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1.
Journal of clinical virology : the official publication of the Pan American Society for Clinical Virology ; 2023.
Article in English | EuropePMC | ID: covidwho-2254122

ABSTRACT

Background : The COVID-19 pandemic led to severe health systems collapse, as well as logistics and supply delivery shortages across sectors. Delivery of PCR related healthcare supplies continue to be hindered. There is the need for a rapid and accessible SARS-CoV-2 molecular detection method in low resource settings. Objectives : To validate a novel isothermal amplification method for rapid detection of SARS-CoV-2 across seven sub-Sharan African countries. Study design : In this multi-country phase 2 diagnostic study, 3,231 clinical samples in seven African sites were tested with two reverse transcription Recombinase-Aided Amplification (RT-RAA) assays (based on SARS-CoV-2 Nucleocapsid (N) gene and RNA-dependent RNA polymerase (RdRP) gene). The test was performed in a mobile suitcase laboratory within 15 minutes. All results were compared to a real-time RT-PCR assay. Extraction kits based on silica gel or magnetic beads were applied. Results : Four sites demonstrated good to excellent agreement, while three sites showed fair to moderate results. The RdRP gene assay exhibited an overall PPV of 0.92 and a NPV of 0.88. The N gene assay exhibited an overall PPV of 0.93 and a NPV 0.88. The sensitivity of both RT-RAA assays varied depending on the sample Ct values. When comparing sensitivity between sites, values differed considerably. For high viral load samples, the RT-RAA assay sensitivity ranges were between 60.5 and 100% (RdRP assay) and 25 and 98.6 (N assay). Conclusion : Overall, the RdRP based RT-RAA test showed the best assay accuracy. This study highlights the challenges of implementing rapid molecular assays in field conditions. Factors that are important for successful deployment across countries include the implementation of standardized operation procedures, in-person continuous training for staff, and enhanced quality control measures.

2.
J Clin Virol ; 162: 105422, 2023 05.
Article in English | MEDLINE | ID: covidwho-2254123

ABSTRACT

BACKGROUND: The COVID-19 pandemic led to severe health systems collapse, as well as logistics and supply delivery shortages across sectors. Delivery of PCR related healthcare supplies continue to be hindered. There is the need for a rapid and accessible SARS-CoV-2 molecular detection method in low resource settings. OBJECTIVES: To validate a novel isothermal amplification method for rapid detection of SARS-CoV-2 across seven sub-Sharan African countries. STUDY DESIGN: In this multi-country phase 2 diagnostic study, 3,231 clinical samples in seven African sites were tested with two reverse transcription Recombinase-Aided Amplification (RT-RAA) assays (based on SARS-CoV-2 Nucleocapsid (N) gene and RNA-dependent RNA polymerase (RdRP) gene). The test was performed in a mobile suitcase laboratory within 15 min. All results were compared to a real-time RT-PCR assay. Extraction kits based on silica gel or magnetic beads were applied. RESULTS: Four sites demonstrated good to excellent agreement, while three sites showed fair to moderate results. The RdRP gene assay exhibited an overall PPV of 0.92 and a NPV of 0.88. The N gene assay exhibited an overall PPV of 0.93 and a NPV 0.88. The sensitivity of both RT-RAA assays varied depending on the sample Ct values. When comparing sensitivity between sites, values differed considerably. For high viral load samples, the RT-RAA assay sensitivity ranges were between 60.5 and 100% (RdRP assay) and 25 and 98.6 (N assay). CONCLUSION: Overall, the RdRP based RT-RAA test showed the best assay accuracy. This study highlights the challenges of implementing rapid molecular assays in field conditions. Factors that are important for successful deployment across countries include the implementation of standardized operation procedures, in-person continuous training for staff, and enhanced quality control measures.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , SARS-CoV-2/genetics , COVID-19/diagnosis , Pandemics , Sensitivity and Specificity , Nucleic Acid Amplification Techniques/methods , Real-Time Polymerase Chain Reaction , Africa South of the Sahara , RNA, Viral/genetics
3.
Viruses ; 15(1)2022 Dec 20.
Article in English | MEDLINE | ID: covidwho-2234782

