xxxxxTransmission

Gliederung

The Virus

Ecology + Fomites

Aboubakr

Stability of SARS-CoV-2 and other coronaviruses in the environment and on common touch surfaces and the influence of climatic conditions: a review. Transbound Emerg Dis. A comprehensive review of the available data (by May 21, 2020) on the stability of coronaviruses, including SARS‐CoV‐2, from previous reports, to help understand its environmental survival (Aboubakr 2020).

 

wang

Super-factors associated with transmission of occupational COVID-2019 infection among healthcare staff in Wuhan , China. Don’t touch your nose: This cross-sectional study was conducted among 92 frontline members of medical staff. The main factor that contributed to COVID-19 infections was touching the cheek, nose and mouth while working, emphasizing the need to strengthen hand, oral and nasal hygiene practices. Wearing the right type or size of PPE every time as required and following the operation specifications and operation instructions improved self-protection (Wang Y 2020).

Pastorino

Prolonged infectivity of SARS-CoV-2 in fomites. Emerg Infect Dis. 2020. Clean surfaces! The authors observed a steady infectivity (< 1 log10 drop) on plastic, a 3.5 log10 decrease on glass, and a 6 log10 drop on aluminum within 96 hours. Data showed that SARS-CoV-2 infectivity was remarkably preserved in the presence of proteins (bovine serum albumin), regardless of the type of surface (Pastorino 2020).

Matson

Environmental conditions affect the stability of the virus in nasal mucus and sputum. The virus is more stable at low temperature and low humidity conditions, whereas warmer temperatures and higher humidity shortened half-life (Matson 2020). Although infectious virus was undetectable after 48 hours, viral RNA remained detectable for 7 days.

 

Routes of transmission

Respiratory

Morawska

It is Time to Address Airborne Transmission of COVID-19. Clinical Infectious Diseases, July 6, 2020. In their comment, the authors appeal to the medical community and to all relevant national and international bodies to recognize the potential for airborne spread of COVID-19. Given the significant potential for inhalation exposure to viruses in microscopic respiratory droplets (microdroplets) at short to medium distances (up to several meters, or room scale), the authors are advocating for the use of preventive measures. This includes sufficient and effective ventilation (supply clean outdoor air, minimize recirculating air) particularly in public buildings, workplace environments, schools, hospitals, and aged care homes, but also supplement general ventilation with airborne infection control (such as local exhaust, high efficiency air filtration, and germicidal ultraviolet lights). Third, overcrowding has to be avoided, particularly in public transport and public buildings (Morawska 2020).

Reducing transmission of SARS-CoV-2. Aerosol transmission of viruses must be acknowledged as a key factor leading to the spread of infectious respiratory diseases. This viewpoint summarizes current research that is already leading to a better understanding of the importance of airborne transmission (Prather 2020).

Dhand

After inhalation, larger respiratory droplets are filtered by the nose or deposit in the oropharynx, whereas smaller droplet nuclei are carried by the airstream into the lungs where their site of deposition depends on their mass, size and shape and is governed by various mechanisms (Dhand 2020).

Airborne particles could also be produced by various aerosol generating procedures, such as suctioning or tracheal intubation, and by aerosol generators, especially jet nebulizers. (Dhand 2020).

Airborne transmission of this virus has not been established, but is possible under special circumstances. (Dhand 2020).

Everything you always wanted to know about… coughs and sneezes. A total of 79 references are used to explain how larger droplets produced by coughing and sneezing settle quickly, and the force with which they are expelled determines how far they are dispersed. Nice visuals in the supplement at the end of the paper. (Dhand 2020).

Jayaweera

Interestingly, the nosocomial transmission by airborne SARS-CoV-2 virus-laden aerosols in healthcare facilities may be plausible. Hence, clearly defined, science-based administrative, clinical, and physical measures are of paramount importance to eradicate the COVID-19 pandemic from the world (Jayaweera 2020).

