As the novel coronavirus disease 2019 (COVID-19) pandemic spreads rapidly across the globe many unanswered questions about the basic biology and epidemiology of the disease hamper our response strategies and limit our ability to achieve control and prevent a rebound or so-called “second wave”. One such crucial question is: To what degree do asymptomatic cases contribute to transmission? Early, small studies on this subject have found wide ranging estimates of the prevalence of asymptomatic carriers, and just a handful of studies so far have documented viral shedding by asymptomatic cases . We recently re-examined China’s COVID-19 case report data to investigate this question . This Editorial aims to describe how asymptomatic cases contribute to transmission and what the implications are for control strategies.
Asymptomatic COVID-19 cases are those having positive results from either viral nucleic acid or antibody testing yet not having classical symptoms (i.e., fever, dry cough, fatigue). In a report of the first 72,314 COVID-19 cases in China, the proportion of such asymptomatic cases was 1% — only 889 cases had been documented [3, 4]. However, these researchers underscored the high likelihood of this being an understatement of the true prevalence of asymptomatic infection because of the inherent difficulty of finding these cases [3, 4]. Also, it should be noted that community transmission in China was limited primarily to Wuhan City, and to a lesser extent in Hubei Province, while the 30 other provinces/municipalities/autonomous regions only had clusters of cases. The prevalence of asymptomatic cases may differ in areas with versus without community transmission. Indeed, until recently asymptomatic cases were only being found through rapid screening of close contacts of symptomatic cases, intensive investigation of case clusters, and active testing campaigns.
Background As of June 8, 2020, the global reported number of COVID-19 cases had reached more than 7 million with over 400000 deaths. The household transmissibility of the causative pathogen, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), remains unclear. We aimed to estimate the secondary attack rate of SARS-CoV-2 among household and non-household close contacts in Guangzhou, China, using a statistical transmission model.
Methods In this retrospective cohort study, we used a comprehensive contact tracing dataset from the Guangzhou Center for Disease Control and Prevention to estimate the secondary attack rate of COVID-19 (defined as the probability that an infected individual will transmit the disease to a susceptible individual) among household and non-household contacts, using a statistical transmission model. We considered two alternative definitions of household contacts in the analysis: individuals who were either family members or close relatives, such as parents and parents-in-law, regardless of residential address, and individuals living at the same address regardless of relationship. We assessed the demographic determinants of transmissibility and the infectivity of COVID-19 cases during their incubation period.
Findings Between Jan 7, 2020, and Feb 18, 2020, we traced 195 unrelated close contact groups (215 primary cases, 134 secondary or tertiary cases, and 1964 uninfected close contacts). By identifying households from these groups, assuming a mean incubation period of 5 days, a maximum infectious period of 13 days, and no case isolation, the estimated secondary attack rate among household contacts was 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 [OR] 0∙23 [95% CI 0∙11–0∙46]) and among adults aged 20–59 years (OR 0∙64 [95% CI 0∙43–0∙97]). Our results suggest greater infectivity during the incubation period than during the symptomatic period, although differences were not statistically significant (OR 0∙61 [95% CI 0∙27–1∙38]). The estimated local reproductive number (R) based on observed contact frequencies of primary cases was 0∙5 (95% CI 0∙41–0∙62) in Guangzhou. The projected local R, had there been no isolation of cases or quarantine of their contacts, was 0∙6 (95% CI 0∙49–0∙74) when household was defined on the basis of close relatives.
Interpretation SARS-CoV-2 is more transmissible in households than SARS-CoV and Middle East respiratory syndrome coronavirus. Older individuals (aged ≥60 years) are the most susceptible to household transmission of SARS-CoV-2. In addition to case finding and isolation, timely tracing and quarantine of close contacts should be implemented to prevent onward transmission during the viral incubation period.
In March, 2020, WHO declared COVID-19 a global pandemic. At the time of writing, the UK has the highest number of recorded fatalities in Europe, with London regarded as the epicentre of infection in the UK.
