The various strategies laid out by experts in Pakistan are focused on a tiered approach whereby neighborhoods will be locked down and the extent of lockdown will be determined by the number of cases identified. These strategies miss the mark on one very important aspect: Locking down neighborhoods can create concentrated pockets of infection given that social distancing and hand hygiene cannot be enforced at such a micro-level. Additionally, 40% of the country does not have access to water and soap at home. These proposed ‘smart’ lockdown will, therefore, increase the probability of transmission of the virus to the most vulnerable population (elderly who are at home and those with chronic illnesses).
The issue of identifying what constitutes a neighborhood notwithstanding, let’s say a pooled test identifies a certain neighborhood where the infection is present. Further testing reveals the need for a lockdown- you lock down the area for 14 days but due to poor understanding of social distancing and hygiene- the virus keeps spreading in that neighborhood. You do a follow-up test after 14 days. You don’t find a positive test. The probability of this follow up test being a false negative is somewhere in the range of 0.25 to 0.30 (some have pegged it even higher). This might be due to poor viral load (early phase of infection) or low sensitivity of the kit. Either way, the uncertainty around opening this neighborhood is immense. So, are we going to continue to shut down these neighborhoods over and over again? Given the amount of deprivation that most of these neighborhoods face- we face a catch 22: data shows that deprived population is at a higher risk of dying from COVID-19 and simultaneously they face the health threats that emerge from poverty (which is the biggest precursor to poor health) as well as diseases of despair. So what is the point of the lockdown if it is not crunching the virus and is increasing the health burden due to forgone healthcare and income?
Through seroprevalence testing, we know that the actual prevalence of the disease is on an order of magnitude 30 to 85 times higher than reported cases in the west. Although antibody testing has its limitations given its specificity and sensitivity, these can be accounted for through rigorous methodology as well as through adding appropriate weights in the statistical analysis. The concerns around the accuracy of the test also abound when it comes to the RT-PCR test being used to identify people infected with SARS-CoV-2 but we have circumvented that problem through repeat testing and testing at different points during the incubation and disease phase. Furthermore, the antibody doesn’t capture those who fought off the virus without an antibody response, which means the prevalence may even be higher, it is still offering key insights. This higher prevalence is good news as it shows that we had grossly overestimated the fatality rate. Given our population density and strong person to person network- it would be fairly safe to assume that the prevalence is much higher than cases reported. This should also be obvious given our limited testing capacity. Lockdowns are effective because they create the necessary social distance required to reduce transmission and that too if implemented in the earliest phase of the epidemic. It is very difficult to ensure with accuracy the exact time when a viral epidemic of respiratory infection has started in a region. Positive tests are not the same thing as the incidence of the disease so what testing reveals is not the epidemic curve but rather (crudely speaking) number of tests done. By the time the first death was reported in NY- it had already been a month since the virus was in circulation.
The critical discussion of weak immune systems and chronic illnesses catching up to us in an acute infection should be at the heart of the public health discourse right now. The lack of promotive and preventive dimensions of public health will continue to deliver such crises in the future and even when those crises emerge we should remember that lockdown is not a real policy option. A lockdown makes sense if we are caught off guard and we are biding time to create policy solutions. Quarantine and selective isolation are the key public health interventions, not lockdown.
The virus has to complete its cycle- you can spread the deaths by flattening the curve but you can’t avoid them via lockdown. The way you can partially avoid them is through herd immunity that is achieved by exposing healthy individuals to the virus. Yes, some healthy individuals will have negative outcomes- but unfortunately, some healthy individuals will always have negative outcomes. We have to assess this risk against the day to the day background risk of life. The COVID-19 death risk in people <65 years old is equivalent to the death risk from driving between 13 and 101 miles per day for 11 countries and 6 US states. The younger you are the lesser the risk. Those who say that there is no evidence for herd immunity confuse what WHO has stated. The absence of evidence is being read as evidence of absence. We have enough precedent in terms of fighting off coronaviruses and other viruses to reasonably assume that herd immunity is the most likely outcome. If herd immunity is not possible then a permanent lockdown till we die of some other ailment is in order – as the implication is that vaccines would also be ineffective.
Based on the best data available we need to:
· Revisit pandemic models that were developed in a situation of limited data and critically identify their shortcomings instead of continuing to follow their results. Find updated international models to serve as a proxy for local policymaking
· Isolate those facing the highest risk (elderly, those with chronic conditions and immuno-compromised)
· Identify areas that can promote super-spreading of disease (mosques, bus stops) and institute social distancing mechanisms there. We need smart usage of law enforcement and our limited public health infrastructure.
· If the government wants to pursue a test, trace, isolate (not lockdown) strategy- the quality of the test has to be improved and the time for processing of the test has to be reduced drastically to isolate before further transmission.
· Isolation SOP’s (Standard Operating Procedures) need to be developed for the layman and should be tested before implementation.
· Roll back the lockdown by opening the society to the least at-risk population. The stronger the immune systems of those being exposed to virus the lesser the probability of transmission and the lesser the intensity of the illness. In this vein, keeping the schools closed is counterintuitive. Keeping the schools closed seems to be a political decision rather than a technical one.
· Start a nationwide educational campaign on public health spanning issues such as building a stronger immune system, social distancing measures, and hygiene.
· Start an educational campaign on the strategic and safe use of masks that avoids cross-contamination. Though there is mixed evidence on the efficacy of masks- they can be (if cross-contamination and a false sense of security can be avoided) a constant reminder to stay vigilant.
· Concomitantly, establish clean water units and start a countrywide soap dispensing campaign
· Poor immune system and spread of much of the infectious diseases in Pakistan can be attributed to poor sanitation. Improvement of sanitation facilities will make the population resilient towards infectious diseases and greatly reduce the overall burden of diseases in the country. Much of the increase in life expectancy over the last 100 years is attributed to non-medical public health interventions such as hygiene and improved sanitation.