Screening

1. Houben RM, Dodd PJ. The Global Burden of Latent Tuberculosis Infection: A Re-estimation Using Mathematical Modelling. PLoS Med. 2016;13:e1002152. doi: 10.1371/journal.pmed.1002152.

2. Global tuberculosis report 2020. Geneva: World Health Organization; 2020 (https://apps.who.int/iris/ bitstream/handle/10665/336069/9789240013131-eng.pdf, accessed 19 February 2021).

Illustrations of 6 possible screening algorithms for children (Fig A.5.1 - A.5.5 for child contacts and Fig. A.5.6 for children <10 years living with HIV).

The tables below contain modelled estimates of the performance and outcomes of the screening algorithms described in Annex 3, when applied to different subpopulations of people living with HIV: outpatients not on ART, outpatients on ART, and inpatients. For each subpopulation, a model is presented of 1,000 persons being screened with a representative TB prevalence. The models were informed by the results of the IPD analysis that was commissioned to evaluate the performance of the W4SS and alternative screening tools in people living with HIV.

Illustrations of 11 possible screening algorithms for people living with HIV.

Illustrations of 10 possible algorithms for screening individuals aged 15 years and older among the general population and high-risk groups where screening is recommended.

Screening algorithms for children are listed in Annex 5.

Children 0 to < 15 years with a close contact with TB

Any of the following screening algorithms can be used:

Fig. A.5.1 Screening with symptoms (page 90)

Fig. A.5.2 Screening with CXR (page 91)

Children living with HIV should be followed up closely in the health-care system and should be screened for TB at every routine contact with an HIV care provider, at a health facility or in the community. Given the high risk of progression to TB disease and the high mortality rate, combined symptom screening should also be done at every contact with the health-care system, including events such as vaccination days, maternal health appointments, at nutritional screening and at food support programmes.

There are currently inadequate data to extrapolate use of CXR, CRP or mWRDs as screening tests in adults to children < 10 years living with HIV. Tests for TB infection are not useful for TB screening (see also 6.2.4).

Children with HIV who are < 10 years should be screened for TB at every encounter with a health-care worker, with the following screen: cough, fever, poor weight gain or close contact with someone who has TB.

Children living with HIV have a high risk of rapid progress to severe disease and death if a diagnosis of TB is missed. A child with HIV infection is 3.5 times more likely to progress to TB disease than a child who is HIV-negative (39). An estimated 16% of paediatric deaths from TB are among HIV-positive children, resulting in 36 000 deaths annually (2). It is for this reason that WHO strongly recommends that children with HIV be screened for TB.