Molecular typing of enteroviruses: comparing 5'UTR, VP1 and whole genome sequencing methods.

Enteroviruses (EV) commonly cause hand, foot and mouth disease (HFMD), and can also cause potentially fatal neurological and systemic complications. In our laboratory, sequencing 5' untranslated region (UTR) of the viral genome has been the routine method of genotyping EVs. During a recent localised outbreak of aseptic meningitis, sequencing the 5'UTR identified the causative virus as EV-A71, which did not fit with the clinical syndrome or illness severity. When genotyped using a different target gene, VP1, the result was different. This led us to evaluate the accuracy of the two different target genome regions and compare them against whole genome sequencing (WGS). We aimed to optimise the algorithm for detection and characterisation of EVs in the diagnostic laboratory. We hypothesised that VP1 and WGS genotyping would provide different results than 5'UTR in a subset of samples. Clinical samples from around New South Wales which were positive for EV by commercial polymerase chain reaction (PCR) assays were genotyped by targeting three different viral genome regions: the 5'UTR, VP1 and WGS. Sequencing was performed by Sanger and next generation sequencing. The subtyping results were compared. Of the 74/118 (63%) samples that were successfully typed using both the 5'UTR and the VP1 method, the EV typing result was identical for 46/74 (62%) samples compared to WGS as the gold standard. The same EV group but different EV types were found in 22/74 (30%) samples, and 6/74 (8%) samples belonged to different EV groups depending on typing method used. Genotyping with WGS and VP1 is more accurate than 5'UTR. Genotyping by the 5'UTR method is very sensitive, but less specific.

Laboratory diagnosis of severe acute respiratory syndrome coronavirus 2.

The first laboratory confirmed case of Coronavirus disease 2019 (COVID-19) in Australia was in Victoria on 25 January 2020 in a man returning from Wuhan city, Hubei province, the People's Republic of China. This was followed by three cases in New South Wales the following day. The Australian Government activated the Australian Health Sector Emergency Response Plan for Novel Coronavirus on 27 February 2020 in anticipation of a pandemic. Subsequently, the World Health Organization declared COVID-19 to be a Public Health Emergency of International Concern followed by a pandemic on 30 January 2020 and 11 March 2020, respectively. Laboratory testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus responsible for COVID-19, is key in identifying infected persons to guide timely public health actions of contact tracing and patient isolation to limit transmission of infection. This article aims to provide a comprehensive overview of current laboratory diagnostic methods for SARS-CoV-2, including nucleic acid testing, serology, rapid antigen detection and antibody tests, virus isolation and whole genome sequencing. The relative advantages and disadvantages of the different diagnostic tests are presented, as well as their value in different clinical, infection control and public health contexts. We also describe the challenges in the provision of SARS-CoV-2 diagnostics in Australia, a country with a relatively low COVID-19 incidence in the first pandemic wave but in which prevalence could rapidly change.

Timing and frequency of chlamydia and gonorrhoea testing in a cross-sectional study of HIV postexposure prophylaxis recipients.

OBJECTIVES: Australian HIV postexposure prophylaxis (PEP) guidelines recommend Chlamydia trachomatis (CT) and Neisseria gonorrheae (NG) testing at both baseline and 2-week postexposure visits. We aimed to determine the diagnostic yield of testing at one or more visits, and predictors of infection. METHODS: Data were collected from patients prescribed PEP at RPA Sexual Health over a 4-year period from January 2008 to December 2011. Predictors of CT/NG were assessed by logistic regression. RESULTS: 282 individuals presented for PEP on 319 occasions during the study period. The majority (94.3%) were male and over 90% of presentations followed unprotected anal sexual exposures. Most (279, 87.5%) had CT/NG testing at least once. Almost half (153, 48.0%) of baseline presentations, two-thirds (214, 67.1%) of 2-week presentations and over a quarter (88, 27.6%) of both presentations included CT/NG testing. CT/NG was diagnosed at baseline in eight (5.2%, 95% CI 2.3% to 10.0%) presentations. A new CT/NG diagnosis occurred at the 2-week visit in 18 (8.4%, 95% CI 5.1% to 13.0%) presentations, of whom 7 tested negative and 11 were not tested at baseline. Over one-quarter (28.1%) of PEP recipients reported sexual contact between baseline and 2-week visits. Independent predictors of CT/NG at baseline were recent sex work (OR 48.0, 95% CI 3.77 to 611.94); and at 2 weeks a known HIV-positive PEP exposure source (OR 3.54, 95% CI 1.04 to 12.06) and sex between baseline and 2-week visits (OR 3.63, 95% CI 1.10 to 11.96). CONCLUSIONS: Our findings suggest that screening PEP recipients for CT/NG at both baseline and 2 weeks may be warranted.