5 Preventing childhood tuberculosis
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- Principles of prevention
- BCG immunisation
- Avoiding exposure to TB bacilli
- TB prophylaxis (TB preventive therapy) in children
- National tuberculosis programme
- Community involvement
- Controlling the spread of HIV infection
- Case studies
When you have completed this unit you should be able to:
- List ways of preventing tuberculosis.
- Provide BCG immunisation.
- Reduce the risk of exposure to TB bacilli.
- Give TB prophylaxis when indicated.
- Report a case of tuberculosis.
- Describe the aims of the national tuberculosis programme.
- Give ways of educating the community about tuberculosis.
- Understand the importance of reducing the spread of HIV if the tuberculosis epidemic in South Africa is to be controlled.
Principles of prevention
5-1 How can the risk of childhood tuberculosis be decreased?
- BCG immunisation
- Avoiding exposure to adolescents and adults with tuberculosis
- TB prophylaxis in children
- Reporting and effectively treating cases of tuberculosis
- Educating the community about tuberculosis
- Controlling the spread of HIV
5-2 What is BCG?
BCG (Bacille Calmette Guerin) is a freeze-dried live vaccine. It is made from a weakened live (attenuated) form of Mycobacterium bovis, the bacilli which causes tuberculosis in cattle and sometimes in children who drink milk that was not pasteurised. BCG is included in the expanded programme on immunisation (EPI) in children.
- In South Africa the Danish strain of BCG is being used. Each year over 100 million doses of BCG are given worldwide. BCG was first used in 1921.
5-3 Why should children be immunised with BCG?
BCG does not prevent infection with TB bacilli but reduces the risk of TB meningitis and disseminated TB in young children by 75%. Unfortunately it is less effective in preventing pulmonary TB, especially in malnourished children and children with HIV infection. It also gives less protection in older children, adolescents and adults which makes reimmunisation at an older age unnecessary.
BCG reduces the risk of disseminated tuberculosis and tuberculous meningitis in children.
5-4 How should BCG be stored and mixed?
BCG vaccine should be stored in a refrigerator between 2 and 8 °C and must not be frozen. Keep it and the diluent on the middle shelf. It must also be kept out of direct sunlight. To prepare the vaccine for administration the vial of diluent should be added to the vial of dried vaccine. Do not use alcohol or ether to clean the top of the vial as it may kill the BCG. After adding the diluent, the vaccine will last for six hours if kept in a refrigerator or cool box. After six hours the vaccine must be discarded as the bacilli may be dead.
5-5 When should BCG be given?
Usually BCG is given during the first few days after birth in well infants and on the day of discharge from hospital or clinic in infants who have been ill or are very preterm (less than 32 weeks gestation). If there is any doubt about whether BCG was given after birth or discharge, it should be given at six weeks with the other routine immunisations. BCG is not usually given to children older than one year and most clinics do not stock BCG.
5-6 Should some newborn infants not be given BCG?
Although, BCG immunisation can cause local (at the injection site), regional (axillary lymph node) or disseminated (distant) BCG infection in HIV-infected infants, in South Africa BCG is given to all infants after birth. However, infants known to be infected with HIV should not be given BCG if this has not already been given at birth.
5-7 How is BCG given?
BCG is given by intradermal injection over the right upper arm as follows:
- Add 1 ml of diluent into the vial containing BCG. Gently turn the vial upside down at least five times until fully mixed. Do not shake.
- Draw up 0.05 ml of BCG vaccine in a sterile syringe (a special syringe to accurately measure 0.05 ml).
- Clean an area of skin over the right deltoid muscle (upper arm) with soap and water, not an alcohol swab.
- Stretch the skin over the right deltoid muscle with your thumb and forefinger. Slowly insert the needle intradermally (bevel facing up). Insert the needle for less than 2 mm into the skin. The needle can be seen through the skin.
- Inject the 0.05 ml of vaccine. A wheal (raised lump) indicates that the intradermal injection has been given successfully. The most common error is to inject the BCG under the skin when no wheal will be seen. With no wheal, start again at a different site and inject into the skin.
It is important that BCG is given correctly.
5-8 What are the adverse effects of BCG immunisation?
