Adetifa Ifedayo M O, Muhammad Abdul Khalie, Jeffries David, Donkor Simon, Borgdorff Martien W, Corrah Tumani, D'Alessandro Umberto
Disease Control and Elimination Theme, Medical Research Council Unit-The Gambia, Atlantic Boulevard, Fajara, PO Box 273, Banjul, The Gambia.
Academic Medical Centre, University of Amsterdam, Amsterdam, Netherlands.
PLoS One. 2015 Oct 14;10(10):e0139354. doi: 10.1371/journal.pone.0139354. eCollection 2015.
A Tuberculin skin test (TST) survey was conducted to assess the prevalence of latent TB Infection (LTBI) and to estimate the annual risk of M. tuberculosis infection (ARTI) in Gambian school children. The results are expected to contribute to understanding of Tuberculosis epidemiology in The Gambia.
This was a nationwide, multi-cluster survey in children aged 6-11 years. Districts, 20 of 37, were selected by probability proportional to size and schools by simple random sampling. All TST were performed using the Mantoux method. Height and weight measurements were obtained for all participants. We calculated prevalence of LTBI using cut-off points of 10mm, the mirror and mixture modelling methods.
TST readings were completed 13,386 children with median age of 9 years (interquartile range [IQR] 8-10 years). Mixture analysis yielded a cut-off point of 12 mm, and LTBI prevalence of 6.9% [95%CI 6.47-7.37] and the ARTI was 0.75% [95%CI 0.60-0.91]. LTBI was associated gender and urban residence (p <0.01). Nutritional status was not associated with non-reactive TST or sizes of TST indurations. ARTI did not differ significantly by age, gender, BCG vaccination or residence.
This estimates for LTBI prevalence and ARTI were low but this survey provides updated data. Malnutrition did not affect estimates of LTBI and ARTI. Given the low ARTI in this survey and the overlapping distribution of indurations with mixture modelling, further surveys may require complementary tests such as interferon gamma release assays or novel diagnostic tools.
开展了一项结核菌素皮肤试验（TST）调查，以评估冈比亚学童中潜伏性结核感染（LTBI）的患病率，并估计结核分枝杆菌感染的年度风险（ARTI）。预期结果将有助于了解冈比亚的结核病流行病学情况。
这是一项针对6至11岁儿童的全国性多群组调查。按规模比例概率抽样选择了37个区中的20个区，并通过简单随机抽样选择学校。所有TST均采用曼托试验法进行。获取了所有参与者的身高和体重测量值。我们使用10毫米的临界值、镜像和混合建模方法计算LTBI的患病率。
完成了13386名儿童的TST读数，中位年龄为9岁（四分位间距[IQR]8至10岁）。混合分析得出临界值为12毫米，LTBI患病率为6.9%[95%CI 6.47 - 7.37]，ARTI为0.75%[95%CI 0.60 - 0.91]。LTBI与性别和城市居住情况相关（p<0.01）。营养状况与TST无反应或TST硬结大小无关。ARTI在年龄、性别、卡介苗接种或居住情况方面无显著差异。
此次对LTBI患病率和ARTI的估计较低，但该调查提供了最新数据。营养不良并未影响LTBI和ARTI的估计。鉴于本次调查中ARTI较低，且硬结分布与混合建模有重叠，进一步的调查可能需要补充检测，如干扰素γ释放试验或新型诊断工具。
