Monkeypox

Reviewed by , providing nurse training at Yale New Haven Health-Bridgeport Hospital since 2022. Previously in healthcare and education at Griffin Hospital, St. Vincent's College of Nursing and Sacred Heart University Medical Center.

The monkeypox virus can be transmitted from animals to humans through direct contact with infected animals’ blood, bodily fluids, or skin lesions. Various animals, including Gambian pouched rats, rope squirrels, tree squirrels, different monkey species, dormice, and others, have been documented to carry the virus in African regions. It is believed that rodents are the primary source of the virus, but its exact natural source remains unidentified. Consumption of undercooked meat or other products from infected animals can also pose a potential risk. Individuals living or working near forested areas are more likely to have indirect exposure to animals carrying the monkeypox virus.

Human-to-human transmission can occur through close contact with the skin lesions of an infected person, respiratory secretions, or contaminated objects. Transmission via respiratory droplets typically requires prolonged close contact, which puts family members, healthcare workers, and other close contacts of active cases at higher risk. The longest documented chain of transmission has occurred through person-to-person infections. The cessation of smallpox vaccination may contribute to decreased immunity in communities.

Transmission from mother to child can result in congenital monkeypox occurring during birth or through close contact afterward. While close contact is a recognized transmission risk, the potential for sexual transmission remains unclear and warrants further investigation through additional studies.

Transmission

The monkeypox virus can be transmitted from animals to humans through direct contact with infected animals’ blood, bodily fluids, or skin lesions. Various animals, including Gambian pouched rats, rope squirrels, tree squirrels, different monkey species, dormice, and others, have been documented to carry the virus in African regions. It is believed that rodents are the primary source of the virus, but its exact natural source remains unidentified. Consumption of undercooked meat or other products from infected animals can also pose a potential risk. Individuals living or working near forested areas are more likely to have indirect exposure to animals carrying the monkeypox virus.

Human-to-human transmission can occur through close contact with the skin lesions of an infected person, respiratory secretions, or contaminated objects. Transmission via respiratory droplets typically requires prolonged close contact, which puts family members, healthcare workers, and other close contacts of active cases at higher risk. The longest documented chain of transmission has occurred through person-to-person infections. The cessation of smallpox vaccination may contribute to decreased immunity in communities.

Transmission from mother to child can result in congenital monkeypox occurring during birth or through close contact afterward. While close contact is a recognized transmission risk, the potential for sexual transmission remains unclear and warrants further investigation through additional studies.

Signs and symptoms

Symptoms of monkeypox typically manifest after an incubation period of 5 to 21 days following exposure to the virus. Initial symptoms may include backache, headache, high temperature, muscle aches, chills, swollen glands, joint pain, and exhaustion. Within one to five days after the onset of symptoms, a rash usually develops, initially appearing on the face before spreading to other areas such as the anus, genitals, and mouth. Anal pain or bleeding may also occur.

The rash can be mistaken for chickenpox. It starts as raised spots and progresses to small fluid-filled blisters, eventually forming scabs that fall off. Flu-like symptoms may precede the rash by one to four days.

Monkeypox remains contagious from the onset of symptoms until the rash resolves and all scabs have detached. The illness typically lasts two to four weeks, during which new skin forms over the affected areas.

Diagnosis

To accurately diagnose the monkeypox virus, clinicians must consider various differential diagnoses, including measles, chickenpox, scabies, syphilis, bacterial skin infections, and medication-related allergies. Lymphadenopathy during the prodromal stage is a key clinical feature distinguishing monkeypox from smallpox and chickenpox.

A suitable sample should be collected and securely transported to a competent laboratory when monkeypox is suspected. The reliability of confirmation hinges on the quality and type of specimen and the standard of laboratory testing, following national and international protocols.

PCR (Polymerase chain reaction) is preferred due to its sensitivity and accuracy. Optimal samples for monkeypox testing include skin lesions, dry crusts, and fluid from vesicles and pustules. If feasible, a biopsy may be considered, with lesion samples stored in sterile, dry tubes at cold temperatures. Blood PCR tests may yield inconclusive results due to the short duration of viremia.

Antibody and antigen detection methods lack specificity for monkeypox due to serological cross-reactivity with orthopoxviruses. However, they are suitable with adequate facilities. A vaccination history, particularly with vaccinia-based vaccines, can lead to false positives. Comprehensive patient information, including age, onset dates for fever and rash, collection date, patient status, and rash stage, should accompany specimens to optimize testing accuracy.

Prevention

A vaccine for monkeypox, derived from the smallpox vaccine, is currently only accessible through clinical trials. Preventing the spread of the virus relies on minimizing contact with infected animals and reducing person-to-person transmission. To mitigate the risk of contracting monkeypox, observe the following precautions:

  • Avoid contact with individuals suspected of carrying the virus.
  • Refrain from handling infected animals, particularly those exhibiting symptoms or deceased.
  • Avoid contact with contaminated materials or bedding that could harbor the virus.
  • Ensure thorough cooking of all animal-derived food products.
  • Practice regular handwashing with soap and water.
  • Employ barrier methods such as condoms and dental dams during intimate activities.
  • Clean and disinfect frequently touched surfaces.
  • Utilize personal protective gear when caring for infected individuals.
  • Wear a mask covering both nose and mouth when near others.

Treatment

While no specific medications are tailored for treating monkeypox virus infections, the genetic similarity between smallpox and monkeypox allows for the use of antiviral vaccines and drugs designed to combat smallpox to prevent and address monkeypox infections.

Antiviral medications such as tecovirimat (TPOXX) may be prescribed for individuals at high risk of severe illness, particularly those with weakened immune systems. Should you develop symptoms of monkeypox, it’s crucial to consult your doctor, even if you haven’t been in contact with anyone diagnosed with the virus.

Fortunately, the majority of monkeypox cases resolve within two to four weeks without the need for medical intervention.

Works cited

Reviewed by , providing nurse training at Yale New Haven Health-Bridgeport Hospital since 2022. Previously in healthcare and education at Griffin Hospital, St. Vincent's College of Nursing and Sacred Heart University Medical Center.

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This page was last updated on Apr 23, 2024. of this page.