Carraturo

Reviewing the current literature, these authors come to the conclusion that COVID-19 airborne spread via particulates is not a major transmission route. Virus persistance in water, wastewater, and sludge is very low at more than 20 °C (Carraturo 2020).

Abbas

Surfing the COVID-19 scientific wave. Lancet June 30, 2020. Harsh, relentless (maybe justified?) critical letter on the methodological flaws of the experiment of visualizing speech-generated oral fluid droplets (see below). The authors are “surprised that experiments in one person were published in a leading scientific journal” and state that the experiment had “more to do with sialoquence (spraying saliva when speaking) than with SARS-CoV-2” (Abbas 2020). Anfinrud P Stadnytskyi V Bax CE Bax A. Visualizing speech-generated oral fluid droplets with laser light scattering. N Engl J Med. 2020; 382: 2061-2063. Full-text: https://www.nejm.org/doi/full/10.1056/nejmc2007800

 

Mother-to-Child

Bastug

Virolactia in an Asymptomatic Mother with COVID-19. Breastfeed Med. Another case report of a pregnant woman with subclinical COVID-19 whose breast milk sample obtained after delivery tested positive for SARS-CoV-2 by RT-PCR. In addition, although an initial nasopharyngeal swab (NPS) sample from the neonate resulted negative, neonatal NPS, stool, and blood samples obtained after breastfeeding were all positive in real-time RT-PCR assay (Bastug 2020).

Stool, urine

Du W, Yu J, Liu X, Chen H, Lin L, Li Q. Persistence of SARS-CoV-2 virus RNA in feces: A case series of children. J Infect Public Health. 2020 Jun 7. PubMed: https://pubmed.gov/32546439. Full-text: https://doi.org/10.1016/j.jiph.2020.05.025

During follow-up examination after discharge, seven out of ten children contained SARS-CoV-2 virus RNA in their fecal specimens, despite all patients showing negative results in respiratory tract specimens. One out of those seven patients relapsed. The median time from onset to being negative in respiratory tract and fecal specimens was 9 days and 34.43 days, respectively (Du W 2020).

Sexual transmission

Guo

Absence of SARS-CoV-2 in Semen of a COVID-19 Patient Cohort. Andrology. No virus in the semen: all of 23 brave patients with SARS-CoV-2 infections (12 of them still positive in sputum and fecal specimens) tested negative for SARS‐CoV‐2 RNA in semen specimens (Guo L 2020).

Cats and dogs

Newman

Two domestic cats with respiratory illnesses lasting 8 and 10 days were the first reported companion animals with SARS-CoV-2 infection in the United States. Both cats were owned by persons with suspected or confirmed COVID-19. According to the authors, persons with COVID-19 should avoid contact with animals. Companion animals that test positive for SARS-CoV-2 should be monitored and separated from persons and other animals until they recover. Good news: both cats fully recovered (Newman 2020).

Anthroponotic risk of SARS-CoV-2, precautionary mitigation, and outbreak management. Lancet Microbe, July 02, 2020. Important comment on the evidence of infection of animals with SARS-CoV-2 that has been shown experimentally both in vivo and in vitro for mammals including monkeys, cats, ferrets, rabbits, foxes, and hamsters, while bioinformatic studies also predict infectivity of pigs and wild boar among other mammals. According to the authors, we should also consider the potential for transmissibility, not just infection (Edwards 2020).

Exaggerated risk of transmission of COVID-19 by fomites. Lancet Inf Dis July 03, 2020. A note of caution, to curb excesses that become counterproductive. According to the author, the chance of transmission through inanimate surfaces is very small, and only in instances where an infected person coughs or sneezes on the surface, and someone else touches that surface soon after the cough or sneeze (within 1–2 h). Although periodically disinfecting surfaces and use of gloves are reasonable precautions especially in hospitals, he believes that fomites that have not been in contact with an infected carrier for many hours do not pose a measurable risk of transmission (Goldman 2020).

