Key Facts

*There is no treatment or vaccine available to combat the disease, although the previous vaccination against smallpox has proven highly effective in preventing monkeypox as well.

*Monkeypox virus is transmitted to humans by a variety of wild animals, but its secondary spread is limited by human to human transmission.

*Monkeypox is a rare disease that occurs primarily in remote areas of central and western Africa near tropical rainforests.

Monkeypox is a zoonotic viral disease (a virus transmitted from animals to humans) whose symptoms are very similar to those seen in the past in patients with smallpox, although clinically less serious. After smallpox was eradicated in 1980 and vaccination against smallpox was subsequently discontinued, monkeypox emerged as the most dangerous virus of the poxvirus family to public health. Monkeypox occurs mainly in central and western Africa, often near tropical rainforests, and is becoming increasingly common in urban areas. Its host animals include a group of non-human primates and rodents.

Monkeypox virus is a double-enveloped DNA virus belonging to the genus Orthopoxvirus of the family Poxviruses. Monkeypox was first detected in humans in 1970 in the Democratic Republic of the Congo in a 9 year old boy who lived in an area where smallpox was eradicated in 1968. Most cases have since been reported in rural rainforest areas of the Congo Basin and West Africa, and human cases are increasingly being reported throughout Central and West Africa.

Since 1970, human cases of monkeypox have been reported in 11 African countries: Benin, Cameroon, Central African Republic, Democratic Republic of the Congo, Gabon and Côte d'Ivoir, Liberia, Nigeria, Republic of the Congo, Sierra Leone and South Sudan. The true burden is not yet clear for monkeypox. For example, in 1996-1997 an outbreak was reported in the Republic of the Congo Democracy has a lower fatality rate and a higher attack rate than usual. An outbreak of chickenpox (caused by a varicella virus that is not of the poxvirus strain) has coincided with monkeypox, which may explain actual or potential changes in the transmission dynamics in this case. Nigeria has been experiencing a major outbreak since 2017, with more than 500 suspected cases, more than 200 confirmed cases and a case fatality ratio of nearly 3 percent. Cases continue to be reported today.

Monkeypox poses a threat to global public health because its impact is limited to the countries of West and Central Africa, but extends to the entire world. The disease was first reported in 2003 outside Africa in the USA and was associated with contact with infected domestic prairie dogs. This outbreak resulted in more than 70 cases of monkeypox in the United States, and monkeypox was also reported in travelers from Nigeria to Israel in September 2018, to the United Kingdom in September 2018, December 2019, May 2021 and May 2022, and to Singapore in May 2019, and to the USA in July and November 2021. In May 2022, multiple cases of monkeypox were detected in several non-endemic countries. Studies are underway to understand the epidemiology of the disease, sources of infection, and transmission patterns.

Disease Transmission

Infection can be transmitted from animal to human (zoonotic disease) through direct contact with the blood of infected animals, their bodily fluids, skin lesions or mucous secretions. The transmission of infection from one person to another can result from close contact with respiratory secretions or skin lesions of a person or recently contaminated objects. Transmission through respiratory droplets usually requires prolonged face-to-face contact, which puts health workers, family members, and other people in contact with active cases at an increased risk of infection. On the other hand, the longest documented chain of community transmission of infection in recent years spanned from six to nine consecutive infections from one person to another. This may reflect reduced immunity in all population groups due to discontinuation of smallpox vaccination. The infection can also be transmitted through the placenta from the mother to the fetus (which may lead to congenital monkeypox) or through close contact during and after childbirth. While close physical contact is a known risk factor for transmission, it is not yet clear whether monkeypox is specifically transmitted through sexual transmission. Studies in this regard should be conducted to better understand this risk.

Signs and Symptoms

The incubation period for monkeypox (the time interval from infection to symptom onset) is usually 6 to 13 days but can be take from 5 to 21 days.

Infection can be divided into two periods:

*Invasive period (lasting between 0 and 5 days), characterized by fever, severe headache, swollen lymph nodes, back and muscle pain, and severe weakness (loss of energy). Enlarged lymph nodes are characteristic of monkeypox compared to other diseases that may at first appear similar to it (chickenpox, measles, smallpox).

*The rash period that usually begins within 1 to 3 days of the onset of the fever. The rash is most often concentrated on the face and extremities, rather than the trunk.

Diagnosis

The clinical differential diagnosis that should be considered includes other rash diseases, such as chickenpox, measles, bacterial dermatitis, scabies, syphilis, and drug allergies. Enlargement of the lymph nodes during the onset of the disease can be a clinical feature that distinguishes it from chickenpox and smallpox.

If monkeypox is suspected, health workers must take an appropriate sample from the patient and transport it safely to a laboratory with appropriate capabilities for examination. Confirmation of monkeypox depends on the type and quality of the sample and the type of laboratory examination. Hence, samples must be packed and shipped in accordance with national and international requirements. Polymerase chain reaction (PCR) is preferred as a laboratory test due to its accuracy and sensitivity.

Vaccination

It has been shown by several observational studies that vaccination against smallpox is approximately 85 percent effective in preventing monkeypox. Thus, a previous vaccination against smallpox may cause the disease in its mild form.

Treatment

Clinical monkeypox care must be fully optimized to relieve symptoms, manage complications, and prevent long-term consequences. Patients should be given adequate fluids and food to maintain their good nutritional status. Secondary bacterial infections must be treated