Predictors of severity and prolonged hospital stay of viral acute respiratory infections (ARI) among children under five years in Burkina Faso, 2016-2019.

BACKGROUND: Viruses are the leading etiology of acute respiratory infections (ARI) in children. However, there is limited knowledge on drivers of severe acute respiratory infection (SARI) cases involving viruses. We aimed to identify factors associated with severity and prolonged hospitalization of viral SARI among children < 5 years in Burkina Faso. METHODS: Data were collected from four SARI sentinel surveillance sites during October 2016 through April 2019. A SARI case was a child < 5 years with an acute respiratory infection with history of fever or measured fever ≥ 38 °C and cough with onset within the last ten days, requiring hospitalization. Very severe ARI cases required intensive care or had at least one danger sign. Oropharyngeal/nasopharyngeal specimens were collected and analyzed by multiplex real-time reverse-transcription polymerase chain reaction (rRT-PCR) using FTD-33 Kit. For this analysis, we included only SARI cases with rRT-PCR positive test results for at least one respiratory virus. We used simple and multilevel logistic regression models to assess factors associated with very severe viral ARI and viral SARI with prolonged hospitalization. RESULTS: Overall, 1159 viral SARI cases were included in the analysis after excluding exclusively bacterial SARI cases (n = 273)very severe viral ARI cases were common among children living in urban areas (AdjOR = 1.3; 95% CI: 1.1-1.6), those < 3 months old (AdjOR = 1.5; 95% CI: 1.1-2.3), and those coinfected with Klebsiella pneumoniae (AdjOR = 1.9; 95% CI: 1.2-2.2). Malnutrition (AdjOR = 2.2; 95% CI: 1.1-4.2), hospitalization during the rainy season (AdjOR = 1.71; 95% CI: 1.2-2.5), and infection with human CoronavirusOC43 (AdjOR = 3; 95% CI: 1.2-8) were significantly associated with prolonged length of hospital stay (> 7 days). CONCLUSION: Younger age, malnutrition, codetection of Klebsiella pneumoniae, and illness during the rainy season were associated with very severe cases and prolonged hospitalization of SARI involving viruses in children under five years. These findings emphasize the need for preventive actions targeting these factors in young children.

Influenza surveillance capacity improvements in Africa during 2011-2017.

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.

Epidemiology of influenza in West Africa after the 2009 influenza A(H1N1) pandemic, 2010-2012.

BACKGROUND: Over the last decade, capacity for influenza surveillance and research in West Africa has strengthened. Data from these surveillance systems showed influenza A(H1N1)pdm09 circulated in West Africa later than in other regions of the continent. METHODS: We contacted 11 West African countries to collect information about their influenza surveillance systems (number of sites, type of surveillance, sampling strategy, populations sampled, case definitions used, number of specimens collected and number of specimens positive for influenza viruses) for the time period January 2010 through December 2012. RESULTS: Of the 11 countries contacted, 8 responded: Burkina Faso, Cote d'Ivoire, Mali, Mauritania, Niger, Nigeria, Sierra Leone and Togo. Countries used standard World Health Organization (WHO) case definitions for influenza-like illness (ILI) and severe acute respiratory illness (SARI) or slight variations thereof. There were 70 surveillance sites: 26 SARI and 44 ILI. Seven countries conducted SARI surveillance and collected 3114 specimens of which 209 (7%) were positive for influenza viruses. Among influenza-positive SARI patients, 132 (63%) were influenza A [68 influenza A(H1N1)pdm09, 64 influenza A(H3N2)] and 77 (37%) were influenza B. All eight countries conducted ILI surveillance and collected 20,375 specimens, of which 2278 (11%) were positive for influenza viruses. Among influenza-positive ILI patients, 1431 (63%) were influenza A [820 influenza A(H1N1)pdm09, 611 influenza A(H3N2)] and 847 (37%) were influenza B. A majority of SARI and ILI case-patients who tested positive for influenza (72% SARI and 59% ILI) were children aged 0-4 years, as were a majority of those enrolled in surveillance. The seasonality of influenza and the predominant influenza type or subtype varied by country and year. CONCLUSIONS: Influenza A(H1N1)pdm09 continued to circulate in West Africa along with influenza A(H3N2) and influenza B during 2010-2012. Although ILI surveillance systems produced a robust number of samples during the study period, more could be done to strengthen surveillance among hospitalized SARI case-patients. Surveillance systems captured young children but lacked data on adults and the elderly. More data on risk groups for severe influenza in West Africa are needed to help shape influenza prevention and clinical management policies and guidelines.

