AIDS 2016: Training Community Health Workers Leads to Surge in TB Diagnoses in Malawi


An intervention using community health workers -- who normally provide case management support for HIV-positive pregnant women and their families -- to also provide intensified tuberculosis (TB) case finding was associated with a dramatic 20-fold increase in TB detection at a very busy antiretroviral therapy (ART) clinic in rural Malawi, according to a study presented at the 21st International AIDS Conference last week in Durban.

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The findings were presented by Katie Simon from the Baylor College of Medicine Children’s Foundation Malawi, in Lilongwe, Malawi, who also noted that the intervention led to the detection of more pediatric TB, which previously was simply not being diagnosed at the facility.

HIV and TB in Malawi

TB is the most common most common infectious cause of death among people living with HIV in Malawi (and globally). TB is undiagnosed in at least half of the HIV-positive people who have died of TB -- and some autopsy studies indicate that TB is identified in up to two-thirds of the people who die in hospitals in sub-Saharan Africa.

TB diagnosis can be particularly difficult in settings such as Malawi, which has to manage a high prevalence of HIV (9.6% among adults) despite severe resource constraints -- including a profound healthcare worker shortage. Consequently, "Malawi has task shifted to the extreme," said Simon, "with the bulk of the care provided by nurses and clinical officers to nearly 980,000 people living with HIV." The demands placed upon these health care workers is only set to increase, as the country is now transitioning to offering ART for everyone diagnosed with HIV.

An unintended consequence of these overburdened health workers and facilities may be that quite a few cases of TB are being missed. The TB prevalence in the country has recently been revised upwards from 160 cases per 100,000 to 280 cases per 100,000 -- and almost 70% of the TB cases in Malawi are in HIV-positive individuals. The national guidelines recommend routine intensified case finding (ICF) whenever a person with HIV attends a health facility, and the Ministry of Health’s data suggest that ICF coverage stands at 98%.

"But if you look at the yield of ICF, it’s only 0.2 percent -- so something doesn’t quite add up there," said Simon.

The World Health Organization’s recommended 4-symptom TB screen -- which looks for a positive response to any of the following questions: have you had a cough in the last 24 hours, any fever, night sweats, or unexplained weight loss? -- is highly sensitive for TB in people with HIV. However, in practice in very busy clinic settings, some over-burdened health providers may not perform the screen at every clinic visit. Simon said there is relatively little evidence of how to improve case detection in such routine settings.

Onepotential solution tried in other settings has been more task shifting, so Simon and her colleagues considered whether Tingathe, a U.S.-funded community health worker program could assist with intensified TB case finding. This program is in operation at Salima District Hospital, a large rural public hospital in Lilongwe, and a number of other facilities near the central and southeastern districts of Malawi.

The Tingathe community health workers who are based at facilities but have a reach into the community focus primarily on the prevention of mother-to-child transmission of HIV and the early infant diagnosis of HIV. They are trained to provide case management for pregnant women and their children, but also to conduct active HIV case finding and assist with tracing anyone who is lost to follow-up.

The Intervention

An intervention was implemented at Salima District Hospital, which has about 4800 people on ART. The community health workers who were stationed at the facility received a 1-day training on TB screening. This involved an introduction to the 4-question TB screen as well as an orientation to the process or flow that individuals who screened positive would have to go through in order to be diagnosed with TB.

Once trained, these community health workers provided screening to people attending the ART clinic. Anyone who responded affirmatively to any of the 4 questions was then triaged for immediate clinical assessment -- in other words, moved to the front of the queue -- and the clinician would then evaluate per protocol for TB, using smear microscopy and Xpert MTB/Rif tests in parallel (as opposed to serially) with a chest X-ray if necessary according to Malawian guidelines.

Critically, these individuals were then assigned a community health worker case manager who would be responsible for helping them through the cascade until their final diagnosis. Those who were diagnosed with TB were then started on TB treatment, and provided adherence support from the community health worker at the facility, or via home visits if a problem with adherence was identified. The community health worker case managers assisted with community tracing for anyone who was lost to follow up, and linked with other community health workers for combined home-based TB and HIV contact tracing.

The Evaluation

To evaluate the effectiveness of the intervention, Simon and colleagues looked at 16 months of pre- and post-intervention data, which were abstracted from registers and tools used by the community health workers. A single-group interrupted time series analysis (a method developed to assess the impact of a policy or practice when randomization is deemed unethical or impractical) was used to assess impact.

"During the 16 months prior to the interventions, a case of TB was diagnosed approximately every other month, and following the intervention there were about 10 diagnoses made monthly," Simon reported. This represented a 20-fold increase (p<0.0001). The increase in case detection began immediately in the first month of the intervention, with an immediate increase of 6.7 monthly diagnoses (p<0.0001). The rate of increase of monthly TB diagnoses improved by 0.78 diagnoses per month in the post-intervention period compared to the pre-intervention period (p=0.026).

Engaging community health workers involved in maternal and child health may have also helped prioritize diagnoses in children. "Particularly of note to me as a pediatrician is that pediatric TB was not diagnosed at all in this cohort during the 16 months prior to the intervention, but in the 6 months following 9 cases of childhood TB were diagnosed and started on treatment," said Simon.

Simon noted there are a number of limitations to the evaluation. For instance, the study is limited to a single site, and there may be some bias in how data were collected pre- and post-intervention. Because of the uncontrolled nature of the study, "we have to interpret causation with care," she said. She added that it is possible that the health workers may have "cherry picked" people, screening and triaging those they thought were most likely to have TB, but she wasn’t convinced that it was a weakness in a clinic that sees over 200 patients per day.

"Obviously the intent is that every patient with HIV should be screened for TB at every clinic visit. But practically speaking, this doesn’t happen," she said

Conclusions and Looking Forward

Future work will be needed to assess whether the impact of the intervention persists and what impact it has on the treatment outcomes for these patients. The evaluation has some patient-level analyses still pending to take a look at what the impact of this intervention is on time to treatment initiation and on mortality.

Regardless, the researchers have now expanded this intervention to other facilities covered by the community health worker program. "We now have 20 facilities implementing this model, so it will be interesting to find out if this expansion sees similar results," Simon concluded. She added that it will also be important to see whether the program and contact tracing will be sustainable in this setting.

Simon closed her talk with a Malawian proverb so applicable to the context and need for task shifting to accomplish HIV and TB targets in these settings: "Mutu umodzi suzenga denga" -- one person alone cannot raise a roof.



R Flick, K Simon, A Munthali et al. Yield of community health worker-driven intensified case finding for tuberculosis among HIV-positive patients in rural Malawi. 21st International AIDS Conference (AIDS 2016). Durban, July 18-22. Abstract WEAB0205LB.