Schlottau K,

SARS-CoV-2 in fruit bats, ferrets, pigs, and chickens: an experimental transmission study. Lancet Microbe . Lucky pigs. The authors intranasally inoculated twelve fruit bats (Rousettus aegyptiacus), 12 ferrets (Mustela putorius), pigs (Sus scrofa domesticus), and 20 chickens (Gallus gallus domesticus) with TCID50 of a SARS-CoV-2 isolate per animal. Pigs and chickens could not be infected intranasally or oculo-oronasally by SARS-CoV-2, whereas fruit bats showed characteristics of a reservoir host. Virus replication in ferrets resembled a subclinical human infection with efficient spread (Schlottau 2020).

 

Transmission event

Virus

Transmittor

Shrestha

Distribution of Transmission Potential during Non-Severe COVID-19 Illness. Clin Inf Dis 29 June 2020. Infectivity lasts ten days. In 230 HCW with non-severe COVID-19, viral loads declined by orders of magnitude within a few days of symptom onset. Of the area under the curve (the distribution of transmission potential over time during the course of illness) spanning symptom onset to 30 days, 86.3% lay within the first 5 days, 96.9% within the first 7 days, and 99.7% within the first 10 days. The only variable significantly associated with viral load was time from onset of symptoms (Shrestha 2020).

Transmission setting

Nosocomial

Ortega

Personal Protective Equipment and Covid-19. Helpful video, demonstrating the complex procedure for putting on and removing PPE that has been recommended by the CDC to minimize the risk of exposure to infectious material during the care of patients with COVID-19 (Ortega 2020 ).

Rickman HM, Rampling T, Shaw K, et al.

Nosocomial transmission of COVID-19: a retrospective study of 66 hospital-acquired cases in a London teaching hospital. Clin Infect Dis. A good example for working up a catastrophy, learning from mistakes. Of 435 cases of PCR-positive inpatients in a London hospital, 47 (11%) met the definition for definite hospital acquisition, with a further 19 (4%) probable hospital-acquired. Symptom onset for these 66 hospital acquired cases was a median of 26 days (IQR 13-55) from admission. 24 (36%) patients died. Evidence of patient-to-patient transmission through contact in the same hospital bay was found in 55% (Rickman 2020).

El-Boghdadly

Risks to healthcare workers following tracheal intubation of patients with COVID-19: a prospective international multicentre cohort study. Tracheal intubation exposes health care workers to a substantial risk of acquiring SARS-CoV-2 infection. In a prospective international multicentre cohort study, 1,718 healthcare workers participated in 5,148 tracheal intubation episodes of patients with suspected or confirmed COVID‐19 (503 hospitals, 17 countries). The overall incidence of the primary endpoint (lab‐confirmed COVID‐19 diagnosis or new symptoms requiring self‐isolation or hospitalisation) was 10.7% over a median follow‐up of 32 days (El-Boghdadly 2020).

Maltezou

SARS-CoV-2 infection in healthcare personnel with high-risk occupational exposure: evaluation of seven-day exclusion from work policy. In this study, 3,398 occupationally-exposed HCW were followed prospectively, among them 1,599 (47.1%) with low-risk, 765 (22.5%) with moderate-risk, and 1,031 (30.4%) with high-risk exposures. Of the 66 HCW with COVID-19, 46, 7, and 13 had a history of high-, moderate- or low-risk exposure. Male gender, administrative personnel, underlying disease and high-risk exposure were significantly associated with an increased risk for the onset of COVID-19. HCW with high-risk occupational exposure to COVID-19 had increased probability of serious morbidity, healthcare seeking, hospitalization and absenteeism (Maltezou 2020).

Super-spreading

Xu

A study of 1,407 transmission pairs that formed 643 transmission clusters in mainland China identified 34 super-spreaders, with 29 super-spreading events occurring outside of households. This is consistent with a recent study (Leclerc 2020) on transmission settings of COVID-19 (e.g., hospitals, residential care, prisons, boarding schools, cruise ships) (Xu XK 2020).

