While some people hope that outbreaks of the new coronavirus will wane as temperatures rise, but pandemics often don’t behave in the same way as seasonal outbreaks, reports BBC in an investigation conducted by BBC Future.
Many infectious diseases such as flu, typhoid, measles etc. wax and wane with the seasons. Considering the nature of coronavirus infection, many people are now asking whether we can expect similar seasonality. Since it first emerged in China around mid-December, the virus has spread quickly, with the number of cases now rising most sharply in Europe and the US.
Many of the largest outbreaks have been in regions where the weather is cooler, leading to speculation that the disease might begin to tail off with the arrival of summer. Many experts, however, have already cautioned against banking too much on the virus dying down over the summer.
And they are right to be cautious. The virus that causes Covid-19 – which has been officially named SARS-CoV-2 – is too new to have any firm data on how cases will change with the seasons. The closely related Sars virus that spread in 2003 was contained quickly, meaning there is little information about how it was affected by the seasons.
But there are some clues from other coronaviruses that infect humans as to whether Covid-19 might eventually become seasonal.
An unpublished analysis comparing the weather in 500 locations around the world where there have been Covid-19 cases seems to suggest a link between the spread of the virus and temperature, wind speed and relative humidity. Another unpublished study has also shown higher temperatures are linked to lower incidence of Covid-19, but notes that temperature alone cannot account for the global variation in incidence.
Further as-yet-unpublished research predicts that temperate warm and cold climates are the most vulnerable to the current Covid-19 outbreak, followed by arid regions. Tropical parts of the world are likely to be least affected, the researchers say.