they do not function normally due to the low concentrations of complement.

With all these deficiencies in the immature immune system of the newborn infant, especially if it is born preterm, it is not surprising that infections are common. By the age of a few months the immune system functions better and the growing infant becomes less susceptible to infections as it gets older.

12-5 How can you prevent infection in newborn infants?

There are many simple ways in which infections can be prevented in the newborn infant:

  1. Hand spraying and hand washing before touching an infant is the most important method of preventing infection in the nursery. Hands should be washed with a carbolic soap (e.g. Lifebuoy) when entering the nursery or when soiled with stool. Before handling an infant in the nursery, spray your hands with an antiseptic spray containing chlorhexidine and alcohol (e.g. D-Germ). It is best to handle infants in the nursery as little as possible as most infections are spread by hands. There is no evidence that gowns or masks reduce cross-infection.

    Everyone must always wash or spray their hands before handling an infant.

  2. Breastfeeding. Breast milk contains antibodies, lymphocytes, phagocytes and complement and, therefore, protects the gut of the infant from infections. Breast milk also encourages the growth of harmless bacteria in the gut and, thereby, lessens the growth of harmful bacteria.

    Breast milk protects infants against infections.

  3. The aseptic preparation of formula feeds, and the boiling of bottles and teats, in the milk kitchen is essential to prevent contaminated feeds. Clean preparation of formula at home is also important. It is better to use a cup rather than a bottle as it is easier to clean.
  4. Vernix has antibacterial properties and, therefore, should not be washed off routinely at delivery. After a few hours it is absorbed by the skin.

    Do not routinely wash off vernix after delivery.

  5. Bathing infants with a carbolic soap (e.g. Lifebuoy) or chlorhexidine (e.g. Bioscrub) reduces colonisation with harmful bacteria. Sweet smelling, white or coloured soaps are often not antibacterial.
  6. Stethoscopes and other instruments should be sprayed with an antiseptic spray (e.g. D-Germ) before an infant is examined.
  7. Routine care of the umbilical stump with alcohol (surgical spirits) prevents infection.
  8. Immunisation of all pregnant women with tetanus toxoid prevents neonatal tetanus complicating cord infection.
  9. Routine prophylactic eye care after delivery with tetracycline, chloromycetin or erythromycin ointment or povidone-iodine drops prevents conjunctivitis resulting from colonisation with Gonococci during delivery.
  10. Avoid kissing newborn infants as this may spread harmful viruses such as Herpes simplex. Parents or staff with active herpes infection of the lips must be very careful when handling infants.
  11. Avoid overcrowding in nurseries by keeping normal infants with their mothers whenever possible.

    The risk of cross-infection in a nursery increases with overcrowding.

  12. Skin-to-skin care (kangaroo mother care) to colonise the infant with the mother’s bacteria (rather than the hospital bacteria) is an important method of reducing serious infection.

    Skin-to-skin care reduces serious infections in hospital.

  13. Isolation of infected infants is usually not needed if a policy of frequent hand washing is practised in the nursery. However, infants with gastroenteritis should not be nursed near well infants. If possible, newborn infants should not be nursed in a general children’s ward but rather in a special newborn nursery.
  14. It is not necessary to restrict visits of parents and family in the nursery provided that strict hand washing and hand spraying are enforced. There is no need for visitors to wear masks or gowns. Children with coughs and colds should not visit.

12-6 What are the sources of infection?

The infant may be colonised or infected:

  1. Before delivery. This may be due to infection crossing the placenta from the mother’s blood stream to cause a chronic intra-uterine infection (non-bacterial) in the fetus, e.g. syphilis and HIV, or due to an acute infection (bacterial) spreading from the vagina into the membranes and liquor, i.e. chorioamnionitis.
  2. During delivery. The infant is colonised as it passes through the cervix and vagina during delivery and may present with infection hours or days after delivery, e.g. Gonococcal conjunctivitis.
  3. After delivery. When the newborn infant becomes colonised and may later be infected in the home or nursery, e.g. Staphylococcal infection of the umbilical cord.
Note
Nosocomial infections are infections acquired in hospital when organisms are spread from one infant to another. They usually present at 72 hours or more after birth. Earlier infections usually result from colonisation during labour or delivery.

Infants that are born at home and then brought to hospital soon after delivery are often incorrectly regarded as infected and, therefore, not allowed into the nursery. These infants are only rarely infected and do not spread infection to the infants born in hospital. They should be cared for in the nursery and not in a general ward with older children.

12-7 How are infections classified?

For convenience, infections in the newborn infant can be divided into:

  1. Minor acute infections, which usually do not kill the infant.
  2. Major acute infections, which may kill the infant.
  3. Chronic intra-uterine infections where the fetus has been infected across the placenta.

Minor infections

12-8 What are the common, minor infections?

The common minor acute infections in the newborn infant are:

  1. Conjunctivitis
  2. Infection of the umbilical cord
  3. Skin infection
  4. Oral thrush

12-9 What are the signs of conjunctivitis?

Conjunctivitis presents in one or both eyes with:

  1. An exudate (discharge) from the eyes
  2. Redness of the conjunctivae
  3. Oedema of the eyelids

The degree of conjunctivitis can be divided into mild, moderate and severe:

  1. Mild conjunctivitis consists of a slight muco-purulent discharge causing a dry exudate on the eyelashes. The eyelids tend to stick together.
  2. Moderate conjunctivitis presents with redness of the conjunctivae with an obvious purulent discharge. Pus is present in the eye when the lids are separated.
  3. Severe conjunctivitis has a marked purulent discharge with oedema of the eyelids. Pus spurts from the eye and runs down the cheeks when the eyelids are opened. In the most severe cases, it is not possible to separate the eyelids due to the oedema.

Mild conjunctivitis is the most common while severe conjunctivitis the least common form of conjunctivitis.

12-10 What are the causes of conjunctivitis?

