Monkeypox: How worried should we be?

Monkeypox is usually a self-limited disease with symptoms lasting from two to four weeks. Severe cases occur more commonly among children and are related to the extent of virus exposure, patient health status and nature of complications. 

Monkeypox virus is not new like the Sars-Cov-2 virus. A Danish scientist, Dr Preben Christian Alexander von Magnus first discovered this zoonotic virus from a laboratory-bred, long-tailed macaque monkey aka crab-eating macaque in 1958. 

Since then many small laboratory outbreaks of Monkeypox have been reported in many animal care facilities around the world. The first human case of the virus however was recorded in the Democratic Republic of Congo in 1970. 

Since then, it has mostly been reported from rainforest regions of the Congo basin, particularly in the Democratic Republic of Congo. In 2003, for the first time, the West African type (clade) monkeypox virus was found in US pet owners. 

The virus supposedly travelled to the US via rodents imported from Ghana. Later this virus was found in Europe, other parts of North America, the Middle East and Australia on a smaller scale. 

The 2022 monkeypox outbreak started in the UK on May 6 through a British resident who travelled to Nigeria and returned to the UK on May 4th. Since then this virus has now been recorded in 23 countries. As of May 31,  A total of 557 cases have been confirmed worldwide, including 321 from the EU. 

The UK still is seeing the highest number of cases (108). Cases are either confirmed by monkeypox virus-specific Polymerase Chain Reaction (PCR) or Orthopoxvirus positive PCR followed by sequence confirmation or specific virus. The number is increasing daily. There are more probable as well as possible cases every day and numbers are slowly but surely creeping upward. 

Monkeypox is an enveloped DNA virus belonging to the Poxviridae family, the same family of smallpox but not as virulent as the latter. There are two distinct genetic clades of the monkeypox virus: the central African (Congo Basin) clade and the West African clade. 

The Congo Basin clade has historically caused more severe disease and was thought to be more transmissible. The recent cases belong to the West African clade of monkeypox, which is relatively mild: Around 1% of people who contract may die compared to the central African (Congo Basin) for which the death rate could be as high as 10%. 

Microbes that have DNA as a genome are less susceptible to mutations compared to those that have RNA genomes such as SARS Cov-2. Therefore, scientists are less concerned about frequent mutations of this virus and thus the emergence of the superbug is unlikely.  

Smallpox has been eradicated globally with a successful vaccination programme in 1980 and the last case was recorded in 1977. For smallpox, however, the death rate was extremely high (10-75%) and that depended on the severity and nature of smallpox dissemination before vaccination. 

Monkeypox may not be highly contagious among people when compared with Covid-19; however, human-to-human transmission occurs through direct contact with skin lesions, bodily fluids or large respiratory droplets of infected individuals. 

Transmission is limited to close household contacts or health care workers not wearing personal protective equipment. In many countries, a higher number of the case has been found in the homosexual population on this new circulating strain of the monkeypox virus. 

However, that does not mean this group of people should be stigmatised. This disease could transmit to anyone who will get direct contact with skin lesions or bodily fluids. Maybe coincidentally, those people somehow were exposed to the virus and may be due to their close networking. 

Monkeypox starts with flu-like symptoms like many other zoonotic diseases. The prodromal phase (interval from exposure to onset of symptoms) of monkeypox is usually from six to 13 days but can range from five to 21 days. The incubation period is usually 2-5 days characterised by fever, intense headache, swelling of the lymph nodes, back pain, muscle aches and lethargy (lack of energy). 

Skin blisters may appear within 1-3 days of the appearance of fever. The rash tends to be more concentrated on the face and extremities. As per WHO, "the rash tends to be more concentrated on the face and extremities rather than on the trunk. It affects the face (in 95% of cases), palms of the hands and soles of the feet (in 75% of cases). Also affected are oral mucous membranes (in 70% of cases), genitalia (30%), conjunctivae (20%), as well as the cornea. 

The rash evolves sequentially from macules (lesions with a flat base) to papules (slightly raised firm lesions), vesicles (lesions filled with clear fluid), pustules (lesions filled with yellowish fluid), and crusts which dry up and fall off. The number of lesions varies from a few to several thousand. In severe cases, lesions can coalesce until large sections of skin slough off."

Diagnosis may be done clinically; however, sometimes could be challenging because of similar other rash related illnesses such as chicken pox, measles etc. PCR also called Nucleic Acid Test  (NAT) is the preferred laboratory test given its accuracy and sensitivity and many laboratories in Bangladesh are now capable of doing these tests. 

Optimal sample collection using proper safety measures is essential. Preferred samples could be the roof or fluid from vesicles and pustules including dry swabs or swabs in Universal Transport Medium (UTM) of lesions or exudate and need to maintain a cold chain for shipment following proper biosafety guidelines. Oropharyngeal swabs, nasopharyngeal swabs, EDTA blood and urine can also be considered for testing during febrile phases.

Smallpox vaccines were found effective by about 85% in preventing money pox. Those individuals who have had smallpox vaccines will have significant protection and thus will have a milder infection if exposed. 

The supply of small vaccines may be an issue. Other monkeypox therapies are tecovirimat and brincidofovir — both antiviral medications — and vaccinia immune globulin is also available. These therapies were originally designed for smallpox but also work for monkeypox as well. 

Since Bangladesh can produce generic drugs, it is better to have the products ready for use when needed if not available already. The average person need not be concerned unless they are immunocompromised or have other health conditions. 

In my understanding, the Govt. of Bangladesh has taken appropriate actions such as implementing temperature checks at the airports and land borders, which will help to isolate if someone did not have the blister.
Bangladesh having become the first confirmed country to enact seafarer restrictions in the wake of the global spread of monkeypox deserves credit. Following Bangladesh, other nations are also looking at tightening rules as well.

Now the million-dollar question, how worried should we be about this virus.  I would certainly be worried because Bangladesh is a densely populated country where many people sleep in the same room in low-income households. The weather here is most often hot and humid. On top of that, thousands of travellers are entering the country using Hazrat Shahjalal International Airport, the country's largest airport. Certainly, these factors will create an optimal atmosphere for the transmission as well as dissemination of cases in the community and seeing cases in Dhaka or Bangladesh may be a matter of time only. 

The Author is an international expert on zoonotic and arthropod-borne diseases and has directed the Zoonotic and Emerging Pathogens Laboratory of BCCDC Public Health Laboratory in British Columbia, Canada since 1998. He is also a Clinical Professor at the Department of Pathology and Laboratory Medicine, University of British Columbia, Canada.
 
Disclaimer: The views and opinions expressed in this article are those of the author and do not necessarily reflect the opinions and views of The Business Standard.