Your browser doesn't support javascript.
Show: 20 | 50 | 100
Results 1 - 20 de 147
Filter
1.
BMC Infect Dis ; 22(1): 208, 2022 Mar 03.
Article in English | MEDLINE | ID: covidwho-1779610

ABSTRACT

BACKGROUND: The Public Health Services in the Rotterdam region, the Netherlands, observed a substantial decrease of non-COVID-19 notifiable infectious diseases and institutional outbreaks during the first wave of the COVID-19 epidemic. We describe this change from mid-March to mid-October 2020 by comparing with the pre-COVID-19 situation. METHODS: All cases of notifiable diseases and institutional outbreaks reported to the Public Health Services Rotterdam-Rijnmond between 1st January and mid-October 2020 were included. Seven-day moving averages and cumulative cases were plotted against time and compared to those of 2017-2019. Additionally, Google mobility transit data of the region were plotted, as proxy for social distancing. RESULTS: Respiratory, gastrointestinal, and travel-related notifiable diseases were reported 65% less often during the first wave of the COVID-19 epidemic than in the same weeks in 2017-2019. Reports of institutional outbreaks were also lower after the initially imposed social distancing measures; however, the numbers rebounded when measures were partially lifted. CONCLUSIONS: Interpersonal distancing and hygiene measures imposed nationally against COVID-19 were in place between mid-March and mid-October, which most likely reduced transmission of other infectious diseases, and may thus have resulted in lower notifications of infectious diseases and outbreaks. This phenomenon opens future study options considering the effect of local outbreak control measures on a wide range of non-COVID-19 diseases. Targeted, tailored, appropriate and acceptable hygiene and distancing measures, specifically for vulnerable groups and institutions, should be devised and their effect investigated.


Subject(s)
COVID-19 , Communicable Diseases , COVID-19/epidemiology , Communicable Diseases/epidemiology , Humans , Netherlands/epidemiology , SARS-CoV-2 , Travel , Travel-Related Illness
3.
PLoS One ; 17(3): e0264682, 2022.
Article in English | MEDLINE | ID: covidwho-1724857

ABSTRACT

Global and local whole genome sequencing of SARS-CoV-2 enables the tracing of domestic and international transmissions. We sequenced Viral RNA from 37 sampled Covid-19 patients with RT-PCR-confirmed infections across the UAE and developed time-resolved phylogenies with 69 local and 3,894 global genome sequences. Furthermore, we investigated specific clades associated with the UAE cohort and, their global diversity, introduction events and inferred domestic and international virus transmissions between January and June 2020. The study comprehensively characterized the genomic aspects of the virus and its spread within the UAE and identified that the prevalence shift of the D614G mutation was due to the later introductions of the G-variant associated with international travel, rather than higher local transmissibility. For clades spanning different emirates, the most recent common ancestors pre-date domestic travel bans. In conclusion, we observe a steep and sustained decline of international transmissions immediately following the introduction of international travel restrictions.


Subject(s)
COVID-19/transmission , COVID-19/virology , Infection Control/methods , SARS-CoV-2/genetics , Travel/statistics & numerical data , Adolescent , Adult , Aged , COVID-19/epidemiology , Child , Child, Preschool , Female , Genome, Viral/genetics , Humans , Male , Middle Aged , Molecular Typing/methods , Mutation , Phylogeny , RNA, Viral , SARS-CoV-2/isolation & purification , Sequence Analysis, RNA , Travel-Related Illness , United Arab Emirates/epidemiology , Whole Genome Sequencing , Young Adult
4.
Nat Commun ; 13(1): 1012, 2022 02 23.
Article in English | MEDLINE | ID: covidwho-1709629

ABSTRACT

Mitigation of SARS-CoV-2 transmission from international travel is a priority. We evaluated the effectiveness of travellers being required to quarantine for 14-days on return to England in Summer 2020. We identified 4,207 travel-related SARS-CoV-2 cases and their contacts, and identified 827 associated SARS-CoV-2 genomes. Overall, quarantine was associated with a lower rate of contacts, and the impact of quarantine was greatest in the 16-20 age-group. 186 SARS-CoV-2 genomes were sufficiently unique to identify travel-related clusters. Fewer genomically-linked cases were observed for index cases who returned from countries with quarantine requirement compared to countries with no quarantine requirement. This difference was explained by fewer importation events per identified genome for these cases, as opposed to fewer onward contacts per case. Overall, our study demonstrates that a 14-day quarantine period reduces, but does not completely eliminate, the onward transmission of imported cases, mainly by dissuading travel to countries with a quarantine requirement.