In the newborn infant conjunctivitis is usually caused by:

  1. Chlamydia trachomatis. It is sexually transmitted and causes infection of the cervix. During vaginal delivery the eyes of the infant may be colonised with Chlamydia as the infant passes through the cervix. Chlamydial conjunctivitis, which is usually mild, develops in one or both eyes a few days after delivery. The infection lasts a few weeks and then resolves spontaneously if not treated. Chlamydia is probably the commonest cause of conjunctivitis in the newborn infant.

    Note
    In some infants the Chlamydia organism may spread and infect the upper airways via the nasolacrimal duct. From here the infection spreads to the lungs and can cause pneumonia a few weeks after birth. Another strain of Chlamydia causes trachoma. Chlamydia is an unusual organism with features of both bacteria and viruses. It responds to antibiotics like bacteria but can only be grown in cell culture like a virus.
  2. Gonococcus (Neisseria gonorrhoeae). This bacteria causes mild, moderate or severe conjunctivitis. Severe conjunctivitis is most important as it can result in blindness. Like Chlamydia, the Gonococcus is sexually transmitted and causes a cervicitis. The eyes of the infant are colonised during vaginal delivery and conjunctivitis develops hours or days thereafter.

    The Gonococcus causes severe conjunctivitis which may result in blindness.

  3. Staphylococcus. This, and other bacteria acquired in the nursery after delivery, can also cause conjunctivitis.

    It is very difficult to identify the cause of the conjunctivitis by clinically examining the eye, although most cases of severe infection are caused by the Gonococcus. Gonococci and Staphylococci can be seen on a Gram stain of pus wiped from the eye. They can also be cultured in the laboratory. Unfortunately Chlamydia is not seen on a Gram stain and is very difficult to culture. The clinical diagnosis of Chlamydia conjunctivitis, therefore, is rarely confirmed.

Note
Chlamydial infection can be confirmed by an immunofluorescent test performed on pus swabbed from the eye.

12-11 What is the management of conjunctivitis?

The choice of treatment depends on the severity of the conjunctivitis as the causative organism is often not known at the time of diagnosis.

  1. Mild conjunctivitis can usually be treated by cleaning the eye with saline or warm water if the lashes become sticky. A local antibiotic is frequently not needed. However, if the infection does not recover in a few days, tetracycline or chloromycetin ointment should be used 6 hourly for 5 days. Tetracycline, chloromycetin and erythromycin ointment will kill Gonococcus but only erythromycin and tetracycline will treat Chlamydia.
  2. Moderate conjunctivitis should be treated by cleaning the eye and then instilling tetracycline or chloromycetin ointment 3 hourly or more frequently if needed. Usually 5 days treatment is needed.
  3. Severe conjunctivitis is a medical emergency as it can lead to blindness if not promptly and efficiently treated. The infection is usually due to the Gonococcus and treatment consists of irrigating the eye and giving intramuscular ceftriaxone.
    • The pus must be washed out of the eye with saline or warm water. This must be started immediately and repeated frequently enough to keep the eye clear of pus. The simplest way of irrigating the eye is to use a vacolitre of normal saline via an administration set.
    • Intramuscular Ceftriaxone daily for 3 days must be given. Many strains of Gonococcus are now resistant to penicillin. Therefore intramuscular or intravenous penicillin should only be used if ceftriaxone is not available. Local antibiotic drops alone are inadequate for treating a severe conjunctivitis as the infection may have already spread to involve the whole eye.
    • Only when this treatment has been started should the infant be referred urgently to hospital for further management.
    • If possible a pus swab should be taken before treatment is started to confirm the diagnosis of Gonococcal conjunctivitis. When positive, the mother and her partner must be treated. Also look for other sexually transmitted diseases such as syphilis.

Intramuscular ceftriaxone is used to treat severe conjunctivitis.

12-12 What are the signs of an infected umbilical cord?

A healthy umbilical cord stump is white and soft at delivery. With good cord care it becomes dark brown and dehydrated within a few days, and at no stage does it smell offensive or have an exudate.

Infection of the umbilical cord (omphalitis) presents with:

  1. An offensive (smelly) discharge over the surface of the cord.
  2. Failure of the cord to become dehydrated (i.e. the cord remains wet and soft).
  3. Erythema of the skin around the base of the cord (a flare).

The commonest site of infection is at the base where the cord meets the skin. There is no oedema of the skin around the base of the cord with an uncomplicated cord infection. The infant is generally well when the infection is localised to the cord only.

Umbilical cord infection may spread to the anterior abdominal wall (cellulitis) from where it may cause a peritonitis or septicaemia. Signs that the infection of the umbilical cord has extended to the abdominal wall are:

  1. Redness and oedema of the skin around the base of the cord.
  2. Abdominal distension often with decreased bowel sounds and vomiting (peritonitis).
  3. The infant is generally unwell with the features of septicaemia.

Cellulitis, peritonitis and septicaemia are not minor but major infections and the infant may die if not treated immediately.

Infection of the umbilical cord may also cause tetanus in the newborn infant if the mother has not been fully immunised.

12-13 What are the causes of umbilical cord infection?

Infection of the umbilical cord usually is caused by:

  1. Bacteria that colonise the infant’s bowel such as Escherichia coli
  2. Staphylococcus
  3. Clostridium tetani that causes tetanus

12-14 How do you treat umbilical cord infection?

With good preventative cord care, infection of the umbilical cord should not occur. Prevention consists of routine applications of alcohol (surgical spirits) to the cord every 6 hours until it is dehydrated. Antibiotic powder is not used. Never cover the cord as this keeps it moist.

If the infection is localised to the umbilical cord, and there are no signs of cellulitis, peritonitis, septicaemia or tetanus, then treatment consists simply of cleaning the cord frequently with surgical spirits. Neither local nor systemic antibiotics are needed. The cord should be carefully cleaned with a swab and adequate amounts of spirits every 3 hours to clear the infection and hasten dehydration. Special attention must be paid to the folds around the base of the cord which often remain moist. Within 24 hours the infection should have resolved. Keep a careful watch for signs that the infection may have spread beyond the umbilicus.

Cellulitis of the abdominal wall around the base of the cord (redness and oedema of the skin), peritonitis or septicaemia must be treated with parenteral antibiotics.

