Viral Etiology of Influenza-Like Illnesses in Antananarivo, Madagascar, July 2008 to June 2009

In Madagascar, despite an influenza surveillance established since 1978, little is known about the etiology and prevalence of viruses other than influenza causing influenza-like illnesses (ILIs).From July 2008 to June 2009, we collected respiratory specimens from patients who presented ILIs symptoms in public and private clinics in Antananarivo (the capital city of Madagascar). ILIs were defined as body temperature ≥38°C and cough and at least two of the following symptoms: sore throat, rhinorrhea, headache and muscular pain, for a maximum duration of 3 days. We screened these specimens using five multiplex real time Reverse Transcription and/or Polymerase Chain Reaction assays for detection of 14 respiratory viruses. We detected respiratory viruses in 235/313 (75.1%) samples. Overall influenza virus A (27.3%) was the most common virus followed by rhinovirus (24.8%), RSV (21.2%), adenovirus (6.1%), coronavirus OC43 (6.1%), influenza virus B (3.9%), parainfluenza virus-3 (2.9%), and parainfluenza virus-1 (2.3%). Co-infections occurred in 29.4% (69/235) of infected patients and rhinovirus was the most detected virus (27.5%). Children under 5 years were more likely to have one or more detectable virus associated with their ILI. In this age group, compared to those ≥5 years, the risk of detecting more than one virus was higher (OR = 1.9), as was the risk of detecting of RSV (OR = 10.1) and adenovirus (OR = 4.7). While rhinovirus and adenovirus infections occurred year round, RSV, influenza virus A and coronavirus OC43 had defined period of circulation.In our study, we found that respiratory viruses play an important role in ILIs in the Malagasy community, particularly in children under 5 years old. These data provide a better understanding of the viral etiology of outpatients with ILI and describe for the first time importance of these viruses in different age group and their period of circulation

Global circulation of respiratory viruses: from local observations to global predictions

International audienc

Short message service sentinel surveillance of influenza-like illness in Madagascar, 2008–2012

International audiencePROBLEM: The revision of the International Health Regulations (IHR) and the threat of influenza pandemics and other disease outbreaks with a major impact on developing countries have prompted bolstered surveillance capacity, particularly in low-resource settings. APPROACH: Surveillance tools with well-timed, validated data are necessary to strengthen disease surveillance. In 2007 Madagascar implemented a sentinel surveillance system for influenza-like illness (ILI) based on data collected from sentinel general practitioners. SETTING: Before 2007, Madagascar's disease surveillance was based on the passive collection and reporting of data aggregated weekly or monthly. The system did not allow for the early identification of outbreaks or unexpected increases in disease incidence. RELEVANT CHANGES: An innovative case reporting system based on the use of cell phones was launched in March 2007. Encrypted short message service, which costs less than 2 United States dollars per month per health centre, is now being used by sentinel general practitioners for the daily reporting of cases of fever and ILI seen in their practices. To validate the daily data, practitioners also report epidemiological and clinical data (e.g. new febrile patient's sex, age, visit date, symptoms) weekly to the epidemiologists on the research team using special patient forms. LESSONS LEARNT: Madagascar's sentinel ILI surveillance system represents the country's first nationwide "real-time" surveillance system. It has proved the feasibility of improving disease surveillance capacity through innovative systems despite resource constraints. This type of syndromic surveillance can detect unexpected increases in the incidence of ILI and other syndromic illnesses

Early-warning health and process indicators for sentinel surveillance in Madagascar 2007-2011

