Background RT-PCR has become the primary method to diagnose viral diseases, including SARS-CoV-2. RT-PCR detects RNA, not infectious virus, thus its ability to determine duration of infectivity of patients is limited. Infectivity is a critical determinant in informing public health guidelines/interventions. Our goal was to determine the relationship between E gene SARS-CoV-2 RT-PCR cycle threshold (Ct) values from respiratory samples, symptom onset to test (STT) and infectivity in cell culture. Methods In this retrospective cross-sectional study, we took SARS-CoV-2 RT-PCR confirmed positive samples and determined their ability to infect Vero cell lines. Results Ninety RT-PCR SARS-CoV-2 positive samples were incubated on Vero cells. Twenty-six samples (28.9%) demonstrated viral growth. Median TCID50/ml was 1780 (282-8511). There was no growth in samples with a Ct > 24 or STT > 8 days. Multivariate logistic regression using positive viral culture as a binary predictor variable, STT and Ct demonstrated an odds ratio for positive viral culture of 0.64 (95% CI 0.49-0.84, p<0.001) for every one unit increase in Ct. Area under the receiver operating characteristic curve for Ct vs. positive culture was OR 0.91 (95% CI 0.85-0.97, p<0.001), with 97% specificity obtained at a Ct of >24. Conclusions SARS-CoV-2 Vero cell infectivity was only observed for RT-PCR Ct < 24 and STT < 8 days. Infectivity of patients with Ct >24 and duration of symptoms >8 days may be low. This information can inform public health policy and guide clinical, infection control and occupational health decisions. Further studies of larger size are needed.

The coronavirus disease (COVID-19) pandemic is causing widespread interruptions in medical education. With little warning, clinical rotations were cancelled and medical students were sent home. While pre-clinical students transitioned to online curricula, clinical students were left without discreet educational goals. Simultaneously, medical doctors were scrambling to maintain competence in the face of rapidly evolving COVID-19 information. Here, we describe an education program that integrates medical students into interdisciplinary teams to review emerging COVID-19 research that directly answers questions sent in by medical doctors.

Impoverished communities often turn to illegal extraction of resources from protected areas to alleviate economic pressures or to make monetary gains. Such practices can cause ecological damage and threaten animal populations. These communities also often face a high disease burden and typically do not have access to affordable health care. Here we argue that these two seemingly separate challenges may have a common solution. In particular, providing health care to communities adjacent to protected areas may be an efficient and effective way to reduce the disease burden while also improving local perceptions about protected areas, potentially reducing illegal extraction. We present a case study of a health centre on the edge of Kibale National Park, Uganda. The centre has provided care to c. 7,200 people since 2008 and its outreach programme extends to c. 4,500 schoolchildren each year. Contrasting the provision of health care to other means of improving community perceptions of protected areas suggests that health clinics have potential as a conservation tool in some situations and should be considered in future efforts to manage protected areas.

Testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) relies on reverse transcription polymerase chain reaction (RT-PCR), which amplifies SARS-CoV-2 genetic material. 1 Nasopharyngeal or oropharyngeal RT-PCR sensitivity is highest when performed early after symptom onset. 2-4 2 Test sensitivity varies according to specimen type and disease severity In patients who progress to have lower respiratory tract disease, the sensitivity of nasopharyngeal and oropharyngeal RT-PCR declines and the yield from lower respiratory tract samples, such as samples taken from sputum, endotracheal tube and bronchoalveolar lavage, increases. 4 Lower respiratory tract samples may reveal a positive result when nasopharyngeal and oropharyngeal sampling has not.

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