ABSTRACT

Three epidemic waves of coronavirus disease-19 (COVID-19) occurred in Madagascar from March 2020 to May 2022, with a positivity rate of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) of 21% to 33%. Our study aimed to identify the impact of COVID-19 on the epidemiology of seasonal respiratory viruses (RVs) in Madagascar. We used two different specimen sources (SpS). First, 2987 nasopharyngeal (NP) specimens were randomly selected from symptomatic patients between March 2020 and May 2022 who tested negative for SARS-CoV-2 and were tested for 14 RVs by multiplex real-time PCR. Second, 6297 NP specimens were collected between March 2020 and May 2022 from patients visiting our sentinel sites of the influenza sentinel network. The samples were tested for influenza, respiratory syncytial virus (RSV), and SARS-CoV-2. From SpS-1, 19% (569/2987) of samples tested positive for at least one RV. Rhinovirus (6.3%, 187/2987) was the most frequently detected virus during the first two waves, whereas influenza predominated during the third. From SpS-2, influenza, SARS-CoV-2, and RSV accounted for 5.4%, 24.5%, and 39.4% of the detected viruses, respectively. During the study period, we observed three different RV circulation profiles. Certain viruses circulated sporadically, with increased activity in between waves of SARS-CoV-2. Other viruses continued to circulate regardless of the COVID-19 situation. Certain viruses were severely disrupted by the spread of SARS-CoV-2. Our findings underline the importance and necessity of maintaining an integrated disease surveillance system for the surveillance and monitoring of RVs of public health interest.


Subject(s)
COVID-19 , Influenza, Human , Respiratory Syncytial Virus, Human , Respiratory Tract Infections , Viruses , Humans , COVID-19/epidemiology , Influenza, Human/epidemiology , SARS-CoV-2/genetics , Pandemics , Madagascar/epidemiology , Seasons , Respiratory Tract Infections/epidemiology , Viruses/genetics , Respiratory Syncytial Virus, Human/genetics
4.
Influenza Other Respir Viruses ; 16(6): 994-1003, 2022 11.
Article in English | MEDLINE | ID: covidwho-1909401

ABSTRACT

BACKGROUND: Health care workers (HCWs) represent a vulnerable population during epidemic periods. Our cohort study aimed to estimate the risk of infection and associated factors among HCWs during the first wave of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in Madagascar. METHODS: A prospective cohort study was carried out in three hospitals that oversaw the first cases of COVID-19. Monthly ELISA-based serological tests were conducted, and nasopharyngeal swabs were collected in the case of symptoms linked to COVID-19 for RT-PCR analysis. Survival analyses were used to determine factors associated with SARS-CoV-2 infection. RESULTS: The study lasted 7 months from May 2020. We included 122 HCWs, 61.5% of whom were women. The median age was 31.9 years (IQR: 26.4-42.3). In total, 42 (34.4%) had SARS-CoV-2 infections, of which 20 were asymptomatic (47.6%). The incidence of SARS-CoV-2 infection was 9.3% (95% CI [6.5-13.2]) person-months. Sixty-five HCWs presented symptoms, of which 19 were positive by RT-PCR. When adjusted for exposure to deceased cases, infection was more frequent in HCWs younger than 30 years of age (RR = 4.9, 95% CI [1.4-17.2]). CONCLUSION: Our results indicate a high incidence of infection with SARS-CoV-2 among HCWs, with a high proportion of asymptomatic cases. Young HCWs are more likely to be at risk than others. Greater awareness among young people is necessary to reduce the threat of infection among HCWs.


Subject(s)
COVID-19 , Adolescent , Adult , COVID-19/diagnosis , COVID-19/epidemiology , Cohort Studies , Female , Health Personnel , Humans , Madagascar/epidemiology , Male , Prospective Studies , SARS-CoV-2/genetics
5.
IJID Regions (Online) ; 2:82-89, 2021.
Article in English | EuropePMC | ID: covidwho-1905204