12-15 What is tetanus?

Tetanus in the newborn infant (tetanus neonatorum) is caused by the bacterium, Clostridium tetani, which infects dead tissues such as the umbilical cord. Clostridium tetani usually occurs in soil and faeces, which may be placed on the cord or other wounds as a traditional practice. It produces a powerful toxin that affects the nervous system.

Tetanus presents with:

  1. Increased muscle tone, especially of the jaw muscles and abdomen.
  2. Generalised muscle spasms and convul­sions, often precipitated by stimulation such as handling or loud noises.
  3. Respiratory failure and death in untreated infants, due to spasm of the respiratory muscles.

12-16 How do you manage tetanus?

Tetanus can be prevented by:

  1. Good cord care
  2. Immunising all pregnant women with tetanus toxoid if tetanus is common in the region.

The emergency treatment of tetanus consists of:

  1. Keeping the airway clear and giving oxygen.
  2. Not stimulating the infant.
  3. Stopping spasms with 1 mg diazepam (Valium) intravenously or rectally, repeatedly until the spasms stop. You may have to mask ventilate the infant.
  4. Transferring the infant urgently to the nearest level 2 or 3 hospital.
Note
Hospital management of tetanus includes penicillin, human anti-tetanus immunoglobulin, tracheotomy, paralysis and ventilation.

12-17 What are the signs and causes of skin infection?

The 2 commonest forms of skin infection in the newborn infant are:

  1. Bullous impetigo caused by the Staphylo­coccus which presents as pus-filled blisters usually seen around the umbilicus or in the nappy area.
  2. A rash caused by the fungus Candida albicans. This almost always occurs in the nappy area and presents as a red, slightly raised, ‘velvety’ rash which is most marked in the skin creases.

Rashes that frequently mimic skin infections are:

  1. Erythema toxicum which usually appears on day 2 or 3 after delivery as red blotches which develop small yellow pustules in the centre. The rash is most marked on the face and chest and disappears after about a week. The cause is not known, the infants remain generally well and no treatment is needed. This rash is important as it may look like a Staphylococcal infection.
  2. Nappy rash is due to irritation of the skin by stool and urine and, unlike a Candida rash, usually spares the creases.
  3. Sweat rash may present as small, clear blisters on the forehead or a fine red rash on the neck and trunk. Both are due to excessive sweating when an infant is kept too warm. Blisters are caused by the droplets of sweat that are not able to get through the upper layer of the skin while the red rash is due to the irritant effect of the salty sweat on the skin. Treat both rashes by washing the infant, to remove the sweat, and prevent overheating.
  4. Pustular melanosis is usually present at birth as small blisters that soon burst to leave a small, peeling, pigmented area of skin. Sometimes the blisters have already burst before delivery. The infants are well and the rash slowly disappears without treatment.
Note
The blisters in bullous impetigo are filled with Gram-positive cocci and pus cells while the pustules in erythema toxicum are filled with eosinophils only.

12-18 How do you treat skin infections?

If vernix is not routinely washed off immediately after birth and if strict attention is paid to hand washing and spraying, skin infection should not be a problem in a nursery.

  1. Bullous impetigo is treated by washing the infant in chlorhexidine (e.g. Bioscrub) twice a day for 5 days. Do not cover the infected area with a nappy. Treat any cord infection. Wash hands well after handling the infant to prevent the spread of infection to other infants. If the infant remains generally well, local or systemic antibiotics are not needed. However, if the infant should become unwell and show any signs of septicaemia, then urgent treatment with parenteral antibiotics is indicated.
  2. Candida rash should be treated with topical mycostatin (Nystatin) cream and the area should not be covered. Allow the infant to sleep prone on a nappy to keep the infected area of skin exposed to the air. A little sunshine will also help but do not let the infant get too hot or sunburned. If the rash does not improve in 48 hours, give oral mycostatin drops also to decrease the number of Candida spores in the stool.

12-19 What is the cause and clinical presentation of oral thrush?

Oral thrush (candidiasis or moniliasis) is caused by the fungus Candida albicans, which may also cause skin infections. Oral thrush presents as patches of white coating on the tongue and mucous membrane of the mouth. Unlike a deposit of milk curds, sometimes seen after a feed, thrush cannot be easily wiped away. The degree of infection varies from mild to severe:

  1. With mild infection there are only scattered areas of thrush with the remainder of the mucous membrane appearing healthy. The infant also sucks well. Mild thrush is very common, especially in breastfed infants.
  2. In contrast, with severe infection there are extensive areas of thrush. The tongue and mucous membrane are red and the infant feeds poorly due to a painful mouth. The infant appears miserable and may lose weight or even become dehydrated.

Repeated, severe oral thrush in a young infant should always suggest AIDS.

12-20 How would you treat oral thrush?

The treatment of oral thrush depends on the degree of infection:

  1. Mild thrush usually does not need to be treated as it does not cause discomfort and the infant feeds normally. The infection usually clears spontaneously. Sometimes the infection may become severe.
  2. Severe thrush requires treatment as it interferes with feeding. The treatment of choice is 1 ml mycostatin drops (Nystatin) into the mouth after each feed. Mycostatin ointment can also be used and should be wiped onto the oral mucous membrane with a swab or clean finger. Treatment should be continued for a week. Gentian violet can be used if mycostatin is not available. It is very messy, however, and may occasionally cause mucosal damage.

It is essential to also look for and treat the source of infection:

  1. In a breastfed infant the source usually is Candida colonisation of the mother’s nipples. Mycostatin ointment should be smeared on the nipple and areolae after each feed. If the mother has a monilial vaginal discharge, this should be treated with mycostatin vaginal cream to reduce skin colonisation with Candida.
  2. In bottle-fed infants, the bottles and teats must be boiled after the feed. Disinfectant solutions such as Milton and Jik are very useful to prevent bacterial contamination of bottles but may not kill Candida. Rather use a cup than a bottle for feeding as it is easier to clean. Dummies should be boiled.

If the infant is treated, but the source is not correctly managed, the oral thrush will return once the treatment is stopped.