Mani

In the University of Washington Medicine system and its affiliated organizations, between March 12 and April 23, a total of 3,477 symptomatic employees were tested; 185 (5.3%) employees tested positive for COVID-19. The prevalence of SARS-CoV-2 was similar when comparing frontline HCWs (5.2%) to non-frontline staff (5.5%). (Mani 2020).

 

Temperature and Climate

US, India, Brasil – warm climate doesn’t prevent SARS-CoV-2 to spread in a community.

 

Prevention

Bielecki M,

Social distancing alters the clinical course of COVID-19 in young adults: A comparative cohort study. Important finding that was long suspected: viral inoculum during infection or mode of transmission may be key factors determining the clinical course of COVID-19. The authors prospectively studied an outbreak in Switzerland among a population of 508 predominantly male soldiers with a median age of 21 years. Infections were followed in two spatially separated cohorts with almost identical baseline characteristics – before and after implementation of stringent social distancing. Results: of 354 soldiers infected prior to the implementation of social distancing, 30% fell ill. In contrast, none out of 154 soldiers in which infections (confirmed by NP swabs or serology) appeared after implementation of social distancing developed COVID-19 (Bielecki 2020).

 

Chu

Awaiting results from (difficult) randomised trials, the currently best available evidence suggests for all public and healthcare settings (Chu DK 2020) the FPE protection triade of

Physical distancing of at least 1 m, better 2 m.

Face mask, ideally N95 or similar.

Eye protection (mandatory in health care settings and similar).

Dau

Why N95 Should Be the Standard for All COVID-19 Inpatient Care. Ann Int Med 2020. Important viewpoint emphasizing that N95 respirators achieve better filtration of airborne particles than medical masks if used properly and continuously. According to the authors, guideline recommendations that do not support N95 use for all inpatient COVID-19 management should consider reevaluating existing data or at least acknowledge the issues raised (Dau 2020).

Oosterhoff

Attitudes and Psychological Factors Associated With News Monitoring, Social Distancing, Disinfecting, and Hoarding Behaviors Among US Adolescents During the Coronavirus Disease 2019 Pandemic. JAMA. Interesting survey on 770 adolescents’ beliefs about COVID-19 and community attachment as well as attitudes and psychological factors that inform their response to the pandemic. Many teens reported not engaging in pure social distancing (69%), but they were monitoring the news (89%) and disinfecting daily (88%). Some teens reported hoarding (20%). Greater social responsibility was associated with more disinfecting and news monitoring and less hoarding. Greater self-interest values were associated with less social distancing and more hoarding (Oosterhoff 2020).

 

 

 

Outlook

In mid-July

Jing JQ, Liu MJ, Yuan J. Household secondary attack rate of COVID-19 and associated determinants in Guangzhou, China: a retrospective cohort study. Lancet Infect Dis. 2020. https://doi.org/10.1016/S1473-3099(20)30471-0

Are children less susceptible? Using a comprehensive contact tracing dataset, the authors estimated secondary attack rate among household contacts to be 12.4% (95% CI 9.8–15.4) when household contacts were defined on the basis of close relatives, and 17.1% (13.3–21.8) when household contacts were defined on the basis of residential address. Compared with the oldest age group (≥ 60 years), the risk of household infection was lower in the youngest age group (< 20 years; odds ratio 0.23) and among adults aged 20–59 years (OR 0.64).

 

Du W, Yu J, Liu X, Chen H, Lin L, Li Q. Persistence of SARS-CoV-2 virus RNA in feces: A case series of children. J Infect Public Health. 2020 Jun 7. PubMed: https://pubmed.gov/32546439. Full-text: https://doi.org/10.1016/j.jiph.2020.05.025

During follow-up examination after discharge, seven out of ten children contained SARS-CoV-2 virus RNA in their fecal specimens, despite all patients showing negative results in respiratory tract specimens. One out of those seven patients relapsed. The median time from onset to being negative in respiratory tract and fecal specimens was 9 days and 34.43 days, respectively.

