Prevalence of syphilis infection among migrant workers in Qatar

A collaborative study by the Infectious Disease Epidemiology Group at Weill Cornell Medicine-Qatar and Qatar University found that the prevalence of lifetime and recent syphilis infections among migrant craft and manual workers in Qatar was approximately 1% and 0.1%, respectively. These rates align with global trends, highlighting an overlooked disease burden with implications for both health and social well-being.

Conducted by Nasrallah et al. and published in BMJ Open, the study, titled “Prevalence of Syphilis Infection Among Migrant Workers in Qatar: A Nationwide Cross-Sectional Survey,” underscores the need for targeted programs to address sexually transmitted infections and improve the broader sexual health needs of this population.

Citation: Nasrallah GK, Chemaitelly H, Ismail AIA, et al. Prevalence of syphilis infection among migrant workers in Qatar: a nationwide cross-sectional survey. BMJ Open. 2024 Nov 27;14(11):e083810. doi: 10.1136/bmjopen-2023-083810.

Weblink: https://bmjopen.bmj.com/content/14/11/e083810

Dynamics of Neisseria gonorrhoeae transmission among female sex workers and clients

Researchers at the Infectious Disease Epidemiology Group at Weill Cornell Medicine-Qatar found that in low-partner-number heterosexual sex work networks (HSWNs), a large proportion of Neisseria gonorrhoeae (NG) incidence occurs among female sex workers (FSWs). NG prevalence was 13 times higher among FSWs than their clients and three times higher among clients than their spouses. However, interventions were shown to substantially reduce incidence in such HSWNs.

Conducted by Ayoub et al. and published in Epidemics, the study, titled “Dynamics of Neisseria gonorrhoeae Transmission Among Female Sex Workers and Clients: A Mathematical Modeling Study,” suggested that NG epidemiology in HSWNs represents a “fragile epidemiology,” highly responsive to interventions, even if they are incremental, partially efficacious, and applied only to FSWs.

Citation: Ayoub HH, Tomy M, Chemaitelly H, et al. Dynamics of Neisseria gonorrhoeae transmission among female sex workers and clients: A mathematical modeling study. Epidemics. 2024 Sep;48:100785. doi: 10.1016/j.epidem.2024.100785. Epub 2024 Aug 5.

Weblink: https://www.sciencedirect.com/science/article/pii/S175543652400046X

Global and regional incidence and prevalence of herpes simplex virus infections and genital ulcer disease in 2020

Researchers at the Infectious Disease Epidemiology Group at Weill Cornell Medicine-Qatar, the University of Bristol, and the World Health Organization estimated that in 2020, globally, 26 million people aged 15-49 acquired a new herpes simplex virus type 2 (HSV-2) infection, 520 million were living with HSV-2, and 188 million experienced at least one episode of genital ulcer disease (GUD) caused by HSV-2. Additionally, 17 million people in the same age group acquired a new genital herpes simplex virus type 1 (HSV-1) infection through sexual transmission, 376 million were living with genital HSV-1, and 17 million had at least one episode of GUD caused by HSV-1.

The study by Harfouche et al., titled “Estimated Global and Regional Incidence and Prevalence of Herpes Simplex Virus Infections and Genital Ulcer Disease in 2020: Mathematical Modelling Analyses,” published in Sexually Transmitted Infections, highlights the need for new prevention and treatment strategies, including prophylactic and therapeutic HSV vaccines, to control infections and reduce the associated disease burden.

Citation: Harfouche M, AlMukdad S, Alareeki A, et al. Estimated global and regional incidence and prevalence of herpes simplex virus infections and genital ulcer disease in 2020: mathematical modelling analyses. Sex Transm Infect. 2024 Dec 10:sextrans-2024-056307. doi: 10.1136/sextrans-2024-056307.

Weblink: https://sti.bmj.com/content/early/2024/11/12/sextrans-2024-056307

Prevalence of one STI as a predictor for another

A collaborative study by the Infectious Disease Epidemiology Group at Weill Cornell Medicine-Qatar and Hokkaido University in Japan investigated the concurrent transmission of HIV, herpes simplex virus type 2 (HSV-2), chlamydia, gonorrhea, and syphilis in men who have sex with men (MSM) sexual networks. The study found that gonorrhea prevalence was a strong predictor of HIV prevalence, while HSV-2 and syphilis prevalences were weak predictors of each other.

Conducted by Omori et al. and published in Infectious Disease Modelling, the study, titled “Can the Prevalence of One STI Serve as a Predictor for Another? A Mathematical Modeling Analysis,” highlights the complex dynamics of sexually transmitted infections (STIs) within sexual networks. The findings demonstrate how different STIs exhibit distinct epidemiological patterns while also revealing ecological associations facilitated by their shared mode of transmission, allowing for predictive relationships between STI prevalences.

Citation: Omori R, Chemaitelly H, Abu-Raddad LJ. Can the prevalence of one STI serve as a predictor for another? A mathematical modeling analysis. Infect Dis Model. 2024 Dec 12;10(2):423-428. doi: 10.1016/j.idm.2024.12.008.

Weblink: https://www.sciencedirect.com/science/article/pii/S2468042724001349

Hepatitis C virus transmission among people who inject drugs in the Middle East and North Africa

Researchers at the Infectious Disease Epidemiology Group at Weill Cornell Medicine-Qatar estimated the hepatitis C virus (HCV) incidence rate among people who inject drugs (PWID) in the Middle East and North Africa (MENA) region at approximately 10 per 100 person-years, with an estimated 42,364 new infections annually, accounting for 17% of all cases. These figures varied significantly across countries.

A 75% reduction in needle/syringe sharing was projected to decrease chronic infection prevalence by approximately 14%, the incidence rate by 34%, and annual new infections by 24%. Achieving 75% direct-acting antiviral treatment coverage by 2030 would lower chronic infection prevalence by approximately 65%, the incidence rate by 35%, and annual new infections by 25%.

Conducted by Makhoul et al. and published in The Lancet’s eClinicalMedicine, the study, titled “Hepatitis C Virus Transmission Among People Who Inject Drugs in the Middle East and North Africa: Mathematical Modeling Analyses of Incidence and Intervention Impact,” highlights the substantial HCV burden among PWID in MENA. While interventions show potential, only large-scale or multi-intervention strategies can achieve meaningful reductions in HCV transmission.

Citation: Makhoul M, Mumtaz GR, Ayoub HH, et al. Hepatitis C virus transmission among people who inject drugs in the Middle East and North Africa: mathematical modeling analyses of incidence and intervention impact. EClinicalMedicine. 2025 Jan 15;80:103040. doi: 10.1016/j.eclinm.2024.103040.

Weblink: https://www.thelancet.com/journals/eclinm/article/PIIS2589-5370(24)00619-9/fulltext