Studies detail monkeypox transmission risks

A study of nearly 400 samples taken from men with monkeypox reveals a high prevalence of the virus on skin, throat and anal swabs compared to blood or urine – with detections in semen in the medium- and high viral loads in skin and anal swabs.

Two other new studies detail the risk of transmission in a tattoo parlor and healthcare facilities, and in US news, officials report a monkeypox-related death in Ohio.

Viral DNA found on skin swabs from 88% of men

The new analysis of 356 samples from 50 men in France infected with monkeypox shows that detection of viral DNA by polymerase chain reaction (PCR) was more frequent from skin swabs (88% of men), throat (77%) and anus (71%), than semen (54%), blood (29%) or urine (22%).

The highest viral DNA loads were consistently found in skin and anal swabs, and lesions were common on the anus and genitals, continuing to suggest that sexual contact is the main route of transmission. The study, published in The Lancet Infectious Diseases is one of many new studies aimed at describing the risks of poxvirus transmission in the real world.

The researchers assessed viral load using cycle threshold (Ct) values, which are lower when viral loads are high. Viral loads were significantly higher for skin lesions (Ct, 19.8) and anal samples (Ct, 20.9) than for throat (27.2), semen (27.8), d urine (31.1) or blood (32.8).

The median age in the study was 34, with 44% of the men being HIV-positive. On day 14 of the swab, the proportion of positive samples decreased significantly on the skin and in the anus, throat, blood, urine and semen samples.

“High MPXV viral loads from the skin and mucous membranes, including genital and anal sites, suggest that transmission most likely occurs through direct body contact rather than through the respiratory route or through contact with bodily fluids, which which should help refine prevention messages delivered to individuals most at risk of the virus,” the authors wrote.

They added: “The detection of MPXV at high concentrations in the anal region, in the mouth and in semen is consistent with sexual practices potentially implicated in the spread of the virus among men who have sex with men, in particular more skin contact. linked to sexual or non-sexual proximity.

In a comment On the study, Italian researchers said the results add to a growing body of literature on monkeypox transmission, which is urgently needed as the world has seen more than 50,000 cases in the past 4 months. , of which 95% among men who have sex with men.

“Further investigations are needed to obtain a consistent understanding of the transmission factors that enabled the extraordinary penetration of active MPXV infection into human communities worldwide,” the authors said.

High attack rate during tattoo outbreak

Also published in the Lancet Infectious Diseases is a report on several cases of monkeypox linked to a piercing and tattoo parlor in Cadiz, Spain. Of 54 exposed clients, 20 (37%) contracted the disease from July 19 to August 3.

All piercings and tattoos were done by an employee who did not have monkeypox, but was in close contact with a possible index case on July 6. This person got pierced while suffering from a rash and generalized skin inflammation.

Of the 20 exposed clients, 8 were under 18 and 13 were women. In 90% of cases, patients developed a rash at the piercing or tattoo. Subsequent surface sampling showed largely contaminated and unsanitary conditions, with detectable monkeypox viral DNA on work tables and chairs, as well as sharp objects and other work implements.

“Together, these results suggest that monkeypox virus can be transmitted through exposure to contaminated piercing or tattooing equipment and, potentially through contaminated hands, due to poor aseptic measures and improper handling of materials” , the authors concluded.

Nurses infected after taking samples

In another study highlighting the routes of transmission, practitioners writing Emerging infectious diseases describe the infections of two Brazilian nurses 5 days after taking samples from a patient with monkeypox.

The authors say the virus was most likely transmitted through contact with contaminated objects. Nurses visited the patient at his home and had no skin-to-skin contact with the patient, and they reported no sharps injuries. They wore N95 respirators and gloves, but did not disinfect clipboards and sample collection boxes.

“Our report provides evidence supporting the hypothesis that the two [healthcare workers] the infections observed in this study were transmitted by exposure to fomites with surfaces in the patient’s home, their own [personal protective equipment]or exterior surfaces of the specimen transport box,” the authors wrote.

US tracking second death from monkeypox

In the United States, Ohio reported its first death from monkeypox, in a man with underlying health conditions. This marks the second confirmed deaths from monkeypox in the United States.

The United States has confirmed 25,613 cases of monkeypox. In his third technical report on the outbreak, the US Centers for Disease Control and Prevention said activity appeared to peak in August. The median age of patients is 34 and there was (yesterday) one official virus-related death.

US authorities have confirmed 29 pediatric cases, according to the report.

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