Subject(s)
COVID-19/prevention & control , Communicable Diseases, Imported/prevention & control , Quarantine/legislation & jurisprudence , SARS-CoV-2/genetics , COVID-19/epidemiology , COVID-19/transmission , Communicable Diseases, Imported/epidemiology , Communicable Diseases, Imported/transmission , Contact Tracing , England/epidemiology , Genome, Viral/genetics , Genomics , Health Impact Assessment , Humans , SARS-CoV-2/classification , Travel/legislation & jurisprudence , Travel-Related Illness
6.
J Korean Med Sci ; 37(3): e31, 2022 Jan 17.
Article in English | MEDLINE | ID: covidwho-1634056

ABSTRACT

Since severe acute respiratory syndrome-coronavirus-2 variant B.1.1.529 (omicron) was first reported to the World Health Organization on November 24, 2021, the cases of the omicron variant have been detected in more than 90 countries over the last month. We investigated the clinical and epidemiological characteristics of the first 40 patients with the omicron variant who had been isolated at the National Medical Center in South Korea during December 4-17, 2021. The median age of the patients was 39.5 years. Twenty-two patients (55%) were women. Seventeen patients (42.5%) were fully vaccinated, and none were reinfected with the omicron. Eighteen (45%) had recent international travel history. Half of the patients (19, 47.5%) were asymptomatic, while the others had mild symptoms. Six patients (15%) showed lung infiltrations on chest image; however, none required supplemental oxygen. These mild clinical features are consistent with recent case reports on the omicron variant from other countries.


Subject(s)
COVID-19/epidemiology , SARS-CoV-2/isolation & purification , Severity of Illness Index , Adolescent , Adult , Aged , COVID-19/diagnosis , COVID-19/pathology , Diagnostic Tests, Routine , Female , Humans , Male , Middle Aged , Republic of Korea/epidemiology , SARS-CoV-2/genetics , Travel , Travel-Related Illness , Young Adult
8.
J Korean Med Sci ; 36(50): e346, 2021 Dec 27.
Article in English | MEDLINE | ID: covidwho-1595229

ABSTRACT

In November 2021, 14 international travel-related severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) B.1.1.529 (omicron) variant of concern (VOC) patients were detected in South Korea. Epidemiologic investigation revealed community transmission of the omicron VOC. A total of 80 SARS-CoV-2 omicron VOC-positive patients were identified until December 10, 2021 and 66 of them reported no relation to the international travel. There may be more transmissions with this VOC in Korea than reported.


Subject(s)
COVID-19/transmission , SARS-CoV-2 , Travel-Related Illness , Adult , Aged , Aged, 80 and over , COVID-19/epidemiology , Female , Humans , Male , Middle Aged , Republic of Korea/epidemiology , Young Adult
9.
MMWR Morb Mortal Wkly Rep ; 70(5152): 1782-1784, 2021 Dec 31.
Article in English | MEDLINE | ID: covidwho-1594423

ABSTRACT

The B.1.1.529 (Omicron) variant of SARS-CoV-2 (the virus that causes COVID-19) was first detected in specimens collected on November 11, 2021, in Botswana and on November 14 in South Africa;* the first confirmed case of Omicron in the United States was identified in California on December 1, 2021 (1). On November 29, the Nebraska Department of Health and Human Services was notified of six probable cases† of COVID-19 in one household, including one case in a man aged 48 years (the index patient) who had recently returned from Nigeria. Given the patient's travel history, Omicron infection was suspected. Specimens from all six persons in the household tested positive for SARS-CoV-2 by reverse transcription-polymerase chain reaction (RT-PCR) testing on December 1, and the following day genomic sequencing by the Nebraska Public Health Laboratory identified an identical Omicron genotype from each specimen (Figure). Phylogenetic analysis was conducted to determine if this cluster represented an independent introduction of Omicron into the United States, and a detailed epidemiologic investigation was conducted. This activity was reviewed by CDC and was conducted consistent with applicable federal law and CDC policy.§.


