Following the announcement of the first confirmed case of monkeypox in the United Kingdom on May 7, confirmed or suspected cases have been found in several countries, and there may be multiple chains of transmission.
Monkeypox is a viral zoonotic disease whose pathogen, monkeypox virus, is a “close relative” of smallpox virus, first discovered in 1958, isolated and identified from a group of monkeys used for research when they developed a “pox-like” infection, hence the name. Since the eradication of smallpox in humans in 1980, monkeypox virus has become the orthopox virus with the greatest public health impact.
The clinical manifestations of monkeypox are similar to smallpox, but the disease is milder. Monkeypox can be transmitted from animal to human through direct close contact, or from person to person, mainly through blood and body fluids.
Origin of monkeypox
Monkeypox virus was first (1958) isolated from monkeys in a laboratory in Copenhagen, Denmark, and later, other animals in Africa, rodents were found to be the most likely natural hosts, and squirrels and rats could also be infected.
Monkeypox virus belongs to the same genus Orthopoxvirus as smallpox virus. Monkeypox virus infection in monkeys and humans is more difficult to distinguish from smallpox in terms of clinical signs and histopathology. Monkeypox virus is rectangular in shape, and can be grown in culture in African green monkey kidney cells, causing cytopathic lesions. Inoculation of rabbits with monkeypox virus produced only skin lesions and keratitis, whereas inoculation of mice with monkeypox virus in the brain produced encephalitis.
How is monkeypox virus transmitted?
Humans are infected with monkeypox, primarily through bites from infected animals, or direct contact with blood, body fluids, skin or mucosal injury sites of infected animals. Consumption of improperly cooked infected animals is also a risk factor and is usually transmitted from animal to human, and occasionally human-to-human transmission of monkeypox can occur. It is generally considered to be transmitted by a large number of respiratory droplets containing poison during direct, prolonged face-to-face contact. In addition, monkeypox can be transmitted through direct contact with bodily fluids of an infected person or virus-contaminated objects, such as clothing and bedding, and mother-to-child transmission can also occur.
What are the main areas where monkeypox is found?
Monkeypox is predominantly endemic in western and central Africa, with most cases reported to date in African countries such as the Democratic Republic of Congo (DRC), Central African Republic, and Nigeria. Over the past few years, the epidemiological profile of monkeypox has changed and its occurrence has expanded as the number of countries reporting monkeypox cases and infections outside of Africa has been increasing without direct travel links. Many of the recently identified infections are among homosexual, bisexual, or other men who have sex with men.
To prevent epidemics, the movement of small African mammals and monkeys should be restricted or prohibited, which can effectively slow the spread of the virus outside of Africa. Infected animals should be isolated from other animals and quarantine should be implemented immediately, and those that may have had contact with infected animals should be quarantined for 30 days and observed for monkeypox symptoms.
What are the symptoms of monkeypox infection?
Clinical symptoms are similar to those of smallpox, but to a lesser extent. The incubation period is 6 to 13 days, with a maximum of 21 days. The initial onset of the disease is characterized by fever, general malaise, fatigue, headache, myalgia, and swollen lymph nodes. Afterwards, a widespread rash appears, which starts as a maculopapular rash and soon develops into a herpetic rash, forming small pustules, with some lesions having a tendency to bleed and finally crusting and peeling off. The rash usually starts on the face and spreads to all parts of the body. Secondary infections, bronchitis, and sepsis may occur, and the disease is self-limiting, with most patients recovering within a few weeks. Severe illness and death are common in children and immunodeficient individuals, and are also associated with the infected person’s own condition. Epidemic morbidity and mortality rates vary widely and have been about 3% to 6% in recent years.
How can I prevent monkeypox?
The use of smallpox vaccine to prevent monkeypox in humans has an 85% effectiveness rate. However, smallpox was eradicated worldwide and smallpox vaccination was discontinued in 1980. Currently, the United States and the European Union reserve the relevant vaccines for high-risk groups, and we do not yet have a monkeypox vaccine for widespread vaccination of the population.
There is no specific treatment available. The principle of treatment is to isolate the patient and prevent secondary infection of the skin lesion.
Post time: May-30-2022