Monthly Notifiable Disease Surveillance Report - May 2017

Thursday 21st September 2017


Key notifiable disease trends

Legionellosis: 32 cases of legionellosis (12 confirmed, 2 probable and 18 under investigation) were notified in May 2017 compared to 11 cases notified during the previous month, and 18 during the same month of the previous year (Figure 1). Cases were reported from Waitemata (8 cases), Northland, Canterbury, Southern (5 cases each), Counties Manukau (4 cases), Auckland (3 cases), Taranaki and West Coast (1 case each) DHBs. The Legionella species was identified for 16 cases as: L. pneumophila (6 cases), L. longbeachae (6 cases), L. sainthelensi (3 cases) and L. dumoffii (1 case).

Leptospirosis: 24 cases of leptospirosis (16 confirmed and 8 under investigation) were notified in May 2017 compared to seven cases notified during the same month of the previous year. The highest number of cases was reported from Waikato (6 cases) Nelson Marlborough (4 cases) and Waitemata (3 cases) DHBs. Cases were reported in the 40–49 years (8 cases), 30–39 years, 50–59 years (5 cases each), 60–69 years (4 cases), 20–29 years and 70 years and over (1 case each) age groups. Occupation was recorded for 70.8% (17/24) of cases. Of these, 12 were engaged in occupation as farmers/farm workers or meat workers which has previously been identified as high risk exposure to Leptospira species. Of the five cases that did not report a high-risk occupation (or had no occupation recorded), three reported contact with farm or wild animals and one had recreational water contact. One case did not have any risk factor information recorded.

Mumps: 55 cases of mumps (45 confirmed, 5 probable and 5 under investigation) were notified in May 2017 compared with zero cases notified during the same month of the previous year (Figure 2). The cases were reported from Waitemata (32 cases), Counties Manukau (11 cases), Waikato (6 cases), Auckland, Canterbury (2 cases each), Northland and Nelson Marlborough DHBs (1 case each). Cases were in the 15–19 years (14 cases), 20–29 years (13 cases), 10–14 years (11 cases), 30–39 years (7 cases), 1–4 years (4 cases), 5–9 years, 40–49 years (2 cases each), less than one year and 50–59 years (1 case each) age groups. Fifteen cases were recorded as being vaccinated against mumps, of which six cases had received two doses of the vaccine and eight cases had received just one dose. One further case had been vaccinated, but no dose information was available.

Pertussis: 134 cases of pertussis (68 confirmed, 50 probable, 6 suspected, and 10 under investigation) were notified in May 2017 compared to 70 cases in the same month of the previous year. The 12-month rate for the period ending 31 May (25.2 cases per 100,000) was lower than at the same time in the previous year (27.4 per 100,000). Nine cases were hospitalised and no deaths were reported. Fifty-four percent (73/134) of cases were laboratory-confirmed (15 by culture, 49 by PCR, 9 by culture and PCR). The highest number of cases was reported from Southern (26 cases), followed by Capital & Coast and Canterbury (18 cases each) and Waitemata (14 cases) DHBs. Cases ranged in age from one month to 81 years, with 22.4% (30/134) under five years of age (including 8 cases aged less than 1 year). The highest numbers of cases were in the 1–4 years (22 cases) and 50–59 years (16 cases) age groups. One interim Bordetella pertussis outbreak (case numbers yet to be determined) was created in May.

