New Delhi: While encephalitis is a possible complication of monkeypox, co-infections with other diseases as well as immunity level can play a vital role in the deaths caused by the virus, experts said on Wednesday.
More than 25,000 cases of monkeypox have been reported from 78 countries, as per the World Health Organization (WHO).
Together from endemic and non-endemic countries, a total of 10 deaths have been reported. These include Nigeria (3), Central African Republic (2), Ghana (1); Spain (2), Brazil (1) and India (1).
Initial investigations have attributed encephalitis as the reason for all the deaths outside of Africa, except for Brazil. Encephalitis is an acute inflammation of the brain, caused majorly by either a viral infection or the immune system mistakenly attacking brain tissue.
In Brazil, the death of a 41-year-old man due to monkeyox was due to lymphoma, a type of cancer. He was immunocompromised and was, therefore, at higher risk of severe disease.
In the case of the 22-year-old man who died in Kerala, after testing positive in the UAE, media reports quoted officials noting the reason as brain encephalitis.
After returning from UAE, the youth had sought treatment against severe fatigue and encephalitis. He reportedly also tested positive for Epstein-Barr virus, the cause of infectious mononucleosis.
The death of a 31-year-old and a 44-year-old in Spain was also due to monkeypox-associated encephalitis. So far, reports suggest that both were previously healthy and not immunocompromised.
According to Dipu TS, Associate Professor of Division of Infectious Diseases at Amrita Hospital in Kochi: “Encephalitis is a rare but possible complication of monkeypox”.
“But coinfections with other viruses which can cause encephalitis like Japanese encephalitis, nipah, and herpes has to be ruled out before attributing it to monkeypox,” Dipu told IANS.
The monkeypox virus has two distinct genetic clades: 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.
Genomic sequencing data has suggested that the west African clade, known to be associated with milder disease and a lower case fatality rate, is responsible for the current outbreak.
Although the monkeypox disease is self-limiting in nature, as evident in the current outbreak, the experts noted that the small number of deaths may not provide sufficient data to prove that encephalitis is the main cause of the disease.
They stressed the need for more clearer data as during the Covid to ascertain the cause.
“Encephalitis is one of the complications of monkeypox; in a few cases it can affect the brain. And the deaths may be due to that. But it would be too early to really predict with just a handful of fatalities,” epidemiologist Amitav Banerjee told IANS.
He said that the chances of a coinfection cannot be ruled out. Moreover, as per data from the UK about 60 to 70 per cent monkeypox cases had co-infection with HIV.
“We require more detailed data on people who got encephalitis, like what is the immune status of that person. There are other concerns which require more detailed investigation. We cannot jump to conclusions,” said Banerjee, who is also Professor and Head of Community Medicines at D Y Patil Medical College in Pune.
He noted that the disease is currently “very concerning in high risk groups or clusters of people with multiple sex partners and the spread is something like HIV”. He suggested the need for increasing monkeypox surveillance among the high-risk population like for HIV.
“The risk of infection to the general population is very low, Banerjee said, adding that the infectious disease should not be a cause for panic or stigma as there is “almost zero mortality in the healthy population”.