 

Dhand R, Li J. Coughs and Sneezes: Their Role in Transmission of Respiratory Viral Infections, Including SARS-CoV-2. Am J Respir Crit Care Med. 2020 Jun 16. PubMed: https://pubmed.gov/32543913. Full-text: https://doi.org/10.1164/rccm.202004-1263PP

Everything you always wanted to know about… coughs and sneezes. A total of 79 references are used to explain how larger droplets produced by coughing and sneezing settle quickly, and the force with which they are expelled determines how far they are dispersed. Nice visuals in the supplement at the end of the paper.

 

Clapham H, Hay J, Routledge I, et al. Seroepidemiologic Study Designs for Determining SARS-COV-2 Transmission and Immunity. Emerg Infect Dis. 2020 Jun 16;26(9). PubMed: https://pubmed.gov/32544053. Full-text: https://doi.org/10.3201/eid2609.201840

Numerous challenges exist in terms of sample collection, what the presence of antibodies actually means, and appropriate analysis and interpretation to account for test accuracy and sampling biases. The authors review strengths and limitations of different assay types and study designs, and discuss methods for rapid sharing and analysis of serologic data.

 

Xu XK, Liu XF, Wu Y, et al. Reconstruction of Transmission Pairs for novel Coronavirus Disease 2019 (COVID-19) in mainland China: Estimation of Super-spreading Events, Serial Interval, and Hazard of Infection. Clinical Infectious Diseases 2020. Full-text: https://doi.org/10.1093/cid/ciaa790

The virus is so fast: This database with detailed demographic characteristics, travel history, social relationships, and epidemiological timelines for 1,407 transmission pairs that formed 643 transmission clusters in mainland China used statistical model fittings to identify the super-spreaders and estimate serial interval distributions. There were 34 primary cases identified as super-spreaders, with 5 super-spreading events occurring within households. Serial intervals were short and were estimated as 5.0 (95% CI: 4.4-5.5) and 5.2 (95% CI: 4.9- 5.7) days for household transmissions and 5.2 (95% CI: 4.6-5.8) and 5.3 (95% CrI: 4.9-5.7) days for non-household transmissions, respectively.

 

Mani NS, Budak JZ, Lan KF, et al. Prevalence of COVID-19 Infection and Outcomes Among Symptomatic Healthcare Workers in Seattle, Washington. Clin Infect Dis. 2020 Jun 16:ciaa761. PubMed: https://pubmed.gov/32548613. Full-text: https://doi.org/10.1093/cid/ciaa761

The authors have stablished two high-throughput employee testing centers in Seattle, Washington with drive-through and walk-through options for symptomatic employees at the University of Washington Medicine system and its affiliated organizations. Between March 12 and April 23, a total of 3,477 symptomatic employees were tested; 185 (5.3%) employees tested positive for COVID-19. The prevalence of SARS-CoV-2 was similar when comparing frontline HCWs (5.2%) to non-frontline staff (5.5%).

 

Rickman HM, Rampling T, Shaw K, et al. Nosocomial transmission of COVID-19: a retrospective study of 66 hospital-acquired cases in a London teaching hospital. Clin Infect Dis. 2020 Jun 20. PubMed: https://pubmed.gov/32562422. Full-text: https://doi.org/10.1093/cid/ciaa816

A good example for working up a catastrophy, learning from mistakes. Of 435 cases of PCR-positive inpatients in a London hospital, 47 (11%) met the definition for definite hospital acquisition, with a further 19 (4%) probable hospital-acquired. Symptom onset for these 66 hospital acquired cases was a median of 26 days (IQR 13-55) from admission. 24 (36%) patients died. Evidence of patient-to-patient transmission through contact in the same hospital bay was found in 55%.