Shigellosis: 29 confirmed cases of shigellosis were notified in May 2017 compared with 10 cases notified during the same month of the previous year. The 12-month rate for the period ending 31 May (4.5 cases per 100,000 population) was higher than at the same time in the previous year (2.5 per 100,000). The highest numbers of cases were reported from Auckland (6 cases), Waitemata and Counties Manukau (5 cases each) DHBs. The serotype involved was recorded for 96.6% (28/29) of cases: S. sonnei biotype g (8 cases), S. flexneri 6 biotype Boyd 88 (6 cases), S. flexneri 2a (5 cases), S. sonnei biotype a (3 cases), S. flexneri 2b (2 cases), S. boydii 1, S. flexneri, S. flexneri 1b, S. flexneri 1c (1 case each). Information on overseas travel during the incubation period was recorded for 94.4% (28/29) of cases, of which 62.1% (17/28) of cases recorded overseas travel during the incubation period for the disease. Countries visited included: India (4 cases), Fiji, Samoa, Singapore (2 cases each), Indonesia, Peru, Philippines, Thailand, Timor-Leste and Vanuatu (1 case each). Three cases reported overseas travel to more than one country. Of the cases that did not travel overseas one case reported contact with farm animals and nappies, and one case reported consuming water from a non-regular water supply during the incubation period. The remaining 10 cases had no risk factor information recorded. One finalised Shigella outbreak was created in May (2 cases).

VTEC/STEC infection: 62 cases of VTEC/STEC infection (46 confirmed and 16 under investigation) were notified in May 2017 compared to 34 cases confirmed during the same month of the previous year. The 12-month rate for the period ending 31 May 2017 (9.8 cases per 100,000 population) was the same as the rate for the equivalent period the previous year (9.8 cases per 100,000 population). The highest numbers of cases were reported from Southern (12 cases), Waitemata (8 cases), Counties Manukau and Canterbury (7 cases each) DHBs. Cases ranged in age from seven months to 88 years, with the highest number of cases in the 20–29 years (12 cases). Fourteen cases were hospitalised. Thirty-nine cases have been confirmed by the Enteric Reference Laboratory as being infected with VTEC/STEC, and of these the serotype was identified as Escherichia coli O157:H7 (24 cases) and non-O157 (15 cases). The serotype was undetermined in one case but verocytotoxin was detected by PCR. Of the cases for which risk factor information was recorded, 82.9% (29/35) had contact with animals, 25.6% (10/39) had contact with a person with similar symptoms, 24.2% (8/33) had contact with children in nappies, and 11.8% (4/34) had recreational contact with water during the incubation period for the disease. One finalised VTEC/STEC infection outbreak (2 cases) and one interim outbreak (case numbers yet to be determined) was created in May.

Yersiniosis: 75 confirmed cases of yersiniosis were notified in May 2017 compared to 68 cases notified in the same month of the previous year. The highest numbers of cases were reported from Canterbury (15 cases), Waitemata (13 cases), Auckland and Capital & Coast (8 cases each) DHBs. Cases ranged in age from five months to 92 years, with the highest number of cases in the 1–4 years (15 cases), 20–29 years (11 cases), and 30–39 years (10 cases) age groups. Five cases were hospitalised. The Yersinia species involved was identified by ESR for 92.0% (69/75) cases. The most common Y. enterocolitica biotypes reported were Biotype 2 (38 cases), Biotype 3 (13 cases), and Biotype 1A (10 cases). Among the cases for which risk factor information was recorded, 35.7% (10/28) had consumed food from a food premises, 35.7% (10/28) had contact with farm animals, 18.5% (5/27) consumed untreated water, 16.7% (5/30) had recreational contact with water and 10.7% (3/28) had contact with other faecal matter or vomit during the incubation period for the disease.

Zika virus infection: Five cases of zika virus infection (4 confirmed and 1 under investigation) were notified in May 2017 compared to six cases notified during the same month of the previous year. Cases were reported from Southern (2 cases), Auckland, Bay of Plenty, and Nelson Marlborough (1 case each) DHBs. Cases were reported in the 50–59 years (3 cases), 30–39 years and 70 years and over (1 case each) age groups. All cases reported overseas travel during the incubation period to Fiji.

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Report:

Monthly Notifiable Disease Surveillance Report - May 2017

Tables:

Monthly National Totals - May 2017

Monthly DHB Totals - May 2017

Monthly Rolling Totals - May 2017

 

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Monthly Notifiable Disease Surveillance Report - May 2017

Tables:

Monthly National Totals - May 2017

Monthly DHB Totals - May 2017

Monthly Rolling Totals - May 2017

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