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1.
Preprint | EuropePMC | ID: ppcovidwho-296545

ABSTRACT

Background: COVID-19 case data underestimates infection and immunity, especially in low- and middle-income countries (LMICs). We meta-analyzed standardized SARS-CoV-2 seroprevalence studies to estimate global seroprevalence. Objectives/Methods We conducted a systematic review and meta-analysis, searching MEDLINE, Embase, Web of Science, preprints, and grey literature for SARS-CoV-2 seroprevalence studies aligned with the WHO UNITY protocol published between 2020-01-01 and 2021-10-29. Eligible studies were extracted and critically appraised in duplicate. We meta-analyzed seroprevalence by country and month, pooling to estimate regional and global seroprevalence over time;compared seroprevalence from infection to confirmed cases to estimate under-ascertainment;meta-analyzed differences in seroprevalence between demographic subgroups;and identified national factors associated with seroprevalence using meta-regression. PROSPERO: CRD42020183634. Results We identified 396 full texts reporting 736 distinct seroprevalence studies (41% LMIC), including 355 low/moderate risk of bias studies with national/sub-national scope in further analysis. By April 2021, global SARS-CoV-2 seroprevalence was 26.1%, 95% CI [24.6-27.6%]. Seroprevalence rose steeply in the first half of 2021 due to infection in some regions (e.g., 18.2% to 45.9% in Africa) and vaccination and infection in others (e.g., 11.3% to 57.4% in the Americas high-income countries), but remained low in others (e.g., 0.3% to 1.6% in the Western Pacific). In 2021 Q1, median seroprevalence to case ratios were 1.9:1 in HICs and 61.9:1 in LMICs. Children 0-9 years and adults 60+ were at lower risk of seropositivity than adults 20-29. In a multivariate model using data pre-vaccination, more stringent public health and social measures were associated with lower seroprevalence. Conclusions Global seroprevalence has risen considerably over time and with regional variation, however much of the global population remains susceptible to SARS-CoV-2 infection. True infections far exceed reported COVID-19 cases. Standardized seroprevalence studies are essential to inform COVID-19 control measures, particularly in resource-limited regions.

3.
Emerg Infect Dis ; 27(12): 3052-3062, 2021 12.
Article in English | MEDLINE | ID: covidwho-1528794

ABSTRACT

Middle East respiratory syndrome coronavirus (MERS-CoV) infects humans and dromedary camels and is responsible for an ongoing outbreak of severe respiratory illness in humans in the Middle East. Although some mutations found in camel-derived MERS-CoV strains have been characterized, most natural variation found across MERS-CoV isolates remains unstudied. We report on the environmental stability, replication kinetics, and pathogenicity of several diverse isolates of MERS-CoV, as well as isolates of severe acute respiratory syndrome coronavirus 2, to serve as a basis of comparison with other stability studies. Although most MERS-CoV isolates had similar stability and pathogenicity in our experiments, the camel-derived isolate C/KSA/13 had reduced surface stability, and another camel isolate, C/BF/15, had reduced pathogenicity in a small animal model. These results suggest that although betacoronaviruses might have similar environmental stability profiles, individual variation can influence this phenotype, underscoring the need for continual global viral surveillance.


Subject(s)
COVID-19 , Middle East Respiratory Syndrome Coronavirus , Aerosols , Animals , Camelus , Humans , Middle East Respiratory Syndrome Coronavirus/genetics , SARS-CoV-2 , Virulence , Zoonoses
4.
Science ; 374(6566): 377, 2021 Oct 22.
Article in English | MEDLINE | ID: covidwho-1483981

ABSTRACT

The past 30 years have exposed the global public health and economic threats posed by the emergence of infectious pathogens with epidemic and pandemic potential. Severe acute respiratory syndrome (SARS), middle east respiratory syndrome (MERS), influenza, Ebola, Marburg, Lassa, Nipah, Zika, and now SARS coronavirus 2 (SARS-CoV-2) each have been the "Disease X" of their time. The risk of future emergence is driven by multiple forces, including climate change, ecosystem changes, and increasing urbanization. The next Disease X could appear at any time, and the world needs to be better prepared.

