India’s COVID-19 puzzle: Part 2

Viruses like to play games They also behave like boomerangs coming back at you with consistency and force after a lull One look at the history of the deadly 1918 Spanish Flu and 2019rsquos Coronavirus pandemic and you know the above is trueThe Spanish Flu first appeared in early March of 1918 and had all the hallmarks of a seasonal flu But by April that same year it had spread through Italy Spain England and France From September through November cases skyrocketed Lasting two years it saw three distinct waves infecting 500 million and killing 20 to 50 million Experts believe that the fatal severity of the Spanish Flursquos second wave was caused by a mutated virusReceipt of fine issued by the BMC officialsWith the COVID19 pandemic India fared pretty well with a comfortable January and February 2021 after peaking in September 2020 recording more than a million active cases By the first week of February India was barely counting an average of 10000 COVID19 cases per day More than half of Indiarsquos states were not reporting even a single COVIDrelated death In a drastic turn of events a week later India saw a spike of nearly 87000 cases Maharashtra which has accounted for the bulk of Indiarsquos COVID19 cases is now contributing more than 50 per cent of the new cases The fear of a second wave loomsmdashare we in its grip already Is this the work of a mutant virusIt is difficult to say thinks Dr Jay Mullerpattan consultant pulmonologist PD Hinduja Hospital and MRC ldquoDifferent parts of our country have had their own set of waves Delhi has already seen three waves in Mumbai this is probably the beginning of the second wave We have observed that India has trailed a few months behind in comparison to whatrsquos unfolded in Western countries Even in the first wave our peak came two or three months after the US and UK Different parts of the country will experience varied dynamicsrdquoGraphicUday MohiteThe average per million testing for COVID19 in India is 162697 which means the country is on an average conducting 162 lakh tests for every 10 lakh people Is the surge due to an increase in testing then Dr Lancelot Pinto consultant respirologist PD Hinduja Hospital and MRC says ldquoOur hope that this isnrsquot a second wave comes from seroprevalence studies that suggest a significant population across the country has been already infected and the fact that we did not see second waves postDiwali or after New Yearrsquos Eve when people met and gathered in large numbers However we must remember that seroprevalence studies have not shown a uniform prevalence For example slums tend to have a higher prevalence than private apartments and the virtual end of the lockdown may cause new infections leading to a second wave The city of Manaus Brazil is a case in point they proclaimed a level of immunity that was being equated to lsquoherd immunityrsquo last year but experienced a shortage of oxygen during a second wave this year It is good to be optimistic not complacentrdquoThe percentage of individuals in a population that has antibodies to an infectious agent is called seroprevalence According to a survey conducted by a team of researchers at the Banaras Hindu University BHU the seroprevalence frequency in 14 Indian districts encompassing five states varied between 001 and 048 ldquoThis suggests a high level of variability among the regions The minimum antibody positive people were observed in Raipur district of Chhattisgarh whereas maximum antibody positive individuals were found in Ghazipur district of Uttar Pradesh The high prevalence of antibodies in many of the districts suggests that the soft herd immunity in India is underwayrdquo reports the BHU paper titled Estimation of realinfection and immunity against SARSCoV2 in Indian populationsGyaneshwar Chaubey and Dr Jay MullerpattanIndia is therefore not suffering from a second wave argues the paper which is submitted to medrxivorg and is yet to be peerreviewedGyaneshwar Chaubey is a professor of genetics at BHU and one of the main authors of this study A study conducted by him and a team of top genetic experts last year revealed that the Indian genes have protected the population against the Coronavirus In the recent study published on February 8 Chaubey again reassures India that all is well ldquoAt the moment there is a rise in the number of cases in some parts of the country However if you look closely it is not an exponential riseDr Lancelot PintoOutbreaks are being reported in places where less people have got immunity against the virus Letrsquos take the example of Kerala and a couple of countries that were deemed lsquomodelrsquo regions Like Kerala New Zealand southern Australian or European countries like Estonia managed well in the beginning People followed all the lockdown rules and therefore a majority of the population did not get infected