mpox mpox mpox (pronounced /ˈɛmpɒks/ em-poks, formerly known as monkeypox) is an infectious viral disease that can occur in humans and some other animals. symptoms include a rash that forms blisters and then crusts over, fever, and swollen lymph nodes. the time from exposure to onset of symptoms ranges from five to twenty-one days and symptoms typically last from two to four weeks. there may be mild symptoms, and it may occur without any symptoms being apparent. cases may be severe, especially in children, pregnant women or people with suppressed immune systems. this article is about the disease. for the virus that causes the disease, see monkeypox virus. mpoxother namesmonkeypoxmpox rash on arm and leg of a four-year-old girl in 1971specialtyinfectious diseasesymptomsfever, headache, muscle pains, shivering, blistering rash, swollen lymph nodescomplicationssecondary infections, eye infection, visual loss, scarring, encephalitis, sepsis, bronchopneumoniausual onset5–21 days post exposureduration2 to 4 weekstypesclade i, clade ii causesmonkeypox virusdiagnostic methodtesting for viral dnadifferential diagnosischickenpox, smallpoxpreventionsmallpox vaccine, hand washing, covering rash, ppe, keeping away from sick peopletreatmentsupportive, antivirals, vaccinia immune globulinmedicationtecovirimatprognosismost recoverfrequencynot as rare as previously thoughtdeathsup to 3.6% (clade ii), up to 10.6% (clade i, untreated) the disease is caused by the monkeypox virus, a zoonotic virus in the genus orthopoxvirus. the variola virus, the causative agent of smallpox, is also in this genus. it may spread from infected animals by handling infected meat or via bites or scratches. human-to-human transmission can occur through exposure to infected body fluids or contaminated objects, by small droplets, and possibly through the airborne route. people can spread the virus from the onset of symptoms until all the lesions have scabbed and fallen off; with some evidence of spread for more than a week after lesions have crusted. diagnosis can be confirmed by testing a lesion for the virus's dna. there is no known cure. a study in 1988 found that the smallpox vaccine was around 85% protective in preventing infection in close contacts and in lessening the severity of the disease. a newer smallpox and mpox vaccine based on modified vaccinia ankara has been approved, but with limited availability. other measures include regular hand washing and avoiding sick people and animals. antiviral drugs, cidofovir and tecovirimat, vaccinia immune globulin and the smallpox vaccine may be used during outbreaks. the illness is usually mild and most of those infected will recover within a few weeks without treatment. estimates of the risk of death vary from 1% to 10%, although few deaths as a consequence of mpox have been recorded since 2017. several species of mammals are suspected to act as a natural reservoir of the virus. although it was once thought to be uncommon in humans, the quantity and severity of outbreaks has significantly increased since the 1980s, possibly as a result of waning immunity since the stopping of routine smallpox vaccination. the first cases in humans were found in 1970 in the democratic republic of the congo (drc). there have been sporadic cases in central and west africa, and it is endemic in the drc. the 2022 mpox outbreak represents the first incidence of widespread community transmission outside of africa, which was initially identified in the united kingdom in may 2022, with subsequent cases confirmed in 111 countries as of may 2023. the world health organization (who) declared the outbreak a public health emergency of international concern (pheic) between the dates of 23 july 2022 and 10 may 2023. nomenclature on 28 november 2022, the world health organization announced it "will adopt the term mpox in its communications, and encourages others to follow these recommendations". the name monkeypox was criticised for being a misnomer, as monkeys are not the main host or reservoir, for reinforcing stigma about african countries as a source of disease, and encouraging racist stereotypes that compared black people with primates. the change followed an open letter by two dozen african scientists, which argued that these issues were harming the fight to contain the disease outbreak. signs and symptoms progression of mpox after needlestick injury from a pustule mpox lesions on a penis stages of mpox lesion development right tonsillar enlargement with an overlying pustular lesion during the 2022 outbreak. it is possible for a person to be infected with monkeypox virus without showing any symptoms. mpox symptoms tend to begin 5 to 21 days after infection, with early symptoms including headache, muscle pains, fever and fatigue, initially resembling influenza. within a few days of the fever, lesions characteristically appear on the face before appearing on the trunk then elsewhere such as palms of the hands and soles of the feet. the disease can resemble chickenpox, measles and smallpox but is distinguished by the presence of swollen glands which may appear behind the ear, below the jaw, in the neck or in the groin, before the onset of the rash. many cases in the 2022 mpox outbreak presented with genital and peri-anal lesions, fever, swollen lymph nodes, and pain when swallowing, with some patients manifesting only single sores from the disease. three-quarters of affected people have lesions on the palms and soles, more than two-thirds in the mouth, a third on the genitals and one in five have lesions in the eyes. they begin as small flat spots, before becoming small bumps which then fill with at first clear fluid and then yellow fluid, which subsequently burst and scab over, persisting for around ten days. there may be a few lesions or several thousand, sometimes merging to produce large lesions. after healing, the lesions may leave pale marks before becoming dark scars. an unwell person may remain so for two to four weeks. complications complications include secondary infections, pneumonia, sepsis, encephalitis, and loss of vision with severe eye infection. if infection occurs during pregnancy, still birth or birth defects may occur. the disease may be milder in people vaccinated against smallpox in childhood. patel and colleagues, in the bmj, demonstrate that this virus can produce severe symptoms, particularly in hiv-positive people. the descriptive case series reveal that symptoms can be so severe that hospitalization is required in 10% of cases. the study also shows that 75% of patients (15 out of 20 participants) admitted to