 

Jayaweera M, Perera H, Gunawardana B, Manatunge J. Transmission of COVID-19 virus by droplets and aerosols: A critical review on the unresolved dichotomy. Environ Res. 2020 Jun 13;188:109819. PubMed: https://pubmed.gov/32569870. Full-text: https://doi.org/10.1016/j.envres.2020.109819

This review paper “intends to outline the literature” (no doubt they‘ve done it, 139 references!) concerning the transmission of virus-laden droplets and aerosols in different environmental settings. Nice pictures, demonstrating the behavior of droplets and aerosols resulting from a cough-jet of an infected person in various confined spaces.

 

Rafferty M, Nihtianova S, Amirian ES. COVID-19 Safety Grades for Businesses—A Possible Mitigation Tool. JAMA Health Forum June 22, 2020. Full-text: https://jamanetwork.com/channels/health-forum/fullarticle/2767689

The average customer has no reliable way of knowing whether those in a restaurant kitchen or in employee-only areas are following good hygiene, wearing facial coverings, and observing social distancing. Many jurisdictions are relying on public health recommendations for businesses, which depend on cooperation and are legally unenforceable. The authors propose a tactic that could provide some of the requisite knowledge individuals need to make more informed decisions.

 

Carraturo F, Del Giudice C, Morelli M, et al. Persistence of SARS-CoV-2 in the environment and COVID-19 transmission risk from environmental matrices and surfaces. Environ Pollut. 2020 Jun 9;265(Pt B):115010. PubMed: https://pubmed.gov/32570023. Full-text: https://doi.org/10.1016/j.envpol.2020.115010

Reviewing the current literature, these authors come to the conclusion that COVID-19 airborne spread via particulates is not a major transmission route. Virus persistance in water, wastewater, and sludge is very low at more than 20 °C.

 

Wang Y, Wu W, Cheng Z, et al. Super-factors associated with transmission of occupational COVID-2019 infection among healthcare staff in Wuhan , China. J Hosp Infect. 2020 Jun 20:S0195-6701(20)30308-X. PubMed: https://pubmed.gov/32574702. Full-text: https://doi.org/10.1016/j.jhin.2020.06.023

Don’t touch your nose: This cross-sectional study was conducted among 92 frontline members of medical staff. The main factor that contributed to COVID-19 infections was touching the cheek, nose and mouth while working, emphasizing the need to strengthen hand, oral and nasal hygiene practices. Wearing the right type or size of PPE every time as required and following the operation specifications and operation instructions improved self-protection.

 

Chou R, Dana R, Jungbauer R, et al. Masks for Prevention of Respiratory Virus Infections, Including SARS-CoV-2, in Health Care and Community Settings. Ann Int Med 24 Jun 2020. Full-text: https://doi.org/10.7326/M20-3213

According to this “living rapid” review of 39 studies (18 randomized controlled trials and 21 observational studies; 33,867 participants), evidence on mask effectiveness for respiratory infection prevention is stronger in health care than community settings. N95 respirators might reduce SARS-CoV-1 risk versus surgical masks in health care settings, but applicability to SARS-CoV-2 is uncertain.

 

Ortega R, Gonzalez M, Nozari A, et al. Personal Protective Equipment and Covid-19. N Engl J Med 2020; June 25. Full-text: https://doi.org/10.1056/NEJMvcm2014809

Helpful video, demonstrating the complex procedure for putting on and removing PPE that has been recommended by the CDC to minimize the risk of exposure to infectious material during the care of patients with COVID-19.

 

Prather KA, Wang CC, Schooley RT. Reducing transmission of SARS-CoV-2. Science  26 Jun 2020: Vol. 368, Issue 6498, pp. 1422-1424. Full-text: https://doi.org/10.1126/science.abc6197

Aerosol transmission of viruses must be acknowledged as a key factor leading to the spread of infectious respiratory diseases. This viewpoint summarizes current research that is already leading to a better understanding of the importance of airborne transmission.

