More cases of the gastro bug cryptosporidiosis have appeared in Blenheim, with the focus now on early childcare centres, the Nelson-Marlborough medical officer of health says.
Andrew Lindsay said it follows confirmation of the diarrhoea disease in 27 people who swam at Blenheim's Stadium 2000 pool last month.
The pool was temporarily closed after cryptosporidiosis was confirmed.
Dr Lindsay said it was possible that seven further people had contracted the illness from other people who became unwell after swimming at the pool.
He said public health was now seeing further spread of the infection among families and those working or attending early childcare centres.