‘Monkeypox has a lower transmission rate than Covid-19’

New Delhi: India has so far reported nine cases of monkeypox, including one death. As the cases have been slowly rising, the Centre called a high-level meeting with top health experts to revisit the guidelines of monkeypox management. In an interview with The Sunday Guardian, Dr Giridhara R.Babu, Professor and Head, Life Course Epidemiology at Public Health Foundation of India, has expressed that declaring a Public Health Emergency of International Concern (PHEIC) helps in raising awareness about monkeypox, along with improving surveillance.Excerpts:
Q: How effective are the smallpox vaccines against monkeypox since the Union health agency lacks data on vaccine effectiveness?
A: The evidence available from Africa in the 1980s suggests that the smallpox vaccine is at least 85% effective in preventing monkeypox. The effectiveness of the vaccine JYNNEOSTM (also known as Imvamune or Imvanex) is available from a clinical study on immunogenicity and efficacy data from animal studies. Not everyone needs a vaccine. Prevention, early detection, and isolation will control the spread.
Q: What differences do the Covid and monkeypox transmission modes have? Is the transmission rate of monkeypox more severe than Covid?
A: Monkeypox spreads by staying very close and/or by having prolonged contact with someone who has symptoms and this includes maintaining close contact, and coming into contact with contaminated materials such as towels and clothing, also spreads through respiratory droplets spread by prolonged and close face to face interaction. Human-to-human transmission can result from close contact with respiratory secretions, skin lesions of an infected person or recently contaminated objects. On the other hand, Covid spreads through tiny droplets in the air by breathing, talking, sneezing, or coughing and it is highly infectious and can spread even if an individual is infected with Covid, but does not have the symptoms. Although declared as a Public Health Emergency of International Concern (PHEIC) for spreading to newer geographical areas, monkeypox has a low transmission rate compared to Covid-19.
Q: If the cases of monkeypox increase, will India face another lockdown? Is there something to be worried about in the coming days?
A: There is no need for lockdowns as the mode and speed of transmission are different and the outbreaks can be contained with public health measures. There is uncertainty regarding the spread of monkeypox and coinfection with Covid. Spread to new geographical areas in a short span of time, implications of the potential interactions with other infectious agents can impact infectivity patterns, severity, management, and response to vaccination.
Q: Two people with no international travel history have tested positive for monkeypox in Delhi. Is it a sign that the virus has started spreading locally? Can we expect some asymptomatic cases of monkeypox in Delhi?
A: This is because of the long incubation period and lack of awareness in identifying the symptoms. Close contact with infected persons is also responsible for its spread. The persons remain infectious as long as the skin lesions are present. The extent to which asymptomatic infection may occur is unknown.
Q: Some experts have claimed that monkeypox has been around in India for a longer duration and currently, the country is witnessing a distinct cluster of human-to-human transmission that was possibly unrecognized for years. How far do you agree with this?
A: It is possible that low levels of sustained transmission preceded the 2022 outbreak in Europe. As researchers, we can only be informed by evidence. I commend the tenacity and research leading to the publication by Bani Jolly and VinodScaria. Their paper suggests that there is a possibility of sustained human-human transmission spread over multiple countries, not just within India. However, it is not really known why the disease is spread to more than 70 countries in a short period and if it could be linked to any genetic changes in the virus. Their study underlines the greater need for using genomic surveillance to uncover the unknowns and in supplementing epidemiological investigations. More studies can establish the details of the transmission chain and the reasons for its wider spread. Declaring PHIEC is helpful in increasing awareness, improving surveillance and leading to the wider availability of vaccines and diagnostics.
Q: India has already been facing a shortage of healthcare professionals. Is India ready enough to tackle the slow outbreak of the virus as there are no testing kits available so far?
A: There will be a strain on the health system if there is a greater burden but India can definitely tackle outbreaks. At this stage, we are not really sure if it is a slow-spreading limited outbreak or if there could be a high number of cases. Improving the surveillance and public health response will offer us data and confidence to manage this. The Government has accelerated the process for the development of vaccines and diagnostics for the disease. Given the success of rapid development and scale-up for Covid, there is no need to worry regarding the testing kits.
Q: Monkeypox has a very low fatality rate, is the A.2 strain more severe than from B.1 lineage? Which is the most vulnerable group?
A: There is limited information regarding clinical features and mortality associated with different lineages due to the absence of sequencing data for MPXV reservoir isolates from the earlier outbreaks due to orthopoxvirus. In a study published in the Democratic Republic of the Congo, the researchers document the clinical features and severity of four lineages circulating in the reservoir population after introduction into the human population. Lineages A and B resulted in predominantly moderate disease. Also, they found MPV-Z-N2R/OMCP deletion in Lineage B and was significantly associated with human-to-human transmission. Lineages C and D were associated with severe/serious disease. The results show that gene loss pattern with secondary transmission might indicate that monkeypox is fast adapting for efficient replication in humans.
High risk is when there is close contact with respiratory secretions, skin lesions of an infected person or recently contaminated objects. Healthcare workers, household members and other close contacts of active cases are at greater risk. Transmission can also occur via the placenta from mother to foetus or during close contact during and after birth. While close physical contact is a well-known risk factor for transmission, it is unclear at this time if monkeypox can be transmitted through sexual transmission routes.
Eating inadequately cooked meat and other animal products of infected animals, and living in or near forested areas constitutes low risk.
Transmission can occur from direct contact with the blood, bodily fluids, or cutaneous or mucosal lesions of infected animals. Many animals such as rope squirrels, tree squirrels, pouched rats, dormice, several species of monkeys and others can also be infected.
Q: As the Centre has constituted a task force to monitor the situation, are we expecting some severe cases of monkeypox in the future?
A: A taskforce is an essential governance mechanism to monitor and respond to the evolving outbreak. Collaborative efforts to step up epidemiological and genomic surveillance, improve the diagnostics and vaccine/drugs production and manufacturing capacity are essential for many zoonotic diseases in future.