 

Bielecki M, Züst R, Siegrist D, et al. Social distancing alters the clinical course of COVID-19 in young adults: A comparative cohort study. Clin Inf Dis, June 29, 2020. Full-text: https://doi.org/10.1093/cid/ciaa889

Important finding that was long suspected: viral inoculum during infection or mode of transmission may be key factors determining the clinical course of COVID-19. The authors prospectively studied an outbreak in Switzerland among a population of 508 predominantly male soldiers with a median age of 21 years. Infections were followed in two spatially separated cohorts with almost identical baseline characteristics – before and after implementation of stringent social distancing. Results: of 354 soldiers infected prior to the implementation of social distancing, 30% fell ill. In contrast, none out of 154 soldiers in which infections (confirmed by NP swabs or serology) appeared after implementation of social distancing developed COVID-19.

Maltezou HC, Dedoukou X, Tseroni M, et al. SARS-CoV-2 infection in healthcare personnel with high-risk occupational exposure: evaluation of seven-day exclusion from work policy. Clin Inf Dis June 29, 2020. Full-text:  https://doi.org/10.1093/cid/ciaa888

In this study, 3,398 occupationally-exposed HCW were followed prospectively, among them 1,599 (47.1%) with low-risk, 765 (22.5%) with moderate-risk, and 1,031 (30.4%) with high-risk exposures. Of the 66 HCW with COVID-19, 46, 7, and 13 had a history of high-, moderate- or low-risk exposure. Male gender, administrative personnel, underlying disease and high-risk exposure were significantly associated with an increased risk for the onset of COVID-19. HCW with high-risk occupational exposure to COVID-19 had increased probability of serious morbidity, healthcare seeking, hospitalization and absenteeism.

 

Shrestha NK, Canosa FM, Nowacki AS, et al. Distribution of Transmission Potential during Non-Severe COVID-19 Illness. Clin Inf Dis 29 June 2020. Full-text: https://doi.org/10.1093/cid/ciaa886

Infectivity lasts ten days. In 230 HCW with non-severe COVID-19, viral loads declined by orders of magnitude within a few days of symptom onset. Of the area under the curve (the distribution of transmission potential over time during the course of illness) spanning symptom onset to 30 days, 86.3% lay within the first 5 days, 96.9% within the first 7 days, and 99.7% within the first 10 days. The only variable significantly associated with viral load was time from onset of symptoms.

 

Pastorino B, Touret F, Gilles M, de Lamballerie X, Charrel RN. Prolonged infectivity of SARS-CoV-2 in fomites. Emerg Infect Dis. 2020 Sep [date cited]. Full-text: https://doi.org/10.3201/eid2609.201788

Clean surfaces! The authors observed a steady infectivity (< 1 log10 drop) on plastic, a 3.5 log10 decrease on glass, and a 6 log10 drop on aluminum within 96 hours. Data showed that SARS-CoV-2 infectivity was remarkably preserved in the presence of proteins (bovine serum albumin), regardless of the type of surface.

 

Dau NQ, Lau H, Skinner C. Why N95 Should Be the Standard for All COVID-19 Inpatient Care. Ann Int Med 2020, Jun 29. Full-text: https://doi.org/10.7326/M20-2623

Important viewpoint emphasizing that N95 respirators achieve better filtration of airborne particles than medical masks if used properly and continuously. According to the authors, guideline recommendations that do not support N95 use for all inpatient COVID-19 management should consider reevaluating existing data or at least acknowledge the issues raised.

 

Oosterhoff B, Palmer CA. Attitudes and Psychological Factors Associated With News Monitoring, Social Distancing, Disinfecting, and Hoarding Behaviors Among US Adolescents During the Coronavirus Disease 2019 Pandemic. JAMA Pediatr. Published online June 29, 2020. Full-text: https://doi.org/10.1001/jamapediatrics.2020.1876

Interesting survey on 770 adolescents’ beliefs about COVID-19 and community attachment as well as attitudes and psychological factors that inform their response to the pandemic. Many teens reported not engaging in pure social distancing (69%), but they were monitoring the news (89%) and disinfecting daily (88%). Some teens reported hoarding (20%). Greater social responsibility was associated with more disinfecting and news monitoring and less hoarding. Greater self-interest values were associated with less social distancing and more hoarding.

