Association Between Time to First RNA-Negative Test Result Among People With Hepatitis C Virus Infection and Homelessness or Testing at a Correctional or Substance Use Treatment Facility, New York City

Objective Curative treatments for hepatitis C virus (HCV) infection are available, but access and barriers to treatment can delay initiation. We investigated the time to first negative RNA test result among people with HCV infection and examined differences by homeless status and whether people were tested at a correctional facility or substance use treatment facility. Methods We used surveillance data to identify New York City residents first reported with HCV infection during January 1, 2015–December 31, 2018, with ≥1 positive RNA test result during January 1, 2015–November 1, 2019. We used Kaplan–Meier survival analysis to determine the time from the first positive RNA test result to the first negative RNA test result, with right-censoring at date of death or November 1, 2019. We determined substance use treatment, incarceration, or homelessness by ordering facility name and address or from patient residential address. Results Of 13 952 people with an HCV RNA–positive test result first reported during 2015-2018, 6947 (49.8%) subsequently received an RNA-negative test result. Overall, 25% received an RNA-negative test result within 208 (95% CI, 200-216) days and 50% within 902 (95% CI, 841-966) days. Homelessness, incarceration, or substance use treatment was indicated for 4304 (30.9%) people, among whom 25% received an RNA-negative test result within 469 (95% CI, 427-520) days and <50% received an RNA-negative test result during the study period. Conclusions Efforts to connect people to treatment should occur soon after diagnosis, especially for people who could benefit from hepatitis C care coordination.

Payments and freedoms: Effects of monetary and legal incentives on COVID-19 vaccination intentions in Germany

Monetary and legal incentives have been proposed to promote COVID-19 vaccination uptake. To evaluate the suitability of incentives, an experiment with German participants examined the effects of payments (varied within subjects: 0 to 10,000 EUR) and freedoms (varied between subjects: vaccination leading vs. not leading to the same benefits as a negative test result) on the vaccination intentions of previously unvaccinated individuals (n = 782). While no effect could be found for freedoms, the share of participants willing to be vaccinated increased with the payment amount. However, a significant change required large rewards of 3,250 EUR or more. While monetary incentives could increase vaccination uptake by a few percentage points, the high costs of implementation challenge the efficiency of the measure and call for alternatives. As experimental data suggest that considering vaccination as safe, necessary, and prosocial increases an individual’s likelihood of wanting to get vaccinated without payment, educational campaigns should emphasize these features when promoting vaccination against COVID-19.

Managing the risk of a COVID-19 outbreak from border arrivals

In an attempt to maintain the elimination of COVID-19 in New Zealand, all international arrivals are required to spend 14 days in government-managed quarantine and to return a negative test result before being released. We model the testing, isolation and transmission of COVID-19 within quarantine facilities to estimate the risk of community outbreaks being seeded at the border. We use a simple branching process model for COVID-19 transmission that includes a time-dependent probability of a false-negative test result. We show that the combination of 14-day quarantine with two tests is highly effective in preventing an infectious case entering the community, provided there is no transmission within quarantine facilities. Shorter quarantine periods, or reliance on testing only with no quarantine, substantially increases the risk of an infectious case being released. We calculate the fraction of cases detected in the second week of their two-week stay and show that this may be a useful indicator of the likelihood of transmission occurring within quarantine facilities. Frontline staff working at the border risk exposure to infected individuals and this has the potential to lead to a community outbreak. We use the model to test surveillance strategies and evaluate the likely size of the outbreak at the time it is first detected. We conclude with some recommendations for managing the risk of potential future outbreaks originating from the border.

