As countries in the northern hemisphere hard hit by the novel corona virus cling to the hope that warmer weather will bring about a relief and a slowing down of the pandemic , what do the coming winter months hold for countries in the southern hemisphere as they approach their winter months?
Effect of temperature on coronavirus
Scientists do not currently agree on how, air temperature seems to play a role in the transmission of the corona virus. A 2007 research paper published in PLOS Pathogens was one of the first studies to demonstrate how the aerosol spread of influenza virus was dependent upon both ambient relative humidity and temperature.
As the corona virus (COVID-19) began to spread across the world, a group of researchers from the US and Iran found that the coronavirus disease (COVID-19), caused by SARS-CoV-2 had significant community spread in cities and regions along a narrow east- west distribution.This was roughly along the 30-50 N degree corridor.Of particular note was the consistently similar weather patterns in these regions. The average temperature being 5-11 degrees Celsius and an absolute humidity of 4-7g/m3.
The type of spread that was seen in this region was much more significant than what was seen in locations with higher populations and areas with more extensive interaction with China.
This would explain why at the start of the pandemic the virus went from China to Iran skipping more densely populated regions like India. It must be pointed out though ,that cases have sprung up everywhere because of the world’s interconnectedness through travel,however a more forceful growth of cases seemed to be in that zone during the early phases of the pandemic.
In new research from MIT, which used data compiled by Johns Hopkins University, the researchers confirmed that the maximum number of coronavirus transmissions has occurred in regions that had temperatures between 3 and 13 °C during the outbreak. In contrast, countries with mean temperatures above 18 °C have seen fewer than 5% of total cases. This pattern also shows up within the US, where southern states like Texas, Florida, and Arizona have seen a slower growth rate than northern states like Washington, New York, and Colorado. California, which spans north and south, has a growth rate that falls in between.
The African situation
As temperatures begin to cool in the southern hemisphere, the same scenarios being played out in the northern hemisphere may be repeated if environmental temperatures have an effect on the virus.
Africa has had a few months head start in this pandemic. We have watched the effects of the Covid-19 in countries in the northern hemisphere and hopefully have learnt enough to see that we may be in a more precarious situation than developed countries.
The public health interventions taking place world wide are meant to flatten the curve– that means to prevent a lot of people from getting very sick at once and therefore overwhelming the health system. But this obviously assumes access to good healthcare in the first place.
In much of Africa, public healthcare is inaccessible to a huge proportion of the population. The African health system is already under strain from endemic infectious diseases and the emerging non infectious diseases. Africa also battles with high HIV infection rates, with more than a third of HIV-infected Africans unaware of their status and therefore not on suppressive medication, and immunocompromised.Governments heavily rely on donor funds to support the health care systems.Unless there is a miraculously fast overhaul of the continent’s healthcare system, flattening the curve will be an impossible feat once the corona virus takes a greater hold in the continent.
The current primary prevention measures of social distancing,hand washing , banning of large groups of people must continue. However in a densely populated continent where many people live in close quarters and do not have access to running water this will be a great challenge.
What does this mean for Africa
Africa has to take more stringent measures than developed countries have done. Africa can not afford to take a lackadaisical approach to mitigating the effects of covid-19. As policy makers draw up plans on the way forward.They must bear in mind that our situation may be worse in winter and should therefore plan for measures lasting till summer.
The corona virus has an incubation period of up to 14 days so whilst the situation on the ground may appear calm, it is important to know that at the microscopic level the covid 19 is quietly multiplying. Recent modelling based on data from China shows that asymptomatic carriers of the covid-19 may have been responsible for its initial rapid spread there.Therefore Africa can not afford to rely on temperature readings and symptoms when screening travellers from high risk areas. Allowing people from high risk areas to determine for themselves whether they will self isolate or not could have dire consequences for the poor African and our poor health care systems.To survive Africa must nip this scourge in the bud.
By Dr.K Nkanza-Kabaso
The author is a medical doctor specialized in Public Health