May 19, 2022 Author : Carlos Palos Coordinator of the National Commission for Prevention and Control of Infections and Antimicrobial Resistance of the Luz Saúde group Since the beginning of May 2022, several cases of monkeypox have been diagnosed in humans , first in the UK and more recently in Portugal and Spain. How these cases have spread is still unclear. It is already known that one of the first people affected have been in Nigeria, and that there is a higher incidence among men who have sex with other men. Despite the growing number of cases, there is no reason to be alarmed, as transmission between people involves highly intimate contact . What is monkeypox? Monkeypox belongs to a group of diseases called zoonoses . Zoonoses are infectious diseases of animals – domestic and non-domestic – that also affect humans. The disease owes its name to the lesions it causes, which are similar to those seen in smallpox , a disease eradicated since 1980. Monkeypox is caused by an Orthopoxvirus, of the Poxviridae family; It mainly affects monkeys, several species of squirrels and giant rats from the Gambia, all inhabiting in tropical African jungles; Rodents are the main reservoirs, secondarily contaminating other species. Monkeypox is a disease of mandatory medical notification through the national system SINAVE. Monkeypox in man In humans, monkeypox was first identified in 1970 in Congo, country where, after a major outbreak in 1996-1997, the disease became endemic. The first human cases outside Africa occurred in 2003, in the USA, after transmission of the disease to prairie dogs by rodents imported from Africa. The last major outbreak of the disease in humans occurred in Nigeria in 2017 . How is monkeypox transmitted to humans? Monkeypox virus is transmitted to humans after contact with animals or infected people or materials contaminated with the virus. The virus enters the human body through skin lesions, through the respiratory tract or through the mucous membranes . Transmission from animals to humans (primary transmission) is the main source of human infection. It can happen by direct contact with blood, body fluids or disease lesions of infected animals, by eating undercooked meat, or following a bite or scratch by an infected animal. Sick animals may be of intermediate species, not necessarily from endemic areas. Human-to-human transmission (secondary transmission) is rarer and occurs mainly via the air (droplets), by close contact with respiratory secretions, other body fluids, lesions on the skin or genitals, or with objects or clothing recently contaminated by sick people. In pregnant women, the disease can be transmitted to the fetus via the placenta. Signs and symptoms of monkeypox in man After exposure to the virus, incubation period lasts from 5 to 21 days , being in most cases 6-16 days. Initial symptoms include: Fever; Headaches; Generalized muscle and back pain; Intense feeling and lack of energy and tiredness; Enlarged lymph nodes. Between 1-3 days after the onset of fever, skin manifestations appear , characterized by: At first, small reddish lesions, similar to those from rubella or measles; They start being located on the face, then spread to the rest of the body, including the palms and soles. Lesions then evolve into vesicles with liquid (bubbles), which get dry forming crusts after 10 days, and can be hundreds or thousands. Crusts may remain for up to 3 weeks. The mouth, external genitals and eyes often show with blisters. Symptoms last for 2-3 weeks and the disease is usually self-limiting, meaning it goes away on its own . The most serious forms of the disease are associated with: Young ages; Poor overall health status; Greater amount of the inoculated virus and viral variant. Some people living in endemic areas of Africa have the disease without manifestations such as these, which is due to repeated exposures to the virus . Diagnosis Given the rarity of monkeypox in humans outside endemic areas and the fact that the initial manifestations are not specific, the diagnosis is not straightforward . It is important to know if there is a travel history to areas where the disease is endemic or contact with animals from these areas. In the current situation, it is equally important to know if you have had sex with someone with symptoms such as those described above or who came from endemic regions. The monkeypox definitive diagnosis is made with a laboratory analysis , from smears of lesions, blood, or serum from suspected cases. Treatment and prevention of monkeypox There is no specific treatment for monkeypox. When necessary, treatment is symptomatic (symptom-directed) , for example controlling fever and pain with antipyretics and analgesics (such as paracetamol or ibuprofen). In a hospital, infected people must be admitted to dedicated infectious wards and be subjected to contact isolation (use of gowns and gloves) and aerosols (negative pressure room and FFP2 respirators). In the absence of specific vaccination against monkeypox, the main prevention measures are: Avoid contact with animals in or from endemic areas; Wear gloves, protection glasses and a mask when in contact with suspicious animals; Do not eat meat from suspect animals. How to proceed in case of suspected monkeypox? Contact SNS 24 (808 24 24 24) or go to a hospital emergency department , clearly informing health professionals about your situation if: Having symptoms such as those described and having been to an affected area; If you have had a risky behavior such as direct contact with animals in endemic areas or from there or with their fluids, or meat-based diet of these animals; If you have had sex or live with someone with similar symptoms. Also: Always wear a mask , even in places where its use is not mandatory, do not share personal objects and wash your clothes separately. You should wash your hands frequently , with soap and water, and whenever you touch wounds or fluids from infected people. Do not panic. In most cases, monkeypox is self-limiting . More about monkeypox European Centre for Disease Prevention and Control. Factsheet for health professionals on monkeypox . World Health Organization. Monkeypox . The content published in the Health Guide is intended for the general public and is provided for informational and educational purposes only. It does not replace individual medical assessment, diagnosis, or personalized clinical advice from a qualified healthcare professional. The content is produced or reviewed by physicians and other healthcare professionals at Hospital da Luz and is based on the knowledge available at the time of publication or the most recent update, as indicated at the beginning of each item.
