New HIV infections drop, deaths rise among men
At least 16,752 Kenyans were newly infected last year
1mon agoJOHN MUCHANGINews
The results challenge the prevailing assumption that parenteral transmission—HIV spread through shared needles—is the dominant route of infection in this population.Most people who inject drugs (PWID) and are living with HIV in Kenya did not acquire the virus through needle sharing, a new study reveals.
Instead, their primary source of infection is sexual transmission from other groups, including female sex workers (FSW), men who have sex with men (MSM), and the general population (GP). Researchers made the conclusion after genetic sequencing to trace the origins of HIV infections among people who inject drugs in Nairobi and the coast.
They incorporated 303 new HIV-1 sequences from PWID and their sexual and injecting partners with 2,666 previously published Kenyan HIV-1 sequences to find the direction of HIV-1 transmissions involving PWID from the coast and Nairobi. The results indicate only 21 per cent of HIV transmissions within PWID were linked to another PWID.
In contrast, PWID were equally likely to cluster with HIV sequences from female sex workers, men who have sex with men, and the general population. “PWID are not isolated within their own epidemic,” the study emphasizes. “Instead, they are a part of Kenya’s broader HIV network, with most infections originating from sexual contact outside their injecting group.”
Ancestral state reconstruction—an advanced method for analyzing the origins of infections—revealed that transmissions to PWID were 1.5 to 2.8 times more common than transmissions from PWID to other populations.
The results challenge the prevailing assumption that parenteral transmission—HIV spread through shared needles—is the dominant route of infection in this population.
“We found low levels of linked transmission among people who inject drugs despite recruiting many from local sexual and injecting networks,” the researchers noted. “This suggests that most PWID acquire HIV sexually, and efforts to address the epidemic must extend beyond needle-sharing programs.”
Results are published in study, titled “A Phylogenetic Assessment of HIV-1 Transmission Trends Among People Who Inject Drugs From Coastal and Nairobi, Kenya” and published in Virus Evolution. PWID have long been considered a high-risk population for HIV due to needle sharing.
In Kenya, where injection drug use is prevalent along the coast and in urban centres like Nairobi, needle-syringe programmes (NSPs) were introduced in 2013 to reduce parenteral HIV transmission. Methadone maintenance therapy followed in 2014.
These interventions have proven effective, with rates of needle sharing among PWID plummeting to less than 10 per cent in recent years. Despite this success, HIV prevalence among PWID remains alarmingly high—four to five times that of the general population—ranging from 14 per cent to 20 per cent.
Dr. Hanley Kingston, from Washington State University, is the lead author. The other researchers came from the Kenya Medical Research Institute, the Ministry of Health, Kenyatta National Hospital, Population Council, and the Support for Addiction Prevention and Treatment in Africa, among others.
Dr Kingston and his colleagues explain: “Our findings show that while needle-syringe programmes (NSP) have helped curb needle-related transmission, they are insufficient on their own. HIV among PWID is deeply interwoven with the broader epidemic, and sexual networks play a significant role.” These findings have profound implications for HIV prevention strategies targeting PWID.
While NSPs remain vital for harm reduction, the study calls for a more comprehensive approach that addresses sexual transmission. “Interventions must consider the diverse vulnerabilities of this group,” one co-author said.
“Many PWID, particularly women, face overlapping risks as they engage in transactional sex to support their drug use.”
The researchers advocate for integrating sexual health services into harm reduction programs. This includes providing pre-exposure prophylaxis (PrEP), ensuring access to antiretroviral therapy (ART), and addressing gender-specific challenges such as violence and stigma. The study also highlights the importance of addressing intersecting populations. For example, many female PWID also engage in sex work but may not be reached by programs targeting FSW.
“Key populations like PWID, FSW, and MSM often face compounded risks, yet our interventions tend to treat them as separate groups,” the authors said. “We need to break these silos and adopt a more holistic approach.”
HIV prevention among PWID has come a long way since the introduction of harm reduction programs in Kenya. However, the study underscores that the battle is far from over.
“While we have made progress in reducing needle sharing, sexual transmission continues to fuel the epidemic,” says Dr. Kingston, and his colleagues said. “To end HIV among PWID, we must broaden our focus and address the full spectrum of risks they face.”
The researchers hope their findings will inform national and global HIV strategies, ensuring that no population is left behind in the fight against this enduring epidemic.
As the study concludes: “Efforts to control HIV among PWID must go beyond the needle.”
