Transmission risk of SARS-CoV-2 to healthcare workers -observational results of a primary care hospital contact tracing.

BACKGROUND: The coronavirus disease (COVID)-19 epidemic is evolving rapidly. Healthcare workers are at increased risk for infection, and specific requirements for their protection are advisable to ensure the functioning of the basic healthcare system, including the availability of general practitioners (GPs). Understanding the transmission risk is particularly important for guiding evidence-based protective measures in the primary healthcare setting. METHODS: Healthcare worker contacts of an initially undiagnosed COVID-19 case, who were without personal protective equipment, in particular not wearing facemasks, were screened with nasopharyngeal swabs and polymerase chain reaction tests for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), irrespective of respiratory symptoms or fever seven days after initial contact. The details of exposure to the index case were obtained during routine contact investigation after unintentional pathogen exposure. RESULTS: Twenty-one healthcare workers reported contacts with the index case. Three healthcare workers reported respiratory symptoms (cough) or low-grade fever within 4 days. None of them tested positive for SARS-CoV-2 at the time of symptom onset. All 21 healthcare workers tested SARS-CoV-2 negative 7 days after initial index case contact, including the three healthcare workers with previous symptoms. Ten of the 21 healthcare workers reported a cumulative exposure time of >15 minutes. Longer cumulative contact times were associated with more individual contacts, reduced contact time per contact and activities with physical patient contact. The closest relative of the index patient tested SARS-CoV-2 positive 2 days after the index case presented at the hospital emergency department. CONCLUSION: We found a low risk of SARS-CoV-2 transmission in a primary care setting. These findings are compatible with previous reports of the highest transmission probability in household settings with prolonged close contacts. The current protective measures for healthcare workers, including strict adherence to basic standard hygiene and facemasks, offer considerable protection during short periods of contact with symptomatic COVID-19 cases by diminishing the risk of direct and indirect transmission.

COVID-19 in a Patient with Accidental Drug-Induced Neutropenia.

BACKGROUND: Coronavirus disease 2019 (COVID-19) presents with a wide range of illness severity, from asymptomatic disease to severe acute respiratory distress syndrome (ARDS). Immunosuppression is considered a risk factor for severe COVID-19, but there are only few reports on disease progression in immunocompromised patients. CASE SUMMARY: We report the case of a 50-year-old patient with acute COVID-19 pneumonia, who had iatrogenic, clinically relevant bone marrow suppression due to accidental overdose with hydroxyurea, and decreased lung capacity due to a left-sided pneumonectomy 6 months earlier. Symptomatic treatment with oxygen supplementation and pulmonary physical therapy was initiated, and hydroxyurea was discontinued. Over 14 days, the patient's blood counts slowly recovered, and his clinical condition gradually improved, such that supplemental oxygen was no longer necessary and he could be discharged. DISCUSSION: A gradual increase in neutrophil and lymphocyte counts may be preferable to dampen a potentially detrimental immunological response triggered by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Whether patients with severe COVID-19 benefit from immunosuppressive therapy should be further evaluated. LEARNING POINTS: Acute respiratory distress syndrome is a serious complication in COVID-19 and appears to be triggered by a proinflammatory cytokine storm.Immunosuppression may avoid an immune hyper-response triggered by SARS-CoV-2.

Vaccination willingness for COVID-19 among healthcare workers: a cross-sectional survey in a Swiss canton.

AIMS OF THE STUDY: Vaccination is regarded as the most promising response to the COVID-19 pandemic. We assessed opinions about COVID-19 vaccination, willingness to be vaccinated, and reasons for vaccination hesitancy among healthcare workers. METHODS: We conducted a cross-sectional, web-based survey among 3,793 healthcare workers in December 2020 in the Canton of Solothurn, Switzerland, before the start of the national COVID-19 vaccination campaign. RESULTS: Median age was 43 years (interquartile range [IQR] 31-53), 2,841 were female (74.9%). A total of 1,511 healthcare workers (39.8%) reported willingness to accept vaccination, whereas 1,114 (29.4%) were unsure and 1,168 (30.8%) would decline vaccination. Among medical doctors, 76.1% were willing, whereas only 27.8% of nurses expressed willingness. Among the 1,168 healthcare workers who would decline vaccination, 1,073 (91.9%) expressed concerns about vaccine safety and side effects. The willingness of healthcare workers to be vaccinated was associated with older age (adjusted odds ratio [aOR] 1.97, 95% confidence interval [Cl] 1.71-2.27) and having been vaccinated for influenza this year (aOR 2.70, 95% Cl 2.20-3.31). Healthcare workers who reported a lack of confidence in government were less likely to be willing to be vaccinated (aOR 0.58, 95% Cl 0.40-0.84), and women were less willing to be vaccinated than men (OR 0.33, 95% CI 0.28-0.38). CONCLUSION: Less than half of healthcare workers reported willingness to be vaccinated before the campaign start, but proportions varied greatly depending on profession and workplace. Strategies with clear and objective messages that particularly address the concerns of healthcare workers are needed if their willingness to be vaccinated against COVID-19 is to be further increased.