5.
Influenza Other Respir Viruses ; 2021 Oct 05.
Article in English | MEDLINE | ID: covidwho-1455561

ABSTRACT

BACKGROUND: The declaration of Coronavirus disease 2019 (COVID-19) as a Public Health Emergency of International Concern (PHEIC) on 30 January 2020 required rapid implementation of early investigations to inform appropriate national and global public health actions. METHODS: The suite of existing pandemic preparedness generic epidemiological early investigation protocols was rapidly adapted for COVID-19, branded the 'UNITY studies' and promoted globally for the implementation of standardized and quality studies. Ten protocols were developed investigating household (HH) transmission, the first few cases (FFX), population seroprevalence (SEROPREV), health facilities transmission (n = 2), vaccine effectiveness (n = 2), pregnancy outcomes and transmission, school transmission, and surface contamination. Implementation was supported by WHO and its partners globally, with emphasis to support building surveillance and research capacities in low- and middle-income countries (LMIC). RESULTS: WHO generic protocols were rapidly developed and published on the WHO website, 5/10 protocols within the first 3 months of the response. As of 30 June 2021, 172 investigations were implemented by 97 countries, of which 62 (64%) were LMIC. The majority of countries implemented population seroprevalence (71 countries) and first few cases/household transmission (37 countries) studies. CONCLUSION: The widespread adoption of UNITY protocols across all WHO regions indicates that they addressed subnational and national needs to support local public health decision-making to prevent and control the pandemic.

6.
Front Immunol ; 12: 727989, 2021.
Article in English | MEDLINE | ID: covidwho-1450808

ABSTRACT

Background: A growing number of experiments have suggested potential cross-reactive immunity between severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and previous human coronaviruses. We conducted the present retrospective cohort study to investigate the relationship between previous Middle East respiratory syndrome-coronavirus (MERS-CoV) infection and the risk of SARS-CoV-2 infection as well as the relationship between previous MERS-CoV and COVID-19-related hospitalization and mortality. Methods: Starting in March 2020, we prospectively followed two groups of individuals who tested negative for COVID-19 infection. The first group had a previously confirmed MERS-CoV infection, which was compared to a control group of MERS-negative individuals. The studied cohort was then followed until November 2020 to track evidence of contracting COVID-19 infection. Findings: A total of 82 (24%) MERS-positive and 260 (31%) MERS-negative individuals had COVID-19 infection. Patients in the MERS-positive group had a lower risk of COVID-19 infection than those in the MERS-negative group (Risk ratio [RR] 0.696, 95% confidence interval [CI] 0.522-0.929; p =0.014). The risk of COVID-19-related hospitalization in the MERS-positive group was significantly higher (RR 4.036, 95% CI 1.705-9.555; p =0.002). The case fatality rate (CFR) from COVID-19 was 4.9% in the MERS-positive group and 1.2% in the MERS-negative group (p =0.038). The MERS-positive group had a higher risk of death than the MERS-negative group (RR 6.222, 95% CI 1.342-28.839; p =0.019). However, the risk of mortality was similar between the two groups when death was adjusted for age (p =0.068) and age and sex (p =0.057). After controlling for all the independent variables, only healthcare worker occupation and >1 comorbidity were independent predictors of SARS-CoV-2 infection. Interpretation: Individuals with previous MERS-CoV infection can exhibit a cross-reactive immune response to SARS-CoV-2 infection. Our study demonstrated that patients with MERS-CoV infection had higher risks of COVID-19-related hospitalization and death than MERS-negative individuals.