Subject(s)
COVID-19/epidemiology , COVID-19/virology , SARS-CoV-2/genetics , Cluster Analysis , Humans , Male , Middle Aged , Nebraska/epidemiology , Phylogeny , SARS-CoV-2/isolation & purification , Travel-Related Illness
10.
MMWR Morb Mortal Wkly Rep ; 70(50): 1731-1734, 2021 Dec 17.
Article in English | MEDLINE | ID: covidwho-1575734

ABSTRACT

A new variant of SARS-CoV-2 (the virus that causes COVID-19), B.1.1.529 (Omicron) (1), was first reported to the World Health Organization (WHO) by South Africa on November 24, 2021. Omicron has numerous mutations with potential to increase transmissibility, confer resistance to therapeutics, or partially escape infection- or vaccine-induced immunity (2). On November 26, WHO designated B.1.1.529 as a variant of concern (3), as did the U.S. SARS-CoV-2 Interagency Group (SIG)* on November 30. On December 1, the first case of COVID-19 attributed to the Omicron variant was reported in the United States. As of December 8, a total of 22 states had identified at least one Omicron variant case, including some that indicate community transmission. Among 43 cases with initial follow-up, one hospitalization and no deaths were reported. This report summarizes U.S. surveillance for SARS-CoV-2 variants, characteristics of the initial persons investigated with COVID-19 attributed to the Omicron variant and public health measures implemented to slow the spread of Omicron in the United States. Implementation of concurrent prevention strategies, including vaccination, masking, increasing ventilation, testing, quarantine, and isolation, are recommended to slow transmission of SARS-CoV-2, including variants such as Omicron, and to protect against severe illness and death from COVID-19.


Subject(s)
COVID-19/virology , Public Health Surveillance , SARS-CoV-2/genetics , Adolescent , Adult , Aged , COVID-19/epidemiology , COVID-19/prevention & control , COVID-19/transmission , Centers for Disease Control and Prevention, U.S. , Communicable Disease Control/methods , Female , Humans , Male , Middle Aged , Mutation , SARS-CoV-2/isolation & purification , Travel-Related Illness , United States/epidemiology , Young Adult
12.
Hematology ; 26(1): 1007-1012, 2021 Dec.
Article in English | MEDLINE | ID: covidwho-1555722

ABSTRACT

BACKGROUND: Haematological markers such as absolute lymphopenia have been associated with severe COVID-19 infection. However, in the literature to date, the cohorts described have typically included patients who were moderate to severely unwell with pneumonia and who required intensive care stay. It is uncertain if these markers apply to a population with less severe illness. We sought to describe the haematological profile of patients with mild disease with COVID-19 admitted to a single centre in Singapore. METHODS: We examined 554 consecutive PCR positive SARS-COV-2 patients admitted to a single tertiary healthcare institution from Feb 2020 to April 2020. In all patients a full blood count was obtained within 24 h of presentation. RESULTS: Patients with pneumonia had higher neutrophil percentages (66.5 ± 11.6 vs 55.2 ± 12.6%, p < 0.001), lower absolute lymphocyte count (1.5 ± 1.1 vs 1.9 ± 2.1 x109/L, p < 0.011) and absolute eosinophil count (0.2 ± 0.9 vs 0.7 ± 1.8 × 109/L, p = 0.002). Platelet counts (210 ± 56 vs 230 ± 61, p = 0.020) were slightly lower in the group with pneumonia. We did not demonstrate significant differences in the neutrophil-lymphocyte ratio, monocyte-lymphocyte ratio and platelet-lymphocyte ratio in patients with or without pneumonia. Sixty-eight patients (12.3%) had peripheral eosinophilia. This was more common in migrant workers living in dormitories. CONCLUSION: Neutrophilia and lymphopenia were found to be markers associated with severe COVID-19 illness. We did not find that combined haematological parameters: neutrophil-lymphocyte ratio, monocyte-lymphocyte ratio and platelet-lymphocyte ratio, had any association with disease severity in our cohort of patients with mild-moderate disease. Migrant workers living in dormitories had eosinophilia which may reflect concurrent chronic parasitic infection.