Background: Epidemics pose major threats in resource-poor countries, and surveillance tools for their early detection and response are often inadequate. In 2007, a sentinel surveillance system was established in Madagascar, with the aim of rapidly identifying potential epidemics of febrile or diarrhoeal syndromes and issuing alerts. We present the health and process indicators for the five years during which this system was constructed, showing the spatiotemporal trends, early-warning sign detection capability and process evaluation through timely analyses of high-quality data. Methods: The Malagasy sentinel surveillance network is currently based on data for fever and diarrhoeal syndromes collected from 34 primary health centres and reported daily via the transmission of short messages from mobile telephones. Data are analysed daily at the Institut Pasteur de Madagascar to make it possible to issue alerts more rapidly, and integrated process indicators (timeliness, data quality) are used to monitor the system. Results: From 2007 to 2011, 917,798 visits were reported. Febrile syndromes accounted for about 11% of visits annually, but the trends observed differed between years and sentinel sites. From 2007 to 2011, 21 epidemic alerts were confirmed. However, delays in data transmission were observed (88% transmitted within 24 hours in 2008; 67% in 2011) and the percentage of forms transmitted each week for validity control decreased from 99.9% in 2007 to 63.5% in 2011. Conclusion: A sentinel surveillance scheme should take into account both epidemiological and process indicators. It must also be governed by the main purpose of the surveillance and by local factors, such as the motivation of healthcare workers and telecommunication infrastructure. Permanent evaluation indicators are required for regular improvement of the system

Early-warning health and process indicators for sentinel surveillance in Madagascar 2007-2011

Background: Epidemics pose major threats in resource-poor countries, and surveillance tools for their early detection and response are often inadequate. In 2007, a sentinel surveillance system was established in Madagascar, with the aim of rapidly identifying potential epidemics of febrile or diarrhoeal syndromes and issuing alerts. We present the health and process indicators for the five years during which this system was constructed, showing the spatiotemporal trends, early-warning sign detection capability and process evaluation through timely analyses of high-quality data.Methods: The Malagasy sentinel surveillance network is currently based on data for fever and diarrhoeal syndromes collected from 34 primary health centres and reported daily via the transmission of short messages from mobile telephones. Data are analysed daily at the Institut Pasteur de Madagascar to make it possible to issue alerts more rapidly, and integrated process indicators (timeliness, data quality) are used to monitor the system.Results: From 2007 to 2011, 917,798 visits were reported. Febrile syndromes accounted for about 11% of visits annually, but the trends observed differed between years and sentinel sites. From 2007 to 2011, 21 epidemic alerts were confirmed. However, delays in data transmission were observed (88% transmitted within 24 hours in 2008; 67% in 2011) and the percentage of forms transmitted each week for validity control decreased from 99.9% in 2007 to 63.5% in 2011.Conclusion: A sentinel surveillance scheme should take into account both epidemiological and process indicators. It must also be governed by the main purpose of the surveillance and by local factors, such as the motivation of healthcare workers and telecommunication infrastructure. Permanent evaluation indicators are required for regular improvement of the system.

Epidemiological Patterns of Seasonal Respiratory Viruses during the COVID-19 Pandemic in Madagascar, March 2020–May 2022

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

Epidemiology of severe acute respiratory infections from hospital-based surveillance in Madagascar, November 2010 to July 2013.

BACKGROUND:Few comprehensive data exist regarding the epidemiology of severe acute respiratory infections (SARI) in low income countries. This study aimed at identifying etiologies and describing clinical features of SARI-associated hospitalization in Madagascar. METHODS:It is a prospective surveillance of SARI in 2 hospitals for 3 years. Nasopharyngeal swabs, sputum, and blood were collected from SARI patients enrolled and tested for viruses and bacteria. Epidemiological and clinical information were obtained from case report forms. RESULTS:Overall, 876 patients were enrolled in the study, of which 83.1% (728/876) were tested positive for at least one pathogen. Viral and bacterial infections occurred in 76.1% (667/876) and 35.8% (314/876) of tested samples, respectively. Among all detected viruses, respiratory syncytial virus (RSV) was the most common (37.7%; 348/924) followed by influenza virus A (FLUA, 18.4%; 170/924), rhinovirus (RV, 13.5%; 125/924), and adenovirus (ADV, 8.3%; 77/924). Among bacteria, Streptococcus pneumoniae (S. pneumoniae, 50.3%, 189/370) was the most detected followed by Haemophilus influenzae type b (Hib, 21.4%; 79/370), and Klebsiella (4.6%; 17/370). Other Streptococcus species were found in 8.1% (30/370) of samples. Compared to patients aged less than 5 years, older age groups were significantly less infected with RSV. On the other hand, patients aged more than 64 years (OR = 3.66) were at higher risk to be infected with FLUA, while those aged 15-29 years (OR = 3.22) and 30-64 years (OR = 2.39) were more likely to be infected with FLUB (influenza virus B). CONCLUSION:The frequency of influenza viruses detected among SARI patients aged 65 years and more highlights the need for health authorities to develop strategies to reduce morbidity amongst at-risk population through vaccine recommendation. Amongst young children, the demonstrated burden of RSV should guide clinicians for a better case management of children. These findings reveal the need to develop point-of-care tests to avoid overuse of antibiotics and to promote vaccine that could reduce drastically the RSV hospitalizations

