Monkeypox is largely a self-limiting disease, but high-risk groups can have severe consequences

Why? Dr Pragya Yadav is the country’s top scientist at the ICMR-National Institute of Virology (NIV), Pune. She is the group leader of the Maximum containment laboratory at the apex lab, where highly infectious viruses, like the one that causes Monkeypox, would be handled and tested. The Health ministry has directed public health officials at ports, airports and land borders to keep a close watch on suspected Monkeypox cases with the international travel to India. Such cases would be isolated and their clinical specimens would be sent to NIV.

The WHO says that its partner countries are working to better understand the extent and cause of the outbreak of Monkeypox. What do we know so far about this outbreak?

Cases have been reported since May 13. So far 18 countries have reported these cases, all of which are non-endemic for the monkeypox and outside Africa.This has alerted public health authorities around the world. Different approaches to preparedness are being used by the WHO and member states for handling patients and testing the samples. The United Kingdom (UK) has also reported community transmission of Monkeypox, which has made the situation worrisome. But so far, no associated deaths have been reported.

There are no established travel links to the endemic area. This is another concern that raises an alarm. We know that the Monkeypox virus belongs to Orthopoxvirus genus of the Poxviridae family which also contains then deadliest smallpox. Since these are DNA viruses, we need a PCR test. The majority of cases identified from the 18 countries belonged to the West African clade. Their genome sequencing was done from a lesion swab sample of a confirmed case in Portugal and has indicated a very close match of the Monkeypox virus causing the current outbreak, which was first exported from Nigeria to the United Kingdom, Israel and Singapore in 2018 and 2019 .

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The identification of confirmed and suspected cases of Monkeypox with no direct travel link to the endemic area represents a highly event. Surveillance in non-endemic areas has been limited but it is now expanding. As of now, no cases have been reported from the Southeast Asian region, epidemiological investigations are ongoing and a travel advisory has been issued. We continue to discuss various issues on the monkeypox virus.

Since 1970, human cases of Monkeypox have been reported in 11 African countries. Is this the first time that multiple cases of monkeypox have been identified in several non-endemic countries?

You are absolutely right. Cases have been identified in 11 African countries since 1970. But the true burden of the Monkeypox virus was known much later. For example, in 1996-97, there was an outbreak in Congo with a higher incidence and case fatality ratio. Since 2017,

Nigeria has experienced a large outbreak with over 500 suspected cases and over 200 cases with a case fatality ratio of approximately three per cent.

Monkeypox has been reported outside these defined areas in the past. In 2003, the first outbreak outside Africa was reported in the USA. It was linked to contact with infected pet Prairie dogs. The dogs had been co-housed with infected rodents imported from Ghana. This outbreak led to over 70 cases in the US. MonkeypPox was also reported in travelers from Nigeria to Israel in September 2018. UK reported cases in September 2018, Singapore in May 2019 and the US in July and November 2021.. There have been different episodes of imported Monkeypox cases being reported through contact with an animal and community transmission was also established. Coming to May 2022, multiple cases have been identified in several non-endemic countries and the scientific community is making efforts to understand the source of infection and transmission patterns.

What has been the disease prevalence in India linked to Monkeypox?

It is a very relevant and important question. As we all know, Smallpox was a very dangerous disease but using mass immunisation programme, we eradicated this disease in 1978. In India, there is another disease related to the same family: cowpox and buffalopox. Sporadic cases have been reported not only in cows or buffaloes but in humans too, indicating animal to human transmission. However, till now, Monkeypox cases has never been reported in the country. Hence, it is an exotic pathogen. That is why we need more precautionary measures in place because it is a new disease that we have not been exposed to and don’t have immunity against it. That is a big challenge and matter of concern.

Monkeypox is usually a self-limiting disease with symptoms lasting from two to four weeks. What are the key symptoms to watch out for?

Though this disease goes through four different phases, the phase I would like to describe is very important for the disease per se. The first invasion period, which is between 0-5 days, is characterised by fever, headache and lymph node swelling. The swelling of the lymphnodesis is one of the characteristic feature of Monkeypox and is not observed in similar rash causing diseases like chickenpox. Patients also show generalized weakness or lack of energy. Skin eruptions usually show up within two days of fever. The rash is more concentrated on the face as is apparent in 95 per cent cases. In 75 per cent cases, it is found in the palm and sole of the feet. It affects the oral mucous membrane in 70 per cent of the cases. The conjunctiva, cornea of ​​the eye and the genital area can also get affected.

WHO says that severe cases can also occur? Which group is at risk of getting a severe disease?

Though it is largely a self-limiting disease, it can lead to some difficult phases when it affects the lungs and the eyes. The high risk group comprises children, pregnant women and immune-compromised patients, including those who have diabetes. They can have more severe consequences compared to others.

Experts are of the view that vaccines used during the Smallpox eradication program also provide protection against Monkeypox. How robust is this immunity? What does the data suggest?

Since the eradication of smallpox in 1980, the usage of small pox was stopped for the general public. When it was eradicated, the virus was kept in two maximum containment laboratories one in Russia and the other in the USA. In the US, the FDA has approved the Jynneos (Modified Vaccinia Ankara) Smallpox vaccine for vaccination against Monkeypox in 2019. Its effectiveness was concluded from a clinical study. Past data from Africa suggests that this vaccine is at least 85 per cent effective in preventing Monkeypox.

Experts also believe that vaccination after exposure to Monkeypox might help prevent the disease or make it less severe. The Smallpox vaccine gives protection but the waning response with time can lead to re-occurrence. I just want to emphasize that the Smallpox vaccine is not available to the general public. So that is another challenge if anybody wants to go for it.

What kind of preparation and surveillance is India looking at?

Whenever there is a threat of a new viral disease, there is a travel advisory and a preparedness alert issued to all states. The international travel to the endemic and the currently ongoing outbreak regions would be a significant risk factor for the importation of the Monkeypox cases in India. So, any of such cases would be under the surveillance at the entry points. The samples of the symptomatic patients will be referred to NIV, Pune. As I mentioned before, since it is a DNA virus, we will need to do a PCR test and sequencing of genome. We also have the orthopox PCR test, which can rule out other pox viruses, not just the Monkeypox. Based on the confirmation and genome sequencing, the authorities will be informed about the positive cases if at all any.


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