Is reopening safe post COVID-19 case clustering?

 E-mail: farukh.arjmand18@gmail.com

COVID-19 pandemic has taken a heavy toll on  human life and  economy   .Many countries are desperately  looking for  ways to restart their economies and ease their lockdown. People are also eager to start their normal routine life which was suddenly put to a halt since the outbreak of coronavirus in Wuhan,  China in early February 2020 which was linked to a  bizarre food market . Many countries that were hit early by COVID-19, China, South Korea, New Zealand etc have already opened up and relaxed the stay-at- home rules while social distancing and protection gears are being strictly followed. While these countries began easing lockdown restrictions due to decline in new COVID cases to single digits, new cases started re-emerging. Both  China and New Zealand  were declared coronavirus free  by  June 20 without  a locally transmitted case of COVID-19,  however,  this  relief   was  short-lived as new cluster  of cases  emerged in Beijing last week (137 new cases emerged over past  six days ) . On 6^th of May, 29 -year old man was tested positive for SARS-COV-2   after visiting five dance clubs in one night in Seoul’s Itaewon district which later communicated to 96 other club goers who got COVID-19. On 8^th may South Korea responded quickly, postponing plans to reopen schools and urging bars and clubs to shut down again for a month. Therefore, we need to carefully study these kinds of transmission clusters to avoid U-turns and backlash of lockdown restrictions.

There are some interesting trends which were observed by a team of London School of Hygiene and Tropical Medicine, who compiled a database of 231 known COVID-19 cluster cases .  A list of these  trends has been listed  here to  unravel the risk factors.

1. Indoor  settings  dominate partly because the virus  hit during  winter  and  people spent most of the time  indoors which helped dissipate virus particles exhaled by infected person .Therefore, households are most common place for transmission accounting for 15 percent , or 38 of 231 cluster cases.

2. No cluster cases have been linked to eating itself, while sharing food or utensils could pose a risk for infection.

3. The largest known clusters occurred in ships (Diamond Princess cruise ship and USS Teddy Roosevelt aircraft carrier), food packing plants and prisons.

4. Dormitories in Singapore where migrant workers live in cramped conditions saw large number of infections.

Keeping in view of these high risk places, we will have to pay more attention to the places where people live in close quarters over long periods of time. Further, clusters were foundto be associated with indoor sports. In cluster case of 112 cases from Zumba classes in Cheonan, South Korea, pilates and yoga instructor as among those infected but he did not pass the infection to others. High intensity sports that involves heavy breathing in confined spaces could be a prime spot for transmission while   yoga or lower intensity activities might not be risky for transmission. Crowded restaurants are also believed to lead to cluster transmission to customers.  For example, in Guangazhou restaurant, one sick person infected nine others. Air conditioning units cooled different zones and one unit blew directly over the three tables where COVID -19 cases arose assuming that AC may have blown respiratory droplets over to other tables

Since we are going to resume offices, utmost care should be taken to social distancing in commercial offices and residences.  Serious cluster cases in South Korean call centre have revealed  how COVID 19 can emerge in mixed commercial and residential  areas , out of the 1143 people tested ,97 were positive for SARC-Cov-2 . Employees sat side by side and  were  talking on phone for long shifts while 94 patients were on 11^th floor of the building. Keeping tables or desks atleast six feet apart, with plexiglass barriers between tables is highly recommended. The CDC has released reopening guidelines for everything from restaurants to water parks which is highly recommended for  reading  and practise.  

Having claimed almost half a million lives worldwide, COVID-19 has descended the entire world into chaos. This is an unusual situation and it can only be battled successfully with cooperation from all of us.