The novel coronavirus (Covid-19) outbreak, recently declared a pandemic by the World Health Organisation, has taken the world completely by surprise, with governments across the globe scrambling to contain the spread of the virus. Whilst hopes for a vaccine in the immediate short-term are faint, advances in medical technology have enabled us to develop an understanding of the virus with unprecedented speed.
Just two months after the virus first appeared China, the causative virus was identified, its genetic makeup was determined and detection methods were optimised.
Despite these rapid advances, there still remains a great deal of uncertainty. Scientists don’t yet fully understand its transmission route, although person-to-person transmission, through inhalation of droplets in the air, appears to be the most common mode. Other transmission routes have been identified however. Another uncertainty is its low detection rate, especially with mild or asymptomatic cases. A third is how weather might affect transmission.
Currently, Africa has very few cases of Covid-19 compared with most other parts of the world. The highest number of cases have been reported in Egypt (currently 126 cases), but it remains unclear why this is the case.
There is speculation that the virus has not spread because it cannot thrive in warmer regions, like much of sub-Saharan Africa.
The environment and respiratory virus transmission
Among the several environmental factors that influence the survival and spread of respiratory viral infections, air temperature plays a crucial role. Cold weather makes the respiratory system sensitive to infections. This is why people tend to suffer from respiratory infections during cold winter months. In tropical climates, influenza and respiratory viruses are transmitted more during the cold rainy seasons.
Despite the uncertainties surrounding its spread, the SARS-CoV-2 virus may be following this pattern.
Other members of the coronavirus family have displayed a certain degree of sensitivity to weather patterns. For instance, cases of the Severe Acute Respiratory Syndrome (SARS) were 10 times higher in lower temperatures than higher ones.
However, the effect of air temperature is also related to other factors, such as relative humidity as these viruses prefer low humidity.
Also, the Middle East Respiratory Syndrome (MERS) coronavirus was stable in air at low temperatures which could favour its spread. Despite this, the virus did not observe a seasonal trend but rather occurred sporadically. Other factors, such as animal (camel-to-human) transmission and weakened immune systems, also favoured its spread.
African countries need to prepare more
Now that the virus has made its way into Africa, countries on the continent need to be more prepared for greater action to contain the virus, especially if it follows a seasonal pattern.
For example, the peak circulation of flu in South Africa is in the winter season between April and July. In Senegal, the peak season is in the rainy season, from July to October. Many other African countries experience these peaks during the cold rainy season. This could mean that the preparedness of most African countries may soon be tested when these seasons come, especially as many more countries are confirming imported cases into the continent.
African countries need to strengthen their capacity in terms of identifying new cases. Healthcare facilities and personnel need to be well equipped to manage identified cases. The general public needs to be sensitised on how to go about getting medical attention if they suspect any signs or symptoms. Personal and household hygiene practices using detergents, such as bleach, need to be encouraged to prevent possible environmental transmission.