Investigation of an outbreak of acute respiratory disease in côte d'ivoire in april 2007.

BACKGROUND: This study aim was to investigate an outbreak of human cases of unexplained influenza-like illness and fatal acute respiratory infection (ARI), with simultaneous poultry illness and high mortality raising concerns of possible influenza A (H5N1), virus in Cote d'Ivoire in February and March 2007. MATERIALS AND METHODS: To investigate the outbreak, we conducted active surveillance in the community and reviewed health registries. Persons meeting the case definition were asked to provide nasopharyngeal specimens. On the basis of clinical and epidemiological information, specimens were tested using conventional RT-PCR for the M gene of the influenza viruses and hemagglutinin H5 of avian influenza A (H5N1), virus; negative samples were tested for other respiratory viruses. Specimens from healthy animals were also collected. RESULTS: Between October 2006, and February 2007, 104 suspected cases of Acute Respiratory Disease that included; 31 deaths recorded. We collected and tested 73 nasopharyngeal specimens; of which, 2, were positive for human Coronavirus OC43 and 1 for influenza C virus. No pathogens were identified in animal specimens. CONCLUSIONS: The investigation quickly ruled out influenza A (H5N1), virus as the cause and found laboratory-confirmed cases of influenza C virus and human Coronavirus OC 43 for the first time in both Côte d'Ivoire and in a Sub-Saharan African country. However we were not able to show that these viruses caused the outbreak. Monitoring of influenza viruses must be a priority but other respiratory viruses and non-viral causes may be of interest too.

Investigation of an outbreak of acute respiratory disease in Côte d'Ivoire in april 2007

Background: This study aim was to investigate an outbreak of human cases of unexplained influenza-like illness and fatal acute respiratory infection (ARI); with simultaneous poultry illness and high mortality raising concerns of possible influenza A (H5N1); virus in Cote d'Ivoire in February and March 2007. Materials and Methods: To investigate the outbreak; we conducted active surveillance in the community and reviewed health registries. Persons meeting the case definition were asked to provide nasopharyngeal specimens. On the basis of clinical and epidemiological information; specimens were tested using conventional RT-PCR for the M gene of the influenza viruses and hemagglutinin H5 of avian influenza A (H5N1); virus; negative samples were tested for other respiratory viruses. Specimens from healthy animals were also collected. Results: Between October 2006; and February 2007; 104 suspected cases of Acute Respiratory Disease that included; 31 deaths recorded. We collected and tested 73 nasopharyngeal specimens; of which; 2; were positive for human Coronavirus OC43 and 1 for influenza C virus. No pathogens were identified in animal specimens. Conclusions: The investigation quickly ruled out influenza A (H5N1); virus as the cause and found laboratory-confirmed cases of influenza C virus and human Coronavirus OC 43 for the first time in both Cote d'Ivoire and in a Sub-Saharan African country. However we were not able to show that these viruses caused the outbreak. Monitoring of influenza viruses must be a priority but other respiratory viruses and non-viral causes may be of interest too

Influenza surveillance in 15 countries in Africa, 2006-2010.

BACKGROUND: In response to the potential threat of an influenza pandemic, several international institutions and governments, in partnership with African countries, invested in the development of epidemiologic and laboratory influenza surveillance capacity in Africa and the African Network of Influenza Surveillance and Epidemiology (ANISE) was formed. METHODS: We used a standardized form to collect information on influenza surveillance system characteristics, the number and percent of influenza-positive patients with influenza-like illness (ILI), or severe acute respiratory infection (SARI) and virologic data from countries participating in ANISE. RESULTS: Between 2006 and 2010, the number of ILI and SARI sites in 15 African countries increased from 21 to 127 and from 2 to 98, respectively. Children 0-4 years accounted for 48% of all ILI and SARI cases of which 22% and 10%, respectively, were positive for influenza. Influenza peaks were generally discernible in North and South Africa. Substantial cocirculation of influenza A and B occurred most years. CONCLUSIONS: Influenza is a major cause of respiratory illness in Africa, especially in children. Further strengthening influenza surveillance, along with conducting special studies on influenza burden, cost of illness, and role of other respiratory pathogens will help detect novel influenza viruses and inform and develop targeted influenza prevention policy decisions in the region.