by the virus Immunity in the population was very low These populations are now stepping out of homes and therefore most vulnerable to COVID19 They are the ones causing the resurgence of the infectionrdquo Chaubey explainsThe infection and death rate per million and the case fatality ratio in India remain substantially lower than many of the developed nations Several factors have been proposed including genetics One important factor is that a large chunk of Indian population is asymptomatic when carrying the SARSCoV2 infection Thus the real infection in India is much higher than the reported number of cases Therefore the majority of people is likely to be already immune in the country Chaubey writes in the paperPeople not adhering to social distancing norms despite surge in COVID19 cases buy vegetables at an APMC market in Solapur in February 2021 PicPTITo understand the dynamics of real infection as well as levels of immunity against SARSCoV2 his team performed antibody testing serosurveillance ldquoThe aim was to estimate the level of immunity against COVID19 among urban street vendors We picked vendors for our study since they tend to be the biggest carriers of the virus They come in contact with the homequarantined population and therefore we wanted to see if they have antibodies in themrdquo he addsDuring the months of September 2020 to December 2020 they surveyed such vendors and found out that all the participants in this study were asymptomatic they did not know that they ever had COVID19 ldquoThey all had antibodies in them This suggests that the number of real infections in India is several fold higher than thegovernment reported cases So we may need to reconsider the case fatality ratio The present case fatality ratio of India 144 is significantly lower than the global average 215 Considering our result which shows a far greater number of real infected people the actual case fatality ratio of India could in fact be at least 17 times lower It is therefore likely that most of the hotspots are saturated with the immune people The chance of a second wave is highly unlikelyrdquo the BHU paper concludesStudents leave for their hometowns after Pune authorities announced partial restrictions citing an increase in COVID19 cases in February 2021 PicPTIBut with five Indian states Maharashtra Rajasthan UP MP and Gujarat showing a sharp rise in cases how does team BHUrsquos argument hold Can we really rule out the possibility of a second wave ldquoThere have been relaxations in rules more people are permitted at gatherings and such events have been proven to be superspreaders across the world Lockdown fatigue has also lead to individuals indulging in risky behaviour including eating together with the consequent lack of a mask celebrating and crowding indoors All these could have contributed to an increase Once cases start piling up the nature of spread in epidemics tends to be exponential and measures need to be taken to flatten the exponential curverdquo Dr Pinto explainsInterestingly this second peak was predicted last year by a group of researchers in Pune A modeling study conducted by the Tata Consultancy Services Research TRDCC Pune in collaboration with health group Prayas had said that with the level of relaxation around that time the peak load on critical healthcare people requiring oxygen support ICU ventilators etc can be sustained until Octoberend The team developed a fine grained model and their analysis indicated that a significant number of people from Pune is still susceptible to the infection Dr Shirish Darak senior researcher at Prayas says ldquoThis is a Pune cityspecific model which basically takes into account peoplersquos movement It also provides what the different scenarios would be if we choose particular interventions to curb the spread of the virus in the city What we had predicted last year itself is that if we open up schools malls restaurants theatres etc a wave is likely to occur in March 2021 And that more or less has come truerdquoAccording to this study the way the epidemic will further evolve in these places will depend on the local dynamicsmdashsuch as demographic characteristics population density peoplersquos mobility and migration testing and quarantine interventions and societal compliance to preventive behaviours mask use social distancing not crowding Their model essentially created a digital twin of a particular area in this case a digital twin of Pune Their predictions for last year read ldquoOur analysis shows that different wards are at different stages of the epidemic By midAugust 2020 in some wards of Pune with crowded dense localities around 3540 per cent were already infected As against in some wards eg Kothrud Warje Aundh this proportion is likely to be as low as 15 per cent A majority of the infections is being seen to occur through household contacts Along with that