Tanzania HIV Impact Survey: Tracking Progress and Informing Action

CDC works with partners around the world to measure progress towards controlling the HIV epidemic in countries supported by the U.S. President’s Emergency Plan for AIDS Relief (PEPFAR). One important tool used to measure the impact of HIV treatment and prevention programs in PEPFAR-supported countries is the Population-based HIV Impact Assessments (PHIAs) surveys.

In Tanzania the PHIA survey is known as the Tanzania HIV Impact Survey (THIS). This national survey plays a crucial role in measuring Tanzania’s progress in controlling the HIV epidemic. The main goal of THIS is to estimate the number of people living with HIV, the annual number of new infections, and the proportion of individuals who are aware of their HIV status. It also measures the number of people who are receiving effective HIV treatment and who maintain a low or undetectable viral load.

Community mobilizer conducts interviews during the data collection activities in Tanzania.

Community mobilizer conducts interviews during the data collection activities in Tanzania.

THIS 2022-2023 Launch

CDC Tanzania worked closely with multiple local partners in providing technical assistance to conduct THIS 2022-2023. Implementing partners included:

  • The Government of Tanzania through the Tanzania Commission for AIDS
  • The Zanzibar AIDS Commission
  • The Ministries of Health of mainland Tanzania and Zanzibar
  • The National Bureau of Statistics
  • The Office of Chief Government in Zanzibar
  • ICAP at Columbia University

Over 1,130 field staff trained as data collectors, in HIV testing services, and phlebotomy deployed throughout all 31 regions of Tanzania to conduct the survey. The survey included a nationally representative sample of approximately 20,000 randomly selected households and approximately 40,000 people aged 15 years and older.

Despite geographical challenges, this complex fieldwork was completed at remarkable speed. The dedicated teams finalized THIS data collection by March 2023. The teams successfully interviewed nearly 36,000 people and conducting over 33,600 HIV tests in only 4 months.

HIV Progress in Tanzania

Since the start of the PEPFAR program, Tanzania has made significant progress toward epidemic control. Since 2010, the number of new HIV infection has declined an estimated 47%. Recent Joint United Nations Programme on HIV/AIDS (UNAIDS) 2021 data reports that of the 1.7 million people living with HIV in Tanzania:

  • 88% were aware of their status
  • 86% were taking life-saving HIV antiretroviral therapy (ART), and
  • 83% had a HIV viral load that is considered suppressed, meaning it is under 1,000 copies/mL.

These estimates are generated using a model which incorporates data from the first THIS survey, along with routinely collected data from the national HIV program.

Monitoring Field Data Collection

In early February 2023, CDC Tanzania Deputy Country Director Alison Johnson, MPA accompanied the ICAP and National Bureau of Statistics to visit a remote Mwandi village in Kilosa district in the Morogoro region to conduct a monitoring visit. The team observed data collection processes and visited the satellite laboratory which receives, and processes blood samples collected by field teams each day. They also visited the satellite laboratory in Morogoro to observe how specimens were prepared for additional onsite testing and packed for shipping to the survey main laboratory.

Despite complex challenges the staff faced in reaching the survey sites, the experience highlighted the dedication and efficiency of the survey team in collecting valuable data.

Alison Johnson, monitoring THIS household activities at Mwandi village, in Kilosa district, Morogoro region.

Alison Johnson, monitoring THIS household activities at Mwandi village, in Kilosa district, Morogoro region.

Despite the challenges, the experience was enlightening, and it opened our eyes to the challenges faced by this data collection and community mobilizing teams.

Alison Johnson, MPA

Impact and Future

The team will release a national report. Survey datasets will be made accessible to third party investigators using established data sharing agreements, processes, and procedures. The final THIS 2022-2023 report and materials will be disseminated to stakeholders and the public around March 2024.

These survey results will provide Tanzania’s government leaders, medical professionals, civil society organizations, and researchers with a valuable guide to decision-making on HIV policy, programs, and funding, leading to better health, stronger families, and a more prosperous nation.