ABSTRACT

Highlights • A sensitive surveillance case definition can be defined based on specific symptoms.• Intercostal recession and dyspnoea may be used to identify children with respiratory syncytial virus (RSV) infection.• Fever was not necessarily a good predictor of paediatric RSV infection.• Headache may be used to identify influenza infection in children.• Sweats and productive cough may define infection due to Streptococcus pneumoniae in children. Background The lack of rapid, sensitive and affordable diagnostic tests that can distinguish a wide variety of respiratory pathogens at the point of care is an obstacle to the rapid implementation of control measures following events and epidemics. In addition, the absence of a standardized case definition to differentiate putative aetiologies is a challenge to assessing the burden of disease. This study aimed to identify the clinical spectrum of respiratory pathogens commonly associated with respiratory tract infections in the context of disease surveillance. Methods Data obtained from prospective hospital-based severe acute respiratory infection surveillance among children aged <5 years from November 2010 to July 2013 were used in this study. Results Intercostal recession and dyspnoea were predictive of respiratory syncytial virus (RSV) infection, whereas headache and chills were more often observed during influenza A infection. Male patients were at a higher risk for RSV infection than female patients. Productive cough, chills, sweating and weight loss were significantly associated with Streptococcus pneumoniae infection. The presence of fever did not necessarily indicate RSV infection. Conclusions Combined with other examinations, this study shows the value of including the syndromic approach in the panel of diagnostic criteria for rapid identification of the risk of infectious diseases in areas where laboratory diagnostics are challenging. Given the current situation with coronavirus disease 2019, this approach may help decision makers to implement appropriate control measures.

6.
Influenza Other Respir Viruses ; 16(5): 803-819, 2022 09.
Article in English | MEDLINE | ID: covidwho-1895988

ABSTRACT

We aimed to estimate the household secondary infection attack rate (hSAR) of SARS-CoV-2 in investigations aligned with the WHO Unity Studies Household Transmission Investigations (HHTI) protocol. We conducted a systematic review and meta-analysis according to PRISMA 2020 guidelines. We searched Medline, Embase, Web of Science, Scopus and medRxiv/bioRxiv for "Unity-aligned" First Few X cases (FFX) and HHTIs published 1 December 2019 to 26 July 2021. Standardised early results were shared by WHO Unity Studies collaborators (to 1 October 2021). We used a bespoke tool to assess investigation methodological quality. Values for hSAR and 95% confidence intervals (CIs) were extracted or calculated from crude data. Heterogeneity was assessed by visually inspecting overlap of CIs on forest plots and quantified in meta-analyses. Of 9988 records retrieved, 80 articles (64 from databases; 16 provided by Unity Studies collaborators) were retained in the systematic review; 62 were included in the primary meta-analysis. hSAR point estimates ranged from 2% to 90% (95% prediction interval: 3%-71%; I 2 = 99.7%); I 2 values remained >99% in subgroup analyses, indicating high, unexplained heterogeneity and leading to a decision not to report pooled hSAR estimates. FFX and HHTI remain critical epidemiological tools for early and ongoing characterisation of novel infectious pathogens. The large, unexplained variance in hSAR estimates emphasises the need to further support standardisation in planning, conduct and analysis, and for clear and comprehensive reporting of FFX and HHTIs in time and place, to guide evidence-based pandemic preparedness and response efforts for SARS-CoV-2, influenza and future novel respiratory viruses.


Subject(s)
COVID-19 , Influenza, Human , Humans , SARS-CoV-2 , COVID-19/epidemiology , Family Characteristics , Pandemics
7.
Viruses ; 14(5)2022 04 22.
Article in English | MEDLINE | ID: covidwho-1810320

ABSTRACT

The burden of encephalitis and its associated viral etiology is poorly described in Africa. Moreover, neurological manifestations of COVID-19 are increasingly reported in many countries, but less so in Africa. Our prospective study aimed to characterize the main viral etiologies of patients hospitalized for encephalitis in two hospitals in Dakar. From January to December 2021, all adult patients that met the inclusion criteria for clinical infectious encephalitis were enrolled. Cerebrospinal fluids, blood, and nasopharyngeal swabs were taken and tested for 27 viruses. During the study period, 122 patients were enrolled. Viral etiology was confirmed or probable in 27 patients (22.1%), with SARS-CoV-2 (n = 8), HSV-1 (n = 7), HHV-7 (n = 5), and EBV (n = 4) being the most detected viruses. Age groups 40-49 was more likely to be positive for at least one virus with an odds ratio of 7.7. The mortality was high among infected patients, with 11 (41%) deaths notified during hospitalization. Interestingly, SARS-CoV-2 was the most prevalent virus in hospitalized patients presenting with encephalitis. Our results reveal the crucial need to establish a country-wide surveillance of encephalitis in Senegal to estimate the burden of this disease in our population and implement strategies to improve care and reduce mortality.