In the majority of infants a raised nodule develops at the site of the immunisation after two to four weeks. A small crust may develop or it may ulcerate. The nodule will heal by itself and no dressing should be applied. After eight weeks the nodule starts to decrease in size and by six months a small flat scar will form. The lymph nodes in the axilla on that side may enlarge slightly, which is normal. BCG immunisation does not always leave a scar in an infant. It is not necessary to repeat the BCG immunisation if no scar is seen.
The most common adverse effects are local pain and ulceration at the site of the immunisation and enlarged lymph nodes in the axilla and sometimes the neck.
Serious adverse effects in infants who are not HIV infected are very rare. However there is a high risk of serious adverse effects in HIV-infected infants. They include:
- An abscess may form at the site of the BCG immunisation.
- Axillary and rarely cervical (neck) lymph nodes may enlarge rapidly to more than 3 cm. A lymph node abscess may form and a sinus can develop.
- Disseminated BCG which presents in a similar way to disseminated tuberculosis.
- BCG IRIS (immune reconstitution inflammatory syndrome due to BCG) can develop after beginning antiretroviral treatment. This presents with enlarged axillary (arm pit) lymph nodes two to eight weeks after starting antiretroviral treatment.
All HIV-infected infants must be identified as early as possible and referred for investigation and treatment.
- An adverse effect to BCG must be reported if an abscess larger than 10 mm forms at the site of immunisation or an axillary lymph node larger than 15 mm occurs. BCG adverse events are reported to the EPI program.
Avoiding exposure to TB bacilli
5-9 When are children at high risk of exposure to TB bacilli?
There is a high risk of infection when children come into contact with someone who has untreated smear-positive tuberculosis. This is usually an adult with a cavity on chest X-ray. They have a chronic cough but are not aware that they have pulmonary tuberculosis. The risk is the highest if the child lives in the same household (close contact). Children are also at risk if their caregivers or family members they regularly visit have tuberculosis.
This situation is far more common in poor families where there is overcrowding in inadequate, dark, poorly ventilated housing. Children may also be exposed to large numbers of TB bacilli in taxis, buses, clinics or other confined spaces.
- The concentration of TB bacilli in the air, the closeness of contact and the time a person is exposed to the contaminated air are major factors in determining who will become infected. TB bacilli are rapidly killed by direct sunlight.
- Individuals with smear-negative tuberculosis may also transmit Mycobacterium tuberculosis to children although the risk of transmission is lower than from smear-positive individuals.
5-10 How can exposure to TB bacilli be prevented?
- It is the public health responsibility of both the healthcare services and the general public to be aware of anyone who has the symptoms of tuberculosis, especially a chronic cough (more than two weeks). They need to be investigated.
- Improved living conditions with better housing and good nutrition.
- Whenever a child, adolescent or adult is diagnosed with tuberculosis, the family and others living in the same house should be screened for tuberculosis. This is usually done by taking a good history and referring those with symptoms for sputum examination. If the sputum examination is negative and symptoms persist then a chest X-ray must be taken. If there is one person with tuberculosis in the family, there is an increased chance that there will be others.
- Whenever an institutionalized child living in a children’s home or another long-term facility develops tuberculosis, the other children in the home/facility and all adult caregivers should be screened for tuberculosis.
5-11 What is contact tracing?
This is the finding and screening of people (the ‘contacts’) who have been exposed to someone with tuberculosis (the ‘source’). Both adult and child contacts may have undiagnosed tuberculosis and need treatment.
Some children will have TB infection only (a positive Mantoux skin test with no symptoms or signs of disease). Infected children younger than five years of age and children of any age who also have HIV infection will benefit from TB prophylaxis.
Contact tracing of infectious people is a very important part of controlling the spread of tuberculosis in a community. The most effective public health measure to control tuberculosis is the identification and cure of infectious cases.
Contact tracing is an essential part of controlling the spread of tuberculosis.
- While the family are encouraged to bring exposed children and adults with symptoms to be screened at the clinic (passive contact tracing), home visits to screen the family (active contact tracing) should be done, but is not commonly practised in South Africa.
5-12 How can infected patients prevent the spread of tuberculosis?
- By starting anti-TB treatment as soon as possible and taking their medication regularly and correctly.
- By teaching the correct cough behaviour to communities (cough etiquette). This requires adults to cough into a handkerchief and not onto other people. They should cover the nose when sneezing.
- Ensuring that public spaces are well-ventilated by opening windows.
- Meet out of doors if possible.
