HIV-1 is increasing in Fiji

Heterosexual transmission remains the most significant exposure risk for HIV-1 in Fiji, according to a study published in Nature.

The study was authored by 18 doctors and scientists from Fiji, New Zealand, Australia and France.

“Very little is known about the HIV-1 epidemic in Fiji, nor the wider South Pacific region in general, yet new reported HIV-1 infections are increasing,” the authors said.

“As of 2023, there are an estimated 2,000 cases of HIV-1 in Fiji, with heterosexual contact being the main route of transmission.”

A molecular epidemiology approach was used to reveal patterns of viral transmission by collecting venous blood samples from people previously diagnosed with HIV-1.

“Fiji has the second fastest growing HIV-1 epidemic in the Asia-Pacific region, yet little is known about the genetic diversity shaping this outbreak, nor the impact of public health interventions on its trajectory.

“From genetic data from 53 HIV-1 samples, we identified six separate introductions of the virus into Fiji, where at least two of these introductions resulted in sustained transmission.

“Within the two major clusters identified, continued transmission likely lasted about 20 years, followed by a dramatic decline around 2014.”

The authors said the decline in HIV infections in 2014 was due to an increase in public health interventions in Fiji, such as contact tracing, educational campaigns and increasing accessibility to treatment and counselling.

“Heterosexual and unknown transmission within the cluster suggests that heterosexual transmission remains the most important exposure risk.

“Future work should focus on assessing the extent to which risk groups contribute to the overall spread.”

This study demonstrated that a molecular epidemiological surveillance system for HIV-1 in Fiji could provide a better understanding of HIV-1 transmission dynamics in real time, especially among high-risk populations.

“Our results are the first to show how both new introductions and persistent transmission have largely driven the epidemic in Fiji.

“We conclude that public health efforts have likely reduced the transmission rate of the clusters identified here over the past decade.”