 

Abbas M, Pittet D. Surfing the COVID-19 scientific wave. Lancet June 30, 2020. Full-text: https://doi.org/10.1016/S1473-3099(20)30558-2

Harsh, relentless (maybe justified?) critical letter on the methodological flaws of the experiment of visualizing speech-generated oral fluid droplets (see below). The authors are “surprised that experiments in one person were published in a leading scientific journal” and state that the experiment had “more to do with sialoquence (spraying saliva when speaking) than with SARS-CoV-2”.

Anfinrud P Stadnytskyi V Bax CE Bax A. Visualizing speech-generated oral fluid droplets with laser light scattering. N Engl J Med. 2020; 382: 2061-2063. Full-text: https://www.nejm.org/doi/full/10.1056/nejmc2007800

 

Guo L, Zhao S, Li W, et al. Absence of SARS-CoV-2 in Semen of a COVID-19 Patient Cohort. Andrology. 2020 Jun 29. PubMed: https://pubmed.gov/32598557. Full-text: https://doi.org/10.1111/andr.12848

No virus in the semen: all of 23 brave patients with SARS-CoV-2 infections (12 of them still positive in sputum and fecal specimens) tested negative for SARS‐CoV‐2 RNA in semen specimens.

 

Bastug A, Hanifehnezhad A, Tayman C, et al. Virolactia in an Asymptomatic Mother with COVID-19. Breastfeed Med. 2020 Jul 1. PubMed: https://pubmed.gov/32614251. Full-text: https://doi.org/10.1089/bfm.2020.0161

Another case report of a pregnant woman with subclinical COVID-19 whose breast milk sample obtained after delivery tested positive for SARS-CoV-2 by RT-PCR. In addition, although an initial nasopharyngeal swab (NPS) sample from the neonate resulted negative, neonatal NPS, stool, and blood samples obtained after breastfeeding were all positive in real-time RT-PCR assay.

 

Aboubakr HA, Sharafeldin TA, Goyal SM. Stability of SARS-CoV-2 and other coronaviruses in the environment and on common touch surfaces and the influence of climatic conditions: a review. Transbound Emerg Dis. 2020 Jun 30. PubMed: https://pubmed.gov/32603505. Full-text: https://doi.org/10.1111/tbed.13707

A comprehensive review of the available data (by May 21, 2020) on the stability of coronaviruses, including SARS‐CoV‐2, from previous reports, to help understand its environmental survival.

 

Edwards SJL, Santini JM. Anthroponotic risk of SARS-CoV-2, precautionary mitigation, and outbreak management. Lancet Microbe, July 02, 2020. Full-text: https://doi.org/10.1016/S2666-5247(20)30086-0

Important comment on the evidence of infection of animals with SARS-CoV-2 that has been shown experimentally both in vivo and in vitro for mammals including monkeys, cats, ferrets, rabbits, foxes, and hamsters, while bioinformatic studies also predict infectivity of pigs and wild boar among other mammals. According to the authors, we should also consider the potential for transmissibility, not just infection.

 

Sikkema RS, Niewenhuijse DF, O’Toole A, et al. COVID-19 in health-care workers in three hospitals in the south of the Netherlands: a cross-sectional study. Lancet Inf Dis, July 02, 2020. Full-text: https://doi.org/10.1016/S1473-3099(20)30527-2

Social events outside the hospital. In this cross-sectional study at three hospitals located in the south of the Netherlands, from 50 HCWs (and ten patients), complete and near-complete genome sequences were analyzed. Most sequences were grouped into three clusters, with two clusters showing local circulation within the region. The genomic diversity recorded was consistent with multiple introductions through community-acquired infections, and some local amplification related to specific social events in the community, rather than widespread within-hospital transmission. Thus, data do not support widespread nosocomial transmission as the source of infection in patients or health-care workers.