Subject(s)
Blood Cell Count , COVID-19/blood , Pandemics , SARS-CoV-2 , Adult , Anthelmintics/therapeutic use , Antiviral Agents/therapeutic use , COVID-19/drug therapy , COVID-19/epidemiology , Comorbidity , Diabetes Mellitus, Type 2/epidemiology , Dyslipidemias/epidemiology , Eosinophilia/epidemiology , Eosinophilia/etiology , Female , Fever/epidemiology , Fever/etiology , Housing , Humans , Hypertension/epidemiology , Hypoxia/epidemiology , Hypoxia/etiology , Male , Middle Aged , Neutrophils , Parasitic Diseases/drug therapy , Parasitic Diseases/epidemiology , Pneumonia, Viral/blood , Pneumonia, Viral/diagnostic imaging , Pneumonia, Viral/epidemiology , Singapore/epidemiology , Tertiary Care Centers/statistics & numerical data , Transients and Migrants/statistics & numerical data , Travel-Related Illness , Young Adult
13.
Cochrane Database Syst Rev ; 10: CD013717, 2020 10 05.
Article in English | MEDLINE | ID: covidwho-1557155

ABSTRACT

BACKGROUND: In late 2019, first cases of coronavirus disease 2019, or COVID-19, caused by the novel coronavirus SARS-CoV-2, were reported in Wuhan, China. Subsequently COVID-19 spread rapidly around the world. To contain the ensuing pandemic, numerous countries have implemented control measures related to international travel, including border closures, partial travel restrictions, entry or exit screening, and quarantine of travellers. OBJECTIVES: To assess the effectiveness of travel-related control measures during the COVID-19 pandemic on infectious disease and screening-related outcomes. SEARCH METHODS: We searched MEDLINE, Embase and COVID-19-specific databases, including the WHO Global Database on COVID-19 Research, the Cochrane COVID-19 Study Register, and the CDC COVID-19 Research Database on 26 June 2020. We also conducted backward-citation searches with existing reviews. SELECTION CRITERIA: We considered experimental, quasi-experimental, observational and modelling studies assessing the effects of travel-related control measures affecting human travel across national borders during the COVID-19 pandemic. We also included studies concerned with severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS) as indirect evidence. Primary outcomes were cases avoided, cases detected and a shift in epidemic development due to the measures. Secondary outcomes were other infectious disease transmission outcomes, healthcare utilisation, resource requirements and adverse effects if identified in studies assessing at least one primary outcome. DATA COLLECTION AND ANALYSIS: One review author screened titles and abstracts; all excluded abstracts were screened in duplicate. Two review authors independently screened full texts. One review author extracted data, assessed risk of bias and appraised study quality. At least one additional review author checked for correctness of all data reported in the 'Risk of bias' assessment, quality appraisal and data synthesis. For assessing the risk of bias and quality of included studies, we used the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool for observational studies concerned with screening, ROBINS-I for observational ecological studies and a bespoke tool for modelling studies. We synthesised findings narratively. One review author assessed certainty of evidence with GRADE, and the review author team discussed ratings. MAIN RESULTS: We included 40 records reporting on 36 unique studies. We found 17 modelling studies, 7 observational screening studies and one observational ecological study on COVID-19, four modelling and six observational studies on SARS, and one modelling study on SARS and MERS, covering a variety of settings and epidemic stages. Most studies compared travel-related control measures against a counterfactual scenario in which the intervention measure was not implemented. However, some modelling studies described additional comparator scenarios, such as different levels of travel restrictions, or a combination of measures. There were concerns with the quality of many modelling studies and the risk of bias of observational studies. Many modelling studies used potentially inappropriate assumptions about the structure and input parameters of models, and failed to adequately assess uncertainty. Concerns with observational screening studies commonly related to the reference test and the flow of the screening process. Studies on COVID-19 