Major infections

12-21 What are the major infections in newborn infants?

The most frequent major acute infections in newborn infants are:

  1. Septicaemia
  2. Pneumonia
  3. Meningitis
  4. Necrotising enterocolitis

Other less common major infections include urinary tract infections and osteitis.

12-22 What causes septicaemia?

Septicaemia is infection of the blood stream with bacteria which may have colonised the infant before, during or after birth. Septicaemia is often a complication of a local infection, e.g. pneumonia, umbilical cord or skin infection.

Septicaemia can be caused by either Gram-positive bacteria (e.g. Staphylococcus and Group B Streptococcus) or Gram-negative bacteria (e.g. Escherichia coli, Klebsiella and Pseudomonas).

Note
Bacteria are divided into 2 groups depending on their appearance under the microscope after exposure to Gram’s stain. If they take up the stain and appear purple, they are called Gram-positive. In contrast, Gram-negative bacteria do not take up the stain and, therefore, appear pink.

12-23 What are the clinical signs of septicaemia?

The clinical signs of septicaemia are often non-specific, making the early diagnosis of septicaemia difficult. The common clinical signs are:

  1. Lethargy. The infant appears less active than before and is generally unwell. This usually is the earliest sign of septicaemia but unfortunately needs experience to recognise and may be caused by many other conditions.
  2. Poor feeding or poor sucking. The infant may also fail to gain weight or may even lose weight. These signs are of particular importance if the infant had previously been feeding well.
  3. Abdominal distension, vomiting and decreased bowel sounds (ileus).
  4. Pallor. This is only partially explained by anaemia.
  5. Jaundice, which may be due to a raised concentration of both unconjugated and conjugated bilirubin in the blood.
  6. Purpura (petechiae) due to too few platelets. Often also bleeding from puncture sites (due to a disseminated intravascular coagulopathy). This indicates that the infant is severely ill.
  7. Recurrent apnoea.
  8. Hypothermia. Fever is far less common.
  9. Oedema or sclerema (a woody feel to the skin).

The infant may also have signs of a local infection, e.g. umbilical cord infection, pneumonia or meningitis.

A septicaemic infant may present with one or more of these signs. Once most of the clinical signs are present and the diagnosis is easily made, it is often too late to save the infant. An early clinical diagnosis is, therefore, essential.

An early diagnosis of septicaemia in a newborn infant is often difficult.

The diagnosis of septicaemia is confirmed by blood culture. Treatment must be started immediately, however, as it may be a few days before the blood culture results are available.

Note
Unfortunately laboratory investigations are not of much help in making an early diagnosis of septicaemia. A positive blood culture should occur by 48 hours. A total white count of less than 5000, or an immature to total neutrophil ratio of more than 20%, is highly suggestive of septicaemia. A normal CRP (C-reactive protein) does not exclude septicaemia as it may take many hours to become positive. Testing the urine for Streptococcal group B antigen (Wellcogen Strep B kit) is only of limited help in diagnosing septicaemia as it may simply indicate colonisation.

12-24 How should you treat septicaemia?

Management of septicaemia consists of:

  1. General supportive care of a sick infant. Often transfer to a level 3 unit is needed.
  2. Antibiotics. When culture and sensitivity results are available, the most appropriate antibiotic is chosen. While awaiting these results, however, the antibiotics most commonly used are either:
    • Benzyl penicillin 50 000 units/kg/dose plus gentamicin (Garamycin) 5 mg/kg/dose; or cloxacillin 50 mg/kg/dose plus amikacin (Amikin) 5 mg/kg/dose. These are usually the first drug combinations of choice.
    • Cefotaxime (Claforan) 50 mg/kg/dose or ceftriaxone (Rocephin) 50 mg/kg/dose. They are usually the second choice of antibiotic.

Penicillin, cloxacillin and cefotaxime are given in divided doses either intravenously or intramuscularly every 12 hours for infants under one week and every 8 hours after one week of age. Ceftriaxone has the advantage of being given once a day intravenously or intramuscularly. Gentamicin and amikacin are given also intravenously daily. Antibiotics should be continued for 10 days.

It is very important that each hospital has an antibiotic policy which includes guidelines of the appropriate antibiotics to use in severely ill newborns. The choice of antibiotics may vary between hospitals depending on local patterns of antibiotic resistance.

12-25 What causes pneumonia?

Pneumonia may be acquired as the result of colonisation of the upper airways before, during or after delivery:

  1. Before delivery the fetus may be infected by inhaling liquor that is colonised by bacteria that have spread from a chorioamnionitis.
  2. The lungs may be infected by organisms that colonise the infant’s upper airways during delivery.
  3. Most pneumonia in the nursery is due to bacteria that are spread to the infant on the hands of the mother and staff.
Note
Anaerobic bacteria, E. coli and the group B Streptococcus are the commonest organisms infecting the fetus before delivery while the group B Streptococcus and Chlamydia may colonise the infant during delivery. In the nursery, Staphylococcus aureus and bowel organisms are important.

12-26 How should you diagnose pneumonia?

  1. The diagnosis is usually made by observing typical clinical signs.
    • The infant develops signs of respiratory distress (tachypnoea, cyanosis, recession and grunting).
    • Signs of pneumonia may or may not be heard with a stethoscope. Listening to the chest is not a reliable method of diagnosing pneumonia in infants.
    • There are usually also signs of septicaemia.
  2. A chest X-ray will show the typical features of pneumonia with areas of consolidation.

12-27 How should you treat pneumonia?

  1. General supportive care is important. Transfer to a level 3 unit may be needed.
  2. Usually oxygen is needed.
  3. Give intravenous or intramuscular anti­biotics. Usually cefotaxime or ceftriaxone, or penicillin and gentamicin are given.

12-28 How do you diagnose bacterial meningitis?

The diagnosis of meningitis in the newborn infant is often very difficult as it usually does not present with the signs of neck stiffness, full fontanelle, photophobia, vomiting and headache common in older children with meningitis. The infant is usually generally ill and may have signs of septicaemia. In addition the infant may:

  1. Be irritable with a high-pitched cry.
  2. Have abnormal movements or convulsions.
  3. Tend to stare and keep the fists clenched.
  4. Have recurrent apnoea or cyanotic spells.

