Facts about Monkeypox

Introduction

Monkeypox is an infectious zoonosis (a virus that can be transmitted to humans through animal sources) with symptoms that are similar to those observed in the past by smallpox patients, however it is less severe in clinical terms. Since the elimination of smallpox by 1980 and the subsequent reduction of vaccination against smallpox the monkeypox virus has become the most important orthopoxvirus to public health. The majority of cases are found in west and central Africa and is often found in close the vicinity of tropical rainforests and is now being seen in urban regions. Its hosts are animals, which include variety of rodents as well as non-human primates.

facts about monkeypox

The pathogen

Monkeypox virus, an enclosed double-stranded DNA virus which is part of the Orthopoxvirus family belonging to the Poxviridae family. Two distinct genetic clans of monkeypox virus The central African (Congo Basin) Clade and the West African clade. This Congo Basin clade has historically resulted in more severe cases of the disease and was believed to be more transmittable. The geographic division between both clades has so only been observed located in Cameroon which is the sole country in which both clades of virus have been identified.

Monkeypox virus is the natural host of the monkeypox virus.

Many animals have been found to be susceptible to the monkeypox virus. It includes the rope squirrels tree squirrels Gambian pouched ratsand dormice, nonhuman primates, and many other species. Uncertainty persists regarding the evolution of the monkeypox and more research studies are required to determine the precise reservoir(s) and to determine how the virus circulates in the wild.

Outbreaks

Human monkeypox first became apparent on humans in 70 in Democratic Republic of the Congo at the age of 9 months, in the region where smallpox was believed to have been eliminated in. Since then, the majority of instances have come from the rural areas in the Congo Basin, particularly in the Democratic Republic of the Congo and human cases have also been reported from the west and central regions of Africa.

Since the year 1970, human instances of monkeypox have been documented across the following 11 African states: Benin, Cameroon, the Central African Republic, the Democratic Republic of the Congo, Gabon, Cote d’Ivoire, Liberia, Nigeria, the Republic of the Congo, Sierra Leone and South Sudan. The exact burden of monkeypox isn’t known. In the years 1996-97 the outbreak was recorded from the Democratic Republic of the Congo with a lower death rate and higher rate of attack than the norm. The outbreak was also associated with poultrypox (caused via the varicella virus that isn’t the orthopoxvirus) and monkeypox was discovered that could have caused the apparent or real shifts in the dynamics of transmission in this instance. Since the beginning of 2017, Nigeria has experienced a massive outbreak, with more than 500 suspected cases, and more than 200 confirmed cases. There is the rate of death for each case being around 3.3%. The cases continue to be reported up until the present.

Monkeypox is an illness that is of international significance for public health since it is not limited to the countries of central and west Africa however, it also affects all over the world. It was 2003 when the initial monkeypox epidemic outside Africa was reported in the United States of America and was associated with contact with infected prairie dogs. The animals were housed in a kennel with Gambian Dormice and pouched rats, which had been brought into the United States from Ghana. This outbreak has led to more than 70 monkeypox cases within the U.S. The virus has also been observed in travellers to Nigeria in September 2018 to Israel in September of 2018 in the United Kingdom in September 2018 in December, May 2021 and 2022. It was reported and to Singapore at the end of May in 2019 and then to The United States of America in November and July 2021. As of May 20, 2022 a number of instances of monkeypox were reported in several countries that are not endemic to the disease. The research is in progress to study the nature of the disease, the sources of infection, as well as the transmission patterns.

Transmission

Human-to-animals (zoonotic) transmission may result through direct contact with bodily fluids, blood as well as mucosal and cutaneous lesions in animals that are affected. In Africa there is evidence of infection with the monkeypox virus has been observed in a wide variety of species, including rope squirrels, the tree squirrels Gambian poached ratsand dormice from various species of monkeys , and more. The source of the virus is not yet identified although rodents are most likely candidates. Consuming uncooked meat or other products from affected animals could be a risk aspect. Residents living in or close to forests may be exposed or minimal exposure to animals that are infected.

Human-to human transmission can occur due to close contact with the respiratory fluids and skin lesions from the person who is infected or objects that have recently been contaminated. The transmission of respiratory droplets generally requires prolonged contact that puts health professionals family members, household members and close contacts of patients at risk. The longest-recorded chain of transmission within the community has increased in recent years , from 6 to 9 consecutive person-to person infections. This could reflect a decrease in the level of immunity across every community due to the cessation of vaccination against smallpox. Transmission can also occur through the placenta of the mother to the fetus (which could result in an infantic monkeypox) or in close contact after and during the birth. Although close physical contact is well-known as a risk source for transmission, it’s not clear whether monkeypox can be transmitted through sexual transmission pathways. It is necessary to study this to understand the danger.

