Monthly Notifiable Disease Surveillance Report - Aug 2021

Enteric Diseases: There was a decrease in the incidence of some enteric diseases in August 2021, compared with August 2020. This is most likely due to behavioural changes as a result of the national lockdown which began on 18 August. It is likely that exposure to some risk factors decreased during this time, but also that less people sought healthcare and therefore were not tested for enteric diseases.

COVID-19: There were 771 cases of COVID-19 reported in August 2021 (768 confirmed and 3 under investigation), compared with 186 cases for the same month in 2020. Of the 768 confirmed cases, 682 (88.8%) were community cases, 74 (9.6%) were imported cases in managed isolation/quarantine (MIQ) facilities, 11 (1.4%) were international mariners from a ship docked at a New Zealand port, and one was an airline crew member. Eighty cases (10.4%) were hospitalised and one case, aged 70 years and over, died. More information can be found on the ESR COVID-19 dashboard.

Invasive pneumococcal disease: There were 84 cases of invasive pneumococcal disease reported in August 2021, compared with 41 for the same month in 2020. All 84 cases were laboratory confirmed. The majority (52/84, 61.9%) were aged 50 years and over. Four deaths were reported; two in cases aged under 5 years and two in cases aged 70 years and over. A serotype was identified in 80 (95.2%) cases, and the most common serotype was 19A, accounting for 27 (33.8%) cases, including five cases aged under 5 years. Of the two children aged under 5 years that died, one was unimmunised and was due to serotype 7F (a PCV10 serotype) while the other was immunised and due to serotype 21 (a non-PCV10 serotype).

Meningococcal disease: There were eight confirmed cases of meningococcal disease reported in August 2021, compared with five cases for the same month in 2020. There have been 31 confirmed cases for the year to date.
The strain type was identified in seven August cases: six were group B and one was group W. Three of the group B cases were B:P1.7-2,4; two were B:P1.7-12,14; and one was B:P1.5,2. One serogroup B case, aged 20–29 years, died.

Yersiniosis: There were 106 cases of yersiniosis reported in August 2021, bringing the total for the year to date to 973 compared with 708 for the same period in 2020. Yersinia enterocolitica biotype 2/3 serotype O:9 was identified in the majority (509/783, 65.0%) of cases that had been typed. Interviews with Auckland cases and a Health Research Council funded study in Canterbury have both independently identified a strong association with eating pork. Isolates from pork products purchased in the Christchurch area were sequenced and found to cluster with recent cases from Auckland and Canterbury. The Ministry for Primary Industries (MPI) is investigating.

OUTBREAKS

COVID-19: Four outbreaks of COVID-19 were reported in August 2021. The largest was a community outbreak reported from the Auckland region. As of 31 August, 612 cases had been reported in the outbreak. One outbreak involved 11 crew members on board the Rio de la Plata container ship docked in Tauranga, one outbreak involved six cases with transmission occurring both in-flight and within a quarantine facility, and one further outbreak involved four cases in a quarantine facility.

Norovirus: An acute gastroenteritis outbreak linked to oysters was reported from Northland DHB in August 2021. Nine cases were reported (8 probable and 1 confirmed). Cases included processing staff at an oyster farm as well as community cases who had consumed raw oysters. One case displayed diarrhetic shellfish poisoning symptoms while the rest had symptoms consistent with norovirus. One case was hospitalised and samples from both the case and leftover oysters tested positive for norovirus genogroup I. Norovirus genogroup I was also detected in oysters that were not processed. A food recall was issued on 10 August.

Respiratory illness: There were 66 respiratory illness outbreaks reported in August 2021, involving 547 cases. Twenty-three outbreaks were reported as influenza-like illness (ILI) and 43 were reported as acute respiratory infection (ARI). Respiratory syncytial virus (RSV) was identified in 25 outbreaks and influenza A was identified in one. No pathogen was identified in the remaining 40 ILI/ARI outbreaks. Sixty outbreaks were in long-term care facilities, four were in childcare centres, and two were in hospitals.