the hospital were hiv-positive individuals. overall, the study depict a new variety of clinical manifestations including proctitis and rectal perforation. the pictures of genital lesions published in the bmj show the severity of mpox, which is often described as causing moderate symptoms. in other animals the disease has also been reported in dormice, tree squirrels, rope squirrels and non-human primates. rodents such as rats and mice are likely susceptible but not known. signs and symptoms in animals vary among different species. monkeypox virus infected gambian pouched rats may have mild symptoms. during the 2003 us outbreak, affected prairie dogs presented with fever, cough, sore eyes, poor feeding and rash. non-human primates present similarly. they may have breathing problems, facial swelling, mouth ulcers and swollen glands. in cynomolgus monkeys, the time from exposure to symptoms was noted to be around a week. rabbits and rodents typically present with fever, cough, runny nose, sore eyes and swollen glands. they develop small bumps that fill with yellow fluid and may have patches of hair loss and pneumonia. spread among animals occurs via the fecal-oral route and through the nose, through wounds and eating infected meat. death is more likely in baby monkeys. the cdc recommend that animals exposed to monkeypox virus be quarantined for six weeks. causes mpox in both humans and animals is caused by infection with the monkeypox virus – a double-stranded dna virus in the genus orthopoxvirus, family poxviridae. the virus was first identified in captive monkeys and is found mainly in tropical rainforest regions of central and west africa. the two subtypes of virus are clade i and clade ii (formerly congo basin and west african clades respectively, matching the geographical areas). monkeypox viral structure and scale in addition to monkeys, the virus has been identified in gambian pouched rats (cricetomys gambianus), dormice (graphiurus spp.) and african squirrels (heliosciurus, and funisciurus). the use of these animals as food may be an important source of transmission to humans. transmission humans can be infected by an animal via a bite or scratch, bush meat preparation, or by contact with an infected animal's bodily fluids or lesion material. the virus is thought to enter the body through broken skin, the respiratory tract, or the mucous membranes of the eyes, nose, or mouth. once a human is infected, transmission to other humans is common, with family members and hospital staff at particularly high risk of infection. the virus can spread by respiratory (airborne) contact or by direct contact with an infected person's bodily fluids or during pregnancy from mother to fetus. there are indications that transmission can occur during sexual contact, with infectious monkeypox virus able to be isolated from semen samples. prolonged shedding in seminal fluids has raised the possibility of a genital reservoir for monkeypox virus. it is not known if the virus can spread through vaginal fluids. the virus can also spread via fomites or through indirect contact with lesion material, such as through contaminated bedding, even with standard personal protective equipment, likely through inhalation. risk factors for transmission include sharing a bed or room, or using the same utensils as an infected person. increased transmission risk is associated with factors involving the introduction of virus to the oral mucosa. it is not yet known if people without symptoms of mpox can spread the virus. further research about the transmission of the strain responsible for the 2022 outbreak is ongoing, but it is not thought to be different from other strains of the clade ii. people living with hiv according to a centers for disease control and prevention (cdc) report, 41% of cases of mpox were among hiv-positive patients (136 out of 334 patients) between may and july 2022. the new england journal of medicine (nejm) also looked at more than 500 cases from different countries and found that 41% of them were among hiv patients. in addition, a study that looked at nearly 200 cases in barcelona and madrid discovered that 40% were hiv-positive. patel and colleagues observed 197 patients from sexual health centres in south london between may and july 2022. they reported 35.5% patients had hiv-1 co-infection. 91.4% of these participants were receiving antiretroviral therapy and 78.6% had an undetectable hiv-1 viral load (<200 copies). the median cd4 count was 664 cells (interquartile range 522-894 cells). the proportion of hiv-positive individuals in these reports is significantly higher than the hiv rate among men who have sex with other men. diagnosis the clinical presentation of mpox clinical differential diagnosis must consider other rash illnesses, such as chickenpox, measles, bacterial skin infections, scabies, syphilis and medication-associated allergies. lymphadenopathy during the prodromal stage of illness can distinguish mpox from chickenpox or smallpox. diagnosis can be verified by testing for the virus. polymerase chain reaction (pcr) testing of samples from skin lesions is the preferred laboratory test. pcr blood tests are usually inconclusive because the virus remains in blood only a short time. to interpret test results, information is required on date of onset of fever, date of onset of rash, date of specimen collection, current stage of rash, and patient age. prevention vaccination against smallpox is assumed to protect against human mpox because they are closely related viruses, and the vaccine protects animals from experimental lethal monkeypox virus challenges. this has not been conclusively demonstrated in humans because routine smallpox vaccination was discontinued following the eradication of smallpox. smallpox vaccine has been reported to reduce the risk of mpox among previously vaccinated persons in africa. the decrease in immunity to poxviruses in exposed populations is a factor in the prevalence of mpox. it is attributed to waning cross-protective immunity among those vaccinated before 1980, when mass smallpox vaccinations were discontinued, and to the gradually increasing proportion of unvaccinated individuals. the united states centers for disease control and prevention (cdc) recommends that persons investigating mpox outbreaks and involved in caring for infected individuals or animals should receive a smallpox vaccination to protect against mpox. persons who have had close or intimate contact with individuals or animals confirmed to have mpox should also be vaccinated. however, the cdc does not recommend pre-exposure