Perceptions on undertaking regular asymptomatic self-testing for COVID-19 using lateral flow tests: A qualitative study of university students and staff

BackgroundThere has been an increased interest from governments in implementing mass testing for COVID-19 of asymptomatic individuals using Lateral Flow Tests (LFTs). Successful implementation of such programmes depends on several factors, including feasibility, acceptability and how people act on test results. There is a paucity of studies examining these issues.ObjectiveWe aimed to examine experiences of university students and staff with experience of regular asymptomatic self-testing using LFTs, and their subsequent behaviours.MethodsWe invited people who were participating in a ‘weekly testing’ feasibility study. We conducted semi-structured remote interviews between December 2020 and January 2021. Additional qualitative data from a survey were also analysed. Data were analysed thematically.ResultsWe interviewed 18 and surveyed 214 participants. Participants were motivated to regularly self-test as they wanted to know whether or not they were infected with SARS-CoV-2. Most reported that a negative test result did not change their behaviour but it did provide them with reassurance to engage with permitted activities. In contrast, some participants reported making decisions about visiting other people when they would not have done so otherwise, because they felt reassured by a negative test result. Participants valued the test training but some participants still doubted their ability to carry out the test. Participants were concerned about safety of attending test sites with lots of people and reported home testing was most convenient.ConclusionsIf governments want to increase uptake of LFT use, clear messages highlighting the benefits of regular testing for family, friends and society in identifying asymptomatic cases are needed. This should be coupled with transparent communication about accuracy of LFTs and how to act on either a positive or negative result. Concerns about safety, convenience of testing, and ability to do tests need to be addressed to ensure successful scaling up asymptomatic testing.

Maternal and Perinatal Outcomes in Patients with Suspected COVID-19 and Their Relationship with a Negative RT-PCR Result

This study was designed to examine maternal-perinatal outcomes in pregnant women with suspected coronavirus disease 2019 (COVID-19) according to the result of a real-time reverse transcription polymerase chain reaction (RT-PCR) test and to investigate possible variables that could be useful for predicting a negative RT-PCR result. Participants of this retrospective cohort study were obstetrics patients with suspected COVID-19 who underwent an RT-PCR test in a tertiary hospital in Madrid, Spain. Maternal-perinatal features were analysed according to the results of this test. Clinical, radiological and analytical characteristics that could be associated with a negative result were also explored. In a final subgroup analysis, patients were included if they had pneumonia and a negative test result for the virus. Out of the 111 obstetric patients with suspected COVID-19 that were enrolled, 38.7% returned a negative result. In this RT-PCR-negative group, we recorded lower rates of pneumonia (21.4% vs. 45.6%, p = 0.009), severe or critical clinical features (4.7% vs. 11.8% and 0.0% vs. 5.9%, p = 0.02, respectively), lower lactate dehydrogenase (LDH) levels (168 UI/L vs. 224.5 UI/L, p = 0.003), a greater need for maternal treatment (60.3% vs 24.4%, p < 0.001), a reduced need for oxygen therapy (2.4% vs 28.8%, p < 0.001) and a lower rate of intensive care unit admission (0.0% vs. 3.7%, p = 0.046) than the RT-PCR-positive group. While no differences were found in other variables, the monocyte count was higher (946.2/μL vs. 518.8/μL, p = 0.022) in this group. The predictive model for a negative test result included the monocyte count, LDH level and no need for oxygen therapy. This model was able to identify 73.5% of patients with a negative RT-PCR result. Only 11% of the patients with pneumonia testing negative for the virus had IgG antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The proportion of pregnant women with suspected COVID-19 and a negative RT-PCR result was nearly 39%. In these patients, the symptoms were mild and the systemic severity of the disease was lower. The monocyte count, LDH level and no need for oxygen therapy were the factors that were more related to a negative test result in this group. These variables could be used to guide the management of patients with suspected COVID-19, mainly while waiting for RT-PCR results or in settings where this test is not available.

