First in a Decade Study Shows HHV-8 Drop in Istanbul’s HIV Population
Three Turkish scientists, in a new study titled ‘Marked temporal decline in human herpesvirus-8 seroprevalence among people living with HIV in Istanbul, Türkiye,’ have bridged a longstanding gap in knowledge regarding the seroprevalence of human herpesvirus-8. The study authors are Yağmur Ekenoğlu Merdan, Selim Merdan, and Pınar Etiz.
Human herpesvirus-8 (HHV-8)
In 1994, Yuan Chang and Patrick S. Moore discovered HHV-8, the virus that causes Kaposi’s sarcoma, a skin condition characterized by red or purple patches, most commonly seen in people living with HIV/AIDS. According to the researchers, although HHV-8-related tumors are most frequent in HIV-positive individuals, they have also been reported in other immunosuppressed or elderly individuals, and occasionally in patients with congenital immunodeficiencies.
The virus is spread primarily through direct contact with bodily fluids, especially through sexual transmission. Knowing the prevalence of the virus indicates how much of the population is exposed to infection and helps public health services plan prevention and testing measures.
Scientists state that the current prevalence of the virus is about 40% in sub-Saharan Africa, 10% in Mediterranean countries, 2–4% in Northwestern Europe, Southeast Asia, and the Caribbean, and 5–20% in the United States. They also warn that the number of publications on the epidemiology of HHV-8 is limited and incomplete.
The first and largest study on the seroprevalence of this virus in over a decade in Istanbul
To bridge this gap, scientists conducted the first and largest study in more than ten years on the seroprevalence of this virus among people living with HIV. Seroprevalence shows how many people in a population have antibodies in their blood to a specific virus or bacterium, indicating what portion of the population has already been exposed to the infection.
The corresponding author of the study, Assistant Professor Dr. Yağmur Ekenoğlu Merdan from Biruni University Faculty of Medicine, explained that she discovered the lack of information on HHV-8 prevalence among HIV patients in their country through her bibliometric analysis.
Her analysis, published in March 2023, showed that in Turkey, between 2001 and 2020, only 40 scientific publications were produced on HIV/AIDS-associated HHV-8/KSHV, indicating the limited scope of research in this area. The first publication appeared in 2001, while the highest number of publications was recorded in 2013 and 2020. Most of the publications were in English (82.5%), in the form of articles (82.5%), and in the field of medical sciences (95%). The most frequently used keyword was Kaposi’s sarcoma, highlighting the main focus of the research.
This emphasizes the significant lack of recent and comprehensive data on HHV-8 seroprevalence in Turkey, making it difficult to obtain a complete and accurate picture of how the virus circulates among people living with HIV.
The study and the results
In this study, 368 people living with HIV provided blood samples at six major hospitals in Istanbul. It should also be noted that there were 48 women and 320 men, with an overall average age of 42.10 years (20-83 years). A standard laboratory test (ELISA) was used to detect IgG antibodies against HHV-8. Information on age, gender, and HIV-RNA results was recorded for each sample, allowing a detailed analysis of how the virus circulates among different groups of people. The results showed that HHV-8 IgG seropositivity was only 3%, an unexpectedly low value compared with previous studies from Turkey.
Notably, there were no seropositive cases among adults under 35 years of age, while the highest prevalence was observed in the 51–60 age group, at 5.3%. Analysis by gender showed a slightly higher seropositivity in women (4.2%) compared with men (2.8%), but the difference was not statistically significant. These findings suggest that HHV-8 circulation among people living with HIV in Istanbul has decreased significantly. According to the study, the absence of antibodies in younger adults may indicate a recent reduction in saliva-mediated transmission, potentially associated with pandemic-driven measures.
Bibliometric research should be conducted on other viruses to identify gaps in the literature
When asked what the reasons were for the lack of studies on this topic in the past 10 years, Dr. Ekenoğlu Merdan said: “I don’t know exactly why, but I suspect scientists’ attention has shifted to higher-incidence, sexually transmitted diseases in general. Perhaps they felt the disease profile of HHV-8 wasn’t significant enough. Of course, studies are needed that include more comprehensive and detailed demographic data, both on a large scale and locally. I also think bibliometric research should be conducted on other viruses to identify gaps in the literature.”
The study provides the first reliable sero-epidemiological assessment of HHV-8 in Turkey in more than a decade. These results may help guide future virus surveillance, prevention, and strategic decision-making in the field of health. As Dr. Ekenoğlu Merdan adds, “What I am most proud of in our research is presenting new data on a microorganism that has long been truly neglected in my country.”
Image: Serologic testing
