Study topic: Household tuberculosis contact tracing among children under five in
the rural Kweneng District - Botswana.
Purpose: Screening of young children exposed to tuberculosis (TB) in a
household setting is widely recommended, but rarely implemented in some
endemic countries. The aim of this study was to screen household under five
children who have been exposed to smear-positive pulmonary tuberculosis (PTB)
of adult cases; to explore and describe the initial follow-up of these children by the
Kweneng district health care system; and to determine clinical outcomes
(occurrence of TB disease and latent tuberculosis infection) among those children.
Methods and procedures: In a nested case-control type study design, under 5
years child contacts of 200 randomly selected adult smear positive pulmonary TB
patients, were enrolled and evaluated for TB infection and disease. Risk factors
were compared between those with TB and those without TB. Data was collected
during the study period (December 2005 through November 2006) through faceto-face
interviews using a pre-designed data collection tool. Child contacts were
then investigated at their respective nearest health facility using Tuberculin Skin
Test (TST), clinical examination, and chest x-ray (CXR). Finally child contacts
were diagnosed as follow: No TB, Latent Tuberculosis Infection (LTBI), or TB
disease. We defined LTBI as having a TST ≥10 mm at 48–72 hours.
Major results: A total of 497 child contacts were recruited, of which 278 (55.9%
[95%CI: 51.4% - 60.3%]) and 219 (44.1% [95%CI: 39.7% - 48.6%]) were
respectively girls and boys both in age group: 0-24 months: 51 (10.3% [95% CI:
7.8% - 13.4%]) and 25-59 months: 446 (89.7% [95% CI: 86.6% - 92.2%]).
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Among all children 19 (3.8% [95% CI: 2.4% - 6.0%]) were found not vaccinated.
The duration of exposure to TB case ranged from 1 to 4 months; and the social
proximity of child contact to TB case was as follow: 185 (37.2% [95%CI: 33.0% -
41.7%]) were first degree relatives, 304 (61.2% [95%CI:56.7% - 65.4%]) distant
relatives, and 8 (1.6% [95%CI: 0.8% - 3.3%]) child contacts were not related to
the cases. The respondent dissatisfaction rate about TB screening (follow-up) by
the health care system was 163 (81.50%).
Of 497 child contacts, 104 (20.9% [95%CI: 17.5% - 24.8%]) were initially
screened for TB at the time the TB index cases were diagnosed. 163 (81.5%
[95%CI: 75.4% - 86.6%]) respondents were dissatisfied about the initial follow-up
and screening of child contacts by the health care system. Among all 497 child
contacts evaluated at the time of this study, LTBI prevalence rate was 35.0%
[95%CI: 30.8% - 39.4%], and the prevalence of TB disease was 3.4% [95% CI:
2.1% - 5.5%].
Under five children who had been screened initially were less likely to have TB
infection or disease identified during the evaluation by this study, than those who
had not been screened (OR=0.296, X2 = 20.202, p < 0.001) by Kweneng health
care system.
Main Conclusions: This is the first comprehensive household TB contact tracing
in under five children exposed to smear positive TB from adult cases in the rural
Botswana. The study found that health care services in Kweneng were not
adequately implementing TB contact tracing of household under five children.
When children were followed up during this study, we documented a high
prevalence rate of TB infection and disease among child contacts who had not
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been followed up and screened for TB by the health system. This not only
suggests that under five child living in the same household with an adult TB case
in rural Botswana is at high risk of LTBI and active TB disease; but it also
evidently supports the benefice and importance of household contact tracing in
enhancing case finding and prevention of tuberculosis disease (Triasih, 2015).
Recommendations: A scale-up of targeted household contacts tracing for under
five children followed by appropriate management can enhance early case
detection and lower the risk of TB transmission among under five children.
A targeted tuberculosis contact tracing with an emphasis on younger children
should be made a priority by the Botswana National TB Programme (BNTP). The
policy needs to clarify who is responsible and accountable for TB contact tracing
services. The gap between guidelines and practice, and the human resource
capacity should be addressed. An improved training of TB care providers on
guidelines in Kweneng district will be important in strengthening TB contact
tracing.