If meningitis is suspected, a lumbar puncture must be done to confirm or exclude the diagnosis. The sample of cerebrospinal fluid (CSF) must be examined for chemistry and cells, and it must be cultured for bacteria.

Note
In the first week of life the normal values are:
Protein 0.25–2.5 g/l
Glucose 2.2–3.3 mmol/l
Polymorphs 0–15 per mm³
Lymphocytes 0–15 per mm³

12-29 How do you treat bacterial meningitis?

  1. Bacterial meningitis in the newborn infant is usually caused by Gram-negative bacilli (e.g. E. coli or Klebsiella) or the Group B Streptococcus. The choice of antibiotics must cover both these groups of bacteria and also cross well from the blood stream into the cerebrospinal fluid. The drugs usually used are either cefotaxime 50 mg/kg/dose intravenously or intramuscularly every 12 hours or ceftriaxone 100&mg/kg/dose as a daily dose. The antibiotic should be given for 14 days. Half the infants with bacterial meningitis die despite treatment while half the survivors have permanent brain damage. Deafness, convulsions and cerebral palsy are common complications.
  2. To prevent or treat convulsions give phenobarbitone 20 mg/kg intravenously or intramuscularly, then follow with 5 mg/kg orally daily until the infant is clinically well.
  3. These ill infants need good supportive care and may need transfer to a level 3 unit.

12-30 What is necrotising enterocolitis?

Necrotising enterocolitis (NEC) is necrosis (death) of part or all of the small and large intestine. It is usually seen in 2 groups of newborn infants:

  1. Term infants who have had severe intrapartum hypoxia which has caused ischaemia and damage to the gut.
  2. Preterm infants who have been infected in the nursery. This form of necrotising enterocolitis may occur in epidemics.

12-31 What are the clinical signs of necrotising enterocolitis?

Either ischaemia or infection damages the bowel wall, and the infant presents with:

  1. Signs of septicaemia and often shock.
  2. Abdominal distension and ileus. The abdomen is tender when palpated.
  3. Vomiting which is often bile stained.
  4. Blood in the stool. This may only be detected when the stool is tested for occult blood.

An X-ray of the abdomen may show air in the bowel wall. This finding will confirm the clinical diagnosis of necrotising enterocolitis. All infants with one or more clinical signs of necrotising enterocolitis should have an X-ray taken of the abdomen.

Always think of necrotising enterocolitis when an infant presents with a distended abdomen.

While some infants with necrotising enterocolitis recover with treatment, others develop complications that can lead to death:

  1. Bowel perforation
  2. Massive haemorrhage from the gut
  3. Septicaemia
  4. Malabsorption and multiple strictures as late complications after the acute illness

12-32 What is the management of necrotising enterocolitis?

These are extremely ill infants who must be referred to a level 2 or 3 hospital. Before transferring them, the following management is needed:

  1. A nasogastric tube must be passed to relieve the bowel distension.
  2. Keep nil per mouth and start an intravenous infusion. Stabilised human serum or fresh frozen plasma may be needed to treat shock.
  3. Give general supportive care.
  4. Give penicillin, gentamicin and metro­nidizole intravenously.
Note
At the referral unit, parenteral nutrition is usually needed for a week or 2 while the damaged gut recovers. Bowel resection may be needed for extensive necrosis or perforation. Mortality following surgery is high. Metronidazole (Flagyl) 25 mg/kg/day is given orally or intravenously 8 hourly.

Chorioamnionitis

12-33 What is chorioamnionitis?

Chorioamnionitis is a common acute inflammation of the chorion, amnion and placenta. Normally the intra-uterine cavity is sterile during pregnancy. However, bacteria from the vagina sometime spread through the cervical canal and infect the chorion, amnion and placenta, resulting in chorioamnionitis. The infection may then spread to the amniotic fluid (amniotic fluid infection syndrome) and colonise the fetus. Fortunately most bacteria causing chorioamnionitis (anaerobes) colonise but usually do not infect the fetus. However, some bacteria, such as E. coli and the group B Streptococcus, may infect the fetus causing pneumonia and septicaemia.

Chorioamnionitis may occur with intact membranes, although it is most common after prolonged rupture of the membranes. Chorioamnionitis weakens the membranes and, therefore, is often the cause rather than the complication of preterm or prelabour rupture of the membranes.

Most bacteria causing chorioamnionitis stimulate the chorion and amnion to produce prostaglandins and, thereby, induce labour. Chorioamnionitis is the commonest cause of preterm labour and, therefore, should be suspected in all preterm infants born after the spontaneous onset of labour or prelabour rupture of the membranes.

Chorioamnionitis can cause preterm labour and prelabour rupture of the membranes.

12-34 How can you diagnose chorioamnionitis after delivery?

Chorioamnionitis is usually asymptomatic in the mother and, therefore, is often not diagnosed before delivery. Only if the infection is severe will the mother develop fever, abdominal tenderness and possibly an offensive vaginal discharge. If the infection has spread to the amniotic fluid, the infant may smell offensive at delivery. Most of these colonised infants will be clinically well but some will develop signs of infection at or soon after delivery. Severe chorioamnionitis may also cause placental oedema and result in fetal hypoxia.

Note
The diagnosis of chorioamnionitis can be made at birth by examining a sample of gastric aspirate, collected within 30 minutes of delivery, under the microscope. The presence of pus cells indicates chorioamnionitis while bacteria on a Gram stain indicates amniotic fluid colonisation as well. The stripped amnion appears cloudy. Whether the infant is infected or only colonised must be decided on clinical examination.

12-35 How do you manage an infant with chorioamnionitis?

Usually the infant appears well and does not need to be treated. However, parenteral antibiotics should be given if:

  1. The infant is clinically ill with signs of pneumonia or septicaemia.
  2. The infant weighs less then 1500 g.
Note
A gastric aspirate with Gram-positive cocci in pairs suggests infection with the group B Streptococcus. These infants should be treated with parenteral ampicillin for 48 hours if the infant appears well, and for a full 5 day course if clinically ill.

