Reports of influenza and a host of other infectious diseases have plummeted as the COVID-19 pandemic has driven people into lockdowns.
In many places, social distancing measures aimed at curbing the spread of the new coronavirus may be smothering the spread of other infectious diseases at the same time. But, in other places, the pandemic may simply be masking disease spread, as people may avoid seeking care for more routine infections while health care systems stretched thin by the pandemic may struggle to conduct routine, surveillance, testing, and reporting.
Some of the resulting declines are dramatic. Countries across the Southern Hemisphere have reported much lower numbers of influenza than usual. Australia, for instance, began 2020 with a relatively high level of flu—reporting around 7,000 lab-confirmed cases in both January and February. But the outbreak crashed in March, with reports of only 229 cases in April, compared with nearly 19,000 in April 2019, as noted by the New Scientist.