Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, London.
TB Centre, London School of Hygiene & Tropical Medicine, London, UK, Africa Health Research Institute, School of Nursing and Public Health, University of KwaZulu-Natal, School of Public Health, University of the Witwatersrand, Johannesburg, South Africa.
Int J Tuberc Lung Dis. 2020 Apr 1;24(4):403-408. doi: 10.5588/ijtld.19.0410.
In South Africa, it is generally estimated that only 0.5-0.6% of people's contacts occur in clinics. Both people with infectious tuberculosis and people with increased susceptibility to disease progression may spend more time in clinics, however, increasing the importance of clinic-based transmission to overall disease incidence. We developed an illustrative mathematical model of transmission in clinics and other settings. We assumed that 1% of contact time occurs in clinics. We varied the ratio of clinic contact time of human immunodeficiency virus (HIV) positive people compared to HIV-negative people, and of people with infectious TB compared to people without TB, while keeping the overall proportion of contact time occurring in clinics, and each person's total contact time, constant. With clinic contact rates respectively 10 and 5 times higher in HIV-positive people and people with TB, 10.7% (plausible range 8.5-13.4%) of TB resulted from transmission in clinics. With contact rates in HIV-positive people and people with TB respectively 5 and 2 times higher, 5.3% (plausible range 4.3-6.3%) of all TB was due to transmission in clinics. The small amount of contact time that generally occurs in clinics may greatly underestimate their contribution to TB disease in high TB-HIV burden settings.
在南非，据估计，仅有 0.5-0.6%的人际接触发生在诊所。具有传染性肺结核的人和更容易发生疾病进展的人可能会在诊所有更多的时间，因此增加了诊所传播对整体疾病发病率的重要性。我们开发了一个说明性的诊所和其他环境中传播的数学模型。我们假设 1%的接触时间发生在诊所。我们改变了艾滋病毒（HIV）阳性者与 HIV 阴性者、有传染性肺结核者与无肺结核者在诊所接触时间的比例，同时保持诊所接触时间的总比例和每个人的总接触时间不变。如果 HIV 阳性者和肺结核者在诊所的接触率分别提高 10 倍和 5 倍，那么 10.7%（合理范围为 8.5-13.4%）的肺结核是在诊所传播的。如果 HIV 阳性者和肺结核者的接触率分别提高 5 倍和 2 倍，那么在诊所传播的肺结核占所有肺结核的 5.3%（合理范围为 4.3-6.3%）。在高结核-艾滋病毒负担环境中，诊所接触时间通常很少，这可能大大低估了其对结核病的贡献。