Seroprevalence of SARS-CoV-2 in healthcare workers from outpatient facilities and retirement or nursing homes in a Swiss canton.

BACKGROUND: Healthcare workers are more frequently exposed to SARS-CoV-2 than the general population. Little is known about healthcare settings outside of hospitals. We studied the seroprevalence of SARS-CoV-2 among healthcare workers in outpatient facilities and retirement or nursing homes in the Canton of Solothurn, Switzerland in the first wave of the COVID-19 pandemic. METHODS: Longitudinal seroprevalence study among healthcare workers with examinations at baseline and 2 months between June and September 2020. The Abbott SARS-CoV-2 IgG and Liaison/Diasorin SARS-CoV-2 S1/S2 IgG assay were used to detect antibodies against SARS-CoV-2. All participants provided demographic information. We report descriptive statistics and calculated the seroprevalence with 95% confidence intervals. RESULTS: We included 357 healthcare workers; their median age was 43 years (interquartile range 29-54), and 315 (88.2%) were female. Forty-nine (13.7%) were physicians, 87 (24.4%) practice assistants and 221 (61.9%) nurses. Overall seroprevalence among healthcare workers in outpatient facilities and retirement or nursing homes was 3.4% (12/357). The 12 seropositive healthcare workers were all nurses (12/221, 5.5%); 11 worked at retirement or nursing homes and one at the hospital's outpatient clinic. Symptoms such as loss of smell or taste, shortness of breath, and fever were more prevalent among seropositive healthcare workers than seronegative healthcare workers. No close contact had detectable antibodies against SARS-CoV-2. CONCLUSIONS: Seroprevalence among healthcare workers was low, but higher among nursing staff of retirement or nursing homes. Healthcare workers at private practices were able to protect themselves well during the first wave of the COVID-19 pandemic.

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Setting-specific Transmission Rates: A Systematic Review and Meta-analysis.

BACKGROUND: Understanding the drivers of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission is crucial for control policies, but evidence of transmission rates in different settings remains limited. METHODS: We conducted a systematic review to estimate secondary attack rates (SARs) and observed reproduction numbers (Robs) in different settings exploring differences by age, symptom status, and duration of exposure. To account for additional study heterogeneity, we employed a beta-binomial model to pool SARs across studies and a negative-binomial model to estimate Robs. RESULTS: Households showed the highest transmission rates, with a pooled SAR of 21.1% (95% confidence interval [CI]:17.4-24.8). SARs were significantly higher where the duration of household exposure exceeded 5 days compared with exposure of ≤5 days. SARs related to contacts at social events with family and friends were higher than those for low-risk casual contacts (5.9% vs 1.2%). Estimates of SARs and Robs for asymptomatic index cases were approximately one-seventh, and for presymptomatic two-thirds of those for symptomatic index cases. We found some evidence for reduced transmission potential both from and to individuals younger than 20 years of age in the household context, which is more limited when examining all settings. CONCLUSIONS: Our results suggest that exposure in settings with familiar contacts increases SARS-CoV-2 transmission potential. Additionally, the differences observed in transmissibility by index case symptom status and duration of exposure have important implications for control strategies, such as contact tracing, testing, and rapid isolation of cases. There were limited data to explore transmission patterns in workplaces, schools, and care homes, highlighting the need for further research in such settings.

Diagnosis of latent tuberculosis infection is associated with reduced HIV viral load and lower risk for opportunistic infections in people living with HIV.

Approximately 28% of the human population have been exposed to Mycobacterium tuberculosis (MTB), with the overwhelming majority of infected individuals not developing disease (latent TB infection (LTBI)). While it is known that uncontrolled HIV infection is a major risk factor for the development of TB, the effect of underlying LTBI on HIV disease progression is less well characterized, in part because longitudinal data are lacking. We sorted all participants of the Swiss HIV Cohort Study (SHCS) with at least 1 documented MTB test into one of the 3 groups: MTB uninfected, LTBI, or active TB. To detect differences in the HIV set point viral load (SPVL), linear regression was used; the frequency of the most common opportunistic infections (OIs) in the SHCS between MTB uninfected patients, patients with LTBI, and patients with active TB were compared using logistic regression and time-to-event analyses. In adjusted models, we corrected for baseline demographic characteristics, i.e., HIV transmission risk group and gender, geographic region, year of HIV diagnosis, and CD4 nadir. A total of 13,943 SHCS patients had at least 1 MTB test documented, of whom 840 (6.0%) had LTBI and 770 (5.5%) developed active TB. Compared to MTB uninfected patients, LTBI was associated with a 0.24 decreased log HIV SPVL in the adjusted model (p < 0.0001). Patients with LTBI had lower odds of having candida stomatitis (adjusted odds ratio (OR) = 0.68, p = 0.0035) and oral hairy leukoplakia (adjusted OR = 0.67, p = 0.033) when compared to MTB uninfected patients. The association of LTBI with a reduced HIV set point virus load and fewer unrelated infections in HIV/TB coinfected patients suggests a more complex interaction between LTBI and HIV than previously assumed.