NEW DELHI: Ashish Sharma, 30, was infected with Covid-19, not once or twice, but four times in the past two years. As he was struggling to regain his strength and health back, he was infected with swine flu earlier this year. “It is as if the viruses have found a perfect host in me,” joked the Delhi resident, who has been falling ill too often in the past two years or so.
The IT professional, after suffering for so long from various health issues, may be trying to put up a brave front by joking about his situation. But in the past two years, especially after the Covid-19 pandemic, many, including children, have complained that they have become more susceptible to illness.
Last year, a survey by LocalCircles, India’s leading community social media platform, said that one in three Indian parents said their children have fallen sick with flu or respiratory symptoms four or more times post Covid. The study said that although children fall sick a couple of times during the year due to changes in weather, the frequency of these illnesses appears to be rising since early 2022 – after the third Covid-19 wave in India.
The reason people are falling ill too often could be due to a cocktail of viruses — from Covid-19, Influenza and H1N1, to dengue and Chikungunya. It is not that people were not falling ill earlier, but of late, it is too often, and their ailments, combined with weakness or even a wracking cough and cold, last longer.
Dr Sunil Rana, associate director of Internal Medicine at Asian Hospital, Faridabad, agreed that we are seeing the emergence of many viruses. He said that people are falling ill so often not only because of new and existing viruses but due to various other reasons like a high-density population, poor hygiene practices, low vaccination rates and weather, which are conducive to the survival and spread of the viruses, by increasing the risk of infection and weakening of the immune system.
Dr Randeep Guleria, chairman of Internal Medicine, Respiratory and Sleep Medicine, Medanta, Gurugram, said, “We are detecting more new viruses now, partly due to improved diagnostic tools and awareness.” The former director of the All India Institute of Medical Sciences (AIIMS) said it is essential to remain vigilant.
“Many of these viruses and bacteria have the potential to cause outbreaks or pandemics, especially since we lack potent anti-viral treatments for many viruses and face growing anti-microbial resistance in bacteria,” he said. “Moreover, human encroachment on animal habitats is causing more viruses to jump species. Viruses previously restricted to animals, such as bats or birds, are evolving and adapting to humans, enabling human-to-human transmission,” added Dr Guleria.
So, what is a virus, and why is it so deadly? Viruses are germs or pathogens that can infect you and make you sick. They can infect humans, plants, animals, bacteria and even fungi. According to a paper by the National Institutes of Health, “A virus is a small microorganism that must infect other cells to replicate.
When a virus enters the human body, the immune system responds by producing antibodies, neutralising it and preventing transmission from the infected person. However, some viruses have evolved ways to evade detection by the human immune system, allowing them to spread undetected until they reach epidemic levels.”
In the past four years, the coronavirus has emerged as the most well-known virus that has had a catastrophic effect on the world, and new variants and sub-lineages are still being detected. Emergence and re-emergence of viruses not only threatens the population but also the healthcare settings in India.
Professor Anil Kaul, director of the Indian Institute of Public Health (IIPH), Hyderabad, and head of Dr Cyrus Poonawalla Center for Infectious Diseases and Pandemic Preparedness Centre, Hyderabad, Telangana, said that viruses and bacteria have been around much longer than humans. Their only purpose is to survive and propagate, and they will do whatever possible to do that.
“Although new or emergent viruses are generally very virulent, their virulence is limited by several host factors, including our natural immunity. If we have been previously infected by a pathogen similar to the emergent one, we may also benefit from cross-immunity,” he said.
What should also be kept in mind is that nearly all emerging viruses, including dengue, Nipah, West Nile, Zika, and coronaviruses, have zoonotic origins, indicating that animal-to-human transmission constitutes a primary mode of acquisition of these diseases, he pointed out.
In August, the World Health Organisation (WHO) updated its list of the ‘most dangerous viruses and bacteria’ that could trigger the next pandemic. The number of pathogens listed has grown to more than 30, including the Influenza A virus, dengue, and Mpox, previously called monkeypox.
The latter caused the World Health Organization, on August 14, to declare a global public health emergency for the second time in two years. The announcement came following an outbreak of the viral infection in the Democratic Republic of Congo, that is fast spreading in neighbouring African countries.
India has also reported its first case of Mpox clade 1b, the fast-spreading and severe viral strain, from Kerala. Sweden and Thailand are the two other countries that have reported clade 1b detection outside Africa. The WHO said that the list of ‘priority pathogens’ will help organisations decide where to focus their efforts in developing treatments, vaccines and diagnostics.
The priority pathogens were selected for their potential to cause a global public health emergency, such as a pandemic, as they are highly transmissible and virulent, and there is limited access to treatments for them. Increasing urbanisation and globalisation, with increased international travel and trade, and climate change, also increase the likelihood that the threat of emerging pathogens will continue.
Factors such as deforestation and habitat changes can also impact how one can come in contact with wild animals and consequently promote virus emergence, said Professor Kaul, who is also the former clinical professor and programme director of Global Health at the Oklahoma State University and Senior Public Health Advisor, US Department of State.
According to Dr Rajeev Jayadevan, co- chairman of the National Indian Medical Association (IMA) Covid Task Force, we are not only under threat from emerging pathogens such as Zika, Nipah and Ebola but also existing pathogens that are undergoing resurgence due to multiple reasons. He said that viruses that cause infectious diseases can either emerge cyclically, like in the case of Covid-19, or become seasonal, like influenza. “With international travel becoming accessible to all, the spread of such diseases can occur rapidly between continents and countries,” he added.
What also adds to the problem is that many viruses causing disease in developing nations are mosquito-borne. “With climate change and inadequate measures for vector control, mosquito-borne viral diseases have become amplified in the past three years,” Dr Jayadevan pointed out.
He said that unless effective vector control measures are undertaken throughout the year, there could be many more people falling ill and also dying in the future. “Climate change has a role not only in facilitating the growth of vectors such as mosquitoes but also in augmenting the activity and spillover of certain viruses.”
However, he said, the pandemic has taught the world the need to be alert and work together against common enemies such as dangerous viruses. “It is because of the speed of our actions that millions of lives were saved during the pandemic.
Since these infectious diseases do not respect national or international boundaries, and with increased globalisation, trade and travel, strong international cooperation and coordination will be essential in combating them effectively,” said Prof Kaul.