Targeted mitigation strategies for halting COVID-19 hotspots

The coronavirus has incited panic worldwide. Now, all countries are fighting a global war against this one tiny enemy. Despite cancellations and lockdowns, the virus is still spreading in India. One question that frequently appears in many people’s minds is whether the country is about to hit the “peak” for cases of COVID-19. That kind of rapid surge tends to start in a few “hotspot” regions because of rapid community transmission and limited mitigation. The peaks are associated with catastrophe, much like the situations in Italy, Spain, the USA, China and other countries.

To avoid these devastating peaks, cities and communities are desperately looking to “flatten the curve” in hotspots or potential hotspots. If the cases are more spread out and consistent over time, the medical system does not get overwhelmed with sudden surges of positive cases at once. Additionally, a flatter curve permits more time to prepare better healthcare plans.

Currently, there is no vaccine available for combating this deadly virus, which is why it is important to ensure that healthcare providers do not become overburdened. The virus mainly spreads from person-to-person or within crowded places via airborne droplets from coughs, sneezes, spit, laughter or talking. It can also transfer from infected surfaces such as objects, phones or doorknobs. It actually spreads more from asymptomatic (no visible signs) than symptomatic (visible illness signs) people.

Mild or serious symptoms may appear within three to 13 days after exposure. The most common symptoms are loss of smell, fever, dry cough, shortness of breath, fatigue or body pains; these can eventually progress to serious lung damage and death. Not all people have the same responses because symptoms depend on level of immunity and pre-existing health issues. This is why the disease is more often fatal for older people and adults with medical conditions such as diabetes, cancer and cardiovascular, kidney or respiratory ailments.

Multifaceted public health interventions, such as total lockdown of hotspots or extension of lockdowns and strict implementation of health advisory (social distancing, stay home, good hygiene, etc.), are associated with improved control of transmission and help flatten the curve of cases. A highly coordinated effort between the government, the public and medical providers is essential for achieving these goals, as per the emerging data from corona outbreaks. This is a social paradigm shift for rapid control of the infection, like seen in South Korea. Hence, strong and competent leadership can make all the difference in flattening the curve. On this front, India did a commendable job with early lockdown and cautious extensions. However, the mitigation efforts cannot be eased just yet, due to risk of a potential “rebound” surge.

Scientifically designed curve strategies (see Figure) are proven to diminish the impending coronavirus surge. Based on the positive hotspots and potential for imminent surge or transmission, urban communities or towns can be designated into coloured zones: red (high risk or uncontrolled surge), orange (moderate risk) and green (mild risk).

Several models have used international cases to extrapolate the relationship between cases versus mitigation efforts. According to scientific papers on public health interventions, the two universal, targeted mitigation plans that can reduce the outbreak and flatten the curve are: widespread testing and quarantine; and social distancing.

Widespread testing and quarantine are the goldstandard for healthcare response. The most accurate test uses RT-PCR to detect viral RNA in throat and nasopharyngeal samples, but this is a relatively slow test, requiring about two to three days to detect viral shedding. A faster, antibody-based test was recently approved, but its accuracy is inconclusive, as per the US Medical Academy report. The antibody test itself takes just minutes to perform, but relies on detecting IgM- and IgG-class antibodies, which are produced three to six and 10-18 days after infection, respectively. Since current testing requires time to obtain accurate results, all suspected cases as well as their close contacts should be quarantined to limit potential viral spread while waiting on-test results.

Social distancing, which means minimising close contact with others, is just as critical to slow the spread of coronavirus. Despite their daily-life limitations and immense economic impact, such measures are able to halt or significantly delay the surge of cases and the death toll overall. Social distancing, alongside other holistic health practices like washing hands and wearing masks, is the most reliable method in communities to halt the spread. These strict prevention efforts can have exponential benefits because preventing even a single new infection can mean avoiding dozens or even hundreds of infections later on.

Despite the risk, many people will need to go to public spaces at some point, to buy food or for other essential reasons.A simple way to limit infection risk during such times is to always wear a mask (preferably N95) when outside. Even people without symptoms may still carry the virus and account for a significant amount of transmission, which can be partially protected against by wearing a proper mask. Keep in mind, however, that an ordinary mask alone does not offer complete protection because there are other methods of infection.

Hospital N95 masks are the best defense against the virus; they have higher filtration efficiencies than surgical masks and home-made fabric masks. The “N95” rating means masks can filter at least 95 per cent of aerosol particles larger than 0.3 microns. A single COVID-19 virus particle is between 0.05 to 0.1 micron, but the particles usually cluster in groups of five or more, making the N95 mesh capable of filtering them. Thus, when available, N95 or equivalent masks provide significant defense from contacting the virus.The efficiency of home-made fabric masks to stop viral spread is uncertain, as per the US Medical Academy. Fabric masks can reduce the transmission of larger droplets, but not of small aerosolized particulates in the 0.3-micron range.

This epidemic will continue for many months or even years, say many experts. Social distancing measures will likely continue for a similarly long time. The eventual end of social distancing measures will depend on how effectively nations and states follow mitigation measures.The worst projection of social distancing is for one to two years until we find a vaccine for this virus. However, if we ease up on mitigation strategies during this time and allow the virus to circulate for many years, it will eventually infect people in a new cycle at reinfection hotspots, and a new period of isolation would start again.

Overall, if we follow scientific guidance well, we will surely contribute to the end of this epidemic. However, if we stop trying or become indulgent, we might remain in catastrophe. So, please stay healthy, stay home, and stop the spread.