MONKEY POX- A Zoonotic Disease

MONKEY POX- A Zoonotic Disease

VIKRAM SINGH GURJAR¹, RASHMI SINGH², YOGENDRA KUMAR MEENA³, and DEVENDRA⁴ Department of Veterinary medicine, PGIVER, Jaipur, Rajasthan University of Veterinary and Animal Sciences, Bikaner.

Introduction

Several viral zoonoses have emerged in recent decades from various parts of the world and caught the attention of public health authorities, including bird flu, contagious ecthyma, Ebola hemorrhagic fever, Hantavirus infection, Hendra virus disease, Nipah virus disease, Rift Valley fever, severe acute respiratory syndrome, swine flu, West Nile fever, ¹³ Covid-19 and now Monkey pox virus infection, etc.

The monkey pox, a sylvatic zoonosis, produces sporadic human infections in dense forests of Central and West Africa.¹⁷ It is serologically linked to smallpox in humans; which is characterized by pock lesion and febrile condition, hence smallpox vaccination can prevent monkey pox in humans.¹⁴ Monkey pox cases were confirmed in the Midwest of the United States of America in the spring of 2003, marking the disease’s first recorded incidence outside of Africa.¹⁷

The monkey pox virus, a member of the Poxviridae family, Chordopoxvirinae subfamily, and Orthopoxvirus genus, is responsible for the now uncommon zoonotic illness known as monkey pox (a genus that includes camel pox, cowpox, vaccinia, and variola viruses). The monkey pox virus and the variola virus, which causes smallpox, are closely related.⁹

According to genome sequencing, there are two clades of monkey pox: Congo Basin and West African, and variations in human pathogenicity and mortality have been seen in the two geographical regions.¹⁷

Transmission

Human-to-human transmission:-

The virus is thought to spread by respiratory droplets during prolonged and direct face-to-face contact. The monkey pox virus can also be transmitted by direct contact with the body fluids of an infected person or contaminated objects, such as bedding or clothes.⁴

Animal-to-human transmission:-

Monkey pox can be transmitted to humans by a bite from an infected animal or direct contact with an animal’s lesions, blood, or body fluids. Direct contact with animals, particularly rodents is considered the prime mode of disease transmission.^{4, 17}

The inoculation or transmission through the placenta (congenital monkey pox) is another method of transmission of disease.¹⁷Viral shedding via feces may represent another exposure source.⁸

Epidemiology

In 1958, At the State Serum Institute in Copenhagen (Danish laboratory), the monkey pox virus was first discovered in experimental monkeys.¹⁶

In 1970, the virus was first time discovered in a human being, a 9-month-old baby boy receiving smallpox treatment in Zaire (now the Democratic Republic of the Congo, DRC), who was confirmed for monkey pox. Which was infected with the smallpox virus.²

Since then, cases of human monkey pox have been reported in various countries in Africa, including Benin, Central African Republic, Cameroon, Cote d’Ivoire, The Democratic Republic of the Congo, Liberia, Gabon Nigeria, Sierra Leone, and South Sudan.⁴

The first cases of monkey pox outside of Africa were identified in the US in 2003.⁵ In Nigeria, There was a significant outbreak of monkey pox in humans was investigated in 2017.¹⁷

In India, On July 15, 2022, confirmed the first case of monkey pox, a 35-year-old man who arrived from the Middle East earlier this week has been confirmed as the first case of monkey pox (WHO South-East Asia Region).

Clinical Signs & Diagnosis

Monkey pox has a 7-14 day incubation period (time from infection to symptoms), although it can be 5-21 days.¹⁷

The case Fatality rate of monkey pox is less than 10%, Young patients are more often the ones who die from monkey pox. The case fatality rate has been between 3-6% in recently found cases.⁷

Most of the clinical characteristics of human monkey pox infection are similar to those of smallpox ³. There are two common forms of monkey pox in humans:-

Febrile prodrome (0-5 days) form: This form is characterized by Fever, Headache, muscle aches, exhaustion, Chills and/or sweats, Sore throat and cough, and Lymphadenopathy.⁷

Skin involvement (rash) form: The monkey pox-affected children showed rashes on different parts of the body, the rash progresses from the macules to papules, vesicles, and pustules, and then there is the formation of crusts.¹⁷

Among non-human primates, monkey pox is a self-limiting rash, before developing into pustules and crusting over, there is a fever and 1 to 4 mm cutaneous papules. An epidermal hyperplastic ring surrounds a red, necrotic, and depressed area in the middle of a typical monkey pox lesion.  These “pocks,” can be seen on the face, limbs, palms, soles, and tail.¹ coughing, nasal discharge, dyspnea, anorexia, facial edema, oral ulcers, or lymphadenopathy may be noticed in severe cases.¹⁰

The clinical manifestation of the disease is not very characteristic to make the diagnosis and therefore, laboratory techniques, like Conventional tests such as viral isolation from a clinical specimen, electron microscopy, and immune-histo-chemistry remain valid techniques but require advanced technical skills and training, as well as a sophisticated laboratory.