Chronic intra-uterine infection

12-36 What is a chronic intra-uterine infection?

A chronic intra-uterine infection is an infection of the fetus that is present for weeks or months before delivery and is caused by organisms that cross the placenta from the mother to the fetus during pregnancy. The infection may result in either:

  1. Miscarriage
  2. Stillbirth
  3. An ill infant that may die after delivery. Ill infants that survive may recover completely or have permanent damage.
  4. An apparently healthy infant that is, however, infected and will develop signs of disease weeks or months after delivery.

12-37 What causes chronic intra-uterine infections?

The important causes of chronic intra-uterine infection are:

  1. Syphilis
  2. Rubella (German measles), which is very important because it causes congenital malformations if the infection takes place during the first 16 weeks of pregnancy (e.g. heart defects, deafness and blindness). Thereafter it only causes fetal infection with damage to many organs. As there is no treatment for congenital rubella, it must be prevented by immunising all children especially girls before puberty.
  3. Cytomegalovirus (CMV) infection is usually asymptomatic. However, it may cause infection of many organs, especially severe damage to the fetal brain resulting in mental retardation and cerebral palsy. Congenital CMV infection is more common if the mother has AIDS.
  4. Toxoplasmosis, which is rare and causes the same problems as CMV infection.

Syphilis

12-38 What is congenital syphilis?

Congenital syphilis is a chronic intra-uterine infection caused by the spirochaete, Treponema pallidum. If the mother has untreated syphilis during pregnancy, the fetus has a 50% chance of becoming infected.

Syphilis causes infection and damage to many organs but, unlike rubella infection, does not cause congenital malformations. Stillbirth and neonatal death are common.

Maternal treatment for syphilis consists of 2.4&million units of benzathine penicillin given intramuscularly weekly for 3 weeks.

12-39 What are the signs of congenital syphilis?

An infant born with congenital syphilis may have one or more of the following signs:

  1. Low birth weight
  2. Blisters and peeling of the hands and feet
  3. Enlarged liver and spleen
  4. Pallor due to anaemia
  5. Petechiae due to too few platelets
  6. Jaundice due to hepatitis
  7. Respiratory distress due to pneumonia
  8. A heavy, pale placenta weighing more than a fifth of the weight of the infant
  9. An X-ray of the legs showing osteitis of the bones around the knee
Note
Osteitis (a metaphysitis) of the lower femur, upper tibia and upper fibula, is a very common X-ray finding and useful diagnostic sign in congenital syphilis.

12-40 Do all infants with congenital syphilis have clinical signs of disease at birth?

No. Some infants with syphilis infection late in pregnancy may have no clinical signs and a normal X-ray of the legs at birth. If untreated, most of these asymptomatic infants will develop clinical signs of syphilis within a few months after delivery.

12-41 How can you confirm the clinical diagnosis of congenital syphilis in an infant after birth?

  1. If the infant has clinical or X-ray signs of syphilis and the VDRL, RPR or syphilis rapid test is positive in either the mother or infant, then the clinical diagnosis of congenital syphilis is confirmed.
  2. It is often difficult to confirm a diagnosis of congenital syphilis if the infant appears clinically well at delivery and the X-ray is normal. If the mother has untreated or partially treated syphilis, or syphilis treated during the last few months of pregnancy, the VDRL, RPR and syphilis rapid test will be positive in both the mother and the infant at delivery. Even if the infant has not been infected, the maternal IgG antibodies that give positive tests cross the placenta. A positive result in an asymptomatic infant, therefore, indicates that the infant has been exposed to maternal syphilis but does not prove that the infant has congenital syphilis.
  3. If the VDRL, RPR or syphilis rapid test is negative in the mother or infant, then congenital syphilis is excluded.

A positive antibody test confirms that the infant has been exposed to syphilis.

Note
All women should be screened for syphilis when booking for antenatal care. A positive VDRL (or RPR or syphilis rapid test) plus TPHA (or FTA) in the mother or infant confirms that the mother has syphilis. A false-negative test may occur if the mother was only infected in the last few weeks of pregnancy. Special tests on the infant’s blood for IgM antibodies, such as the total IgM or the rheumatoid factor (i.e. IgM against the anti-spirochaetal IgG), are only of limited help in diagnosing congenital syphilis as there are many false-positive and false-negative results. A specific IgM test will show whether the infant is producing antibodies against the Treponema as maternal IgM antibodies do not cross the placenta. If tests for specific IgM antibodies are positive in the infant then infection of the infant is confirmed. However, some infants with early infection may not produce IgM.

12-42 How do you treat congenital syphilis?

The method of treatment depends on whether an infant with a positive antibody test for syphilis has or has not clinical signs of congenital syphilis:

  1. If the infant has clinical signs of syphilis give 50 000 units/kg of procaine penicillin daily by intramuscular injection for 10&days. Ten days of treatment should be given to these infants even if the mother has been fully treated. Benzathine penicillin is not adequate to treat infants with clinical signs of congenital syphilis. These infants are often very sick and need good general supportive care in a level 2 hospital.
  2. If the mother has untreated syphilis, has not received a full course of treatment, or was only treated in the last month of pregnancy and the infant has no clinical signs of syphilis, then the infant can be treated with a single intramuscular dose of 50 000 units of benzathine penicillin.
  3. If the mother has received a full course of penicillin and the infant has no signs of syphilis, then the infant usually requires no treatment.
Note
Occasionally infants with no clinical signs of syphilis have a metaphysitis on X-ray. These infants should be treated with 10 days of procaine penicillin. Erythromycin given to the mother for syphilis does not cross the placenta and treat the fetus.

Do not forget to also treat the parents if an infant has congenital syphilis. Always look for other sexually transmitted diseases.

Infants with clinical signs of congenital syphilis must be treated with 50 000 units of procaine penicillin intramuscularly daily for 10 days.

HIV infection

12-43 What is HIV and AIDS?

