Disease Prevention and Control / Communicable Diseases / Tuberculosis
Guidelines for HIV Surveillance among Tuberculosis Patients(2nd ed., World Health Organization TB/HIV Working Group of the Global Partnership to Stop TB and UNAIDS/WHO Working Group on Global HIV/AIDS/STI Surveillance, 2004) | ||
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WHO E-Book (38 pp, PDF) WHO TB Page PAHO TB/HIV Workshops: 2004 | 2003 |
Summary | RecommendationsThese guidelines are addressed to the managers of national tuberculosis programs (NTPs) and national AIDS programs (NAPs), those people responsible for HIV surveillance, and public-health decision-makers at national and subnational level. They form part of the TB/HIV series of documents produced by the Stop TB Department in the World Health Organization and also of the "Second-Generation Surveillance" (SGS) series. The main objective of these guidelines is to provide a framework for the methods to be used for measuring HIV prevalence among tuberculosis patients and to encourage implementation of HIV surveillance. Surveillance of HIV among TB patients is being increasingly recognized as important, as the HIV epidemic continues to fuel the global TB epidemic. In many countries, HIV prevalence in TB patients is a sensitive indicator of the spread of HIV into the general population. Information on HIV levels in TB patients is essential to respond to the increasing commitment to provide comprehensive HIV/AIDS care and support, including antiretroviral therapy (ART), to HIV-positive TB patients. The first edition of these guidelines, published in 1994, detailed one specific approach to determining HIV prevalence—through cluster sampling and unlinked anonymous seroprevalence surveys. The increasing availability of routine HIV-testing and counseling as an entry point to HIV/AIDS care for TB patients has highlighted the need for updated and broader guidelines. WHO's 3 by 5 initiative, to reach 3 million HIV-infected people with antiretroviral therapy by the end of the year 2005, will further increase demand for HIV-testing among TB patients and for knowing the size of the burden of HIV associated TB. HIV-testing is the entry point for ART delivery, and this applies equally to patients with TB. Reliable HIV surveillance systems for TB patients and large-scale access to HIV-testing and -counseling services are cornerstones for effective TB/HIV collaboration. This document outlines the three main methods for HIV surveillance among TB patients: data from the routine testing of TB patients for HIV; sentinel surveillance; and periodic (special) surveys. Selecting the appropriate surveillance strategy will depend on the existing surveillance system, the underlying HIV epidemic status in a country, and the status of ART implementation, as well as the overall TB situation. This document provides an overview of the principal issues to be considered by countries in strengthening their existing surveillance systems or developing new systems and increasing their utility. At all levels of an HIV epidemic (low-level, concentrated, generalized), routine HIV-testing data—when available—should be used for surveillance purposes. These data can be calibrated by periodic (special) or sentinel surveys. In countries where HIV prevalence among TB patients is unknown, a seroprevalence survey should be undertaken as part of the initial assessment of the situation. WHO recommends the following HIV surveillance methods, which vary according to the level of the HIV epidemic:
Periodic sentinel serosurveillance for HIV in general is usually conducted among pregnant women (as a proxy for the general population) or among population groups with high-risk behavior, depending on the level of the epidemic. This surveillance is useful for monitoring the trends in HIV prevalence and can identify, at an early stage, areas where routine HIV counseling and testing of individuals with tuberculosis should be undertaken. HIV tests other than on serum or blood—principally on gingival secretions—are available and being further developed (for example for sputum testing). WHO recommends that further work be done to improve the sensitivity, specificity and therefore the positive predictive value of HIV test on sputum. Until such further work is reported HIV-testing using sputum is only advisable if the HIV prevalence among TB patients is anticipated to be at least 10%. It is intended to pilot these guidelines in several sites around the world in 2004. This will permit evaluation of their feasibility and answer questions regarding sputum-based HIV-testing under different conditions. | |

