Monthly Notifiable Disease Surveillance Report - Aug 2016

Campylobacteriosis: 1114 cases of campylobacteriosis (713 confirmed, 394 probable and 7 under investigation) were notified in August 2016 compared to 488 cases notified during the same month of the previous year (Figure 1). For the 12 month period ending 31 August 2016, the highest rates were in Hawke’s Bay (552.0 cases per 100,000 population, 627 cases), South Canterbury (235.5 per 100,000 population, 9 cases) and West Coast (189.6 per 100,000 population, 1 case) DHBs, compared to a national rate of 148.4 per 100,000 population. Seventy-nine people were hospitalised. Cases ranged in age from 5 months to 100 years, and the highest number of cases was reported in the 70 years and over age group (244 cases). One interim outbreak was created in August (case numbers yet to be determined) for the Havelock North water-related outbreak.

Chikungunya fever: One confirmed case of chikungunya fever was notified in August 2016, the same number of cases notified as the same month of the previous year. Eighteen cases have been notified in the year to date compared to 47 at the same time in the previous year. The case was a male in the 30–39 years age group from Canterbury DHB. The case had travelled to Brazil during the incubation period for the disease.

Cryptosporidiosis: 133 confirmed cases of cryptosporidiosis were notified in August 2016 compared to 79 cases notified during the same month of the previous year. The 12-month rate in August (20.5 cases per 100,000) was higher than at the same time in the previous year (13.4 per 100,000). The highest numbers of cases were reported from Waikato (25 cases), Northland (18 cases) and Counties Manukau (17 cases) DHBs. Cases ranged in age from 10 months to 89 years, with the highest numbers of cases in the 1–4 years (41 cases), 20–29 years (23 cases) and 5–9 years (21 cases) age groups. Among the cases for which risk factor information was recorded, 52.9% (46/87) had contact with farm animals, 43.8% (28/64) had consumed food from a food premises, 41.1% (30/73) had consumed untreated water, and 28.4% (21/74) had attended school, preschool or childcare during the incubation period for the disease. Two interim Cryptosporidium outbreaks were created in August (case numbers yet to be determined).

Dengue fever: 12 cases of dengue fever (10 confirmed and 2 probable) were notified in August 2016 compared to 8 cases notified in the same month of the previous year. All cases had travelled overseas during the incubation period for the disease. Countries visited included: Indonesia and Thailand (3 cases each), Australia, Malaysia, Singapore and Vietnam (2 cases each), Cambodia, Fiji, India, Laos, Philippines and Vanuatu (1 case each). Some cases reported travel to more than one country.

Hepatitis NOS: One confirmed case of hepatitis NOS (hepatitis epsilon) was notified in August 2016. The case was a female in the 50–59 years age group from Canterbury DHB. The case reported being overseas in North America during the incubation period for the disease.

Hydatid disease: Two cases of hydatid disease (1 confirmed and 1 probable) were notified in August 2016. The cases were male, in the 40–49 years and 70 years and over age groups, and from Counties Manukau and Waitemata DHBs, respectively. Both cases were likely to have resulted from historic exposure, one occupational (butcher).

Legionellosis: 14 cases of legionellosis (9 confirmed and 5 under investigation) were notified in August 2016 compared to nine cases notified during the previous month, and seven during the same month of the previous year. Cases were reported from Northland (4 cases), Canterbury (3 cases), Southern (2 cases), Waitemata, Waikato, Bay of Plenty, Lakes and Whanganui (1 case each) DHBs. The Legionella species was identified for eight cases as: L. pneumophila and L. longbeachae (3 cases each), L. micdadei and L. sainthelensi (1 case each). The increase in notifications for the year to date compared to the same time in the previous year (cumulative total 165 in August 2016 compared to 110 in August 2015) may be due to the LegiNZ study, which began in May 2015 and involves 20 hospitals in 17 DHBs.

Leptospirosis: 14 cases of leptospirosis (7 confirmed and 7 under investigation) were notified in August 2016 compared to two cases notified during the same month of the previous year. After further investigation, two cases have since been found not to meet the case criteria. Cases were reported from Hawke’s Bay (3 cases), Waikato and Taranaki (2 cases each), and Waitemata, Capital & Coast, Nelson Marlborough, Canterbury and Southern (1 case each) DHBs. The highest number of cases was in the 50–59 years age group (6 cases). Occupational exposure risk factor information was recorded for 85.7% (6/7) of confirmed cases, all were farmers or farm workers. The other confirmed case had exposure to streams, rivers, or lakes in the 20 days prior to illness. The Leptospira species was recorded for three cases, L. Hardjo (2 cases) and L. Ballum (1 case).

Listeriosis: Three confirmed cases of listeriosis were notified in August 2016. All cases were in the 70 years and over age group, and were of European or Other (2 cases) and Pacific peoples (1 case) ethnicity. Cases were reported from Auckland, Counties Manukau and Hawke’s Bay DHBs (1 case each). Risk factor information was recorded for all cases; two cases reported an underlying illness, one of which reported receiving immunosuppressive drugs. The other case had no known risk factors recorded. The serotype was identified as L. monocytogenes serotype O4 (2 cases) and L. monocytogenes serotype O1/2 (1 case).

Lyme disease: Although not strictly notifiable but interesting to note, one probable case of Lyme disease was notified in August 2016. The case was a female in the 40–49 years age group from Canterbury DHB. Overseas travel during the incubation period for the disease was recorded, and the case reported a forest in Switzerland as the location where the disease was probably acquired.

