Next pandemic: Marburg, Ebola or Bird Flu?…Dr Rana Jawad Asghar

The title is misleading, as the current pandemic has not ended yet. Yes, reported cases have decreased substantially, but this is due to decreased testing. People with apparent symptoms of Covid19 now are not opting for lab testing. This is a global trend and a natural consequence of a pandemic in its fourth year. In early 2020, SARS-COV-2 (virus that causes Covid19) was a novel virus for our bodies which had no experience of dealing with this new virus. Similarly, our doctors and health systems had very little information about risk factors, treatment options and control strategies. But now nearly everyone on this planet has had at least one bout of infection or vaccination. So now our bodies have learned defence skills to deal with this new virus.

But SARS-COV-2 is beating the odds and churning out its variants and subvariants at a phenomenal speed, which significantly escapes both natural and acquired (vaccine) immunity. But still, hospitalisations due to Covid19 are at their lowest in a long-time, showing resilience in our bodies and better treatment protocols. Unless a new variant can escape completely from these defences, we will be at a manageable level for Covid19. A recent subvariant, XBB 1.16, which is more infectious and has been found in two dozen countries, including India, is under watch. Covid19 is still deadlier than flu.

But microorganisms are not waiting for the conclusion of this pandemic to start a new pandemic. With population explosion, climate stress, deforestation and mobility, the world has now converted itself into a big pot of brewing infections capable of spreading like a pandemic. Its no surprise that before 2009 there was no sign of the highly deadly fungus candida auris. But it simultaneously emerged from different corners of the world, with some distinction that we know that each evolved independently of the other.

Ebola is a deadly virus that may kill 25-90% of those infected. It was identified forty 40 ago in Congo and has since caused multiple outbreaks in different countries. Its reservoir is in fruit bats, chimpanzees, gorillas, monkeys and some other animals. Once a human is infected, human to human transmission happens through soiled clothes, bedding, blood and bodily fluids. Most of these outbreaks have happened in Africa, but small outbreaks have happened elsewhere too, linked to travel. The danger in developing countries is that with dismal infection control practices in hospitals, there is huge potential to start major outbreaks locally.

Marburg is as deadly as Ebola, and it has started two new outbreaks that are a matter of concern. Multiple countries, including the US and the UAE, have issued alerts. Though both Ebola and Marburg could kill most who have been infected, they still may not start the next pandemic as they are not airborne like Covid19.

Public health experts were worried about bird flu even before the Covid19 pandemic. It is widely believed that the 1918 pandemic was caused by some type of bird flu. It has the potential to cross species and infect humans and different animals, so controlling it will be difficult. Recent outbreaks of Avian (bird) flu H5N1 have killed hundreds of millions of chickens around the globe, which is one reason why the prices of poultry and eggs have recently gone up. It has already spread to 80 different species of birds and has also killed mammals like seals, dolphins, otters, foxes and dogs. Human transmission until now has been rare, but it has infected around 1,000 people, and half of them have died in the last 20 years, including a few in Pakistan. The danger is in a new variant that may be more successful in human-to-human transmission. An annual flu vaccine is recommended, especially for the elderly and vulnerable.

But as we saw in 2020, instead of a deadly variant of flu, a completely new virus evolved to start a pandemic, killing around 15 million people. As public health professionals, we could keep an eye on potentially pandemic producing viruses, but a totally new virus could also beat them and start a pandemic. The only defence is to set up effective health intelligence and response systems. No weaponry or army could save us from viral threats. Lets understand the reality and get ready for it.

Courtesy The Express Tribune, April 15th, 2023.