Monkeypox overview

# Overview
Monkeypox virus, also known as MPOX, was first identified in monkeys shipped from Singapore to Denmark in 1958. First case of monkeypox in humans was reported in the Republic of the Congo in 1970. Monkeypox virus is a member of orthopoxvirus genus (family Poxviridae). It can be transmitted from animal to animal, animal to human, and human to human. There is little evidence on mother-to-child transmission.

# Historical Perspective
Monkeypox virus was first identified in monkeys shipped from Singapore to Denmark in 1958. First case of monkeypox in humans was reported in a hospitalized child in the Republic of the Congo in 1970. In the following years, monkeypox virus emerged and cases were recorded in 11 African countries. Until the late 1980s, more than 400 cases were recorded. In the early 1990s, the number of reported cases dramatically declined to notably zero cases between 1993 and 1995. In 1996, large number of cases were suspected in an outbreak in Democratic Republic of Congo but only small number of cases were laboratory confirmed.
In 2003, 47 confirmed and probable cases of monkeypox were in the United States. In the following years, there has been cases of monkeypox recorded periodically in non-endemic regions, predominately in the United Kingdom and one in Singapore. All of these cases were imported from endemic regions. In May 2022, case clusters of monkeypox were traced around the world over a short period of time. As of May 22, 2022, a total of 109 cases were recorded and 87 suspected around the world. On June 2, 2022, 780 cases of monkeypox were identified or reported to the World Health Organization. As of June 15, 2022, a total of 2103 laboratory confirmed cases, including one death, have been reported to World Health Organization.

# Pathophysiology
Monkeypox virus is a member of orthopoxvirus genus (family Poxviridae). The monkeypox virus genome consists of linear double-stranded DNA that multiplies in the cytoplasm of infected cell. It has two genetic clades: the west African clade and the central African (Congo Basin) clade. Possible routes of transmission are animal-to-animal, animal-to-human, and human-to-human. Virus is transmitted via direct contact with body fluids or lesions of infection person or animal, direct contact with contaminated materials such as clothing, and via respiratory secretions. The role of vaginal fluids and semen in the transmission of the virus is still being investigated.

# Causes
Animal-to-human transmission: The virus can be acquired through daily exposure to an infected animal or complex exposure to an infected animal (e.g. invasive bite or scratch that breaks the skin). Also through direct contact with lesions or bodily fluids of an infected animal.
Human-to-human transmission: The virus can be acquired through close physical contact with infected person, direct contact with lesions, bodily fluids, or respiratory secretions of an infected person, direct contact with contaminated materials, or via placenta from mother to fetus.

# Differential Diagnosis
- Smallpox
- Chickenpox
- Scabies
- Syphilis
- Bacterial skin infections
- Drug-associated allergy

# Epidemiology and Demographics
Precise prevalence and incidence are difficult to establish due to paucity of reporting in previous outbreaks. The median age in the the 1970s and 1980s was 4 and 5 years. In the 2000s and 2010s, the median age of monkeypox infection increased to 10 and 21 years. In May 2022, the average median age of monkeypox infections was 37 years.

# Risk Factors
Risk factors for contacting monkeypox virus include close physical contact with infected person or animal (including direct contact with lesions, bodily fluids, and respiratory secretions), direct contact with contaminated materials such as towels, eating undercooked meat, and complex exposures to infected animal (e.g., invasive bite or scratch that breaks the skin).

# Complications and Prognosis
Monkeypox is usually a self-limited disease with the symptoms resolving within 2 to 4 weeks. Complications are rare. They include secondary bacterial infection such as pneumonia, sepsis, encephalitis, corneal inflammation of the eyes, and conjunctivitis.

# Diagnosis

## History and Symptoms
The significant information in the patient's history include recent travel to endemic area of monkeypox or possible contact with infected person, animal, or contaminated material. Initial symptoms fever, chills, lymphadenopathy, headache, myalgia, followed by skin rash of multiple lesions that develop and evolve at the same time. The evolvement of the lesions progresses as follows: macular (12 days), papular (12 days), vesicular (12 days), pustular (5-7 days), lastly scab (7-14 days).

## Physical Examination
Depending on the stage of the disease, physical findings may include low-grade fever, enlarged lymph nodes (submental, submandibular, cervical, inguinal), and skin rash with typical progression: Macular (1-2 days), papular (1-2 days), vesicular (1-2 days), pustular (5-7 days), scabs (7-14 days).

## Laboratory Findings
Polymerase chain reaction (PCR) is the preferred test to confirm monkeypox virus (MPXV) given its sensitivity and accuracy. Samples should be obtained from skin lesions, precisely, the roof or fluid from vesicles and pustules, and dry crusts. PCR blood tests are usually inconclusive because the does not live long in the blood.

## EKG
There are no EKG findings associated with monkeypox.

## Ultrasound
Ultrasound may be helpful to assess the fetus well-being in pregnant women with laboratory confirmed monkeypox.

## Other Diagnostic Studies

# Treatment

## Medical Therapy
Currently, there is no proven, safe treatment for monkeypox. To contain the outbreak, the CDC advises using smallpox vaccine, cidofovir, ST-246, and vaccinia immune globulin. Vaccines are not available to public as for now but in an event of larger outbreak, the CDC will establish guidelines on who to receive the vaccine.

## Surgical Therapy
Surgery is not indicated for monkeypox. Monkeypox is usually a self-limiting disease with symptoms lasting from two to four weeks.

## Primary Prevention
The Advisory Committee on Immunization Practices recommends ACAM2000 or JYNNEOS as pre-exposure prophylaxis to individuals at risk of exposure to monkeypox on basis of an occupational assessment.
The CDC recommends proper hand hygiene with soap and water or alcohol-based hand sanitizers after contact with infected animals or humans. Avoid contact with animals that can act as a reservoir for the virus, e.g. rodents. Avoid close contact with lesions, bodily fluids, or respiratory droplets, or contaminated materials such as bedding or towels. Personal protective equipment (PPE) is essential for healthcare workers when handling patients. Isolate infected patients to reduce spread.