Travel restrictions reducing cross-border travel Eleven studies employed models to simulate a reduction in travel volume; one observational ecological study assessed travel restrictions in response to the COVID-19 pandemic. Very low-certainty evidence from modelling studies suggests that when implemented at the beginning of the outbreak, cross-border travel restrictions may lead to a reduction in the number of new cases of between 26% to 90% (4 studies), the number of deaths (1 study), the time to outbreak of between 2 and 26 days (2 studies), the risk of outbreak of between 1% to 37% (2 studies), and the effective reproduction number (1 modelling and 1 observational ecological study). Low-certainty evidence from modelling studies suggests a reduction in the number of imported or exported cases of between 70% to 81% (5 studies), and in the growth acceleration of epidemic progression (1 study). Screening at borders with or without quarantine Evidence from three modelling studies of entry and exit symptom screening without quarantine suggests delays in the time to outbreak of between 1 to 183 days (very low-certainty evidence) and a detection rate of infected travellers of between 10% to 53% (low-certainty evidence). Six observational studies of entry and exit screening were conducted in specific settings such as evacuation flights and cruise ship outbreaks. Screening approaches varied but followed a similar structure, involving symptom screening of all individuals at departure or upon arrival, followed by quarantine, and different procedures for observation and PCR testing over a period of at least 14 days. The proportion of cases detected ranged from 0% to 91% (depending on the screening approach), and the positive predictive value ranged from 0% to 100% (very low-certainty evidence). The outcomes, however, should be interpreted in relation to both the screening approach used and the prevalence of infection among the travellers screened; for example, symptom-based screening alone generally performed worse than a combination of symptom-based and PCR screening with subsequent observation during quarantine. Quarantine of travellers Evidence from one modelling study simulating a 14-day quarantine suggests a reduction in the number of cases seeded by imported cases; larger reductions were seen with increasing levels of quarantine compliance ranging from 277 to 19 cases with rates of compliance modelled between 70% to 100% (very low-certainty evidence). AUTHORS' CONCLUSIONS: With much of the evidence deriving from modelling studies, notably for travel restrictions reducing cross-border travel and quarantine of travellers, there is a lack of 'real-life' evidence for many of these measures. The certainty of the evidence for most travel-related control measures is very low and the true effects may be substantially different from those reported here. Nevertheless, some travel-related control measures during the COVID-19 pandemic may have a positive impact on infectious disease outcomes. Broadly, travel restrictions may limit the spread of disease across national borders. Entry and exit symptom screening measures on their own are not likely to be effective in detecting a meaningful proportion of cases to prevent seeding new cases within the protected region; combined with subsequent quarantine, observation and PCR testing, the effectiveness is likely to improve. There was insufficient evidence to draw firm conclusions about the effectiveness of travel-related quarantine on its own. Some of the included studies suggest that effects are likely to depend on factors such as the stage of the epidemic, the interconnectedness of countries, local measures undertaken to contain community transmission, and the extent of implementation and adherence.


Subject(s)
COVID-19/prevention & control , Pandemics/prevention & control , SARS-CoV-2 , Travel-Related Illness , COVID-19/epidemiology , Communicable Diseases, Imported/epidemiology , Communicable Diseases, Imported/prevention & control , Coronavirus Infections/epidemiology , Coronavirus Infections/prevention & control , Humans , Models, Theoretical , Observational Studies as Topic , Quarantine , Severe Acute Respiratory Syndrome/epidemiology , Severe Acute Respiratory Syndrome/prevention & control
14.
Swiss Med Wkly ; 151: w30079, 2021 11 22.
Article in English | MEDLINE | ID: covidwho-1542902