Subject(s)
COVID-19 , Encephalitis, Viral , Encephalitis , Viruses , Adult , COVID-19/epidemiology , Encephalitis/epidemiology , Encephalitis, Viral/epidemiology , Humans , Prospective Studies , SARS-CoV-2 , Senegal/epidemiology
8.
Front Public Health ; 10: 786060, 2022.
Article in English | MEDLINE | ID: covidwho-1715078

ABSTRACT

Bats are natural reservoirs for both Alpha- and Betacoronaviruses and the hypothesized original hosts of five of seven known zoonotic coronaviruses. To date, the vast majority of bat coronavirus research has been concentrated in Asia, though coronaviruses are globally distributed; indeed, SARS-CoV and SARS-CoV-2-related Betacoronaviruses in the subgenus Sarbecovirus have been identified circulating in Rhinolophid bats in both Africa and Europe, despite the relative dearth of surveillance in these regions. As part of a long-term study examining the dynamics of potentially zoonotic viruses in three species of endemic Madagascar fruit bat (Pteropus rufus, Eidolon dupreanum, Rousettus madagascariensis), we carried out metagenomic Next Generation Sequencing (mNGS) on urine, throat, and fecal samples obtained from wild-caught individuals. We report detection of RNA derived from Betacoronavirus subgenus Nobecovirus in fecal samples from all three species and describe full genome sequences of novel Nobecoviruses in P. rufus and R. madagascariensis. Phylogenetic analysis indicates the existence of five distinct Nobecovirus clades, one of which is defined by the highly divergent ancestral sequence reported here from P. rufus bats. Madagascar Nobecoviruses derived from P. rufus and R. madagascariensis demonstrate, respectively, Asian and African phylogeographic origins, mirroring those of their fruit bat hosts. Bootscan recombination analysis indicates significant selection has taken place in the spike, nucleocapsid, and NS7 accessory protein regions of the genome for viruses derived from both bat hosts. Madagascar offers a unique phylogeographic nexus of bats and viruses with both Asian and African phylogeographic origins, providing opportunities for unprecedented mixing of viral groups and, potentially, recombination. As fruit bats are handled and consumed widely across Madagascar for subsistence, understanding the landscape of potentially zoonotic coronavirus circulation is essential for mitigation of future zoonotic threats.


Subject(s)
COVID-19 , Chiroptera , Severe acute respiratory syndrome-related coronavirus , Animals , Humans , Phylogeny , SARS-CoV-2
9.
Interface Focus ; 12(2): 20210079, 2022 Apr 06.
Article in English | MEDLINE | ID: covidwho-1713825

ABSTRACT

Responses to the early (February-July 2020) COVID-19 pandemic varied widely, globally. Reasons for this are multiple but likely relate to the healthcare and financial resources then available, and the degree of trust in, and economic support provided by, national governments. Cultural factors also affected how different populations reacted to the various pandemic restrictions, like masking, social distancing and self-isolation or self-quarantine. The degree of compliance with these measures depended on how much individuals valued their needs and liberties over those of their society. Thus, several themes may be relevant when comparing pandemic responses across different regions. East and Southeast Asian populations tended to be more collectivist and self-sacrificing, responding quickly to early signs of the pandemic and readily complied with most restrictions to control its spread. Australasian, Eastern European, Scandinavian, some Middle Eastern, African and South American countries also responded promptly by imposing restrictions of varying severity, due to concerns for their wider society, including for some, the fragility of their healthcare systems. Western European and North American countries, with well-resourced healthcare systems, initially reacted more slowly, partly in an effort to maintain their economies but also to delay imposing pandemic restrictions that limited the personal freedoms of their citizens.

10.
Epidemics ; 38: 100533, 2022 03.
Article in English | MEDLINE | ID: covidwho-1540625

ABSTRACT

As the national reference laboratory for febrile illness in Madagascar, we processed samples from the first epidemic wave of COVID-19, between March and September 2020. We fit generalized additive models to cycle threshold (Ct) value data from our RT-qPCR platform, demonstrating a peak in high viral load, low-Ct value infections temporally coincident with peak epidemic growth rates estimated in real time from publicly-reported incidence data and retrospectively from our own laboratory testing data across three administrative regions. We additionally demonstrate a statistically significant effect of duration of time since infection onset on Ct value, suggesting that Ct value can be used as a biomarker of the stage at which an individual is sampled in the course of an infection trajectory. As an extension, the population-level Ct distribution at a given timepoint can be used to estimate population-level epidemiological dynamics. We illustrate this concept by adopting a recently-developed, nested modeling approach, embedding a within-host viral kinetics model within a population-level Susceptible-Exposed-Infectious-Recovered (SEIR) framework, to mechanistically estimate epidemic growth rates from cross-sectional Ct distributions across three regions in Madagascar. We find that Ct-derived epidemic growth estimates slightly precede those derived from incidence data across the first epidemic wave, suggesting delays in surveillance and case reporting. Our findings indicate that public reporting of Ct values could offer an important resource for epidemiological inference in low surveillance settings, enabling forecasts of impending incidence peaks in regions with limited case reporting.