AIDS (Acquired Immune Deficiency Syndrome) is a severe illness caused by the Human Immunodeficiency Virus (HIV). In adults the virus is usually sexually transmitted and causes asymptomatic infection for months or years before the clinical signs of chronic HIV infection appear. Only when HIV infection causes severe illness is it called AIDS. HIV infection usually is confirmed in adults and older children by finding antibodies to the virus in the patient’s blood. In South Africa, more than 25% of pregnant women are infected with HIV.

Common clinical signs of HIV infection in pregnant women include:

  1. Weight loss and general lethargy
  2. Chronic fever
  3. Generalised lymphadenopathy (enlarged lymph nodes)
  4. Persistent diarrhoea
  5. Repeated acute bacterial infections (e.g. pneumonia), tuberculosis or unusual (opportunistic) infections
  6. Recurrent oral thrush
  7. Dementia (loss of memory and changes in behaviour)

HIV infection cannot be cured but this chronic illness can be successfully controlled for many years with antiretroviral treatment while many of the complicating infections can be treated. Every effort must be made to prevent the sexual spread of HIV. Education, safer sex practices and the use of condoms are important.

12-44 Can an infant become infected with HIV?

Yes. If a woman with HIV infection falls pregnant, or gets infected with HIV during pregnancy or while breastfeeding, then her fetus or newborn infant may also become infected. If the correct antiretroviral (ARV) prophylaxis is not given:

  1. The risk of HIV crossing the placenta from the mother to her fetus during pregnancy is 5%.
  2. The risk that the infant will be infected by contact with the virus in maternal blood and secretions during vaginal delivery is 15%.
  3. The risk of HIV infection in the infant from mixed breastfeeding (breast milk plus other liquids or solids) for two years is 15% (5% for the first 6 months, 5% for the second 6 months and 5% for the second year). The risk from exclusive breastfeeding (breast milk only) for 6 months only is much less.

12-45 How can mother-to-child transmission of HIV be prevented?

The risk of mother-to-child transmission (MTCT) can be reduced from approximately 25% to less than 2% with ARV prophylaxis during pregnancy and labour. Usually a single Fixed Dose Combination (FDC) pill is given daily to all HIV positive women from 14 weeks of gestation and during labour. The FDC pill consists of tenofovir (TDF), emtricitabine (FTC) and efavirenz (EFV). As soon as possible after birth the infant should be given an oral dose of nevirapine followed by a daily dose of nevirapine until 6 weeks of age. The mother should be encouraged to exclusively breast feed and continue her FDC until a week after the last breast feed. Women on ARV treatment will continue their ARVs for life.

HIV infection of infants can be prevented if all women are screened for HIV at booking and antiretroviral prophylaxis or treatment given to all HIV positive women during pregnancy and labour and while breastfeeding.

12-46 How can you tell if an infant has HIV infection?

An infant with HIV infection usually appears normal and healthy at delivery. However, between 2 months and 2 years after birth, most infants infected with HIV will present with failure to thrive and repeated infections if not on ARV treatment. Most of these infants will die before 3 years of age if they are not correctly managed with ARVs.

12-47 What is the management of an HIV-exposed infant?

All HIV-exposed infants (i.e. infants born to a mother with HIV infection) must continue with daily nevirapine and have a PCR (polymerase chain reaction) test at 6 weeks of age. At 6 weeks the nevirapine is stopped even if the mother is breast feeding. If the PCR is negative the infant is not infected with HIV and can receive routine primary care. If the PCR is positive the infant is infected with HIV and must be referred to an HIV clinic for lifelong ARV treatment.

Most term infants will need 1.5 ml NVP from birth to six weeks (see dosing in table 12-1).

All HIV-exposed infants should be given a daily dose of NVP for six weeks after delivery.

Table 12-1: NVP dosing guidelines for newborns: NVP syrup 10 mg/ml

Birth weight Daily dosage Quantity
Less than 2.0 kg First 2 weeks: 2 mg/kg
Next 4 weeks: 4 mg/kg
0.2 ml/kg
0.4 ml/kg
2.0 – 2.5 kg Birth to 6 weeks: 10 mg 1.0 ml
More than 2.5 kg Birth to 6 weeks: 15 mg 1.5 ml

All HIV-exposed infants should be given a daily dose of NVP for six weeks after delivery.

12-48 How should HIV-infected women feed their infants?

Exclusive breast­feeding is still recommended in HIV-positive women who are receiving FDC for prophylaxis or treatment. Formula feeding is expensive and often unsafe in poor communities where undernutrition and gastroenteritis are common.

12-49 Can the medical and nursing staff be infected with HIV at delivery?

Yes. The maternal blood and vaginal secretions are infectious if the woman has HIV infection. Proper infectious precautions must be taken for vaginal examinations and deliveries. Gloves should be worn when handling both the infant and placenta at birth. Drying all infants well after delivery will reduce the risk of staff becoming infected. There is no need to bath these infants immediately after birth.

12-50 Can the staff be infected with HIV from a newborn infant?

Yes. The blood of an infant who has HIV infection, even if there are no clinical signs of illness, is infectious. Staff can, therefore, become infected with HIV if they prick themselves with a needle or lancet (a ‘sharp’) that has been used to obtain a blood sample from an infected infant.

Special care is needed when blood is sampled from either an HIV-infected mother or infant. Immediately after the needle or lancet has been withdrawn from the skin, it must be placed in a sharps container. Never leave the needle or lancet lying next to the patient as the nurse or doctor may prick themselves when cleaning up after the procedure. Always have a sharps container at the bedside when collecting a blood sample. While the wearing of gloves for procedures is advised, this will not always protect the person from needle pricks.

Anyone who pricks themselves when taking blood from an HIV positive patient must immediately start on ARV prophylaxis.

All needles and lancets must be placed in a sharps container immediately after use.

Case study 1

An infant is delivered at home by the grandmother. On day 3 the infant develops bilateral purulent conjunctivitis. When the infant is brought to the local clinic the eyelids are swollen due to oedema.

