A foodborne outbreak of Group A streptococcus: an under-recognised method of spread.

Foodborne transmission of Group A Streptococcus (GAS) is a rare cause of pharyngitis outbreaks. This report details a GAS outbreak in New Zealand that was associated with a foodborne route of transmission. This outbreak was relevant in the New Zealand context given the high incidence of rheumatic fever (RF).

A clinical review of mpox for the Aotearoa New Zealand clinician.

The World Health Organization declared mpox (formerly monkeypox) a Public Health Emergency of International Concern in July 2022. Aotearoa New Zealand has reported cases of mpox since July, with reports of locally acquired cases since October 2022. The 2022 global mpox outbreak highlights many features of the illness not previously described, including at-risk populations, mode of transmission, atypical clinical features, and complications. It is important that all clinicians are familiar with the variety of clinical manifestations, as patients may present to different healthcare providers, and taking lessons from the HIV pandemic, that all patients are managed without stigma or discrimination. There have been numerous publications since the outbreak began. Our narrative clinical review attempts to bring together the current clinical evidence for the New Zealand clinician.

Airborne Transmission of SARS-CoV-2 Delta Variant within Tightly Monitored Isolation Facility, New Zealand (Aotearoa).

In New Zealand, international arrivals are quarantined and undergo severe acute respiratory syndrome coronavirus 2 screening; those who test positive are transferred to a managed isolation facility (MIF). Solo traveler A and person E from a 5-person travel group (BCDEF) tested positive. After transfer to the MIF, person A and group BCDEF occupied rooms >2 meters apart across a corridor. Persons B, C, and D subsequently tested positive; viral sequences matched A and were distinct from E. The MIF was the only shared location of persons A and B, C, and D, and they had no direct contact. Security camera footage revealed 4 brief episodes of simultaneous door opening during person A's infectious period. This public health investigation demonstrates transmission from A to B, C, and D while in the MIF, with airborne transmission the most plausible explanation. These findings are of global importance for coronavirus disease public health interventions and infection control practices.

Lack of N2-gene amplification on the Cepheid Xpert Xpress SARS-CoV-2 assay and potential novel causative mutations: A case series from Auckland, New Zealand.

We describe three cases with viral strains that demonstrate impaired N2-gene detection on the Cepheid Xpert Xpress SARS-CoV-2 assay, with two previously undescribed single nucleotide polymorphisms (SNPs): C29197T and G29227T. We propose that these SNPs are likely responsible since they are in close proximity to the previously described C29200T/C29200A SNPs, already shown to abolish N2-gene detection by the Xpert assay. Whether these SNPs abolish N2-gene detection by the Xpert assay individually or only in combination requires more work to elucidate.

SARS-CoV-2 viral load dynamics and real-time RT-PCR cycle threshold interpretation in symptomatic non-hospitalised individuals in New Zealand: a multicentre cross sectional observational study.

We conducted a multicentre cross sectional observational study of laboratory, public health and hospitalisation data for PCR-confirmed COVID-19 cases within the New Zealand Northern Region, between 12 February and 8 June 2020. The aim of this study was to describe population level SARS-CoV-2 upper respiratory tract (URT) viral load dynamics by stratifying positivity rates and polymerase chain reaction (PCR) cycle threshold (Ct) values of URT samples from COVID-19 cases by days since symptom onset, and to explore utility of Ct values in determining length of time post-infection and thus potential infectivity. Of 123,124 samples tested for SARS-CoV-2 by PCR, 579 samples (407 positive and 172 negative) from 368 symptomatic non-hospitalised individuals with PCR-confirmed infection were included. Sample positivity rate was 61.5% (8/13) for pre-symptomatic samples, rising to 93.2% (317/340) for samples collected during the purported symptomatic infectious period (days 0-10 post-symptom onset), and dropping to 36.3% (82/226) for post-infectious period samples (day 11 onwards). URT viral load peaked shortly after symptom onset, with median Ct values ranging 20.00-29.99 until 15 days post-symptom onset, and >30.00 after this time. Of samples with a Ct value of <20.00, 96.1% were collected during the symptomatic infectious period. However, of samples with a Ct value ≥30.00 and ≥35.00, 46.9% and 18.5%, respectively, were also collected during the symptomatic infectious period. The findings of this study indicate that at or soon after symptom onset represents the optimum time to test for SARS-CoV-2 in the URT, with median Ct values suggesting the useful testing window extends until around 15 days post-symptom onset. In asymptomatic individuals or those with unknown dates of symptom onset, Ct values <20.00 imply recent onset/potential infectivity, but Ct values ≥30.00 or ≥35.00 do not exclude recent onset/potential infectivity. Individual sample Ct values should not be used as an absolute marker of length of time post-infection or to exclude infectivity where date of symptom onset is unavailable.

How strong is the relationship between scabies and acute rheumatic fever? An analysis of neighbourhood factors.

AIM: Recent studies have linked scabies with acute rheumatic fever (ARF). We explored the relationship, by neighbourhood, between permethrin dispensing as an indicator of scabies prevalence and ARF cases over the same period. METHODS: Incident cases of ARF notified to public health between September 2015 and June 2018 and the annual incidence of prescribing by neighbourhood over the same period were analysed. Evidence of an association between permethrin and ARF was obtained by carrying out Poisson regression of the rate of ARF in terms of permethrin rate at the census area unit level, with adjustment for ethnicity and socio-economic deprivation. RESULTS: A total of 413 neighbourhoods were included. The incidence of ARF varied between 0 and 102 per 100 000 people per year (mean 4.3). In contrast, the annual incidence of dispensing of permethrin varied between 0 and 3201 per 100 000 people per year (mean 771). A strong association was observed between the two variables. In an adjusted quasi-Poisson model, permethrin-dispensing rates were strongly associated with ARF incidence, with a change from the 16th to the 84th centile associated with a 16.5-fold increase in incidence (95% confidence interval: 3.82-71.6). CONCLUSIONS: Permethrin prescribing as an indicator of scabies is strongly associated with the incidence of ARF. Considered together with other studies, this evidence suggests that improving scabies control may reduce the burden of ARF in New Zealand.