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WCM-Q students’ research published in BMJ

The study suggests that fewer young people are being exposed to herpes simplex type 1 (HSV1) – also known as oral herpes.
The study suggests that fewer young people are being exposed to herpes simplex type 1 (HSV1) – also known as oral herpes.

Two WCM-Q students are named as joint first co-authors on a research study into the changing pattern of herpes infection which has been published in the prestigious UK medical journal BMJ Global Health.

Fourth-year medical students Wajiha Yousuf and Hania Ibrahim conducted the study at the Infectious Disease Epidemiology Group over a two-year period, guided by their supervisors Manale Harfouche, WCM-Q Research Specialist, who is also named as a joint first co-author, and Dr. Laith Abu-Raddad, Professor of Population Health Sciences, the senior author of this study.

WCM-Q's Dr. Laith Abu-Raddad.

The study suggests that fewer young people are being exposed to herpes simplex type 1 (HSV1) – also known as oral herpes – and that the prevalence amongst the population in Europe is falling by 1 percent per year.

The prevalence of the virus, which often manifests itself with cold sores, appears to be declining in younger people but it could be increasingly likely to be transmitted sexually.

HSV-1 is mainly transmitted by oral-to-oral contact, causing oral herpes, but it can also cause genital herpes. The other form of the virus (HSV-2) is sexually transmitted and causes genital herpes.

Both forms of the virus are lifelong and the World Health Organization estimates there are 3.7 billion people under age 50 (67 percent) who have HSV-1 infection globally and 491 million people aged 15-49 (13 percent) worldwide with HSV-2 infection.

Previous research data focused on North America and Europe suggests that there is a decrease in pre-adulthood acquisition of HSV-1, a decline in its population prevalence in youth, and an increase in genital herpes cases that are caused by HSV-1.

The team of researchers from Weill Cornell Medicine-Qatar set out to examine the epidemiology of HSV-1 in Europe. They systematically reviewed HSV-1 related publications, conducted various meta-analyses, assessed pooled prevalence rates in populations, and estimated pooled proportions of HSV-1 viral detection in clinically diagnosed genital ulcer disease and in genital herpes.

Their analysis gathered information from 142 suitable previous publications. From these publications, they extracted 179 overall population prevalence measures, four overall proportions of HSV-1 in genital ulcer disease, and 64 overall proportions of HSV-1 in genital herpes.

The results showed that more than two-thirds (67.4 percent) of the population in Europe tested positive for HSV-1, which is far lower than the historical level of pre-adulthood universal infection in other parts of the world, such as Africa. Around 32.5 percent of children and 74.4 percent of adults were infected in Europe.

Prevalence in the population increased steadily with age, being lowest in those aged below 20 years and highest in those aged over 50 years. Population prevalence in Europe was found to be declining by 1 percent per year, and the contribution of HSV-1 to genital herpes was rising, also by 1 percent per year.

The researchers speculated that reasons for falling prevalence rates of HSV-1 could include a general decrease in both family size and school crowding, as well as improved hygiene and living conditions. The results also showed that half of first-episode genital herpes cases in Europe were due to HSV-1, as opposed to HSV-2 infection.

The authors acknowledged that their systematic review had some limitations, primarily the unavailability of data for 25 of 53 European countries, and had comparatively less data for genital ulcer disease and genital herpes than population prevalence. Nevertheless, these limitations did not appear to have posed a barrier to the interpretation of the results of the study, they said.

The study concluded: “HSV-1 transition in Europe is leading to more heterogeneous and variable transmission by age and geography, and an increasing role for HSV-1 in genital herpes and as a sexually transmitted disease.

“The findings highlight the importance of disease surveillance and monitoring of HSV-1 seroprevalence and genital herpes aetiology, and strengthen the case for an HSV-1 vaccine to limit transmission.”

Wajiha said: “As a medical student, working with Dr. Laith Abu-Raddad, Manale Harfouche and their team was an exceptionally valuable learning experience. Through their continuous support we were able to acquire the skills needed to conduct thorough and meaningful research that will surely shape us into future physician-scientists. We could not be more delighted to have our work contribute to the scientific community.”

Hania said: “Dr. Abu-Raddad and Ms. Harfouche helped us establish our foundation in research and guided us over several years of our project. We’re very pleased that our publication was accepted to BMJ Global Health, and grateful for the invaluable lessons and skills we were able to gain through this experience.”

Dr. Thurayya Arayssi, Senior Associate Dean for Medical Education and Continuing Professional Development at WCM-Q, said: “This is an excellent piece of research and I am delighted that Wajiha and Hania’s hard work has been justly rewarded with publication in such a high-profile journal. A key aim of the curriculum at WCM-Q is to produce physician-scientists who are dedicated not only to healing but also to scientific discovery, and it is therefore extremely gratifying to see our students making the most of the opportunities to engage in research offered by the college.”

The research, titled ‘Herpes simplex virus type 1 in Europe: systematic review, meta-analyses and meta-regressions’ was possible thanks to funding by the Qatar National Research Fund [NPRP 9-040-3-008], and through pilot funding by the Biomedical Research Program at Weill Cornell Medicine-Qatar.