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Mpox (Monkeypox) is spreading rapidly around the world again. It is an infectious disease caused by a virus of the same name that can occur in some animals, including humans. Symptoms start with fever, headache, muscle aches, swollen lymph nodes, and fatigue. This is followed by a rash that forms blisters. Exposure time to symptoms is about 10 days. The duration of symptoms is usually two to four weeks. It can be spread from wild animal meat, animal bites or scratches, bodily fluids, contaminated objects, or close contact with an infected person.
The virus usually spreads among certain sharp-toothed or wild animals in Africa. Diagnosis can be confirmed by testing the DNA of the virus.
The smallpox vaccine can prevent this infection with 85% effectiveness. The first human cases were reported in the Democratic Republic of the Congo in 1970. A disease outbreak in the United States in 2003 was traced to a pet store that sold some rats imported from Ghana. The 2022 outbreak represents the first cases of widespread community transmission outside of Africa, which began in May 2022 in the UK. Infections were later confirmed in Europe, North America and Australia.
Early symptoms of the disease include headache, muscle aches, fever and fatigue. The disease may initially appear similar to chicken pox, measles and smallpox but can be distinguished by the presence of swelling of the glands. These are typically located near the ears and jaw line, on the neck, or in the groin before the rash starts. Within a few days of fever, lesions typically appear on the palms of the hands and soles of the feet before appearing elsewhere on the face.
Monkeypox was first identified in cynomolgus monkeys in a laboratory in Denmark by Preben von Magnus in 1958, after two outbreaks of a smallpox-like disease occurred in a colony of captive monkeys in Malaysia and transported via Singapore. Monkeypox was subsequently found in monkeys in several laboratories in the United States. After 1968, there were no more cases of monkeys in the laboratory as the need for monkeys originally from Asia and Africa to produce polio vaccines decreased. The virus has never been found in Asia, but it is possible that Asian monkeys contracted the disease through captivity and transit or contamination.
The first documented case in humans was in 1970, in an unvaccinated 9-month-old child in Equateur Province, Democratic Republic of the Congo. About 50 cases were reported between 1970 and 1979, more than two-thirds of which were from Zaire. Other origins are from Liberia, Nigeria, Ivory Coast and Sierra Leone. By 1986, more than 400 cases were reported in humans. Small sporadic outbreaks with a mortality rate of 10% and approximately the same rate of human-to-human transmission occur regularly in equatorial central and western Africa.
Two recognised distinct types of monkeypox have been described as the Congo variant and the mild West African variant. Vaccination against smallpox is assumed to provide protection against human monkeypox infection, as they are closely related viruses and the vaccine protects animals against experimentally lethal monkeypox. This has not been conclusively demonstrated in humans because routine smallpox vaccination was discontinued after smallpox was eradicated.
In Africa, the risk of monkeypox has been reported to be low in individuals previously vaccinated against smallpox. Declining virus immunity in exposed populations is a factor in the spread of monkeypox. This is attributed to a decline in cross-protective immunity among those who stopped smallpox vaccination before 1980 and a gradually increasing proportion of unvaccinated individuals.
The United States Centers for Disease Control and Prevention (CDC) recommends that those investigating monkeypox outbreaks and those involved in handling infected people or animals should receive a smallpox vaccine to protect against monkeypox. Anyone who has close contact with people or animals that are confirmed to have monkeypox should also be vaccinated. CDC does not recommend pre-exposure vaccination for veterinarians, veterinary staff, or animal control officers, unless such individuals are involved in field investigations.
The CDC recommends that health care providers use a full set of personal protective equipment (PPE) before caring for an infected person. This includes a gown, mask, goggles and a filtering disposable respirator. An infected person should preferably be isolated in a reverse air pressure room or at least in a private examination room to keep others away from possible contact.
Monkeypox, in both humans and animals, is caused by infection with the monkeypox virus. It is an orthopoxvirus and a double-stranded DNA virus of the Poxviridae family. The virus is mainly found in the tropical rainforests of Central and West Africa. The virus corresponds to a geographic area divided into the Congo Basin and West African clades.
Most human cases of monkeypox are acquired from infected animals, although the route of transmission is unknown. The virus is thought to enter the body through broken skin cells, the respiratory tract, or the mucous membranes of the eyes, nose, or mouth. Once a person is infected, other people, such as the general public, family members and hospital staff, are at particular risk of infection.
Human-to-human transmission is thought to occur primarily through close contact with an infected subject. There are indications that the infection is occurring during intercourse. Animal-to-human transmission can occur through bites or scratches, direct contact with body fluids or wound material, or indirect contact with wound material, such as through contaminated bedding.
It can be transmitted by an animal through a human bite or direct contact with the bodily fluids of an infected animal. The virus can also spread from person to person, through respiratory contact, or through contact with the bodily fluids of an infected person. Risk factors for transmission include sharing a bed or room. An increased infection risk is associated with factors involving the introduction of the virus into the oral mucosa.
Symptoms of monkeypox appear 5 to 21 days after infection. Further research is underway on the infection responsible for the outbreak, but it is not thought to be distinct from other strains of the West African clade. In addition to monkeys, the virus is found in Gambian rats, dormice and African squirrels. Consumption of these animals as food can be an important source of infection in humans.
Most people with mpox will recover within 2–4 weeks. Things to do to help the symptoms and prevent infecting others are: staying home if possible; washing hands often with soap and water or hand sanitiser, especially before or after touching sores, wearing a mask and cover lesions when around other people until rash heals; keeping skin dry and uncovered; avoid touching items in shared spaces and disinfect shared spaces frequently; using saltwater rinses for sores in the mouth; taking warm baths with baking soda for body sores and taking over-the-counter medications for pain like paracetamol.
The writer, an official at Southeast University in Dhaka, is a columnist.
Messenger/Fameema