Physiological stress from critical illness and elective surgery increases serum cortisol concentrations and bioavailability by activation of the hypothalamic–pituitary–adrenal axis, decreased metabolism of cortisol, and a reduction in the amount of binding proteins (eg, cortisol-binding globulin).1, 2 The increase in cortisol is an essential part of the body's stress response, triggering adaptive changes in metabolism, cardiovascular function, and immune regulation.
The effects of COVID-19 on cortisol are currently unknown. It has been suggested that severe acute respiratory syndrome coronavirus (SARS-CoV), the predecessor of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), might trigger an immunogenic response to adrenocorticotropic hormone because of mimicry. Similar mechanisms might apply to SARS-CoV-2, theoretically amplifying morbidity and mortality by inducing a cortisol insufficiency related to critical illness.1, 3 To understand whether this process might be a contributor to the pathophysiology of COVID-19, we did a cohort study describing the acute cortisol concentrations observed in patients with COVID-19.
Existing micronutrient deficiencies, even if only a single micronutrient, can impair immune function and increase susceptibility to infectious disease. Certain population groups are more likely to have micronutrient deficiencies, while certain disease pathologies and treatment practices also exacerbate risk, meaning these groups tend to suffer increased morbidity and mortality from infectious diseases. Optimisation of overall nutritional status, including micronutrients, can be effective in reducing incidence of infectious disease. Micronutrient deficiencies are rarely recognised but are prevalent in the UK, as well as much more widely, particularly in high-risk groups susceptible to COVID-19. Practitioners should be aware of this fact and should make it a consideration for the screening process in COVID-19, or when screening may be difficult or impractical, to ensure blanket treatment as per the best practice guidelines. Correction of established micronutrient deficiencies, or in some cases assumed suboptimal status, has the potential to help support immune function and mitigate risk of infection. The effects of and immune response to COVID-19 share common characteristics with more well-characterised severe acute respiratory infections. Correction of micronutrient deficiencies has proven effective in several infectious diseases and has been shown to promote favourable clinical outcomes. Micronutrients appear to play key roles in mediating the inflammatory response and such effects may be enhanced through correction of deficiencies. Many of those at highest risk during the COVID-19 pandemic are also populations at highest risk of micronutrient deficiencies and poorer overall nutrition. Correction of micronutrient deficiencies in established COVID-19 infection may contribute to supporting immune response to infection in those at highest risk. There is a need for further research to establish optimal public health practice and clinical intervention regimens.
Background: As of April 18, 2020, over 2,000,000 patients had been diagnosed with coronavirus disease-2019 (COVID-19) globally, and more than 140,000 deaths had been reported. The clinical and epidemiological characteristics of adult patients have been documented recently. However, information on pediatric patients is limited. We describe the clinical and epidemiological characteristics of pediatric patients to provide valuable insight into the early diagnosis and assessment of COVID-19 in children.
Methods and findings: This retrospective, observational study involves a case series performed at 4 hospitals in West China. Thirty-four pediatric patients with COVID-19 were included from January 27 to February 23, 2020. The final follow-up visit was completed by March 16, 2020. Clinical and epidemiological characteristics were analyzed on the basis of demographic data, medical history, laboratory tests, radiological findings, and treatment information. Data analysis was performed for 34 pediatrics patients with COVID-19 aged from 1 to 144 months (median 33.00, interquartile range 10.00–94.25), among whom 14 males (41%) were included. All the patients in the current study presented mild (18%) or moderate (82%) forms of COVID-19. A total of 48% of patients were noted to be without a history of exposure to an identified source. Mixed infections of other respiratory pathogens were reported in 16 patients (47%). Comorbidities were reported in 6 patients (18%). The most common initial symptoms were fever (76%) and cough (62%). Expectoration (21%), vomiting (12%), and diarrhea (12%) were also reported in a considerable portion of cases. A substantial increase was detected in serum amyloid A for 17 patients (among 20 patients with available data; 85%) and in high-sensitivity C-reactive protein for 17 patients (among 29 patients with available data; 59%), whereas a decrease in prealbumin was noticed in 25 patients (among 32 patients with available data; 78%). In addition, significant increases in the levels of lactate dehydrogenase and α-hydroxybutyrate dehydrogenase were detected in 28 patients (among 34 patients with available data; 82%) and 25 patients (among 34 patients with available data; 74%), respectively. Patchy lesions in lobules were detected by chest computed tomographic scans in 28 patients (82%). Ground-glass opacities, which were a typical feature in adults, were rare in pediatric patients (3%). Rapid radiologic progression and a late-onset pattern of lesions in the lobules were also noticed. Lesions in lobules still existed in 24 (among 32 patients with lesions; 75%) patients that were discharged, although the main symptoms disappeared a few days after treatment. All patients were discharged, and the median duration of hospitalization was 10.00 (8.00–14.25) days. The current study was limited by the small sample size and a lack of dynamic detection of inflammatory markers.