Excess mortality associated with the COVID-19 pandemic during the 2020 and 2021 waves in Antananarivo, Madagascar

Introduction COVID-19-associated mortality remains difficult to estimate in sub-Saharan Africa because of the lack of comprehensive systems of death registration. Based on death registers referring to the capital city of Madagascar, we sought to estimate the excess mortality during the COVID-19 pandemic and calculate the loss of life expectancy.Methods Death records between 2016 and 2021 were used to estimate weekly excess mortality during the pandemic period. To infer its synchrony with circulation of SARS-CoV-2, a cross-wavelet analysis was performed. Life expectancy loss due to the COVID-19 pandemic was calculated by projecting mortality rates using the Lee and Carter model and extrapolating the prepandemic trends (1990–2019). Differences in life expectancy at birth were disaggregated by cause of death.Results Peaks of excess mortality in 2020–21 were associated with waves of COVID-19. Estimates of all-cause excess mortality were 38.5 and 64.9 per 100 000 inhabitants in 2020 and 2021, respectively, with excess mortality reaching ≥50% over 6 weeks. In 2021, we quantified a drop of 0.8 and 1.0 years in the life expectancy for men and women, respectively attributable to increased risks of death beyond the age of 60 years.Conclusion We observed high excess mortality during the pandemic period, in particular around the peaks of SARS-CoV-2 circulation in Antananarivo. Our study highlights the need to implement death registration systems in low-income countries to document true toll of a pandemic

Aetiological agents and co-infections among patients under 5 years old hospitalised for SARI, November 2010 to July 2012 in Antananarivo, Madagascar.

<p><i>RSV : Respiratory Syncitial Virus; IA : Influenza A; RhV : Rhinovirus; hMPV : human metapneumovirus;Co : coronavirus_co43/NL63/229E; BoV : Bocavirus; PiV : parainfluenza virus 1/2/3; Spn : Streptococcus pneumoniae; Hib : Haemophilus influenzae</i> de type b; <i>Sta : Staphylococcus aureus; Brc : Branhamella catharralis; S : Streptococcus mitis/sanguinis/G/D/equinis/Beta haemolitic; Aero.h : Aero hydromonas; Aeroc spp : Aerococcus spp; Pseu aer : Pseudomonas aeruginosa; List sp : Listeria sp; Ent.spp : Enterobacter spp; Kleb pn : Klebsiella pneumoniae; Ser Mar : Serritia marcescens; Mora sp : Moraxela species; Esch. c : Escherichia coli.</i></p

Patient characteristics and aetiologies according to outcome among patients under 5 years old hospitalized for SARI, November 2010 to July 2012, in Antananarivo, Madagascar.

*<p>Univarite analysis;</p>#<p>Multivariate analysis (variables with p<0.20 on univariate analysis).</p><p>–: reference variable.</p>**<p>Comorbitidy: congenital diseases, malnutrition, prematurity.</p>***<p>Atopic: including atopic food, drug, acaria pollen or asthma comorbidity.</p