- By practising infection control in all healthcare facilities. For example, children who are diagnosed with pulmonary tuberculosis during hospital admission should ideally be isolated in a room with adequate ventilation, either in a negative-pressure ventilated room or in a room with open windows to ensure that the risk of transmitting Mycobacterium tuberculosis is reduced to an absolute minimum. Healthcare facilities should also limit overcrowding in outpatient and pharmacy waiting areas and ensure adequate ventilation of these areas of the facility.
- Patients with pulmonary tuberculosis are usually no longer infectious to others after taking their medication correctly for 14 or more days.
5-13 What investigations should be done on children exposed to infectious patients?
- Careful history and examination for symptoms and signs of tuberculosis
- Mantoux skin test
- Record and plot their weight in the Road-To-Health booklet. Look for lack of weight gain.
- Screen for malnutrition
- HIV screening test if indicated
- If there is any suspicion that a child has tuberculosis then the child must be investigated, which would include a chest X-ray, a sputum sample in older children (above eight years) and gastric aspirate or saline-induced sputum if possible in younger children, for smear and culture.
5-14 How can health workers avoid infection?
Health workers are exposed to TB bacilli, especially while examining patients with a cough or while collecting sputum samples. Masks (N95 respirators) should be worn by healthcare workers when examining patients with pulmonary tuberculosis or suspected of having pulmonary tuberculosis and hands should be washed after the examination. Good ventilation in examination and procedure rooms is essential.
TB prophylaxis (TB preventive therapy) in children
5-15 What is TB prophylaxis in children?
For children exposed to a contact with drug-susceptible pulmonary tuberculosis, INH for six months is used for prophylaxis against tuberculosis in children. The treatment is given daily using the same daily dose as for short-course treatment (10 mg/kg/day).
For children exposed to a contact with drug-resistant pulmonary tuberculosis prophylaxis depends on the resistance pattern of the TB bacilli:
- If the contact has INH-monoresistant pulmonary tuberculosis then a daily dose of rifampicin (15 mg/kg/day) is given for 4 months
- If the contact has rifampicin-monoresistant pulmonary tuberculosis then daily dose of INH (10 mg/kg/day) is given for 6 months
- If the contact has multi-drug resistant pulmonary tuberculosis then 3-drug prophylaxis is recommended i.e. INH (15-20 mg/kg/day), ethambutol (20-25 mg/kg/day) plus levofloxacin (15-20 mg/kg/day) given for 6 months.
- If the contact has extensively drug resistant pulmonary tuberculosis then no prophylaxis is recommended but the child should be followed up closely for two years and effective household infection control practices should be observed. Children who develop symptoms of TB during follow-up should be fully investigated.
5-16 Who should receive TB prophylaxis?
The following children should be given prophylactic treatment:
- Clinically well asymptomatic children under five years of age, or HIV-infected children irrespective of age who have been in close contact with someone who has infectious pulmonary TB. These children are at high risk of developing tuberculosis themselves as they have either immature or depressed immune systems.
- Children under five years or HIV-infected children irrespective of age who have a positive Mantoux skin test, who are clinically well with no symptoms or signs of tuberculosis, have not recently been treated for tuberculosis, nor have a history of close contact with an infectious pulmonary TB case. The positive Mantoux skin test indicates that they have been infected with TB bacilli and are at high risk of the infection progressing to tuberculosis.
- Previous prophylaxis does not protect a child against subsequent TB exposure or infection. If there is re-exposure to a case of infectious pulmonary tuberculosis after prophylaxis has been completed then another course of prophylaxis should be prescribed, provided that the child is less than 5 years of age or HIV-infected. If re-exposure or ongoing exposure occurs while a child is on prophylaxis, then prophylaxis should be continued for as long as the source case remains infectious.
Asymptomatic HIV-negative children of five years and older, who have been in close contact with an adult with untreated pulmonary TB, or have a positive Mantoux test, are not given prophylaxis, as they are at far less risk of developing tuberculosis. However, they should be followed and investigated for tuberculosis if they develop any early symptoms or signs of TB.
Prophylactic treatment is given to well children under five years of age, and HIV-infected children of any age, who have been exposed to someone with untreated tuberculosis.
National tuberculosis programme
5-17 What is the aim of a national tuberculosis programme?
The aim of a national tuberculosis programme is to prevent the spread of tuberculosis and to promote the accurate diagnosis and correct treatment of tuberculosis. This should reduce the mortality and morbidity due to tuberculosis and reduce the risk of drug resistance. The national tuberculosis programme in South Africa (National TB Control Programme) was started in 1996 with widespread implementation of the DOTS strategy.