Screening for diabetic retinopathy using an automated diagnostic system based on deep learning: Diagnostic accuracy assessment

Purpose: To evaluate the diagnostic accuracy of a diagnostic system software for the automated screening of diabetic retinopathy (DR) on digital colour fundus photographs, the 2019 Convolutional Neural Network (CNN) model with Inception-V3. Methods: In this cross-sectional study 295 fundus images were analysed by the CNN model and compared to a panel of ophthalmologists. Images were obtained from a dataset acquired within a screening programme. Diagnostic accuracy measures and respective 95% confidence intervals (CI) were calculated. Results: The sensitivity and specificity of the CNN model in diagnosing referable DR was 81% [95% confidence interval (CI), 66%−90%] and 97% (95% CI, 95%−99%), respectively. Positive predictive value was 86% (95% CI, 72%−94%) and negative predictive value 96% (95% CI, 93%−98%). The positive likelihood ratio was 33 (95% CI, 15−75) and the negative was 0.20 (95% CI, 0.11−0.35). Its clinical impact is demonstrated by the change observed in the pre-test probability of referable DR (assuming a prevalence of 16%) to a post-test probability for a positive test result of 86% and for a negative test result of 4%. Conclusion: A CNN model negative test result safely excludes DR and its use may significantly reduce the burden of ophthalmologists at reading centres.

Managing the risk of a COVID-19 outbreak from border arrivals

In an attempt to maintain elimination of COVID-19 in New Zealand, all international arrivals are required to spend 14 days in government-managed quarantine and to return a negative test result before being released. We model the testing, isolation and transmission of COVID-19 within quarantine facilities to estimate the risk of community outbreaks being seeded at the border. We use a simple branching process model for COVID-19 transmission that includes a time-dependent probability of a false negative test result. We show that the combination of 14-day quarantine with two tests reduces the risk of releasing an infectious case to around 0.1% per infected arrival. Shorter quarantine periods, or reliance on testing only with no quarantine, substantially increases this risk. We calculate the fraction of cases detected in the second week of their two week stay and show that this may be a useful indicator of the likelihood of transmission occurring within quarantine facilities. Frontline staff working at the border risk exposure to infected individuals and this has the potential to lead to a community outbreak. We use the model to test surveillance strategies and evaluate the likely size of the outbreak at the time it is first detected. We conclude with some recommendations for managing the risk of potential future outbreaks originating from the border.

COVID-19 screening during fertility treatment: How do guidelines compare against each other? (Preprint)

UNSTRUCTURED Various fertility scientific societies have published pathways and recommendations for COVID-19 screening during fertility treatments. As there is currently very limited research evidence how to best deliver this screening, it is not surprising that there are noticeable differences between their recommendations. This paper compares the screening pathways recommended by these guidelines, in the light of the emerging evidence. It proposes the more liberal use of viral testing for improving detection of asymptomatic or mildly symptomatic fertility patients. It also argues that a negative test result on symptomatic individuals should not be over-relied upon for allowing the treatment to proceed. In these cases, a low threshold for cancellation may still need to be maintained.

Does improving appropriate use of malaria medicines change population beliefs in testing and treatment? Evidence from a randomized controlled trial

A major puzzle in malaria treatment remains the dual problem of underuse and overuse of malaria medications, which deplete scarce public resources used for subsidies and lead to drug resistance. One explanation is that health behaviour, especially in the context of incomplete information, could be driven by beliefs, pivotal to the success of health interventions. The objective of this study is to investigate how population beliefs change in response to an experimental intervention which was shown to improve access to rapid diagnostic testing (RDT) through community health workers (CHWs) and to increase appropriate use of anti-malaria medications. By collecting data on individuals’ beliefs on malaria testing and treatment 12 and 18 months after the experimental intervention started, we find that the intervention increases the belief that a negative test result is correct, and the belief that the first-line anti-malaria drugs (artemisinin-based combination therapies or ACTs) are effective. Using mediation analysis, we also explore some possible mechanisms through which the changes happen. We find that the experience and knowledge about RDT and experience with CHWs explain 62.4% of the relationship between the intervention and the belief that a negative test result is correct. Similarly, the targeted use of ACTs and taking the correct dose—in addition to experience with RDT—explain 96.8% of the relationship between the intervention and the belief that the ACT taken is effective. As beliefs are important determinants of economic behaviour and might guide individuals’ future decisions, understanding how they change after a health intervention has important implications for long-term changes in population behaviour.