Most new HIV infections occur in lower prevalence countries not prioritised by PEPFAR

The burden of the global HIV epidemic is disproportionately falling on lower-prevalence countries, according to an analysis published in the Journal of Virus Eradication. The majority of new HIV infections, cases of mother-to-child HIV transmission and AIDS-related deaths now occur in countries with HIV prevalence below 4.5%. Lower-prevalence countries also had lower rates of antiretroviral therapy (ART) coverage and early infant diagnosis.

The authors note that international donor organisations such as PEPFAR (President’s Emergency Plan for AIDS Relief) and the Global Fund target their resources at countries with the highest HIV prevalence. Currently, PEPFAR has 13 priority countries. Can targets for the control of HIV be met if countries with lower prevalence are being neglected?

"The international community has galvanised large amounts of funding and grassroots action in higher-prevalence countries, which could be replicated with political will in lower-prevalence countries," the authors say.

Glossary

mother-to-child transmission (MTCT)

Transmission of HIV from a mother to her unborn child in the womb or during birth, or to infants via breast milk. Also known as vertical transmission.

exclusion criteria

Defines who cannot take part in a research study. Eligibility criteria may include disease type and stage, other medical conditions, previous treatment history, age, and gender. For example, many trials exclude women who are pregnant, to avoid any possible danger to a baby, or people who are taking a drug that might interact with the treatment being studied.

epidemiology

The study of the causes of a disease, its distribution within a population, and measures for control and prevention. Epidemiology focuses on groups rather than individuals.

eradication

The total elimination of a pathogen, such as a virus, from the body. Eradication can also refer to the complete elimination of a disease from the world.

key populations

Groups of people who are disproportionately affected by HIV or who are particularly vulnerable to HIV infection. Depending on the context, may include men who have sex with men, people who inject drugs, sex workers, adolescent girls, prisoners and migrants.

They used information from the UNAIDSinfo database for 2017 to compare several key indicators of the HIV epidemic according to whether countries had a high or lower HIV prevalence (above/below 4.5%). Just under half the world’s HIV-positive population live in countries with a prevalence below this threshold.

Countries in North America, Oceania and western Europe were excluded from the analysis. A total of 56 countries, all with HIV epidemics of 40,000 cases or above, were included. These countries make up 88% of the global HIV epidemic, 87% of global new infections and 89% of all AIDS-related deaths.

There were 12 high-prevalence countries with a total of 16.7 million people living with HIV and 44 lower-prevalence countries with 15.1 million people living with HIV. Whereas all the high-prevalence countries were in sub-Saharan Africa, around only half the lower-prevalence countries were.

There were 4.1 new infections per 100 people living with HIV in high-prevalence countries, compared to 5.8 per 100 people living with HIV in lower-prevalence countries.

Adult ART coverage was higher in high- versus lower-prevalence countries (67% vs 47%). As prevalence decreased, so too did ART coverage (p = 0.00325).

There were fewer AIDS-related deaths in high- versus lower-prevalence countries (306,100 vs 530,000).

Coverage of interventions to prevent mother-to-child transmission (PMTCT) decreased as national HIV prevalence decreased (p = 0.028). Coverage was 91% for pregnant women living in higher-prevalence countries, compared to 53% in lower-prevalence countries.

The rate of mother-to-child HIV transmission in high- and lower-prevalence countries was 8% and 17%, respectively. While three of the lower-prevalence countries did achieve a mother-to-child transmission rate below 10% (Rwanda, Brazil and Argentina), nearly half of lower- prevalence countries had a transmission rate of at least 20%, including Nigeria at 23%. Almost two-thirds (61%) of the 171,000 new childhood infections recorded in 2017 occurred in lower-prevalence countries.

Early infant diagnosis rates also increased with national prevalence (p = 0.027). Average early infant diagnosis rates in high- and lower-prevalence countries were 71% and 30%, respectively.

ART coverage for children increased as prevalence increased, averaging at 64% for high-prevalence countries compared to 29% for lower- prevalence countries. AIDS-related deaths were less frequent in high-prevalence countries (4% of HIV-positive children) than in lower-prevalence countries (8%).

“There are several strategies used in higher-prevalence settings that could potentially be applied in lower-prevalence ones, including healthcare systems decentralization, task shifting, ART distribution by community health workers and mobile technology, adherence clubs, support networks and adoption of WHO [World Health Organization] guidelines to test and treat,” comment the authors.

Some lower prevalence countries had good outcomes, with Ethiopia, the Democratic Republic of Congo and Rwanda all showing that improvements in early infant diagnosis rates and ART coverage are possible.

However, they note that lower-prevalence countries may face particular challenges in reaching key populations. Such countries often have unique epidemiological, technological and social challenges to ART delivery.

References

Kempton J et al. Most new HIV infections, vertical transmissions and AIDS-related deaths occur in lower-prevalence countries. Journal of Virus Eradication, 2019.