5-18 Do children with tuberculosis need to be reported?
Yes, TB is a notifiable disease in South Africa. All children who are treated for tuberculosis need to be recorded and reported to the local health (EPI) authority. Children are reported in two age groups, zero to four, and five to 14 years of age.
5-19 Why is it important for children with tuberculosis to be recorded and reported?
It is important that children with tuberculosis are reported and recorded for two main reasons.
- To know how many children require treatment for tuberculosis to ensure sufficient child-friendly treatment courses.
- The number of children with tuberculosis, especially in the zero to four age group, gives an indication of the amount of recently transmitted infection. An evaluation of this group of children gives an indication of the quality of the National TB Programme.
5-20 Do we need to record and report on children receiving prophylaxis?
It is not required at present to register these children. However it would be an advantage if each clinic knew which children were receiving prophylaxis, how many completed the course of prophylaxis, and what the outcome of these children was. This would help with the planning of the service.
5-21 What are the Sustainable Development Goals?
In 2015 the United Nations migrated from the Millennium Development Goals (MDGs) to the Sustainable Development Goals (SDGs). The SDGs are 17 global goals with 169 targets between them covering a broad range of development issues that include ending poverty and hunger, improving health and education, making cities sustainable and combating climate change by 2030. Goal 3 seeks to ensure health and wellbeing for all. One of the targets of this goal is to end epidemics of AIDS, tuberculosis, malaria, neglected tropical diseases and other communicable diseases by 2030.
- The End TB strategy of the WHO spells out steps and investment that are needed to reach the target of ending the global tuberculosis epidemic. Although TB incidence and the annual number of TB deaths is falling globally, at the end of 2019, most WHO regions and many high TB burden countries were not on track to reach the 2020 milestones of the End TB strategy.
5-22 What community education is needed?
It is important that the community in all areas is aware of the following:
- Know that tuberculosis is a common and important disease in South Africa.
- Know how tuberculosis is spread.
- Know the presenting symptoms of tuberculosis.
- Know that treatment takes many months and that adherence is very important.
- Know that tuberculosis can be cured.
5-23 How can the community be educated about the dangers of tuberculosis?
- Via the print (magazines, newspapers) and electronic (radio, television, internet) media.
- By inclusion in the school curriculum.
- Through community organisations (trade unions, church groups).
- At healthcare clinics (posters, information sheets, discussion groups, individual counselling).
- Using peer educators (previous TB patients who have been trained as community workers).
5-24 What are traditional beliefs about tuberculosis?
In most communities there are many misunderstandings and incorrect beliefs about tuberculosis.
- Tuberculosis is caused by bewitchment.
- Tuberculosis is a punishment for some sin committed.
- Tuberculosis is an inherited condition.
- Tuberculosis cannot be cured.
- BCG immunisation prevents all forms of tuberculosis.
These false beliefs often cause a lot of unnecessary suffering. They can only be corrected by community education.
Controlling the spread of HIV infection
5-25 How would controlling the spread of HIV infection reduce the prevalence of tuberculosis?
In South Africa the HIV epidemic has greatly increased the number of both adults and children with tuberculosis. HIV infection lowers the immunity and thereby increases the risk of TB infection progressing to tuberculosis, especially extrapulmonary tuberculosis. A greater number of adults with tuberculosis increases the chance that children in the family and community will be infected with TB bacilli. In addition, more women with tuberculosis increases the risk of vertical transmission to infants (mother-to-child transmission).
Reducing the spread of HIV and tuberculosis in the community is, therefore, essential if the number of children with tuberculosis is to be decreased.
Case study 1
A newborn infant is given BCG immunisation before discharge home from a obstetric care clinic. A month later the mother notices a lump at the site of the immunisation. On examination, the nurse notices mildly enlarged axillary lymph nodes. The child is generally well and thriving.
1. What is BCG?
A weakened (attenuated) form of Mycobacterium bovis, the bacilli which causes tuberculosis in cattle and sometimes in children who drink milk that was not pasteurised. BCG vaccine is included in the expanded programme on immunisation in children.
2. What are the benefits of BCG immunisation?
It induces an immune response which reduces the risk that TB infection will progress to tuberculosis, especially disseminated and miliary tuberculosis in young children. However it does not reduce the risk of TB infection.
