Monthly Notifiable Disease Surveillance Report - Mar 2015

Campylobacteriosis: 418 cases of campylobacteriosis were notified in March 2015 compared to 509 cases notified during the same month of the previous year. For the 12 month period ending 31 March 2015, the highest DHB rates were in South Canterbury (215.1 per 100,000 population, 125 cases), West Coast (189.0 per 100,000 population, 62 cases), and Waikato (188.5 per 100,000 population, 723 cases) compared to a national rate of 144.4 per 100,000 population.

Chikungunya fever: Four cases (3 confirmed and 1 under investigation) were notified in March 2015 compared to zero cases notified during the same month of the previous year. All cases reported overseas travel during the incubation period, to Samoa (2 cases), Kiribati and French Polynesia (1 case each).

Cronobacter species: Two confirmed cases were notified in March 2015. One case was a female in the 10–14 years age group from Lakes DHB and the other was a male in the 40–49 years age group from Capital and Coast DHB.

Cryptosporidiosis: 23 cases of cryptosporidiosis were notified in March 2015 compared to 21 cases notified during the same month of the previous year. The cases ranged in age from 9 months to 93 years, with the highest numbers of cases in the 30–39 years (6 cases) and 1–4 years  (4 cases) age groups. The highest numbers of cases were reported from Canterbury (5 cases), Waitemata and Auckland (4 cases each) DHBs. Among the cases where risk factor information was recorded, 60.0% (3/5) had recreational water contact, 37.5% (3/8) were overseas and 20.0% (1/5) had contact with farm animals during the incubation period.

Hepatitis not otherwise specified (NOS): Two confirmed cases of hepatitis NOS (hepatitis D) were notified in March 2015. The cases were a male and a female both in the 50–59 years age group from Hawke’s Bay and Wairarapa DHBs, respectively.  

Legionellosis: 12 cases (5 confirmed, 3 probable and 4 under investigation) were notified in March 2015 compared to 15 cases notified during the previous month and four during the same month of the previous year (Figure 1). After further investigation, one case has since been found to not meet case criteria. The highest number of cases were reported from Waitemata and Southern (2 cases each) DHBs. The Legionella species was identified for nine of the cases as: L. pneumophila (5 cases), L. longbeachae (3 cases), and L. gormanii (1 case).

Leptospirosis: 14 cases (6 confirmed, 2 probable and 6 under investigation) were notified in March 2015 compared to 10 cases notified during the previous month and one during the same month of the previous year. After further investigation, two cases have since been found to not meet case criteria. The highest number of cases were reported from Whanganui (3 cases) and Waikato (2 cases) DHBs. Eight cases reported a high-risk occupation as a farmer, slaughterer, hunter or forestry worker. One further case reported contact with cattle, sheep, and rabbits. One interim outbreak was reported in March (case numbers yet to be determined).

Measles: Three cases of measles were notified in March 2015 (2 confirmed and 1 under investigation), compared to 50 cases notified during the same month of the previous year. After further investigation, the case under investigation has since been found to not meet case criteria. The confirmed cases were reported from Counties Manukau and Bay of Plenty DHBs. The cases were in the

Ross River virus infection: Two confirmed cases were notified in March 2015. The cases were both female and in the 40–49 years age group from Waikato and West Coast DHBs. Both cases were in Australia during the incubation period.

Salmonellosis: 105 cases of salmonellosis were notified in March 2015 compared to 74 cases notified during the same month of the previous year (Figure 2). After further investigation, one case has since been found to not meet case criteria. The highest numbers of cases were reported from Canterbury (19 cases), Waitemata (15 cases) and Southern (13 cases) DHBs. The cases ranged in age from three months to 82 years, with the highest numbers of cases in the 1–4 years (25 cases) and 20–29 years (19 cases) age groups. Fourteen cases were hospitalised. The Salmonella serotype was identified in 99 (95.2%) of the cases. The most common was S. Typhimurium phage type 101 (12 cases), S.Tyhphimurium phage type 1 (8 cases), and S. Infantis and S. Saintpaul (7 cases each). Among the cases for which risk factor information was recorded 47.1% (24/51) had consumed food from a food premises, 24.6% (14/57) had contact with farm animals and 17.3% (14/81) had travelled overseas. One finalised Salmonella outbreak was reported in March involving three cases.

Toxic shellfish poisoning: One probable case was notified in March 2015. The case was a male in the 30–39 years age group from Nelson Marlborough DHB. The case had collected and consumed kina.

VTEC/STEC infection: 41 cases (31 confirmed and 10 under investigation) were notified in March 2015 compared to 32 cases notified during the same month of the previous year. The highest numbers of cases were reported from Waikato (10 cases) and Waitemata (6 cases) DHBs. Eight cases were hospitalised. The highest numbers of cases occurred in the 1–4 years (10 cases) and 70 years and over (6 cases) age groups. The serotype/organism was identified by the Enteric Reference Laboratory for 39 cases of which 69.2% (27/39) were Escherichia coli O157:H7. Among the cases for which risk factor information was recorded, 61.5% (8/13) had contact with farm animals, 38.9% (7/18) had consumed water from a non-habitual water supply and 33.3% (7/21) had contact with recreational water.

Zika virus: One case was (still under investigation) notified in March 2015. The case was a male in the 50–59 years age group from Bay of Plenty DHB who was in Vanuatu during the incubation period.