longer interactions in enclosed and crowded places is likely to increase transmission risk places such as banks offices factories eateriesrdquoDr Ritu Parchure senior researcher at Prayas adds ldquoWhile we believe that this wave wonrsquot be as bad as the previous one a lot of people can expect to be infected this time aroundrdquoTwo weeks ago the Pune administration announced a night curfew in Pune district from 11 pm to 6 am With a steady rise in cases in the city the curfew has been extended till March 14Several factors influence whether a particular disease is seasonal in nature Some pathogens may spread less well in greater humidity Annual epidemics like influenza may occur because of climate or patterns of social mixingmdashoften driven by the school year or people staying inside more during the winter In this context what are the many factors responsible for Indiarsquos current surge Dr Pinto says that itrsquos clear that weather had not played a role ldquoThere is a theory that lower humidity and lower temperatures facilitate spread of the virus but this is a hypothesis Social mixing has definitely increased over the past few months and this is likely to have played a bigger role than the weatherrdquoSo what do the trends in diagnoses and deaths mean for the future course of the pandemic in India ldquoMortality trends as expected lag behind infection trends by a few weeks With an increase in the number of cases it will be interesting to see whether there is a commensurate increase in the number of hospitalisations and more importantly deaths If for example the latter do not rise despite the former rising we could be dealing with a milder version of the virus this time and that is reassuring If that isnrsquot the case we will have to brace ourselves for circuitbreakers and focal lockdowns to help flatten the curverdquo Dr Pinto thinks That the vaccination drive has gained momentum in Phase 2 with private hospitals roped in and senior citizens showing little vaccine hesitancy will help ldquoStrategically if we could prioritise those who havenrsquot been infected with COVID19 and are in a highrisk category it would significantly ease the healthcare burdenrdquo he addsThe 188992 influenza outbreak had three distinct waves which differed in their virulence The second wave was much more severe particularly in younger adults On the other hand the proportion of 1918 H1N1 influenza pandemic patients who were severely ill or died was much higher in the last two waves compared to the first More recently the 2009 H1N1 influenza pandemic though mild had two distinct waves this virus still commonly shows up in seasonal influenza outbreaks A study of H1N1 influenza in 20092010 revealed that the second wave affected more older people with underlying conditionsSo what is the trend of transmission of the current COVID19 pandemic in India ldquoMortality wise the elderly are more susceptiblerdquo Dr Mullerpattan warns hinting at one of the reasons why Maharashtra could be ahead of other Indian states in numbers The state has a large senior population and is the most urbanised in India two key factors in higher COVID incidence ldquoBut as we see with the opening up of lockdown the younger crowd is likely to go outdoors and socialise Itrsquos expected that the younger might get affected toordquo Dr Mullerpattan warnsHe may be right In the US the average age of those infected is falling complicating predictions about a death toll What is the age group that needs to be most cautious in India right now then ldquoEverybodyrdquo is Dr Mullerpattanrsquos simple responseFor now the UK and the US cases are showing a slight downward trend compared to what they were in December and January ldquoIn early March their numbers are lower but some countries like South Africa and Brazil are still showing a high case load A lot of countries in Europe are announcing lockdowns again including Sweden The Netherlands has imposed a strict lockdown In comparison in Southeast Asia the number of cases isnrsquot that highrdquo he addsExperts think that arguing about whether India is in the second wave could be a waste of time According to the guidelines released by Lisa Maragakis MD MPH an infectious disease specialist at the Johns Hopkins Medicine itrsquos smarter if countries prepare for a spike or second wave in respective regionsldquoContinue to practice COVID19 precautions such as physical distancing handwashing and maskwearing stay in touch with local health authorities who can provide information if COVID19 cases begin to increase in your city or town make sure your household maintains two weeksrsquo worth of food prescription medicines and supplies at all times in case of a lockdown and work with your doctor to ensure that everyone in your household especially children are up to date on vaccines including this yearrsquos flu shotrdquo Maragakis suggests