3. How is BCG immunisation given?
By injection into the skin (intradermal) of the right upper arm (deltoid area). It is important that BCG is stored and mixed correctly. BCG immunisation should be given directly after birth.
4. Would you be worried about the swelling at the immunisation site and the enlarged lymph nodes.
No, as this is a normal response to BCG.
5. What could cause severe adverse effects to BCG?
HIV infection. These infants have a weakened immune system which can result in local BCG abscesses or even disseminated BCG.
6. What is BCG IRIS?
IRIS (immune reconstitution inflammatory syndrome) due to BCG may present with markedly enlarged axillary lymph nodes a few weeks after antiretroviral treatment is started. It is due to the recovery of the immune system.
Case study 2
An unemployed man is diagnosed with pulmonary tuberculosis. He lives with his family, including a 4 year old son, in an overcrowded house. He is concerned that his son may be at risk of developing tuberculosis. Clinically the child is well and not malnourished.
1. What should be the management of this child?
He should be screened for tuberculosis as he is a ‘contact’ and therefore at high risk of infection.
2. What investigations are needed?
A Mantoux skin test and a chest X-ray must be done. A sputum test must be done if the chest X-ray suggests tuberculosis.
3. Should this child be treated for tuberculosis?
Only if there is good evidence to suggest that he developed tuberculosis ( a positive Mantoux test and abnormal chest X-ray). If he appears well and his Mantoux skin test is negative or intermediate, he should be given TB prophylaxis.
4. What is TB prophylaxis?
For children exposed to a contact with drug-susceptible pulmonary tuberculosis, INH for six months is used for prophylaxis against tuberculosis. The treatment is given daily using the same daily dose as for short-course treatment (10 mg/kg/day).
For children exposed to a contact with drug-resistant pulmonary tuberculosis prophylaxis depends on the resistance pattern of the TB bacilli of the contact case.
5. What other children should receive TB prophylaxis?
In addition to well children under five years of age who have been in contact with an adult with pulmonary tuberculosis, children with a positive Mantoux skin test and children with HIV infection should receive INH prophylaxis if they are TB contacts.
6. How can adults with tuberculosis reduce the risk of spreading the infection to their children?
By practising correct cough behaviour (cough etiquette) and taking their medication correctly.
Case study 3
Tuberculosis is common in a small rural community. The headmaster of the primary school wants to involve the whole community in reducing the risk of children developing tuberculosis.
1. How can the community help reduce the prevalence of tuberculosis?
Everyone must be educated about tuberculosis and understand the cause, clinical presentation, how it is spread and the importance of good adherence. They should understand that BCG immunisation, regular weight checks and good nutrition are important for children.
2. How can the community be educated about tuberculosis?
Via the print media (books, newspapers) and electronic media (radio and TV) as well as community organisations.
3. What can be done at the school?
Include tuberculosis in the school curriculum. Education about tuberculosis can also be given to teacher and parent groups.
4. Why should children with tuberculosis be recorded and reported?
So that the prevalence and spread of tuberculosis in the community can be documented. This will help with planning both prevention and treatment.
5. What are the Sustainable Development Goals?
The SDGs are 17 global goals with 169 targets between them covering a broad range development issues that include ending poverty and hunger, improving health and education, making cities sustainable and combating climate change by 2030. Goal 3 seeks to ensure health and wellbeing for all. One of the targets of this goal is to end epidemics of AIDS, tuberculosis, malaria, neglected tropical diseases and other communicable diseases by 2030.
6. Are traditional beliefs about tuberculosis helpful?
Some traditional beliefs lead to misunderstanding and suffering. For example, in some communities people with tuberculosis are believed to be bewitched or are being punished for some sin. It is important for the community to understand the true cause of tuberculosis and know that it can be cured with early diagnosis and correct treatment.
The five most important ‘take-home’ messages
- BCG immunisation reduces the risk of tuberculous meningitis and disseminated tuberculosis in young children.
- TB prophylaxis should be given to children who are under five years of age or HIV infected and have been exposed to an adolescent or adult with infectious tuberculosis or have a positive Mantoux skin test.
- All cases of childhood tuberculosis must be recorded and reported
- Community education about tuberculosis is important in the fight to control the spread of the disease.
- Controlling the HIV epidemic is essential to reduce the incidence of tuberculosis.