Scientists conducting an observational cohort study in an ongoing mpox outbreak in the Democratic Republic of the Congo (DRC), which involves a different clade than the global outbreak, have identified a possible third route of mpox transmission: sexual activity involving heterosexuals.

An outbreak in the DRC's South Kivu province has been under way since August 2023. The outbreak is centered in Kamituga, and scientists have identified a distinct clade 1 mpox strain, which may be a novel subgroup. An international research team published its findings this week in medRxiv, a preprint server hosting studies that are not yet peer-reviewed.

So far, more than 200 mpox cases have been reported in the Kamituga area.

The outbreak made headlines in in late 2023, because it was the first known clade 1 outbreak fueled by sexual transmission. Typically, clade 1 infections involve zoonotic spillovers with some human-to-human spread. Clade 1 infections are known to be more virulent and deadly, with case-fatality rates as high as 10%.

Female sex workers main occupational group

For the study, researchers interviewed 51 of 164 patients who were admitted to Kamituga hospital September 2023 through January 2024. Of that group, 24 were professional sex workers. The most common symptoms were fever and oral and anogenital lesions. Two deaths were reported.

Heterosexual partners were mainly affected, suggesting that heterosexual contact may be the main form of transmission. The investigators wrote that professional sex workers –primarily young women–were the dominant occupational group, suggesting that they and their clients may be at higher risk for contracting mpox.

So far, there's no sign that clade 1 is spreading outside of central Africa, the European Centre for Disease Prevention and Control said in a December risk assessment.

New data released today by the European Centre for Disease Prevention and Control (ECDC) show a surge in sexually transmitted infections (STIs) across the continent.

The latest annual epidemiologic reports from the ECDC show gonorrhea cases in European Union/European Economic Area EU/EEA countries rose by 48%, syphilis cases by 34%, and chlamydia cases by 16% compared with the previous year. New record high notification rates were reported for chlamydia and gonorrhea. For all three STIs, national notifications varied considerably across EU/EEA countries.

Cases of lymphogranuloma venereum and congenital syphilis, which are caused by transmission of the infection from the mother to the fetus, also rose in 2022.

Officials call for more testing, treatment, and awareness

ECDC officials say the increase in STIs, which mirrors trends seen in the United States and other countries, requires "urgent attention and concerted efforts."

"Testing, treatment, and prevention lie at the heart of any long-term strategy," ECDC Director Andrea Ammon, MD, MPH, said in a news release. "We must prioritise sexual health education, expand access to testing and treatment services, and combat the stigma associated with STIs."

Ammon went on to say that education and awareness initiatives, promoting consistent condom use, and fostering open dialogue about STIs can help reduce transmission rates.

The ECDC also noted that gonorrhea, chlamydia, and syphilis can lead to serious health complications—such as pelvic inflammatory disease, chronic pain, and infertility—if they are left untreated. The agency urged people who suspect they may have contracted an STI to immediately seek medical advice to prevent complications and further transmission.

Brazil and Peru continue to report more infections involving Oropouche virus, which is spread by biting midges and certain types of mosquitoes, the Pan American Health Organization (PAHO) said yesterday in an update.

PAHO issued an initial alert about the disease in early February following a rise in cases, mainly in Amazonas state in Brazil. Oropouche virus, part of the orthobunyavirus family, causes symptoms similar to dengue. Symptoms can linger for weeks, and some patients experience aseptic meningitis. There are no specific vaccines or treatments for the disease.

Since the first of the year, Brazilian labs have detected the virus in 2,104 samples, main from people in Amazonas state, where the disease is endemic. Cases have also been reported from Rhondonia, Acre, and Romarina states. All four states are in Brazil's northwestern region.

Peru has reported 146 cases so far this year, the most since it recorded its first cases in 2016. The recent infections were reported in Loreto, Ucayali, and Madre de Dios departments, all in the east, bordering affected areas in Brazil.

Today in PLOS One, researchers report the discovery of a novel herpesvirus in South American fur seals and sea lions.

From 2011 to 2018, Chicago Zoological Society researchers led the sampling of free-ranging South American fur seals and California sea lions in Punta San Juan, Peru, for Otariid gammaherpesvirus 1 (OtGHV1). The virus is linked to high rates of urogenital (bladder, kidney, prostate, and other urinary tract) cancer in free-ranging sea lions in the Northern Hemisphere, which until recently was the only location reporting its presence.

Herpesviruses tend to cause minimal disease in host species but can cause severe illness in other animals. Both fur seals and sea lions are considered endangered in Peru, where populations have declined because of hunting, habitat encroachment, overfishing, and pollution.

A 'significant advancement'

Fourteen of 67 (21%) of urogenital swabs from live animals of both species collected in 2011, 2014, and 2015 tested positive on pan-herpesvirus conventional polymerase chain reaction (PCR). Genetic sequencing revealed a novel virus related to OtGHV1 called Otariid gammaherpesvirus 8 (OtGHV8).