Conclusions: Our data systemically presented the clinical and epidemiological features, as well as the outcomes, of pediatric patients with COVID-19. Stratified analysis was performed between mild and moderate cases. The findings offer new insight into early identification and intervention in pediatric patients with COVID-19.
A clinical trial to evaluate the safety and effectiveness of hydroxychloroquine for the treatment of adults hospitalized with coronavirus disease 2019 (COVID-19) has been stopped by the National Institutes of Health. A data and safety monitoring board (DSMB) met late Friday and determined that while there was no harm, the study drug was very unlikely to be beneficial to hospitalized patients with COVID-19. After its fourth interim analysis the DSMB, which regularly monitors the trial, recommended to the National Heart, Lung, and Blood Institute (NHLBI), part of NIH, to stop the study. NHLBI halted the trial immediately.
The Outcomes Related to COVID-19 treated with hydroxychloroquine among In-patients with symptomatic Disease study, or ORCHID Study, was being conducted by the Prevention and Early Treatment of Acute Lung Injury (PETAL) Clinical Trials Network of NHLBI. The data from this study indicate that this drug provided no additional benefit compared to placebo control for the treatment of COVID-19 in hospitalized patients.
The first participants enrolled in the trial in April at Vanderbilt University Medical Center, Nashville, Tennessee, one of dozens of centers in the PETAL Network. The blinded, placebo-controlled randomized clinical trial aimed to enroll more than 500 adults who are currently hospitalized with COVID-19 or in an emergency department with anticipated hospitalization. More than 470 were enrolled at the time of study’s closure.
On 17 June 2020, WHO announced that the hydroxychloroquine (HCQ) arm of the Solidarity Trial to find an effective COVID-19 treatment was being stopped.
The trial's Executive Group and principal investigators made the decision based on evidence from the Solidarity trial, UK's Recovery trial and a Cochrane review of other evidence on hydroxychloroquine.
Data from Solidarity (including the French Discovery trial data) and the recently announced results from the UK's Recovery trial both showed that hydroxychloroquine does not result in the reduction of mortality of hospitalised COVID-19 patients, when compared with standard of care.
Investigators will not randomize further patients to hydroxychloroquine in the Solidarity trial. Patients who have already started hydroxychloroquine but who have not yet finished their course in the trial may complete their course or stop at the discretion of the supervising physician.
Outside researchers are calling for the retraction of a study published earlier this month in the Proceedings of the National Academy of Sciences (PNAS) that claimed to have discovered a strong correlation between public facemask-wearing and a subsequent decline in confirmed COVID-19 cases. In the challenged study, a team of atmospheric chemists led by Texas A&M chemist Renyi Zhang sought to compare how trends in confirmed diagnoses changed before and after mask-wearing had been mandated in Wuhan, China, Italy, and New York City.
The researchers calculated that mandated masking reduced the number of confirmed cases by more than 78,000 in Italy from April 6 to May 9, and by more than 66,000 in New York City from April 17 to May 9. In addition, the researchers argued that while recommendations like social distancing and frequent hand washing slowed the epidemic, the dramatic reductions in viral transmission in Italy and New York City occurred only after wearing masks in public was mandated. The reduction in confirmed cases occurred, they argued, because masking prevents the transmission of the disease by blocking the atomization of virus-containing respiratory droplets (coughing, sneezing, talking) and their subsequent inhalation by uninfected people. On that evidence, they concluded the airborne spread of the coronavirus that causes COVID-19 is the dominant route of infection.
