Fig. 1 presents an algorithm for testing for TBI and TPT, with separate entry points for people withHIV, household contacts and other people at risk for TBI. More detailed algorithms for screening andtesting for TBI are available in the two handbooks (63,64).The W4SS is recommended for testing all people with HIV at every visit to a health facility or contactwith a health worker to ensure early detection of TB disease. Other clinical features may also be helpful(e.g. poor weight gain in pregnant women and lymphadenopathy). People who have exclusivelyextrapulmonary TB may have clinical manifestations that are not necessarily pulmonary and maytherefore require further evaluation before TB is definitively excluded. Other diseases that cause anyof the four symptoms should be investigated in accordance with national guidelines and sound clinicalpractice. Individuals found not to have TB disease should then be assessed for TPT.Where CXR or interpretation of radiography is not available, the absence of any TB symptoms alonecan be considered sufficient before starting TPT. This would be the most sensitive of all the symptom-based screening rules, and its negative predictive value is high in most settings. Addition of abnormalCXR findings to the symptom screening rule would improve its sensitivity but also increase the logisticsand infrastructure required, the cost to individuals and health services, and the requirement forqualified staff or the availability of CXR with CAD. The optimal frequency of CXR in regular TB screeningof people with HIV is uncertain. Adding CXR to symptom screening at every visit would represent asignificant burden on individuals and health systems. Local authorities should define its applicationand frequency according to their local epidemiology, health infrastructure and resources. Either CXRwith CAD or radiologists or other trained health-care workers must be available to interpret CXR.mWRDs may be useful when greater specificity is desirable, such as when there is limited capacityfor confirmatory testing after a positive screen.The GDG noted that screening with CXR or mWRD should not be a prerequisite or a barrier to initiatingTPT in people with HIV because additional resources are required, in view of the marginal gain innegative predictive value. Conversely, in people with HIV and a low CD4 count, TB disease may bepresent despite a normal CXR. People with HIV who have any of the four symptoms or abnormal CXRfindings may have TB disease and should be investigated for TB and other diseases. Xpert® MTB/RIFshould be used as the initial diagnostic test.TPT should not be withheld from an asymptomatic individual at risk of infection if TBI testing and/orCXR is unavailable, as some people may have both risks (e.g. people with HIV who are also contactsof people with TB), in which case the triage shown in the figure would have to be adapted.1. Recommendations 17It is critical to ensure proper follow-up and evaluation for TB and other diseases in household contactswith abnormal CXR findings or TB symptoms. The investigations should be performed in accordancewith national guidelines and sound clinical practice. Contacts found not to have TB disease shouldbe assessed for TPT. Although TBI testing is not a requirement for initiating TPT, it may be done as apart of eligibility screening where feasible (see section 1.3).A previous history of TB or TPT should not be a contraindication for TPT in cases of re-exposure, afterexclusion of reactivated disease. Such individuals, including those with fibrotic radiological lesions,may be at increased risk of progression (65,66). The choice of TPT also depends on the presenceof contraindications (e.g. active hepatitis or symptoms of peripheral neuropathy when isoniazid isconsidered) or the likelihood of drug–drug interactions, particularly when rifamycin regimes are beingconsidered (see section 1.4).Different symptom screening approaches have different sensitivity and specificity. The facility ofsymptom screening makes it a much more accessible programme option. Symptom screening isstandard in a clinical workup and can be repeated as often as necessary. In contrast, additionalresources are necessary for CXR and mWRDs. Scaling up mWRDs for diagnosis should be prioritized(if full access has not yet been achieved) before scaling it up for screening, as it requires significantresources, including increased capacity in and expansion of diagnostic and sample transport networks.Countries should include the W4SS, CRP, CXR and mWRD in national TB screening algorithmsaccording to their feasibility, the level of the health facility, resources and equity. While all four toolsare recommended for people with HIV, CRP is particularly accurate for TB screening of people whoare not yet receiving ART, and CXR enhances the sensitivity of the W4SS in people receiving ART, bothof which might be considered when choosing algorithms. Consideration should also be given to theadded benefit of including CRP for ruling out TB disease before initiating TPT among people with HIV.CXR has been used to screen for TB for several decades. CXRs are also routinely used to triage peoplepresenting for care who show signs, symptoms or risk factors for TB to determine the most appropriateclinical pathway for proper evaluation. In many settings, however, use of CXR for TB screening andtriage for TB disease is limited by the paucity of health personnel trained to interpret radiographicimages and by substantial intra- and inter-reader variation in its accuracy to detect abnormalitiesassociated with TB (13). CAD is useful in such situations