Coronavirus: distancing delivers knockout blow for flu, measles

The incidence of influenza, chicken­pox, measles and a host of other diseases has plummeted.

Professor Sanjaya Senanayake says the fact that many children did not attend school for much of March and April was ­likely to have been one reason for the drastic reductions in the incidence of many diseases.

The incidence of influenza, chicken­pox, measles and a host of other communicable diseases has plummeted as social distancing breaks the chains of transmission.

There was an average of only six laboratory-confirmed cases of flu diagnosed daily in April, a fraction of the 623 daily cases confirmed this time last year.

Health Department figures also show that incidence of chickenpox, measles, mumps, menin­gococcal, whooping cough, pneumococcal and Qfever have been slashed.

Prior to the introduction of ­social-distancing measures, there were fears that Australia was on track for a severe flu season, with 244 cases being confirmed each day in February. In March, as ­social-distancing measures took effect, the number of laboratory-confirmed cases of flu dropped to 181 a day, and by April the number of diagnosed cases was minuscule.

“The reduction is dramatic,” said La Trobe University epidemiologist Hassan Vally. “It’s clearly as a result of all of the social-distancing measures we’ve got in place, and also that the uptake of the flu vaccine has been amazing for this point of the year.

“People are getting the vaccine, they’re not coming into contact with each other, they’re washing their hands, and that’s having a huge effect on the rate of laboratory-confirmed flu.”

The demand for the flu vaccine has been so high that many GP surgeries have run out of stock. The federal government this week secured an additional three million doses of the seasonal influenza vaccine, bringing the total number available this year to 16.5 million.

Almost 800 people died of influenza in Australia in 2019, and more than 4000 people were hospitalised in what was one of the most severe flu seasons on record.

As well as the dramatic drop in flu cases this year, the spread of other dangerous diseases has been halted. There were 21 cases of measles confirmed in Australia in January, but by March and April that figure was zero. That compares with 45 in March last year.

There have been only 34 cases of chickenpox so far this April, compared with 270 in April last year. The number of cases of whooping cough this month is 141, compared with 793 last April.

And the number of cases of pneumococcal disease so far this April is 34, compared with 164 cases confirmed last April.

Infectious diseases specialist at the Australian National Univer­sity Medical School, Sanjaya Senanayake, said the fact that many children did not attend school for much of March and April was ­likely to have been one reason for the drastic reductions in the incidence of many diseases.

“We know with influenza, children are major drivers of community transmission,” Dr Senanayake said. “I think if schools go back, schools will be big drivers of these non-COVID respiratory virus infections.”

But Professor Vally said it was possible the incidence of many infectious diseases might be reduced on a long-term basis in Australia as a result of the COVID-19 pandemic. “I think our whole society is going to be forever changed as a result of this pandemic,” Professor Vally said.

“I think one of the messages that probably has always been communicated when we’re in the flu season is for people to really look after themselves and the rest of the community by making sure they’re isolated if they have symptoms, making sure they wash their hands a lot.

“All of those messages may not have cut through previously, but now I think people are going to ­realise the importance of those ­hygiene measures and those isolation measures in terms of protecting themselves and others from disease.

“If I was to guess I would suspect that we are going to change our behaviours from this point on. To what extent it reduces these other diseases in the long term is going to be a really interesting question.”