Subject(s)
COVID-19/epidemiology , COVID-19/mortality , Cross Reactions/immunology , Middle East Respiratory Syndrome Coronavirus/immunology , SARS-CoV-2/immunology , Adolescent , Adult , Aged , Aged, 80 and over , Child , Child, Preschool , Female , Hospitalization/statistics & numerical data , Humans , Infant , Infant, Newborn , Male , Middle Aged , Prospective Studies , Retrospective Studies , Saudi Arabia/epidemiology , Young Adult
7.
International Journal of Antimicrobial Agents ; 58:N.PAG-N.PAG, 2021.
Article in English | Academic Search Complete | ID: covidwho-1440055
8.
EClinicalMedicine ; 38: 101024, 2021 Aug.
Article in English | MEDLINE | ID: covidwho-1397306

ABSTRACT

Background: The wearing of medical and non-medical masks by the general public in community settings is one intervention that is important for the reduction of SARS-CoV-2 transmission, and has been the subject of considerable research, policy, advocacy and debate. Several observational studies have used ecological (population-level) data to assess the effect of masks on transmission, hospitalization, and mortality at the region or community level. Methods: We undertook this systematic review to summarize the study designs, outcomes, and key quality indicators of using ecological data to evaluate the association between mask wearing and COVID-19 outcomes. We searched the World Health Organization (WHO) COVID-19 global literature database up to 5 March 2021 for studies reporting the impact of mask use in community settings on outcomes related to SARS-CoV-2 transmission using ecological data. Findings: Twenty one articles were identified that analysed ecological data to assess the protective effect of policies mandating community mask wearing. All studies reported SARS-CoV-2 benefits in terms of reductions in either the incidence, hospitalization, or mortality, or a combination of these outcomes. Few studies assessed compliance to mask wearing policies or controlled for the possible influence of other preventive measures such as hand hygiene and physical distancing, and information about compliance to these policies was lacking. Interpretation: Ecological studies have been cited as evidence to advocate for the adoption of universal masking policies. The studies summarized by this review suggest that community mask policies may reduce the population-level burden of SARS-CoV-2. Methodological limitations, in particular controlling for the actual practice of mask wearing and other preventive policies make it difficult to determine causality. There are several important limitations to consider for improving the validity of ecological data.

9.
N Engl J Med ; 385(2): 179-186, 2021 Jul 08.
Article in English | MEDLINE | ID: covidwho-1358382

ABSTRACT

Viral variants of concern may emerge with dangerous resistance to the immunity generated by the current vaccines to prevent coronavirus disease 2019 (Covid-19). Moreover, if some variants of concern have increased transmissibility or virulence, the importance of efficient public health measures and vaccination programs will increase. The global response must be both timely and science based.


Subject(s)
COVID-19 Vaccines , COVID-19/prevention & control , SARS-CoV-2 , COVID-19/transmission , COVID-19 Vaccines/immunology , Humans , Immunogenicity, Vaccine , Mutation , SARS-CoV-2/pathogenicity , Spike Glycoprotein, Coronavirus/genetics , Virulence
10.
EClinicalMedicine ; 38: 101024, 2021 Aug.
Article in English | MEDLINE | ID: covidwho-1322076

ABSTRACT

Background: The wearing of medical and non-medical masks by the general public in community settings is one intervention that is important for the reduction of SARS-CoV-2 transmission, and has been the subject of considerable research, policy, advocacy and debate. Several observational studies have used ecological (population-level) data to assess the effect of masks on transmission, hospitalization, and mortality at the region or community level. Methods: We undertook this systematic review to summarize the study designs, outcomes, and key quality indicators of using ecological data to evaluate the association between mask wearing and COVID-19 outcomes. We searched the World Health Organization (WHO) COVID-19 global literature database up to 5 March 2021 for studies reporting the impact of mask use in community settings on outcomes related to SARS-CoV-2 transmission using ecological data. Findings: Twenty one articles were identified that analysed ecological data to assess the protective effect of policies mandating community mask wearing. All studies reported SARS-CoV-2 benefits in terms of reductions in either the incidence, hospitalization, or mortality, or a combination of these outcomes. Few studies assessed compliance to mask wearing policies or controlled for the possible influence of other preventive measures such as hand hygiene and physical distancing, and information about compliance to these policies was lacking. Interpretation: Ecological studies have been cited as evidence to advocate for the adoption of universal masking policies. The studies summarized by this review suggest that community mask policies may reduce the population-level burden of SARS-CoV-2. Methodological limitations, in particular controlling for the actual practice of mask wearing and other preventive policies make it difficult to determine causality. There are several important limitations to consider for improving the validity of ecological data.

