Newly Identified Clinical Symptoms of Monkeypox Similar to Common STI Symptoms

Genital lesions, sores on the mouth or anus, and single ulcers are newly identified clinical symptoms of monkeypox, according to research published in The New England Journal of Medicine.

Researchers hope the identification of these new symptoms will aid in future diagnosis and help slow the spread of infection.

“We have shown that the current international case definitions need to be expanded to add symptoms that are not currently included, such as sores in the mouth, on the anal mucosa and single ulcers. These particular symptoms can be severe and have led to hospital admissions so it is important to make a diagnosis,” said Chloe Orkin, MD, MBChB, FRCP, professor of HIV Medicine at Queen Mary University of London and director of the SHARE collaborative in a statement.

Investigators at Queen Mary University of London identified new clinical symptoms of monkeypox infection in a case series resulting from an international collaboration across 16 countries. The study was carried out in response to the emerging global health threat posed by monkeypox. The series reports on 528 confirmed infections at 43 sites between April 27 and June 24, 2022.

Many infected individuals reviewed in the study presented with symptoms not recognized in current medical definitions of monkeypox. These new clinical symptoms included single genital lesions and sores on the mouth or anus.

These symptoms are similar to those of sexually transmitted infections (STIs), leading to potential misdiagnosis. For some patients, anal and oral symptoms have led to hospitalization for management of pain and difficulties swallowing.

The authors highlight that recognizing these clinical symptoms and educating health care professionals to identify and manage this disease are important, especially considering that misdiagnosis can slow detection and hurt efforts to control the spread of the virus.

“In addition, we identified new clinical presentations in people with monkeypox. While we expected various skin problems and rashes, we also found that 1 in 10 people had only a single skin lesion in the genital area, and 15% had anal and/or rectal pain,” said John Thornhill, MD, PhD, consultant physician in Sexual Health and HIV and clinical senior lecturer at Barts NHS Health Trust and Queen Mary University of London, in a statement. “These different presentations highlight that monkeypox infections could be missed or easily confused with common sexually transmitted infections such as syphilis or herpes. We therefore suggest broadening the current case definitions.”

The findings of the study also prompt additional research, according to the authors.

“We have also found monkeypox virus in a large proportion of the semen samples tested from people with monkeypox. However, this may be incidental as we do not know that it is present at a high enough levels to facilitate sexual transmission,” Thornhill said. “More work is needed to understand this better.”

The authors hope their findings will lead to increased rates of diagnosis when persons from at-risk groups present with traditional STI symptoms.

The current spread of the monkeypox virus disproportionately affects men who identify as gay and bisexual, with 98% of infected persons from this group. The authors emphasize that although sexual closeness is identified as the most likely route of transmission in most of these cases, the virus can be transmitted by any close contact through large respiratory droplets and potentially through clothing and other surfaces.

"It is important to stress that monkeypox is not a sexually transmitted infection in the traditional sense; it can be acquired through any kind of close physical contact. However, our work suggests that most transmissions so far have been related to sexual activity—mainly, but not exclusively, amongst men who have sex with men. This research study increases our understanding of the ways it is spread and the groups in which it is spreading, which will aid rapid identification of new cases and allow us to offer prevention strategies, such as vaccines, to those individuals at higher risk,” Thornhill added.

Currently, there is a global shortage for human monkeypox vaccines and treatments. Researchers hope this study will help aid the global response to the virus and public health interventions by helping identify those most at risk of infection.

“Expanding the case definition will help doctors more easily recognize the infection and so prevent people from passing it on. Given the global constraints on vaccine and antiviral supply for this chronically underfunded, neglected tropical infection, prevention remains a key tool in limiting the global spread of human monkeypox infection," Orkin said.

Recognizing the disease, contact tracing, and advising people to isolate are the suggested components of the public health response. The authors suggest that these measures should be developed and implemented while working with at-risk groups to ensure that they are appropriate and non-stigmatizing. Researchers want to prevent messaging that would drive the outbreak underground.

“Wherever the monkeypox virus has shown up, it has tested the ability of our public health systems to respond decisively and urgently during an emergency. It is gratifying to be part of a collective which has worked furiously to gather and share information with each other and with the global public health community,” concluded Keletso Makofane, MPH, PhD, Health and Human Rights Fellow at Harvard University.

Reference

New clinical symptoms identified in largest international study series of confirmed monkeypox cases. ScienceDaily. News release. July 21, 2022. Accessed July 25, 2022. https://www.sciencedaily.com/releases/2022/07/220721204900.htm