With cases reported in a number of countries, human monkeypox infection is generating global interest and concern as an emerging infectious disease threat, even amid a slowly waning COVID-19 pandemic. .
What is monkeypox virus?
Monkeypox is one of a group of closely related viruses in the genus Orthopoxvirus which includes smallpox, cowpox and camelpox. The monkeypox virus was first discovered in the summer of 1958 as a non-fatal, smallpox-like skin disease in captive monkeys at a research institute in Denmark.
The name monkeypox is a misnomer because terrestrial African rodents (rats and squirrels) serve as a natural reservoir of the virus, while monkeys and other primates are considered accidental hosts.
When was monkeypox first reported in humans?
The first known case of human monkeypox infection was reported in the Democratic Republic of the Congo in 1970, in a nine-month-old boy with non-fatal smallpox-like disease.
Since, sporadic human cases have occurred in many central and western African countriesinfections being more common in children and young adults. In countries where monkeypox is endemic (where it is commonly present), the recent increase in cases is thought to be related to climate change, deforestation, war, increased population mobility and decline in herd immunity to smallpox vaccination.
How is monkeypox transmitted?
transmission occurs through close physical contact with animals Where humanstheir bodily fluids, contaminated droplet particles from respiratory secretions or infected skin lesions and indirectly by “fomite” (inanimate objects such as sheets, towels and hard surfaces that can be loaded with infectious virus particles).
Animal bites and consumption of animal meat are common modes of transmission in endemic areas. Secondary infections in unvaccinated close contacts occur in about 12.3% household contacts and 3.3% others.
When was monkeypox first reported in non-African countries?
The first cluster of human monkeypox infections outside of Africa occurred in the United States in 2003. A multi-state outbreak involving 87 children and young adults has been traced to close contact with infected prairie dogs acquired as pets from an animal dealer. The ultimate source of infection turned out to be imported Gambian rats that transmitted the infection to prairie dogs. There were no human fatalities, although three children were seriously ill.
Before 2022, several travel cases had been reported in the United Kingdom, Israel, Singapore and the United States among people who have visited Nigeria.
What do we know about the global epidemic of monkeypox in non-endemic countries?
On May 7, 2022, UK public health authorities were notified of one case of imported human monkeypox infection with a traveler returning from Nigeria. Since then, more than 550 confirmed cases of human infection have been reported in the UK and 29 other countries. Cases have been extremely higher among men who have sex with menalthough the virus is not known to be sexually transmitted.
What are the symptoms of monkeypox?
The clinical manifestations of human monkeypox infection imitate those of smallpox, but are generally much milder. Unlike monkeypox, smallpox is an eradicated disease, has no animal reservoir, and generally does not affect the lymph nodes.
The incubation period of monkeypox in humans ranges from four to 21 days and is followed by a one to five day phase of fever, chills, sweating, fatigue, and tender, enlarged lymph nodes in the neck and groin.
The next phase involves a multi-stage rash which progresses from small patches of skin to papules (small bumps on the skin), followed by vesicles (small bumps filled with clear fluid) and then pustules (small bumps filled with pus). These are most prominent on the face, palms and soles of the feet. The pustules disappear by scarring or crusting over the next two to four weeks.
Exposed individuals may also develop a sore throat, cough and/or rash on the mucous membranes of the mouth.
How serious is monkeypox infection?
The disease is usually mild, although severe illness and death can occur. There are two common genetic variants of monkeypox virus: the Central African variant and the West African variant. Mortality rates 3.6% for the West African variant and 10.6% for the Central African variant have been reported in endemic areas.
However, no deaths have occurred to date in all reported cases outside of Africa. All confirmed cases of the 2022 outbreak in the 30 non-endemic countries are due to West African variant.
Are there other public health recommendations for monkeypox?
People infected with monkeypox must wear surgical masks, and skin lesions should be covered until healed. Items for personal use such as towels and sheets should not be shared. Frequently touched surfaces should be regularly disinfected, contaminated clothing should be washed, and contact with household members and those outside the household should be avoided until the illness is resolved.
Health care workers should use gloves, gowns, and respiratory protection with N95 masks and face shields, and maintain excellent hand hygiene while caring for patients with monkeypox. Patients hospitalized with confirmed or suspected monkeypox should be isolated with airborne, droplet, and contact precautions until no longer infectious.
Does the smallpox vaccine protect against monkeypox?
Smallpox vaccine—administered before or after exposure to monkeypox— can prevent or reduce the effects of human monkeypox infection. However, rare but serious adverse events have been reported with older generation smallpox vaccines. A next-generation, non-replicating, live vaccine is now available and considered safe for use in all populations, including those with compromised immune systems.
The U.S. Centers for Disease Control and Prevention Immunization Practices Advisory Committee recommends pre-exposure prophylaxis (vaccination before exposure to the virus) with the next-generation vaccine for laboratory workers performing diagnostic tests for monkeypox, as well as for Health care workers administer smallpox vaccine or care for patients with monkeypox. (His trade name is Jynneos in the United States, Imvamune in Canada and Imvanex in Europe.)
In Canada and other developed countries, people born before 1972 were likely vaccinated against smallpox. Although immunity after vaccination tends to decline with age, lifelong immunity appears to be the norm after vaccination against smallpox in otherwise healthy individuals, and its cross-protective efficacy against monkeypox is thought to be 85%.
Is monkeypox the next viral pandemic?
The emergence of infectious diseases such as monkeypox in non-endemic areas has created a great deal of anxiety in light of our experience with COVID-19.
Monkeypox was a neglected tropical disease until the current epidemic in the developed world. But the trajectory of these cases, coupled with the pattern of transmission in Africa, suggests the virus will not become a pandemic.
The basic reproduction number (R0), a measure of viral contagiousness, where R0 equals the number of secondary infections transmitted from a single case in an unimmunized population, is 0.6 to 1.0 for the Central African variant, and much lower for the West African variant.
In contrast, the R0 for the omicron variant of SARS-CoV-2 is around 10, and the R0 for measles goes from 11 to 18. The R0 for the West African variant of monkeypox virus may be too low to sustain human-to-human transmission outside endemic areas.
This article is republished from The conversation under Creative Commons license. Read it original article.
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