Humanity's broken relationship with nature comes with a cost. That cost has revealed itself in terrible ways. Loss of lives, loss of jobs, and a shock to our global economy. This pandemic joins a long list of emerging diseases that will continue to undermine global stability unless we fix our relationship with nature. Together we can ensure the response to this global emergency makes our planet and our communities stronger.
People who get their information about coronavirus from social media platforms such as Facebook and YouTube are more likely to believe conspiracy theories about Covid-19 and to have broken key lockdown rules, according to a new UK study by King’s College London and Ipsos MORI.
The findings are based on three separate surveys, and have been published in a peer-reviewed article by King’s College London academics in the leading journal Psychological Medicine.
The figures below and in the new study relate to the most comprehensive of the three surveys, which involved 2,254 interviews with UK residents aged 16-75, carried out online between 20 and 22 May 2020.
Children could be first in the queue for a coronavirus vaccine in order to protect the elderly, a scientific adviser to the Government has suggested.
Professor Peter Openshaw, who sits on the New and Emerging Respiratory Virus Threats Advisory Group (Nervtag), said vaccinating minors, even though they are at low risk from Covid-19, could be an "indirect" method of protecting pensioners, in whom vaccines tend to be less effective.
Giving evidence to the Lords Science and Technology Committee, Prof Openshaw cited the approach taken to combat seasonal influenza, which sees children routinely vaccinated despite not being at high risk.
Potential vaccines against coronavirus are under development across the world.
As if the bushfires weren’t bad enough, we’ve since had the world economy shut down, millions infected with COVID-19 and hundreds of thousands dead. This pandemic feels like we’re in the middle of a real-life Hollywood blockbuster.
Like all good movies, this one will leave us fundamentally changed well after it’s ended. Our world will look and feel very different once the show is over. But not for the better.
Thankfully, the possibility of a vaccine for this virus is looking more plausible. Unfortunately, like a diabolical plot twist, the day the vaccine arrives, so too will the inevitable chorus of those who object to being vaccinated. But unlike hapless movie heroes, we can be prepared for this.
To anti-vaxxers, I have one message: our tolerance for your wilful ignorance is over. We cannot afford, morally or economically, to give any ground to those who choose not to be vaccinated against COVID-19.
The spread of anti-vaccination misinformation on social media, implications for public health and the global fight against COVID-19.
Social media networks are rife with conspiracy theories and misinformation about the origins of the COVID-19 virus and treatments for the disease. Misinformation is not a new phenomenon. However, the rise of social media and changes in how people obtain and consume news, have made misinformation much more infectious: fake news can now spread faster, wider and more freely than ever before. What are the effects of this on public health? And what implications might this have for our fight against the COVID-19 pandemic? In this article, we explore these important questions using a recent ‘test case’: misinformation around the Measles, Mumps and Rubella (MMR) vaccine.
THE THAMES has always been a reflector of the times, says Lara Maiklem, a London “mudlark”. Ms Maiklem spends her days on the river’s foreshore foraging for history’s detritus, from Roman pottery to Victorian clay pipes. She can tell the time of year, she says, just by the type of rubbish she has to sift through: champagne bottles during the first week of January; footballs in summer. The year 2020 has left its own mark. Since the coronavirus reached Britain the mud has sprouted a crop of latex gloves.
In February, half a world away, Gary Stokes docked his boat on Hong Kong’s isolated Soko Island. Soko’s beaches are where OceansAsia, the conservation organisation he runs, sporadically records levels of plastic pollution. Mr Stokes says he is all too accustomed to finding the jetsam the modern world throws up, such as plastic drinks bottles and supermarket carrier-bags. But what he documented that day made news across Hong Kong: 70 surgical facemasks on a 100-metre stretch of beach. Having cleaned it up, he went back four days later. Like a stubborn weed, the masks had returned.
No evidence anyone has died from the coronavirus; Google funds WHO ads; UK lockdown legal challenge fails; Ancient crabs and vaccines; Metabolic health of BAME community not being assessed; Low-fat diets don’t lower cholesterol in familial hypercholesterolemia; UK vaginal mesh scandal