Subject(s)
COVID-19 , COVID-19/epidemiology , Cross-Sectional Studies , Humans , Madagascar/epidemiology , Retrospective Studies , SARS-CoV-2
12.
Influenza Other Respir Viruses ; 16(1): 48-55, 2022 01.
Article in English | MEDLINE | ID: covidwho-1352475

ABSTRACT

BACKGROUND: Households are among the highest risk for the transmission of SARS-CoV-2. In sub-Saharan Africa, very few studies have described household transmission during the COVID-19 pandemic. Our work aimed to describe the epidemiologic parameters and analyze the secondary attack rate (SAR) in Antananarivo, Madagascar, following the introduction of SARS-CoV-2 in the country in March 2020. METHODS: A prospective case-ascertained study of all identified close contacts of laboratory-confirmed COVID-19 infections was conducted in Antananarivo from March to June 2020. Cases and household contacts were followed for 21 days. We estimated epidemic parameters of disease transmission by fitting parametric distributions based on infector-infected paired data. We assessed factors influencing transmission risk by analyzing the SAR. FINDINGS: Overall, we included 96 index cases and 179 household contacts. Adjusted with the best-fit normal distribution, the incubation period was 4.1 days (95% CI 0.7-7.5]). The serial interval was 6.0 days (95% CI [2.4-9.6]) after adjusting with the best-fit Weibull distribution. On average, each index case infected 1.6 family members (95%CI [0.9-2.3]). The mean SAR among close contacts was 38.8% (95% CI [19.5-58.2]) with the best-fit gamma distribution. Contacts older than 35 years old were more likely to be infected, and the highest SAR was found among them. CONCLUSION: The results of our study provide key insights into the epidemiology of the first wave of SARS-CoV-2 in Madagascar. High rates of household transmission were found in Antananarivo, emphasizing the need for preventive measures to reduce community transmission.


Subject(s)
COVID-19 , Adult , Family Characteristics , Humans , Madagascar/epidemiology , Pandemics , SARS-CoV-2
13.
Indoor Air ; 31(6): 2281-2295, 2021 11.
Article in English | MEDLINE | ID: covidwho-1285030

ABSTRACT

The incidence of several respiratory viral infections has been shown to be related to climate. Because humans spend most of their time indoors, measures of indoor climate, rather than outdoor climate, may be better predictors of disease incidence and transmission. Therefore, understanding the relationship between indoor and outdoor climate will help illuminate their influence on the seasonality of diseases caused by respiratory viruses. Indoor-outdoor relationships between temperature and humidity have been documented in temperate regions, but little information is available for tropical regions, where seasonal patterns of respiratory viral diseases differ. We have examined indoor-outdoor correlations of temperature, relative humidity (RH), and absolute humidity (AH) over a 1-year period in each of seven tropical cities. Across all cities, the average monthly indoor temperature was 25 ± 3°C (mean ± standard deviation) with a range of 20-30°C. The average monthly indoor RH was 66 ± 9% with a range of 50-78%, and the average monthly indoor AH was 15 ± 3 g/m3 with a range of 10-23 g/m3 . Indoor AH and RH were linearly correlated with outdoor AH when the air conditioning (AC) was off, suggesting that outdoor AH may be a good proxy of indoor humidity in the absence of AC. All indoor measurements were more strongly correlated with outdoor measurements as distance from the equator increased. Such correlations were weaker during the wet season, especially when AC was in operation. These correlations will provide insight for assessing the seasonality of respiratory viral infections using outdoor climate data, which is more widely available than indoor data, even though transmission of these diseases mainly occurs indoors.