The signs and symptoms

The period of incubation (interval between the onset of infection and the the onset of symptoms) of the monkeypox virus is typically between 6 and 13 days, however it can range between 5 and 21 days.

The infection may be classified into two distinct periods:

• The invasion phase (lasts between 0 and 5 days) is characterized by intense headache, fever and lymphadenopathy (swelling of lymph nodes) as well as back pain, myalgia (muscle pains) and an intense asthenia (lack of energy). Lymphadenopathy is an etiological characteristic of monkeypox in comparison to other illnesses that seem similar in the beginning (chickenpox measles, smallpox)
• the eruption of the skin typically begins after 1-3 days of the fever. The rash is most prominently seen on the face and the extremities instead of the trunk. It is most noticeable on the face (in 90% of cases) as well as the palms of hands as well as the soles of feet (in 75 percent of instances). Additionally, it affects oral mucous membranes (in 70 percent of cases) and the genitalia (30 percent) and conjunctivae (20 20%) and cornea. The rash progresses over time from macules (lesions with a flat-topped bottom) and papules (slightly raised lesions) as well as the vesicles (lesions that are filled with transparent fluid) as well as pustules (lesions filled with yellowish fluid) and crusts that are dry and then fall off. The size of the lesions can range between a few and several thousand. In the most severe instances, lesions may coalesce until huge areas of skin peel off.

Monkeypox can be a self-limiting disease that causes symptoms that last between 2 and 4 weeks. The most severe cases are more frequent in children and are linked to the degree of exposure to virus, the patient’s health condition and the nature of the complications. Immune deficiencies that are underlying may cause more severe results. While vaccination against smallpox could have been protective in the past those who are between 40 and 50 years old (depending of the location) could be more susceptible to the virus because of the end of vaccination against smallpox worldwide following the elimination from the illness. The complications of monkeypox could be secondary, such as bronchopneumonia sepsis, encephalitis and cornea infections which can cause sight loss. The extent to which asymptomatic infections can occur is not known.

The rate of fatality for monkeypox historically has ranged from 0 to 11 percent in the general population . It has been higher in the case of young children. In recent years the rate of fatality has been in the range of 3 to 6.

Diagnosis

The clinical differential diagnosis that must be considered includes other rash illnesses, such as chickenpox, measles, bacterial skin infections, scabies, syphilis, and medication-associated allergies. Lymphadenopathy at the beginning of the course of illness could be a sign of clinical illness to differentiate between monkeypox or smallpox.

If you suspect that monkeypox has occurred health workers must collect the appropriate specimen and then transport it safely to a lab with the proper capacity. Monkeypox confirmation is contingent upon the nature and quality of the sample and the kind of test performed by the laboratory. Therefore, samples should be shipped and packaged according to the requirements of both international and national standards. A polymerase chain reaction (PCR) is the most commonly used laboratory test due to its accuracy and its sensitivity. To be able to determine this, the best tests for diagnosing monkeypox come caused by skin lesions. These include the skin’s roof, or fluid from pustules and vesicles as well as dry crusts. When possible, biopsy may be an option. The samples of lesion must be kept in a dry and sterile tube (no transport media for viral transmission) and kept cool. PCR tests for blood are typically inconclusive due to the brief time frame of viremia compared to the time of specimen collection following symptoms first begin. They shouldn’t be collected regularly from patients.

Because orthopoxviruses can be cross-reactive antigen and antibody detection methods are not able to offer monkeypox-specific confirmation. Antigen detection and serology are not suitable to diagnose or investigate cases when resources are scarce. In addition, recent or distant vaccination with a vaccine based on vaccinia (e.g. those who were vaccinated prior to the eradication of smallpox or more recently vaccinated because of higher risk factors, like orthopoxvirus laboratory workers) could result in False positive results.

To determine the significance of test results It is essential that information about the patient be supplied in the specimens such as the following: the) the date when symptoms first started to manifest fever or a) date of onset of the rash, c) date of the specimen’s collection and the date of collection.) the present condition of the patient (stage of the rash) and e) the age.