Specimens can be analyzed using real-time polymerase chain reaction (RT-PCR) to assess the presence of Ortho-pox virus or monkey pox virus in a lesion sample.¹¹Due to the accuracy and sensitivity, the polymerase chain reaction (PCR) method is considered the mainstay of laboratory diagnosis.¹⁷

The enzyme-linked immune-sorbent test (ELISA) is used to identify IgG and IgM antibodies, and immunohistochemistry is used to detect viral antigens.¹⁵

Smallpox, chickenpox, measles, bacterial skin diseases, scabies, medicament allergies, syphilis, and rickettsial pox are among the most common differential diagnoses.

Although there is no established medication for humans, animal research has shown that antiviral treatment with cidofovir or a comparable acyclic nucleoside phosphonate analogue is beneficial. Animal mortality can be reduced more effectively by antiviral drugs than by administering the smallpox vaccination for medical purposes.¹²

Historical data have indicated that smallpox vaccination with vaccinia virus (another orthopoxvirus) was approximately 85% protective against monkeypox.⁶

The U.S. Food and Drug Administration has authorized JYNNEOS, also known as Imvamune or Imvanex, as an attenuated live virus vaccine for the treatment of monkeypox.⁴

Conclusion

The monkey pox virus is an emerging infectious viral disease transmitted by animals to humans. Fever, rash, and enlarged lymph nodes are common clinical characteristics of monkey pox. The presence of monkey pox is no longer limited to endemic regions. As a result, the monkey pox virus is a dangerous, globally spread illness that is now again on the rise.

For the monkey pox virus infection, there is presently no safe or effective therapy. The FDA has authorized JYNNEOS, a new smallpox vaccine, to prevent both monkey pox and smallpox. To stop the transmission of illness, it is important to practice good hand hygiene after handling sick animals and contaminated biological materials.

References

1. Acha PN and Szyfres B. “Zoonoses and Communicable Diseases Common to Man and Animals”. 3rd Edition Volume I. Pan American Health Organization (PAHO), Washington, D.C.USA. (2001).
2. Breman JG, Kalisa R, Steniowski MV, Zanotto E, Gromyko AI, Arita I. Human monkeypox, 1970–79. Bull World Health Organ. 1980; 58(2):165–182.
3. Breman JG, Henderson DA. Diagnosis and management of smallpox. N Engl J Med 2002; 346:1300–8.
4. CDC. “Monkeypox”. Centers for Disease Control and Prevention, Atlanta, Georgia, USA. (2021).
5. Centers for Disease Control and Prevention. Monkeypox. Available from: https://www.cdc.gov/ poxvirus/monkeypox/index.html.
6. Fine PE, Jezek Z, Grab B, Dixon H. The transmission potential of monkeypox virus in human populations. Int J Epidemiol. 1988; 17(3):643–650.
7. GOI, GUIDELINES FOR MANAGEMENT OF MONKEYPOX DISEASE, Ministry of Health and Family Welfare, 31st May 2022.
8. Hutson CL, Olson VA, Carroll DS, et al. A prairie dog animal model of systemic orthopoxvirus disease using West African and Congo Basin strains of monkeypox virus. J Gen Virol 2009; 90(Pt 2):323–33.
9. (ICTV) ICoToV. Virus Taxonomy: 2020 Release. Available from: https://talk.ictvonline.org/taxonomy.
10. Learned LA, Reynolds MG, Wassa DW, et al. Extended interhuman transmission of monkeypox in a hospital community in the Republic of the Congo, 2003. Am J Trop Med Hyg 2005; 73:428–34.
11. McCollum AM and Damon I K. “Human monkeypox”. Clinical Infectious Diseases 58 (2014): 260-3267.) (Pal M., et al. “Epidemiology, diagnosis and control of monkeypox disease: A comprehensive review”. American Journal of Infectious Diseases and Microbiology 5 (2017): 94- 99.
12. Nalca A. “Reemergence of monkeypox: prevalence, diagnostics, and counter measures”. Clinical Infectious Disease 41 (2005): 1765-1771.
13. Pal M. “Severe acute respiratory syndrome: A newly recognized viral zoonosis of public health concern”. Acta Scientific Microbiology 1 (2018): 1.
14. Renquist DM and Whitney RA. “Zoonoses Acquired From Pet Primates”. University of Wisconsin System Board of Regents, September 11, (2008).
15. Sadeuh-Mba S A., et al. “Monkeypox virus phylogenetic similarities between a human case detected in Cameroon in 2018 and the 2017-2018 outbreak in Nigeria”. Infection and Genetic Evolution 69 (2019): 8-11.
16. Von Magnus P, Andersen EA, Petersen KB, Birch-Andersen A. A pox-like disease in cynomolgus monkeys. Acta Path Microbiol Scand. 1959; 46:159.
17. WHO. “Monkeypox Fact Sheet”. World Health Organization, Geneva, Switzerland. (2019).

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