Subject(s)
Air Pollution, Indoor , Humidity , Temperature , Tropical Climate , Seasons
14.
Influenza Other Respir Viruses ; 15(4): 495-505, 2021 07.
Article in English | MEDLINE | ID: covidwho-1262334

ABSTRACT

BACKGROUND: Influenza surveillance helps time prevention and control interventions especially where complex seasonal patterns exist. We assessed influenza surveillance sustainability in Africa where influenza activity varies and external funds for surveillance have decreased. METHODS: We surveyed African Network for Influenza Surveillance and Epidemiology (ANISE) countries about 2011-2017 surveillance system characteristics. Data were summarized with descriptive statistics and analyzed with univariate and multivariable analyses to quantify sustained or expanded influenza surveillance capacity in Africa. RESULTS: Eighteen (75%) of 24 ANISE members participated in the survey; their cumulative population of 710 751 471 represent 56% of Africa's total population. All 18 countries scored a mean 95% on WHO laboratory quality assurance panels. The number of samples collected from severe acute respiratory infection case-patients remained consistent between 2011 and 2017 (13 823 vs 13 674 respectively) but decreased by 12% for influenza-like illness case-patients (16 210 vs 14 477). Nine (50%) gained capacity to lineage-type influenza B. The number of countries reporting each week to WHO FluNet increased from 15 (83%) in 2011 to 17 (94%) in 2017. CONCLUSIONS: Despite declines in external surveillance funding, ANISE countries gained additional laboratory testing capacity and continued influenza testing and reporting to WHO. These gains represent important achievements toward sustainable surveillance and epidemic/pandemic preparedness.


Subject(s)
Influenza, Human , Respiratory Tract Infections , Africa/epidemiology , Humans , Influenza, Human/epidemiology , Influenza, Human/prevention & control , Pandemics , Respiratory Tract Infections/epidemiology , Surveys and Questionnaires
15.
EBioMedicine ; 68: 103419, 2021 Jun.
Article in English | MEDLINE | ID: covidwho-1258362

ABSTRACT

BACKGROUND: The incidence of the 2020 COVID-19 epidemic in Africa seems to be different from that of the rest of the world, however its true extent is probably underestimated. Conducting population based sero-surveys during the epidemic has moreover been extremely challenging, driving our group and others to study blood donor samples. METHODS: We collected regional epidemiological COVID-19 surveillance data, and simultaneously monitored anti-SARS-CoV-2 antibody seroprevalences monthly throughout the epidemic in 5 major Region-associated Blood Transfusion Centres of Madagascar over a period of 9 months. FINDINGS: Soon after attaining the first epidemic peaks between May and August 2020, both crude and population-weighted test-performance-adjusted seroprevalences of anti-SARS-CoV-2 antibodies was in Malagasy blood donors rapidly increased up to over 40% positivity. INTERPRETATION: These findings suggest a high cumulative incidence of infection and seroconversion, which may have contributed to the observed deceleration of infection rates, but was not sufficient to prevent the second epidemic wave that struck Madagascar in Spring 2021. FUNDING: This project was funded by the United States Agency for International Development.


Subject(s)
Antibodies, Viral/blood , Blood Donors , COVID-19/epidemiology , Epidemics , SARS-CoV-2/immunology , COVID-19/immunology , Female , Humans , Incidence , Madagascar/epidemiology , Male , Population Surveillance , Seroconversion , Seroepidemiologic Studies
17.
Influenza Other Respir Viruses ; 15(4): 457-468, 2021 07.
Article in English | MEDLINE | ID: covidwho-1083542

ABSTRACT

BACKGROUND: Following the first detection of SARS-CoV-2 in passengers arriving from Europe on 19 March 2020, Madagascar took several mitigation measures to limit the spread of the virus in the country. METHODS: Nasopharyngeal and/or oropharyngeal swabs were collected from travellers to Madagascar, suspected SARS-CoV-2 cases and contact of confirmed cases. Swabs were tested at the national reference laboratory using real-time RT-PCR. Data collected from patients were entered in an electronic database for subsequent statistical analysis. All distribution of laboratory-confirmed cases were mapped, and six genomes of viruses were fully sequenced. RESULTS: Overall, 26,415 individuals were tested for SARS-CoV-2 between 18 March and 18 September 2020, of whom 21.0% (5,553/26,145) returned positive. Among laboratory-confirmed SARS-CoV-2-positive patients, the median age was 39 years (IQR: 28-52), and 56.6% (3,311/5,553) were asymptomatic at the time of sampling. The probability of testing positive increased with age with the highest adjusted odds ratio of 2.2 [95% CI: 1.9-2.5] for individuals aged 49 years and more. Viral strains sequenced belong to clades 19A, 20A and 20B indicative of several independent introduction of viruses. CONCLUSIONS: Our study describes the first wave of the COVID-19 in Madagascar. Despite early strategies in place Madagascar could not avoid the introduction and spread of the virus. More studies are needed to estimate the true burden of disease and make public health recommendations for a better preparation to another wave.