11.
Euro Surveill ; 26(24)2021 Jun.
Article in English | MEDLINE | ID: covidwho-1314526

ABSTRACT

We present a global analysis of the spread of recently emerged SARS-CoV-2 variants and estimate changes in effective reproduction numbers at country-specific level using sequence data from GISAID. Nearly all investigated countries demonstrated rapid replacement of previously circulating lineages by the World Health Organization-designated variants of concern, with estimated transmissibility increases of 29% (95% CI: 24-33), 25% (95% CI: 20-30), 38% (95% CI: 29-48) and 97% (95% CI: 76-117), respectively, for B.1.1.7, B.1.351, P.1 and B.1.617.2.


Subject(s)
COVID-19 , SARS-CoV-2 , Basic Reproduction Number , Humans
12.
N Engl J Med ; 385(2): 179-186, 2021 Jul 08.
Article in English | MEDLINE | ID: covidwho-1279936

ABSTRACT

Viral variants of concern may emerge with dangerous resistance to the immunity generated by the current vaccines to prevent coronavirus disease 2019 (Covid-19). Moreover, if some variants of concern have increased transmissibility or virulence, the importance of efficient public health measures and vaccination programs will increase. The global response must be both timely and science based.


Subject(s)
COVID-19 Vaccines , COVID-19/prevention & control , SARS-CoV-2 , COVID-19/transmission , COVID-19 Vaccines/immunology , Humans , Immunogenicity, Vaccine , Mutation , SARS-CoV-2/pathogenicity , Spike Glycoprotein, Coronavirus/genetics , Virulence
14.
JMIR Public Health Surveill ; 7(4): e28945, 2021 04 21.
Article in English | MEDLINE | ID: covidwho-1195985

ABSTRACT

The World Health Organization (WHO) launched the first web-based learning course on COVID-19 on January 26, 2020, four days before the director general of the WHO declared a public health emergency of international concern. The WHO is expanding access to web-based learning for COVID-19 through its open-learning platform for health emergencies, OpenWHO. Throughout the pandemic, OpenWHO has continued to publish learning offerings based on the WHO's emerging evidence-based knowledge for managing the COVID-19 pandemic. This study presents the various findings derived from the analysis of the performance of the OpenWHO platform during the pandemic, along with the core benefits of massive web-based learning formats.


Subject(s)
COVID-19/prevention & control , Education, Distance , Pandemics/prevention & control , COVID-19/epidemiology , Guidelines as Topic , Humans , World Health Organization
16.
Emerg Infect Dis ; 26(6): 1102-1112, 2020 Jun.
Article in English | MEDLINE | ID: covidwho-17702

ABSTRACT

Available animal and cell line models have suggested that specific therapeutics might be effective in treating Middle East respiratory syndrome (MERS). We conducted a systematic review of evidence for treatment with pharmacologic and supportive therapies. We developed a protocol and searched 5 databases for studies describing treatment of MERS and deaths in MERS patients. Risk of bias (RoB) was assessed by using ROBINS-I tool. We retrieved 3,660 unique citations; 20 observational studies met eligibility, and we studied 13 therapies. Most studies were at serious or critical RoB; no studies were at low RoB. One study, at moderate RoB, showed reduced mortality rates in severe MERS patients with extracorporeal membrane oxygenation; no other studies showed a significant lifesaving benefit to any treatment. The existing literature on treatments for MERS is observational and at moderate to critical RoB. Clinical trials are needed to guide treatment decisions.