Measles: Six cases of measles (3 confirmed and 3 under investigation) were notified in August 2016 compared to zero cases notified during the same month of the previous year (Figure 2). After further investigation, three cases have since been found not to meet the case criteria. Cases were reported from Capital & Coast (2 cases) and Auckland (1 case) DHBs. Cases were in the 5–9 years, 20–29 years and 40–49 years age groups (1 case each). Immunisation information was recorded for all cases, of which two cases were immunised and had received one dose of MMR vaccine. One case was not immunised. Two cases were exposed while on family holiday in Indonesia, and the other case had travelled to Indonesia and Malaysia during the incubation period for the disease. One interim measles outbreak was created in August (case numbers yet to be determined).

Meningococcal disease: 13 cases of meningococcal disease (12 confirmed and 1 under investigation) were notified in August 2016 compared to fifteen cases notified during the same month of the previous year. After further investigation, one case has since been found not to meet the case criteria. The following information relates to confirmed cases only. Cases were reported from Southern (5 cases), Capital & Coast (2 cases), Auckland, Counties Manukau, Bay of Plenty, Hawke’s Bay and Canterbury (1 case each) DHBs. Cases were reported in the 20–29 years (4 cases), 1–4 years and 5–9 years (2 cases each), 15–19 years, 40–49 years, 50–59 years and 70 years and over (1 case each) age groups. All cases were hospitalised and one death was reported. All cases were laboratory confirmed and the strain groups were as follows: group B (10 cases, including 6 group B:P1.7-2,4), group C (1 case) and group Y (1 case).

Pertussis: 85 cases of pertussis (29 confirmed, 50 probable, 4 suspect and 2 under investigation) were notified in August 2016 compared to 161 cases in the same month of the previous year. The 12-month rate in August (24.7 cases per 100,000) was higher than at the same time in the previous year (22.6 per 100,000). However, the number of notifications has generally decreased since the 124 notifications in January 2016. Twelve cases were hospitalised and no deaths were reported. Forty percent (34/85) of cases were laboratory-confirmed (8 by culture, 17 by PCR, and 9 by culture and PCR). The highest numbers of cases were reported from Taranaki (15 cases), Canterbury (13 cases) and Waikato (12 cases) DHBs. Cases ranged in age from 1 month to 84 years, with 16.5% (14/85) under 5 years of age (including 8 cases aged less than 1 year). The highest numbers of cases were in the 40–49 years (14 cases) and 15–19 years (13 cases) age groups. One finalised B. pertussis outbreak was created in August (4 cases). 

Rheumatic fever: 19 cases of rheumatic fever (16 initial attack and 3 recurrent attack) were notified in August 2016 compared to seven cases in the same month of the previous year. All cases were from the North Island: Auckland and Counties Manukau (4 cases each), Waitemata, Tairawhiti, MidCentral and Capital & Coast (2 cases each), Waikato, Bay of Plenty and Taranaki (1 case each) DHBs. The cases ranged in age from 8 to 31 years, with the highest numbers of cases in the 10–14 years age group (8 cases). Cases were reported in the Pacific Peoples (10 cases), Māori (7 cases), European or Other and Unknown (1 case each) ethnic groups. Eighteen cases were hospitalised. Numbers are based on report date which may not be a good indicator of newly incident cases as a high proportion of notifications have reporting delays.

Taeniasis: One confirmed case of taeniasis was notified in August 2016. The case was a female in the 20–29 years age group from Capital & Coast DHB. The case was a refugee and had been in Ethiopia during the incubation period for the disease.

Tetanus: One case of tetanus (under investigation) was notified in August 2016. The case was a female in the 20–29 years age group from Taranaki DHB and remains under investigation.

VTEC/STEC infection: 33 cases of VTEC/STEC infection (23 confirmed and 10 under investigation) were notified in August compared to 37 cases confirmed during the same month of the previous year. After further investigation, nine cases have since been found not to meet the case criteria. The 12-month rate in August 2016 (10.2 cases per 100,000) was notably higher than at the same time in the previous year (5.5 per 100,000). Cases were reported from Waitemata (7 cases), Hawke’s Bay (5 cases), Waikato (4 cases), Northland, Counties Manukau, Bay of Plenty (2 cases each), Whanganui and Nelson Marlborough (1 case each) DHBs. Cases ranged in age from 13 months to 73 years, with the highest number of cases in the 1–4 years age group (6 cases). Five cases were hospitalised. Twenty-one 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 (11 cases) and non-O157 (10 cases). Of the cases for which risk factor information was recorded, 66.7% (8/12) had contact with animals, 36.4% (4/11) had contact with children in nappies, and 25.0% (3/12) had contact with a person with similar symptoms during the incubation period for the disease. The increase in notifications for DHBs in the Auckland region may be due to a change in laboratory methods in July 2015; all faecal specimens are now screened for VTEC/STEC using PCR. One finalised outbreak was created in August (2 cases).

Yersiniosis: 84 cases of yersiniosis (82 confirmed and 2 under investigation) were notified in August 2016 compared to 68 cases notified in the same month of the previous year. After further investigation, two cases have since been found not to meet the case criteria. The highest numbers of cases were reported from Canterbury (14 cases) and Waitemata (11 cases) DHBs. Cases ranged in age from 5 months to 85 years, with the highest number of cases in the 30–39 years (14 cases), 20–29 years and 50–59 years (12 cases each) age groups. Twelve cases were hospitalised. The Yersinia species involved was identified for 89.0% (73/82) cases; Y. enterocolitica (67 cases) and Y. pseudotuberculosis (6 cases). The most common Y. enterocolitica biotypes reported were biotype 2 (42 cases) and 1A (12 cases). Among the cases for which risk factor information was recorded, 39.3% (11/28) had consumed food from a food premises, 26.5% (9/34) had contact with nappies, 14.6% (6/41) had contact with other symptomatic people, and 11.4% (5/44) had contact with farm animals during the incubation period for the disease.