Subject(s)
COVID-19/epidemiology , Adult , Asymptomatic Infections/epidemiology , COVID-19/diagnosis , COVID-19/transmission , COVID-19 Nucleic Acid Testing , Epidemiological Monitoring , Female , Genome, Viral/genetics , Humans , Madagascar/epidemiology , Male , Middle Aged , Nasopharynx/virology , SARS-CoV-2/classification , SARS-CoV-2/genetics , SARS-CoV-2/isolation & purification , Travel
19.
Int J Infect Dis ; 103: 338-342, 2021 Feb.
Article in English | MEDLINE | ID: covidwho-943190

ABSTRACT

OBJECTIVES: Quantitative estimates of the impact of infectious disease outbreaks are required to develop measured policy responses. In many low- and middle-income countries, inadequate surveillance and incompleteness of death registration are important barriers. DESIGN: Here, we characterize how large an impact on mortality would have to be for being detectable using the uniquely detailed mortality notification data from the city of Antananarivo, Madagascar, with application to a recent measles outbreak. RESULTS: The weekly mortality rate of children during the 2018-2019 measles outbreak was 161% above the expected value at its peak, and the signal can be detected earlier in children than in the general population. This approach to detect anomalies from expected baseline mortality allows us to delineate the prevalence of COVID-19 at which excess mortality would be detectable with the existing death notification system in Antananarivo. CONCLUSIONS: Given current age-specific estimates of the COVID-19 fatality ratio and the age structure of the population in Antananarivo, we estimate that as few as 11 deaths per week in the 60-70 years age group (corresponding to an infection rate of approximately 1%) would detectably exceed the baseline. Data from 2020 will undergo necessary processing and quality control in the coming months. Our results provide a baseline for interpreting this information.


Subject(s)
COVID-19/epidemiology , Disease Outbreaks , Adolescent , Adult , Aged , Aged, 80 and over , COVID-19/mortality , Child , Child, Preschool , Female , Humans , Infant , Infant, Newborn , Limit of Detection , Madagascar/epidemiology , Measles/epidemiology , Measles/mortality , Middle Aged , Prevalence , SARS-CoV-2 , Young Adult
20.
Influenza Other Respir Viruses ; 15(3): 407-412, 2021 05.
Article in English | MEDLINE | ID: covidwho-894770

ABSTRACT

The COVID-19 pandemic caused by the novel coronavirus SARS-CoV-2 continues to have a major impact on healthcare and social systems throughout the world. As the clinical and epidemiological features of COVID-19 have many parallels with influenza, it is important to ensure optimal management of both respiratory diseases as we anticipate their continued co-circulation. In particular, there is a need to ensure that effective surveillance and diagnostic capacities are in place to monitor these and other respiratory viruses, as this will underpin decisions on the appropriate clinical management of the respective diseases. As such, we propose a series of key recommendations for stakeholders, public health authorities, primary care physicians and surveillance bodies that will help mitigate the combined risks of concurrent influenza epidemics and the COVID-19 pandemic. We advocate the judicious use of influenza vaccines and antivirals, particularly among groups at high risk of complications, with healthcare workers also considered a priority for vaccination. It is likely that the increased use of emerging technologies such as telemedicine and contact tracing will permanently change our approach to managing infectious disease. The use of these technologies, alongside existing pharmaceutical strategies, will ensure that we achieve a holistic approach to the global public health measures needed to deal with the combined threat of influenza and COVID-19. Ensuring that this approach is optimal will be key as we move from a reactive pandemic response towards preparing for the long-term management of the remarkable clinical burden associated with these respiratory pathogens.


Subject(s)
COVID-19/epidemiology , Coinfection/epidemiology , Influenza, Human/epidemiology , SARS-CoV-2 , COVID-19/diagnosis , COVID-19/prevention & control , COVID-19/transmission , Humans , Influenza, Human/diagnosis , Influenza, Human/prevention & control , Influenza, Human/transmission
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