Monthly Notifiable Disease Surveillance Report - Jan 2019

Enteric Diseases: Enteric infections are the most common notifiable diseases, and several are increasing in incidence. This increase is partly due to changes in laboratory testing practices with a shift from culture methods to multiplex PCR, which tests for several diseases at the same time. This means more diseases are likely to be detected and in a more timely manner. For further information, see the 2016 Annual Notifiable Disease Report Commentary.

Campylobacteriosis: There were 951 cases of campylobacteriosis notified in January 2019, compared with 727 cases for the same month in 2018. The increase occurred in the first half of the month, but campylobacteriosis notifications have since returned to normal levels. The increase largely occurred in the Auckland region and Waikato DHB. Local investigations did not identify a common source and the increase was thought to be due to a hyper-endemic season, although changes in laboratory testing practices in Waikato DHB may also have contributed.

Hydatid disease: There was one case of hydatid disease reported in January 2019. The case died when a hydatid cyst ruptured. Exposure was determined to be historical, and the disease was most likely contracted from dogs.

Paralytic shellfish poisoning: There was one suspected case of paralytic shellfish poisoning notified in January 2019. The case had eaten tuatua recreationally harvested from Rarawa beach in Northland. A shellfish biotoxin alert had previously been issued for the Northland East Coast.

Pertussis: There were 241 cases (176 confirmed, 52 probable, 4 suspect and 9 under investigation) of pertussis notified in January 2019, compared with 501 cases for the same month in 2018. A national outbreak is ongoing. For more information see the latest Pertussis Report.

OUTBREAKS

Measles: Two measles outbreak were reported in January 2019. One was from Waikato DHB and involved 10 cases from four families. Cases were all unimmunised and mainly teenagers. The genotype (B3) identified was identical to that of an Auckland imported case in late November, however the link between the Auckland case and the Waikato cases was not identified.

The second outbreak was reported from Bay of Plenty DHB and involved three cases (genotype D8). The index case is believed to have acquired the infection while on a cruise in South East Asia. Two secondary cases from one household were reported to Waikato DHB.

Salmonellosis: A cluster of Salmonella Typhimurium phage type 108/170 was identified during January 2019. A total of 64 confirmed cases and two probable cases met the outbreak case definition. This was a national outbreak involving cases from 18 DHBs. Cases were investigated for potential food sources introduced in late December to the food chain, however a source has not been confirmed.