The number of New Zealanders catching the flu has dropped by 87 percent

Data from the Southern Cross Medical Library has seen an overall 65 percent decline in a dozen of its usually prevalent infectious diseases - such as tonsillitis, strep throat and glandular fever.

Chief Medical Officer Dr Stephen Child says it directly corresponds to the Covid-19 lockdown and the social distancing and hygiene practices we've all adopted.

He says infectious diseases are a huge burden on the health system.