Results released Monday from the Zambia-South Africa TB and AIDS Reduction (ZAMSTAR) program study demonstrate that household counseling – defined as the unpacking of concerns about TB and HIV within households and facilitating prompt diagnosis and treatment – significantly reduced tuberculosis (TB) prevalence.
Twenty-four communities across Zambia and South Africa’s Western Cape Province participated in the study, which tested ways to interrupt the transmission of TB in communities with a high burden of TB and HIV through additional TB control mechanisms. Each community was randomly allocated to receive one of four interventions:
- Clinic based TB and HIV interventions by ensuring the following:
- TB and HIV program collaboration
- All TB clients tested for HIV
- All voluntary HIV counseling and testing clients screened for TB
- Enhanced case finding using community-based interventions to improve awareness of TB and HIV. Three components of enhanced case employed at the community and health centre level:
- Fast track to sputum collection for smear at the health center.
- Schools education campaign.
- Mobile sputum collection points with community advocacy using local youth drama groups.
- Household interventions to increase case finding by using a strategy of integrated TB/HIV care, applied at the household level that aim to:
- Improve TB case holding
- Facilitate active case finding of TB in household contacts of TB cases
- Provide TB preventive therapy to those at risk (asymptomatic HIV-positive individuals and children less than six years old)
- Increase access to HIV counseling and testing
- Increase dialogue within the household that enables HIV-negative individuals to reduce their risk of becoming infected with HIV
- Provide a route for administration, with enhanced adherence, of antiretroviral drugs.
- Combination of all the above interventions.
The large-scale, community-randomized trial demonstrated that the household intervention reduced the prevalence of culture-positive tuberculosis by 22 percent as compared to the communities that did not receive the intervention. The study team evaluated the primary outcomes using prevalence data of culture-positive TB among a randomly selected population of adults in each arm of the trial, measured three years into the intervention.
“A total of roughly 1 million individuals were touched by the ZAMSTAR interventions in the two study countries and the interventions cost less than one U.S. dollar per person per year to implement,” according to a press release.
In conjunction with district and provincial health services, the communities received support to improve TB and HIV care and service integration; as well as either one or both enhanced TB case finding and household counseling. More than 9,000 households, about one in fifteen households in the intervention communities, were visited.
“In the era of HIV, this is the first community-randomized trial of a public health intervention to be shown to have an impact on the epidemiology of TB at community-level,” said Dr. Peter Godfrey-Faussett, one of three ZAMSTAR Principal Investigators and Professor of Infectious Diseases and International Health at London School of Hygiene and Tropical Medicine (LSHTM), in the press release.
The $27 million Bill & Melinda Gates Foundation-funded study was a collaboration between the Zambia AIDS Related TB (ZAMBART) Project, the Desmond Tutu TB Centre (DTTC) at Stellenbosch University and LSHTM, as one of three large studies within the Consortium to Respond Effectively to the AIDS and TB Epidemics (CREATE).
“The trial found that TB transmission rates were still higher than all previous community-based surveys in Africa, with up to one-third of grade 1 to 3 school-children already infected with TB,” according to the release.
Other interesting study conclusions include:
- In addition to the reduced prevalence rate, children living in the communities that received the household counseling intervention were half as likely to become infected with TB.
- Many people with TB in the trial did not seek health services when ill and often when they did go, the clinic staff did not suspect TB readily enough.
- Approximately 25 percent of all the most infectious (sputum smear positive) cases that were diagnosed in the “Enhanced Case Finding” communities were found because of the intervention.