Subject(s)
Antiviral Agents/therapeutic use , Coronavirus Infections/drug therapy , Middle East Respiratory Syndrome Coronavirus , Coronavirus Infections/virology , Humans
17.
J Infect Public Health ; 13(3): 418-422, 2020 Mar.
Article in English | MEDLINE | ID: covidwho-7352

ABSTRACT

BACKGROUND: Approximately half of the reported laboratory-confirmed infections of Middle East respiratory syndrome coronavirus (MERS-CoV) have occurred in healthcare settings, and healthcare workers constitute over one third of all secondary infections. This study aimed to describe secondary cases of MERS-CoV infection among healthcare workers and to identify risk factors for death. METHODS: A retrospective analysis was conducted on epidemiological data of laboratory-confirmed MERS-CoV cases reported to the World Health Organization from September 2012 to 2 June 2018. We compared all secondary cases among healthcare workers with secondary cases among non-healthcare workers. Multivariable logistic regression identified risk factors for death. RESULTS: Of the 2223 laboratory-confirmed MERS-CoV cases reported to WHO, 415 were healthcare workers and 1783 were non-healthcare workers. Compared with non-healthcare workers cases, healthcare workers cases were younger (P < 0.001), more likely to be female (P < 0.001), non-nationals (P < 0.001) and asymptomatic (P < 0.001), and have fewer comorbidities (P < 0.001) and higher rates of survival (P < 0.001). Year of infection (2013-2018) and having no comorbidities were independent protective factors against death among secondary healthcare workers cases. CONCLUSION: Being able to protect healthcare workers from high threat respiratory pathogens, such as MERS-CoV is important for being able to reduce secondary transmission of MERS-CoV in healthcare-associated outbreaks. By extension, reducing infection in healthcare workers improves continuity of care for all patients within healthcare facilities.


Subject(s)
Coronavirus Infections/epidemiology , Coronavirus Infections/transmission , Health Personnel , Middle East Respiratory Syndrome Coronavirus , Adult , Coronavirus Infections/mortality , Cross Infection/epidemiology , Cross Infection/transmission , Female , Humans , Infectious Disease Transmission, Patient-to-Professional/prevention & control , Laboratories , Male , Middle Aged , Retrospective Studies , Risk Factors , World Health Organization
18.
Lancet ; 395(10229): 1063-1077, 2020 03 28.
Article in English | MEDLINE | ID: covidwho-3836

ABSTRACT

The Middle East respiratory syndrome coronavirus (MERS-CoV) is a lethal zoonotic pathogen that was first identified in humans in Saudi Arabia and Jordan in 2012. Intermittent sporadic cases, community clusters, and nosocomial outbreaks of MERS-CoV continue to occur. Between April 2012 and December 2019, 2499 laboratory-confirmed cases of MERS-CoV infection, including 858 deaths (34·3% mortality) were reported from 27 countries to WHO, the majority of which were reported by Saudi Arabia (2106 cases, 780 deaths). Large outbreaks of human-to-human transmission have occurred, the largest in Riyadh and Jeddah in 2014 and in South Korea in 2015. MERS-CoV remains a high-threat pathogen identified by WHO as a priority pathogen because it causes severe disease that has a high mortality rate, epidemic potential, and no medical countermeasures. This Seminar provides an update on the current knowledge and perspectives on MERS epidemiology, virology, mode of transmission, pathogenesis, diagnosis, clinical features, management, infection control, development of new therapeutics and vaccines, and highlights unanswered questions and priorities for research, improved management, and prevention.


Subject(s)
Coronavirus Infections/epidemiology , Cross Infection/epidemiology , Epidemics , Middle East Respiratory Syndrome Coronavirus , Adrenal Cortex Hormones/therapeutic use , Adult , Animals , Antibodies, Monoclonal/therapeutic use , Antiviral Agents/therapeutic use , Camelus , Child , Clinical Laboratory Techniques , Coronavirus Infections/prevention & control , Coronavirus Infections/transmission , Critical Care , Cross Infection/prevention & control , Cross Infection/transmission , Female , Global Health , Humans , Immunity, Innate/physiology , Immunocompromised Host , Infection Control , Plasma , Pregnancy , Pregnancy Complications, Infectious/epidemiology , Pregnancy Complications, Infectious/prevention & control , Risk Factors , Travel , Viral Vaccines , Zoonoses/transmission
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