ABSTRACT

OBJECTIVE: This study aimed to assess the public perception of COVID-19 vaccination certificates as well as potential differences between individuals. METHODS: Between 17 March and 1 April 2021, a self-administered online questionnaire was proposed to all persons aged 18 years and older participating in the longitudinal follow-up of SARS-CoV-2 seroprevalence studies in Geneva, Switzerland. The questionnaire covered aspects of individual and collective benefits, and allowed participants to select contexts in which vaccination certificates should be presented. Results were presented as the proportion of persons agreeing or disagreeing with the implementation of vaccination certificates, selecting specific contexts where certificates should be presented, and agreeing or disagreeing with the potential risks related to certificates. Logistic regression was used to calculate odds ratios for factors associated with certificate non-acceptance. RESULTS: Overall, 4067 individuals completed the questionnaire (response rate 77.4%; mean age 53.3 ± standard deviation 14.4 years; 56.1% were women). About 61.0% of participants agreed or strongly agreed that a vaccination certificate was necessary in certain contexts and 21.6% believed there was no context where vaccination certificates should be presented. Contexts where a majority of participants perceived a vaccination certificate should be presented included jobs where others would be at risk of COVID-related complications (60.7%), jobs where employees would be at risk of getting infected (58.7%), or to be exempt from quarantine when travelling abroad (56.0%). Contexts where fewer individuals perceived the need for vaccination certificates to be presented were participation in large gatherings (36.9%), access to social venues (35.5%), or sharing the same workspace (21.5%). Younger age, no intent for vaccination, and not believing vaccination to be an important step in surmounting the pandemic were factors associated with certificate non-acceptance. CONCLUSION: This large population-based study showed that the general adult population in Geneva, Switzerland, agreed with the implementation of vaccination certificates in work-related and travel-related contexts. However, this solution was perceived as unnecessary for access to large gatherings or social venues, or to share the same workspace. Differences were seen with age, sex, education, socioeconomic status, and vaccination willingness and perception, highlighting the importance of taking personal and sociodemographic variation into consideration when predicting acceptance of such certificates.


Subject(s)
COVID-19 , Travel , Adult , COVID-19 Vaccines , Female , Humans , Middle Aged , SARS-CoV-2 , Seroepidemiologic Studies , Switzerland , Travel-Related Illness , Vaccination
15.
Int J Environ Res Public Health ; 18(22)2021 11 13.
Article in English | MEDLINE | ID: covidwho-1512362

ABSTRACT

BACKGROUND: North Americans report insufficient moderate-to-vigorous physical activity (MVPA) and ample sedentary behaviors (SBs), suggesting possible barriers to an active lifestyle. This study compared self-reported MVPA and SB before and during COVID-19 "Stay-at-Home" restrictions as a potential barrier across North America. METHODS: Questionnaires were distributed from 21 April to 9 May 2020. ANOVAs compared data overall and by group (age, sex, race, income, education, employment status). RESULTS: During restrictions, 51.4% (n = 687) of the 1336 responses (991 female, 1187 Caucasian, 634 18-29 years) shifted to work from home and 12.1% (n = 162) lost their job. Overall, during restrictions, 8.3% (n = 110) fewer reported work-related MVPA (-178.6 ± 20.9 min/week). Similarly, 28.0% (n = 374) fewer reported travel-related MVPA, especially females and younger age groups. While the 7.3% (n = 98) fewer reporting recreational MVPA was not statistically significant (-30.4 ± 11.5 min/week), there was an increase in SB (+94.9 ± 4.1 min/week) in all groups, except the oldest age group (70+ years). Locomotive activities and fitness class remained the predominant MVPA mode. Of those reportedly using facilities (68%; n = 709) before COVID, 31.3% (n = 418) would not return due to it "being unsafe". CONCLUSION: While barriers related to pandemic restrictions had a negative short-term impact on MVPA and SB in North America, the long-term impact is unknown.


