Community health campaigns provide an opportunity to detect previously undiagnosed cases of tuberculosis (TB), investigators report in the online edition of the Journal of Acquired Immune Deficiency Syndromes. Research conducted in rural Uganda showed that incorporating TB screening into community health campaigns offering universal HIV testing led to the diagnosis of undetected TB cases. Overall, approximately 3000 people need to be screened to identify one new case of TB, but among people with HIV and chronic cough, the yield was one new TB diagnosis per 80 screens.
“Our data suggest that coupling population-based HIV and TB testing within a multi-disease health campaign approach provides an innovative method to increase detection of smear-positive TB cases while rapidly increasing HIV testing coverage,” write the authors. “The burden of undiagnosed TB disease and the number needed to screen and identify one new TB case are within the range of prior estimates from TB prevalence surveys in sub-Saharan Africa.”
Globally, HIV and TB are a leading cause of death due to infectious disease. Even though effective antibiotic therapy is available, TB remains an important cause of mortality in East Africa, largely because of late diagnosis and under-diagnosis of the infection.
Investigators wanted to see if shifting TB detection out of clinical settings and into the community would lead to the detection of previously undiagnosed cases of the infection. They therefore analysed data obtained from a multi-disease community health campaign conducted between 2013 and 2014 in seven rural communities in eastern Uganda.
The study forms part of the larger SEARCH study, an investigation of the effectiveness of mutli-disease prevention campaigns in maximising HIV diagnosis, treatment and viral suppression in the east African setting.
TB screening was incorporated into population-wide HIV testing. Study staff worked with local community leaders to identify all eligible adults and to promote the community health campaign. For a two-week period, HIV testing, together with screening for TB and other health conditions, were provided at well-known and convenient community locations. Individuals were offered a rapid HIV test, and those testing positive had point-of-care CD4 monitoring and were linked to ongoing care. For TB screening, all participants were asked if they had a cough, and if this was present if it was persistent, lasting for more than two weeks. People with a prolonged cough were asked to provide a spontaneous sputum sample which was sent for microscopy evaluation with results returned the same day. Staff contacted all individuals with positive microscopy results.
A total of 36,785 adults were identified in the baseline census and 27,214 (74%) of these individuals attended a community health campaign. The median age of those attending was 30 years and 57% were women. Almost all (99%) accepted the offer of an HIV test, with 3.5% testing positive.
Cough was reported by 5786 participants (21%) and 2876 (11%) reported a persistent cough. The rate of persistent cough was higher in older people, in women compared to men (11.4% vs. 9.5%, p < 0.001) and in HIV-positive rather than HIV-negative people (17% vs. 10%).
Only 38% of people with a persistent cough were able to expectorate sputum. Factors associated with being able to produce a sputum sample were older age (p < 0.001) and HIV-positive status (p < 0.001).
Sputum samples from ten individuals were positive for acid-fast bacilli. Three of these individuals were HIV-positive, and one of these people was newly diagnosed with HIV thanks to the community health campaign.
Nine of the TB diagnoses were new; the other case had previously been detected at a local health centre. Six of the new cases had microscopy results suggesting their TB was highly contagious.
Overall, 0.31% of people were newly diagnosed with TB. The number of people needed to screen using symptoms and microscopy to identify a single new case was 3024. The number of people with prolonged cough who required screening with microscopy to identity a new case was 320, the figure falling to 80 per case for HIV-positive people with chronic cough.
All nine people with newly detected TB were linked to care and initiated TB therapy. This treatment was completed by six people. One individual experienced treatment failure and initiated a second-line regimen; one individual was lost to follow-up; one person died of trauma before completing their treatment.
The investigators acknowledge their study was limited by the lack of a cost-effectiveness analysis.
“Our multi-disease community health campaign approach provided an opportunity to increase TB case detection and treatment and to reduce the burden of undiagnosed TB disease in rural Uganda, in the context of population-wide, HIV testing scale-up,” conclude the authors.
Ssemmondo E et al. Population-based active TB case finding during large-scale mobile HIV testing campaigns in rural Uganda. J Acquir Immune Defic Syndr, online edition. DOI: 10.1097/QAI.000000000001142 (2016).