Monkeypox Virus

Quick Information Sheet for Healthcare Workers

19 May 2022

ALERT: Multiple cases of Monkeypox reported from USA & Europe!

A. General Info

  1. The first description of Monkeypox was reported in 1958 among monkeys kept for research purposes.
  2. The first known human infection with Monkeypox was in 1970 in Democratic Republic of Congo.
  3. Monkeypox is a rare disease caused by Monkeypox virus. The virus belongs to Orthopoxvirus genus of Poxviridae family. The same genus as the viruses for both smallpox and cowpox infection. 
  4. Majority of outbreaks and infections have been reported from African countries; primarily DRC.
  5. From time to time, cases have been reported outside Africa linked to international travel and transport of animals.
  6. Last year DRC reported more than 6000 cases while Nigeria reported 3000 cases.
  7. African rodents and non-human primates have been known to harbor the virus and are thought to be the source for human transmission. Specific primary natural reservoir is yet unknown.
  8. The recent cases described from Europe and USA are linked to international travel from African countries. Cases have been described from July 2021 and November 2021 by US CDC.
  9. The current alert is related to pockets of outbreaks in multiple countries; USA, UK, Spain, Portugal, etc.
  10. Person-to-person transmission is uncommon. However, among the cases in UK, a number of cases have no known travel history to Africa, thus raising concern about undetected community spread. 
  11. There are reports of possible transmission from a primary case to a HCW in one setting.

B. Transmission

  1. Transmission occurs when a person comes in contact with the virus from an animal, human or contaminated materials.
  2. The virus enters body via broken skin, respiratory system and other mucus membranes.
  3. Animal-to-human transmission is documented from bites, scratches, raw-meat (contaminated) handling, direct/indirect contact with body/lesion fluids.
  4. Human-to-human transmission is thought to be primarily via respiratory droplets. However, in the recent outbreak, a newer mechanism, is suspected to be at play; sexual transmission. One cluster is identified among individuals who self-identify as gay (male to male) or bisexual. Investigators report that this could signify sexual transmission or just the close contact associated with the sexual act.

C. Incubation Period

  1. Incubation period is usually 7-14 days but can range from 5-21 days.

D. Signs and Symptoms

  1. Prodrome begins with:
  • Fever
  • Headache
  • Muscle aches
  • Backache
  • Swollen lymph nodes
  • Chills
  • Exhaustion

The typical rash often develops after 1-3 days (sometimes longer) from onset of fever. The skin lesions typically follow stages before falling off.

  • Enanthem (tongue/mouth)
  • Macules 1-2 days
  • Papules 1-2 days
  • Vesicles 1-2 days
  • Pustules 5-7 days
  • Scabs 7-14 days

Rash typically begins on face/ mouth, but could appear anywhere on the body. In recent series, genital lesion have been frequently described.  

  1. The illness usually lasts 2-4  weeks.
  2. Historically 1 out 10 infected cases died from complications associated with it. However, in the recent out-break, case fatality, so far, is lower at <1%.
  3. Complications of monkeypox include secondary infections, sepsis, bronchopneumonia, encephalitis, infection of the cornea with ensuing loss of vision. 

E. Diagnosis

  1. Clinical diagnosis is possible when contact history, signs and symptoms match.
  2. Laboratory diagnosis could be possible with tests done on lesion fluid:
  • Virus isolation
  • PCR
  • Histopathology with virus identification.

Sample collections have to be with strict PPE, as the fluid itself is infectious. In our context, at present time, laboratory diagnosis and confirmation is limited/not possible.

F. Treatment

  1. There is currently no specific proven, safe treatment. Antiviral drugs and Vaccinia immune globulin (VIG) have been used with variable success.
  2. Treatment is symptomatic and supportive care.

G. Prevention

  1. Infection can be prevented by avoiding (taking protective precautions during essential) contact with symptomatic humans and animals that could harbor the virus (rodents and other dead or sick animals) particularly in localities with known transmission.
  2. Standard infection control practices and barrier nursing can help prevent nosocomial spread in healthcare settings.
  3. Practice contact and respiratory isolation of suspected/known cases. Use contact and respiratory droplet precautions in isolation settings.
  4. Contact precautions in healthcare settings: hand hygiene, disposable gowns, gloves when handling, surface disinfection (bedding, etc), linen decontamination, safe body fluid disposal, etc.
  5. Droplet precautions in healthcare settings: suitable PPE including mask, goggles/shields, etc.
  6. Vaccines are available. Approved by US FDA. Smallpox vaccine work against Monkeypox. Limited global stockpiles are available for smallpox vaccine. US ACIP is evaluating the vaccine for protection of people at risk due to occupational exposures.
  • ACAM2000: A replication-competent vaccinia virus vaccine. It is a sub-cutaneous, single dose vaccine delivered via multiple puncture technique.
  • Aventis Pasteur Smallpox Vaccine (APSV): Also a replication-competent vaccinia virus vaccine. Replacement for ACAM2000. It is also a sub-cutaneous, single dose vaccine delivered via multiple puncture technique.
  • Jynneos, Imavamune, Imvanex: Replication-deficient attenuated live virus vaccine. It is used as a subcutaneous 2 dose, 4 weeks apart shot. If previously vaccinated against Smallpox, a single dose is sufficient. 


  • WHO
  • CDC, USA.
  • Various news outlets