Children’s TB rise worries experts
By Naftali Mungai and Aghan Daniel
Source: MESHA Features and Website
August 22, 2007

NAIROBI - Tuberculosis in children is on the rise globally, especially in Africa where high poverty levels are contributing to this disturbing development.

Globally TB in children increased by about 1% in 2006 compared with 2005 and has been doing this for nearly a decade. The global increase in the burden of TB is primarily driven by the exponential growth in TB in Africa especially in those countries with a HIV prevalence of more than 5% in the general population (this includes Kenya). As the burden of TB increases in the general population, there is a proportionate increase in TB children who can only get TB from adults.

According to Dr Evans Amukoye of the Kenya Association for the Prevention of Tuberculosis and Lung Disease (KAPTLD), 10 per cent of people treated for TB in Kenya are children under the age of 15 years.

Children exposed to adults with smear-positive pulmonary TB have a high risk for infection, and this risk increases with the degree of contact. In countries with a high incidence of TB, risk for infection among children in contact with adults with TB is 30–50 per cent, which is much higher than that reported by industrialized countries,’ says Emerging Infectious Diseases Vol. 12, No. 9, September 2006, a publication of the Centre for Communicable Diseases.


The global prevalence of TB and HIV globally is 0.18 per cent and 8 per cent of TB cases are co-infected with HIV. In Kenya 50 per cent of children with TB are co-infected with HIV.

Dr Amukoye says that studies in South Africa found out that 8 per cent of HIV positive children admitted for pneumonia had TB.

In Zambia from autopsy results, 18 per cent of children who died from respiratory causes had positive culture for TB. Other studies also found out that TB was the second commonest cause of death after the first birthday.

“Even though children are not as infectious as smear positive adults, TB is a major cause of morbidity and mortality,” says the physician.

In Kenya, which is classified as a high TB burden country, prevalence of TB infection is over 60 per cent. There is a difference between TB infection and TB disease. Most people infected with the TB germ do not in fact develop TB disease because their immune (defence) system is able to contain the TB germ and keep it in a dormant harmless state. However, if there is a weakening of the immune system, say as a result of HIV infection, dormant TB infection may activate and lead to TB disease. In the general population up to 40% (this is a crude estimate) may be infected by the TB germ.

The epidemiology of TB is such that the life time risk for developing tuberculosis after infection in untreated patients is 43 per cent in infants, 24 per cent in 1-5 years and 15 per cent in adolescents compared to immuno-competent adults, who have a lifetime risk of 5 to 10 per cent when untreated. Thus the low immunocompetence of children renders them more susceptible to developing TB if untreated.

“It is unfortunate that the diagnosis of intra-thoracic disease is especially difficult in younger patients yet it is the most common manifestation in HIV-positive and negative children,” says Dr Amukoye.

Dr Chakaya, the chairman of KAPTLD adds that the diagnosis of intra-thoracic TB in symptomatic children with negative sputum smears should be based on the finding of radiographic abnormalities consistent with TB and either a history of exposure to an infectious case or evidence of TB infection. “For such patients if culture facilities are available, sputum should be obtained either by expectoration or induced gastric lavage,” he adds.

Among the risk factors for getting the disease are HIV, extremes of age and other immune compromised states. Diabetes, malignancy and Immuno-suppressive drugs can also lead to development of TB.

The risk factors for getting infection are poverty, overcrowding, poor housing where there is inadequate light and ventilation; malnutrition; lack of access to appropriate health care leading to a long period of infectivity and exposure to a high load of open TB.

The diagnosis of TB in HIV infected children is also not easy. This is because the Polymerase Chain Reaction (PCR) test which is used is widely unavailable in the country. In this situation, chronic fever may be the only presenting symptom.

“The history of contact is important but many TB and HIV positive people may be coughing due to many other causes. A chest X-ray may give similar findings to other conditions,” says Dr Amukoye. Among the measures recommended for preventing TB infection, according to the physician, should be a reduction in risk factors for infection. These include alleviation of poverty, reducing infection to disease progression and reducing the immune suppressive condition and here HIV is key.


However according to Dr Victor Ombeka patients with extra-pulmonary TB and in children, the response to treatment is best assessed clinically and that follow-up radiographic examinations are usually unnecessary and may be misleading. “Children under five years old and persons with HIV who have been in contact with an infectious case should be evaluated for both latent infection with the TB germ and for active TB,” he says.

Treatment of latent infection should be a priority and drug prophylaxis against primary infection in infants should be carried out.

Dr Amukoye says that it is critical that factors that lead to high rates of infection be addressed. These are lack of awareness, poverty, poor housing and a high TB load. By increasing awareness, improving housing and reducing TB load, the high rates of infection can be reduced substantially. Dr Ombeka recommends that children under five years living in the same household as sputum smear-negative patient should be targeted for preventive therapy after exclusion of active TB.

Early diagnosis, adherence to treatment to increase cure rates and reducing development of resistance will play a key role in reducing the children’s TB burden,” says Dr Amukoye.

Factors that lead to high rates of disease also need to be addressed. These will include reduction of HIV and protecting those at risk in this respect. “Drug prophylaxis in children needs to be evaluated in our set-up to address drug resistance and adverse events,” concludes the physician.