Therapeutics

The treatment of monkeypox patients should be optimized to reduce symptoms, prevent complications and stop chronic sequelae. Patients should receive food and fluids to ensure an adequate nutritional state. Infections with secondary bacterial causes are treated according to the indications. A drug that fights viruses called tecovirimat was created for smallpox and was approved through the European Medicines Agency (EMA) for the treatment of monkeypox by 2022 following data from animals as well as human studies. It’s not yet readily accessible.

When used to treat patients in the future, tecovirimat must monitor in a research setting with the intention of collecting data in the future.

Vaccination

Smallpox vaccination was shown through a series of observational studies to be around 90% effective in the prevention of monkeypox. Thus, prior smallpox vaccination may result in milder illness. The evidence of previous vaccination against smallpox is typically seen by a scab across the arm’s upper part. Presently the initial (first-generation) smallpox vaccinations are not accessible to the general population. Some lab personnel or health professionals may have been given a more recent smallpox vaccine to safeguard themselves from exposure to orthopoxviruses within the workplace. A brand new vaccine that is based on a modified type of vaccinia virus (Ankara strain) was approved for the prevention of monkeypox in the year 2019. It is a two-dose vaccination that is not widely available. Smallpox and monkeypox vaccinations are designed in formulations based upon the vaccinia virus because of the cross-protection that is provided by the immune response against orthopoxviruses.

Prevention

The promotion of awareness of risk factors and informing people on the steps you can adopt to limit the chances of being exposed to this virus are the primary method of prevention for monkeypox. Research studies are currently in progress to determine the viability and effectiveness of vaccination in the prevention and treatment of monkeypox. Certain countries have or are creating policies that offer vaccination to those who could be at risks, such as laboratory personnel, rapid-response teams, and health workers.

Reduced risk of human-to-human transmission

The monitoring and prompt identification of new cases is essential for preventing outbreaks. In the case of human monkeypox outbreaks close contact with affected persons is the main risk factor for the monkeypox virus infection. Members of the household and health care workers are more at risk of being infected. Health workers who are caring for patients who have known or confirmed monkeypox infection, or who handle specimens from them, must follow normal precautions to prevent infection. If they can, patients who have been vaccination-free against smallpox should be chosen to take care of the patient.

Human and animal samples taken from animals suspected of having monkeypox virus infection must be handled by experienced staff operating in labs that are well-equipped. Patients’ samples must be properly ready for transport using triple-packaging in line with WHO guidelines for the transportation for infectious agents.

The detection in the month of May 2022 of clusters of monkeypox-related cases in several countries that are not endemic and have no travel connections to the endemic region is unusual. Additional investigations are being conducted to identify the probable cause of the infection and to limit the spread. Since the cause of this outbreak is being researched it is essential to examine the possible routes of transmission to protect the public’s health. More information about the outbreak is available here.

Eliminating the possibility of zoonotic transmission

In the course of time, most human illnesses have been the result of the primary transmission of disease from animal to human. Contact with wild animals that is not protected particularly those sick or dead, as well as blood, their meat and other components should be avoided. Furthermore, all food items that contain animal parts or meat must be cooked thoroughly before consumption.

Stopping monkeypox with restrictions on trading in animals

Certain countries have implemented rules that limit the importation of rodents as well as non-human primates. Animals in captivity that could be affected by monkeypox should be separated from all other mammals and put in immediate quarantine. Animals that may have come in contact with an animal that is infected should be kept in quarantine and treated with the same precautions as other animals and monitored for symptoms of monkeypox for a period of 30 days.

What is the relationship between monkeypox and smallpox?

The appearance of monkeypox is similar to that of smallpox which is an orthopoxvirus disease that has been eliminated. Smallpox could be transmitted more easily and often fatal since around 70% of sufferers passed away. The last instance of naturally contracted smallpox happened in the year 1977. Then, in the year 1980, smallpox was declared eliminated worldwide following an extensive global program of vaccinations and confinement. It’s been forty to more than a decade since the world stopped routine vaccination against smallpox using vaccinia-based vaccinations. Because vaccination protects against the spread of monkeypox across west and central Africa those who are not vaccinated are also now more susceptible to infection with the monkeypox virus.

While smallpox has stopped occurring naturally, the health system is always on guard in the event that it might be re-discovered by natural means, lab accident, or intentional release. To ensure that the world is prepared should there be a recurrence of smallpox, more effective vaccines, and diagnostics, as well as antiviral agents, are being created. These could be helpful in the prevention and treatment of monkeypox.

WHO responds

WHO helps Member States with surveillance, readiness and outbreak response actions for countries affected by monkeypox. More details can be found here.