Subject(s)
COVID-19 , Sedentary Behavior , Accelerometry , Aged , Employment , Exercise , Female , Humans , SARS-CoV-2 , Travel , Travel-Related Illness
17.
Lancet Glob Health ; 9(12): e1658-e1666, 2021 12.
Article in English | MEDLINE | ID: covidwho-1475185

ABSTRACT

BACKGROUND: Advances in SARS-CoV-2 sequencing have enabled identification of new variants, tracking of its evolution, and monitoring of its spread. We aimed to use whole genome sequencing to describe the molecular epidemiology of the SARS-CoV-2 outbreak and to inform the implementation of effective public health interventions for control in Zimbabwe. METHODS: We performed a retrospective study of nasopharyngeal samples collected from nine laboratories in Zimbabwe between March 20 and Oct 16, 2020. Samples were taken as a result of quarantine procedures for international arrivals or to test for infection in people who were symptomatic or close contacts of positive cases. Samples that had a cycle threshold of less than 30 in the diagnostic PCR test were processed for sequencing. We began our analysis in July, 2020 (120 days since the first case), with a follow-up in October, 2020 (at 210 days since the first case). The phylogenetic relationship of the genome sequences within Zimbabwe and global samples was established using maximum likelihood and Bayesian methods. FINDINGS: Of 92 299 nasopharyngeal samples collected during the study period, 8099 were PCR-positive and 328 were available for sequencing, with 156 passing sequence quality control. 83 (53%) of 156 were from female participants. At least 26 independent introductions of SARS-CoV-2 into Zimbabwe in the first 210 days were associated with 12 global lineages. 151 (97%) of 156 had the Asp614Gly mutation in the spike protein. Most cases, 93 (60%), were imported from outside Zimbabwe. Community transmission was reported 6 days after the onset of the outbreak. INTERPRETATION: Initial public health interventions delayed onset of SARS-CoV-2 community transmission after the introduction of the virus from international and regional migration in Zimbabwe. Global whole genome sequence data are essential to reveal major routes of spread and guide intervention strategies. FUNDING: WHO, Africa CDC, Biotechnology and Biological Sciences Research Council, Medical Research Council, National Institute for Health Research, and Genome Research Limited.


Subject(s)
COVID-19/epidemiology , Epidemics , Genome, Viral , Public Health Surveillance , SARS-CoV-2/genetics , Travel-Related Illness , Adolescent , Adult , COVID-19/transmission , COVID-19/virology , Child , Child, Preschool , Female , Humans , Infant , Male , Middle Aged , Molecular Epidemiology , Retrospective Studies , Whole Genome Sequencing , Young Adult , Zimbabwe/epidemiology
18.
Nat Commun ; 12(1): 5705, 2021 09 29.
Article in English | MEDLINE | ID: covidwho-1442779

ABSTRACT

COVID-19 transmission rates are often linked to locally circulating strains of SARS-CoV-2. Here we describe 203 SARS-CoV-2 whole genome sequences analyzed from strains circulating in Rwanda from May 2020 to February 2021. In particular, we report a shift in variant distribution towards the emerging sub-lineage A.23.1 that is currently dominating. Furthermore, we report the detection of the first Rwandan cases of the B.1.1.7 and B.1.351 variants of concern among incoming travelers tested at Kigali International Airport. To assess the importance of viral introductions from neighboring countries and local transmission, we exploit available individual travel history metadata to inform spatio-temporal phylogeographic inference, enabling us to take into account infections from unsampled locations. We uncover an important role of neighboring countries in seeding introductions into Rwanda, including those from which no genomic sequences were available. Our results highlight the importance of systematic genomic surveillance and regional collaborations for a durable response towards combating COVID-19.


