Critical factors in future covid19 decision-making

THE EDITOR: At a White House briefing on April 23 the Undersecretary for Science and Technology at Homeland Security said initial lab findings showed “the virus is dying at a much more rapid pace from exposure to higher temperatures and humidity.”

This factor has fed the developing consensus in the US that covid19 will be seasonal and endemic, that given the number of susceptible people still out there the spread will continue in the summer months, though at a lower level than the first wave, before returning for a second fall/winter peak. Earlier studies support this conclusion.

A team from Sun Yat-sen University in Guangzhou, China, the heart of the coronavirus outbreak, studied every novel coronavirus case confirmed around the world between January 20 and February 4, including cases in more than 400 Chinese cities and regions.

The information garnered was modelled against official meteorological data from across China and the capital cities of each country affected. The analysis indicated that case numbers rose in line with the average temperatures up to a peak of 8.72 degrees Celsius and then declined.

The conclusion was that warmer, more humid weather would make covid19 less stable and thus less transmissible as has been the case for earlier coronavirus pathogens.

Other researchers have looked at virus spread in countries like Australia, Singapore, Thailand, and Malaysia and found the spread was different from that in Europe and the US, that most of the cases in warmer countries were related to international travel and very close contact – like partners and health workers.

According to the authorities, an estimated 20,000 people came to TT for Carnival festivities and another 20,000 just beat the lockout deadline three weeks later. Our 116 cases were all linked to international travel with only a single family of five people exhibiting local spread.

What does the foregoing mean for decision makers in TT as they contemplate easing the lockout and lockdown measures? For starters they must recognise that as commendable as the results of the measures taken to combat covid19 have been, the magnitude of success was greatly buttressed by not just the lockdown and lockout policies and practices pursued but also the fact that since the festive season TT has been experiencing unbearably hot and humid weather.

Next our decision makers must know when to veer away from the lock-step approach to management of flu viruses in TT. We use the same timeframes – fall and winter months – to delineate when to expect surges of respiratory illness in the country although we only have dry and wet seasons: We import flu vaccines which compositions comprise molecules to frustrate offending viruses that prevail in temperate climates, and we declare our flu season to be over when decision makers in temperate climates make such pronouncements.

The appeal here is for policymakers not to become locked in to adopting everything “they” do. We should not be talking about resurges or second waves; there is little evidence to support a first wave nor has the virus become endemic in TT.

Similarly, decisions about Carnival should not rest on availability and accessibility of a vaccine or success of lockdown policies. Neither was in place during the aforementioned periods of large population influxes and we survived relatively unscathed.

Climate is a large factor in predicting how covid19 performs. Future policies and practices must not diminish its importance. It will help frame more rational policies and practices as we disengage from current lockout and lockdown.

KENWYN H NICHOLLS

via e-mail