Unesp Journal | Diagnosis is one of the challenges to control monkeypox virus

Fabio Mazzitelli

Monkeypox (MPX), or simian smallpox, was the cause of an epidemiological alert issued on July 7 by the Center for Epidemiological Surveillance (CVE) of the government of São Paulo, due to the increasing number of diagnoses of the disease in the state of São Paulo, which at that time registered 75 of the 106 confirmed cases in the country (70.8%). In the national report produced on July 21, the number of confirmations had increased fivefold, with 607 cases, with 438 notifications in São Paulo (72.2%).

What most worries health authorities is a set of characteristics that, together, are making monkeypox a very fast-spreading disease in non-endemic countries, including Brazil. “Monkeypox is a disease that, in short, is extremely difficult to deal with,” says infectious disease specialist Alexandre Naime Barbosa, a professor at the Botucatu Campus School of Medicine (FMB-Unesp).

Virus of the same genus (Orthopoxvirus) as those of smallpox, cowpox and vaccinia, used in the production of the smallpox vaccine in humans, monkeypox has skin-to-skin contact as the main route of transmission between humans. The main symptoms of the disease are a rash, fever, and inflamed lymph nodes. Skin sores, which can take up to 21 days to appear after infection, can appear on the face, hands, feet, chest and genitals, among other parts of the body, have a high viral load and are therefore highly transmissible, requiring the carrying the virus respects a prolonged isolation period of up to 40 days – the individual initially presents a redness on the skin that evolves into a papule with a small vesicle (bubble with liquid), which only stops transmitting the virus after it is completely healed.

According to the World Health Organization (WHO), most cases reported in outbreaks in non-endemic countries involve mainly, but not exclusively, men who have sex with men. Although so far the risk for the general population of developing more severe clinical cases of the disease is low, with an indication of hospitalization, there is a greater risk for children, pregnant women, the elderly and immunocompromised people, indicates the CVE alert.

The disease has spread to non-endemic regions

Smallpox was first recorded in humans in the 1970s in West Africa and, over the last few decades, it has become an endemic disease in some countries in that region, including Cameroon and the Democratic Republic of Congo. In 2022, monkeypox began to draw the attention of health authorities and the scientific community after the emergence and spread of cases in non-endemic areas, such as Europe, the United States and Brazil itself.

As it is transmitted in non-endemic areas, with records of an important percentage of asymptomatic cases and atypical clinical presentation (different from what was usually reported in Africa, where there were reports of more severe cases), it is necessary that health professionals are well prepared. for the current outbreak and alerts for suspecting a case and referring it to testing – surveillance phases, case investigation, patient identification and contact tracing.

An example of the difficulty in diagnosing monkeypox, according to Unesp professor Alexandre Naime Barbosa, is a recent report of a testing work carried out with participants at the Tomorrowland electronic music festival in Belgium. At the entrance to the festival, volunteers were selected to collect material via swab for laboratory examination. The results indicated that 13% had the monkeypox virus, but were asymptomatic, with no skin lesions.

“I will cite the example of a patient that I attended by telemedicine in Brazil. He was an MSM patient (Man having sex with man) and came to me because he had a lesion in the corner of his mouth, a pustule. Any doctor could tell that, a small vesicle with purulent contents, was acne, a pimple. But there was a whole context”, says the infectologist, describing a confirmed case of monkeypox.

“Right now, it is important to alert us so that we can make the diagnosis and try to prevent transmission and, above all, prevent monkeypox from reaching the most vulnerable populations, those immunosuppressed or at the extremes of age. Citizens’ responsibility is very important to stop the transmission of monkeypox”, says Alexandre Naime Barbosa.

Ignorance of the population and long isolation of the patient are challenges for disease control

Added to the challenge of diagnosis are two other points that increase the difficulty in controlling the disease, according to the professor: the lack of a broad awareness and education campaign about monkeypox, avoiding both inappropriately labeling it (despite the name , the current outbreak does not involve the participation of monkeys in the transmission to humans) as well as stigmatizing the carrier of the virus (which is not restricted to the gay or bisexual public), which also depends on the training of the health network; and the long incubation period (up to 21 days) and isolation (up to 40 days), which includes an indication of a severe restriction of social activities, regardless of whether the symptoms are mild.

“Isolation basically depends on the healing of injuries. Isolation time is a problem because imagine a young, active individual, going to parties, are you going to hold this young person at home for four weeks?” asks Alexandre Naime Barbosa. “Right now, we’re seeing a very tiny tip of the iceberg, a crumb of what we probably have in terms of the number of real cases. That’s why I said it’s a disease where contingency is practically impossible,” he says.

According to the most recent update from the US Centers for Disease Control and Prevention (CDC) on July 21, there are reports of monkeypox in 72 countries this year on five continents, with a total of 15,848 confirmed cases. , with 98.5% in countries with no previous history of disease outbreak. The leading nations in number of cases have in common well-articulated health systems or well-established laboratory networks, which facilitate diagnosis: Spain (3,125 cases), the United States (2,592), Germany (2,191), the United Kingdom (2,137) and France (1,453).

With no reports of serious cases in non-endemic areas so far, treatment for monkeypox is basically symptomatic – there are two antivirals on the market that could be used in the event of more serious clinical conditions.

In terms of prevention, health authorities recommend the use of a mask in public, frequent hygiene of hands and environments to reduce the risk of contagion, in addition to seeking a health service if symptoms appear.

In case of suspicion or confirmation of a close case, as transmission also occurs through contact with objects and fabrics used by the virus carrier, it is recommended not to share bedding, towels, cutlery, cups, among other personal objects, as well as avoiding kisses, hugs and sexual intercourse until the wound heals.

Still as a prevention strategy, there is already a vaccine, the same used for other diseases caused by viruses of the same family Poxviridae, whose genus Orthopoxvirus is the most relevant from the point of view of infection in humans. There is no production or registration of this vaccine in Brazil yet. “But you will need it at some point”, warns the Unesp professor.

Image above: diagnostic test for monkeypox disease. Credit: Depositphotos

*Information cards: ACI Unesp art team, with information from the Epidemiological Surveillance Center (CVE-SP)