Finding Where HIV Is Spreading: Malawi's Recent-Infection Surveillance and One Clinic's Response, 2024

Malawi has made progress toward controlling HIV, but an estimated 12,000 new infections still occurred there in 2023. To find where the virus is spreading now, the country runs recent HIV infection surveillance.

How the surveillance works

A recent infection testing algorithm combines a rapid test for recent infection with a viral load result to classify each new diagnosis as:

Where recent infections cluster, HIV is probably still being passed on.

Finding the signal

Data from April–September 2023 were analyzed with spatial scan statistics, which look for clusters of health facilities whose rates of recent infection are significantly higher than chance would explain. The rate is the number of recent infections per 100,000 people at risk — recent infections divided by recent infections plus negative test results.

• Of 289 facilities running the surveillance, 26, in eight signals, had higher-than-expected rates. A public health response began at all 26.
• This report covers one of two public health clinics in a signal in Malawi's southern region, responding in May 2024: expected rate 3.36 per 100,000; actual rate 16 per 100,000.

CDC reviewed the work and deemed it not research.

The investigation

After checking the clinic's testing and diagnosis data against national figures, a multidisciplinary team — government and nongovernmental partners and the clinic's own health care workers — got to work:

1. Program data. Seven set indicators from the U.S. President's Emergency Plan for AIDS Relief monitoring database, covering testing, prevention and treatment from April 2022 to September 2023, were reviewed with site-level data:
2. • people tested who got their results;
   • people 15 and older who tested positive;
   • people found and tested through index testing, in which health care workers help someone who tests positive identify sexual partners, and children and young people under 19, who may be at risk;
   • people newly started on antiretroviral therapy (ART);
   • people receiving ART;
   • the share of people on ART with a suppressed viral load (under 1,000 copies of HIV per mL of blood);
   • people newly started on preexposure prophylaxis (PrEP).
3. Community voices. Two focus groups with 19 community representatives — faith leaders, shop owners and leaders of HIV community groups — discussed the gaps.
4. Plans. The team reviewed everything together and drew up recommendations and action plans.

Gap 1: too little viral suppression

Viral suppression among people on ART stayed below the 95% target — most of all among 15- to 19-year-olds, at 53% to 59%. Sticking to ART is what brings suppression, and although adherence wasn't measured, interviews pointed to barriers:

• parents reluctant to tell young people who had acquired HIV at birth about their status;
• inaccurate care and treatment information from some faith leaders;
• no privacy during adherence counseling.

Response: enhanced adherence counseling (an individual needs assessment, counseling and education sessions, and follow-up phone calls); educating faith leaders and involving them in ART advocacy; and sessions to help parents disclose HIV status to their children.

Gap 2: PrEP stuck at a low level

Although PrEP had become more widely available over the previous 18 months, the number of people newly starting it didn't grow, moving between 13 and 36 over those 18 months. Interviews suggested why:

• HIV-related stigma;
• little awareness that PrEP was available;
• too few health care workers trained to provide it.

In early 2023, PrEP services had been moved away from ART services to reduce stigma — but neither the move nor PrEP's continued availability had been well explained to the community.

Response: train more health care workers to provide PrEP, offer it at several service points, and run community awareness campaigns.

Why it matters

Timely surveillance of recent infections, combined with other data, can point to exactly where services are falling short — and to the people to involve in fixing them — as part of the push to bring the HIV/AIDS epidemic under control.

Sources

Based on Stephens R, Mfungwe H, Chalira D, et al., "Notes from the Field: Public Health Response to Surveillance for Recent HIV Infections — Malawi, May 2024," MMWR volume 74, number 20, Centers for Disease Control and Prevention; a work of the United States government in the public domain.