1. What is the probable cause of the conjunctivitis?

Gonococcus (Neisseria gonorrhoeae). This is the commonest cause of a purulent conjunctivitis (conjunctivitis with pus). Most infants are infected during delivery.

2. How could the conjunctivitis have been prevented?

By placing tetracycline or chloromycetin ointment into the infant’s eyes after delivery.

3. Is the conjunctivitis mild, moderate or severe? Give your reasons.

Severe, as the eyelids are swollen.

4. What is the danger of a severe purulent conjunctivitis?

The cornea may become soft and perforate, causing blindness.

5. What is the correct treatment of a severe conjunctivitis?

The eyes must be washed out with saline, water or penicillin drops to remove the pus. They should then be washed out or irrigated repeatedly until the pus stops forming. In addition, cefotaxime or ceftriaxone must be given by intramuscular injection daily for 3&days. Only when the eyes are clean and the first dose of antibiotic has been given should the infant be referred to hospital for further treatment.

Case study 2

A breastfed infant is brought to the clinic on day 10. The mother reports that the infant refuses the breast and cries when she tries to feed. On examination the infant is generally well but has a white coating of the tongue and mucous membrane of the mouth.

1. What is the diagnosis?

Severe oral thrush (or candidiasis) caused by the fungus Candida albicans. The infant is hungry but will not feed because of a sore mouth. Oral thrush must always be differentiated from milk curds, which can easily be wiped off, leaving a healthy mucous membrane underneath.

2. What is the danger of severe thrush?

The infant can become dehydrated due to not feeding.

3. What is the correct treatment?

Mycostatin (Nystatin) drops 1 ml should be placed in the mouth and repeated after every feed. Within a few hours the thrush should be improving. Continue treatment for a week. If the infant is dehydrated, nasogastric feeds or intravenous fluid may be needed for a few hours. The mother should put mycostatin cream on her nipples to prevent reinfecting her infant.

Case study 3

A 5-day-old preterm infant becomes lethargic and has a short apnoeic attack. The abdomen is mildly distended and bowel sounds are absent. The skin temperature is 35&°C.

1. What do you think is wrong with this infant?

The infant probably has septicaemia as this can present with lethargy, apnoea, an ileus and hypothermia. However, it may also have meningitis which can present with apnoea, or necrotising enterocolitis which can present with lethargy and an ileus.

2. What investigations are needed?

A blood culture to diagnose septicaemia, a lumbar puncture to diagnose bacterial meningitis, and an abdominal X-ray and stool examination for occult blood to diagnose necrotising enterocolitis are essential.

3. What is the management of septicaemia?

Benzyl penicillin 50 000 units/kg/day and gentamicin 7.5 mg/kg/day are usually given in divided doses intravenously or intramuscularly every 8 to 12 hours. Cefotaxime or ceftriaxone can also be used. The choice of antibiotic may be changed when the sensitivity results of the blood culture are obtained. Antibiotics are usually continued for 10 days.

Good supportive care is also essential. This infant will need intravenous fluids, nasogastric drainage, incubator care and careful obser­vations. Skin temperature and respiration rate must be carefully monitored in this infant. The infant will need to be transferred to a level 2 or 3 hospital.

Case study 4

An unbooked patient delivers a 2000 g infant with peeling skin on the hands and feet and an enlarged liver and spleen. The placenta is pale and weighs 680 g.

1. What is the clinical diagnosis?

Congenital syphilis. This is suggested by the peeling rash on hands and feet, the hepato­splenomegaly and the heavy, pale placenta in a low birth weight infant. Syphilis should also be suspected in all unbooked patients.

2. How would you confirm the diagnosis?

The VDRL and TPHA in both mother and infant will be positive. An X-ray of the legs will almost certainly show the typical features of syphilic osteitis.

3. What is the treatment of an infant with clinical signs of congenital syphilis?

Procaine penicillin 50 000 units/kg intramuscularly each day for 10 days.

4. What is the treatment if the infant appears well but the mother has untreated syphilis?

If the infant has no clinical signs of syphilis the treatment is a single dose of 50 000 units benzathine penicillin.

5. How can congenital syphilis be prevented?

All pregnant women must be screened by using VDRL (or RPR) and TPHA (or FTA) blood tests, in the first trimester if possible, and be fully treated with benzathine penicillin if found to have syphilis.

Case study 5

A mother who is known to be HIV positive has a vaginal delivery at term. She has received ARV prophylaxis from 14 weeks pregnant. The infant appears clinically normal but develops mild jaundice on day 5. A sample of blood is taken from the infant’s heel for a total serum bilirubin measurement.

1. What is the chance that this infant has been infected with the HIV virus?

The risk is less than 2% as the mother has been correctly managed with ARV prophylaxis. The risk is about 20% if both mother and infant are not given ARV prophylaxis.

2. Would you expect clinical signs of HIV at birth in this infant?

No. Infants infected with HIV usually appear healthy at birth and remain well for the first few months of life.

3. How is HIV infection diagnosed in a newborn infant?

All HIV-exposed infants will have a positive HIV screening test. However, the PCR test is positive only in HIV-infected infants. The PCR test is usually done at 6 weeks in infants who are born to HIV positive mothers.

4. Should this mother be advised to breastfeed or formula feed?

She should be encouraged to exclusively breast feed and continue her ARV prophylaxis until a week after the last breast feed.

5. What is the danger to the staff if a sample of blood is collected from this infant?

If the infant is infected with HIV, the nurse or doctor may also become infected with HIV if they prick their finger after collecting a sample of the infant’s blood.

6. How can the staff protect themselves?

By placing the needle or lancet into a sharps container immediately after it has been used.

Video

Sepsis

Video by the Global Health Media Project made available under a Creative Commons Attribution-NonCommercial-NoDerivatives License

Skin infection

Video by the Global Health Media Project made available under a Creative Commons Attribution-NonCommercial-NoDerivatives License

Thrush

Video by the Global Health Media Project made available under a Creative Commons Attribution-NonCommercial-NoDerivatives License

Umbilical infections

Video by the Global Health Media Project made available under a Creative Commons Attribution-NonCommercial-NoDerivatives License

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