Subject(s)
COVID-19/virology , Genome, Viral/genetics , SARS-CoV-2/genetics , Travel-Related Illness , Adult , COVID-19/diagnosis , COVID-19/epidemiology , COVID-19/transmission , Epidemiological Monitoring , Female , Humans , Male , Phylogeny , Phylogeography , RNA, Viral/genetics , RNA, Viral/isolation & purification , Rwanda/epidemiology , SARS-CoV-2/isolation & purification , SARS-CoV-2/pathogenicity , Whole Genome Sequencing
19.
BMC Infect Dis ; 21(1): 799, 2021 Aug 11.
Article in English | MEDLINE | ID: covidwho-1440904

ABSTRACT

BACKGROUND: The COVID-19 pandemic has elicited imposition of some form of travel restrictions by almost all countries in the world. Most restrictions currently persist, although some have been gradually eased. It remains unclear if the trade-off from the unprecedented disruption to air travel was well worth for pandemic containment. METHOD: A comparative analysis was conducted on Singapore, Taiwan, Hong Kong and South Korea's COVID-19 response. Data on COVID-19 cases, travel-related and community interventions, socio-economic profile were consolidated. Trends on imported and local cases were analyzed using computations of moving averages, rate of change, particularly in response to distinct waves of travel-related interventions due to the outbreak in China, South Korea, Iran & Italy, and Europe. RESULTS: South Korea's travel restrictions were observed to be consistently more lagged in terms of timeliness and magnitude, with their first wave of travel restrictions on flights departing from China implemented 34 days after the outbreak in Wuhan, compared to 22-26 days taken by Singapore, Taiwan and Hong Kong. South Korea's restrictions against all countries came after 91 days, compared to 78-80 days for the other three countries. The rate of change of imported cases fell by 1.08-1.43 across all four countries following the first wave of travel restrictions on departures from China, and by 0.22-0.52 in all countries except South Korea in the fifth wave against all international travellers. Delayed rate of change of local cases resulting from travel restrictions imposed by the four countries with intrinsic importation risk, were not observed. CONCLUSIONS: Travel restriction was effective in preventing COVID-19 case importation in early outbreak phase, but may still be limited in preventing general local transmission. The impact of travel restrictions, regardless of promptness, in containing epidemics likely also depends on the effectiveness of local surveillance and non-pharmaceutical interventions concurrently implemented.


Subject(s)
COVID-19 , Pandemics , Hong Kong/epidemiology , Humans , Pandemics/prevention & control , Republic of Korea/epidemiology , SARS-CoV-2 , Singapore/epidemiology , Taiwan/epidemiology , Travel , Travel-Related Illness
20.
J Travel Med ; 28(8)2021 12 29.
Article in English | MEDLINE | ID: covidwho-1429273

ABSTRACT

BACKGROUND: A large cluster of 59 cases were linked to a single flight with 146 passengers from New Delhi to Hong Kong in April 2021. This outbreak coincided with early reports of exponential pandemic growth in New Delhi, which reached a peak of > 400 000 newly confirmed cases on 7 May 2021. METHODS: Epidemiological information including date of symptom onset, date of positive-sample detection and travel and contact history for individual cases from this flight were collected. Whole genome sequencing was performed, and sequences were classified based on the dynamic Pango nomenclature system. Maximum-likelihood phylogenetic analysis compared sequences from this flight alongside other cases imported from India to Hong Kong on 26 flights between June 2020 and April 2021, as well as sequences from India or associated with India-related travel from February to April 2021 and 1217 reference sequences. RESULTS: Sequence analysis identified six lineages of SARS-CoV-2 belonging to two variants of concern (Alpha and Delta) and one variant of public health interest (Kappa) involved in this outbreak. Phylogenetic analysis confirmed at least three independent sub-lineages of Alpha with limited onward transmission, a superspreading event comprising 37 cases of Kappa and transmission of Delta to only one passenger. Additional analysis of another 26 flights from India to Hong Kong confirmed widespread circulation of all three variants in India since early March 2021. CONCLUSIONS: The broad spectrum of disease severity and long incubation period of SARS-CoV-2 pose a challenge for surveillance and control. As illustrated by this particular outbreak, opportunistic infections of SARS-CoV-2 can occur irrespective of variant lineage, and requiring a nucleic acid test within 72 hours of departure may be insufficient to prevent importation or in-flight transmission.


Subject(s)
Air Travel , COVID-19 , Travel-Related Illness , COVID-19/epidemiology , COVID-19/transmission , Disease Outbreaks , Hong Kong , Humans , India , Phylogeny
SELECTION OF CITATIONS
SEARCH DETAIL