Acute Febrile Illness and Influenza Disease Burden in a Rural Cohort Dedicated to Malaria in Senegal, 2012–2013

Abstract

BackgroundAfrican populations are considered to be particularly vulnerable to fever illnesses, including malaria, and acute respiratory disease, owing to limited resources and overcrowding. However, the overall burden of influenza in this context is poorly defined and incidence data for African countries are scarce. We therefore studied the fever syndrome incidence and more specifically influenza incidence in a cohort of inhabitants of Dielmo and Ndiop in Sokone district, Senegal.MethodsDaily febrile-illness data were prospectively obtained from January 2012 to December 2013 from the cohort of the villages of Dielmo and Ndiop, initially dedicated to the study of malaria. Nasopharyngeal swabs were collected from, and malaria diagnosis tests (thick blood smears) carried out on, every febrile individual during clinical visits; reverse transcriptase-polymerase chain reaction was used to identify influenza viruses in the samples. Binomial negative regression analysis was used to study the relationship between the monthly incidence rate and various covariates.ResultsIn Dielmo and Ndiop, the incidence of malaria has decreased, but fever syndromes remain frequent. Among the 1036 inhabitants included in the cohort, a total of 1,129 episodes of fever were reported. Influenza was present all year round with peaks in October-December 2012 and August 2013. The fever, ILI and influenza incidence density rates differed significantly between age groups. At both sites, the adjusted incidence relative risks for fever syndromes and ILI were significantly higher in the [6–24 months) than other age groups: 7.3 (95%CI: [5.7–9.3]) and 16.1 (95%CI: [11.1–23.3]) respectively. The adjusted incidence relative risk for influenza was significantly higher for the [0–6 months) than other age groups: 9.9 (95%CI: [2.9–33.6]). At both sites, incidence density rates were lowest among adults > = 50 years.ConclusionsIn this rural setting in Senegal, influenza was most frequent among the youngest children. Preventive strategies targeting this population should be implemented.

Asymptomatic carriage of Streptococcus pneumoniae detected by qPCR on the palm of hands of populations in rural Senegal

“…A relationship could be made between S . pneumoniae infections in these villagers, a previous study on influenza like illnesses (ILI) had found that the incidence rates differed significantly between age groups, and were highest in the [6–24 month) and [0–6 month) age groups [36]. These results are comparable to ours.…”

“…From 2012 to 2013, the overall flu incidence density rate was 19.2 per 100 person-years. The flu incidence density rates were significantly different between age groups, the highest being in the [6–24 months) age group (30.3 to 50.7 per 100 person years) [36].…”

Preliminary results of official influenza and acute respiratory infection surveillance in two towns of Burkina Faso, 2013–2015

“…We found a high proportion of hospital outpatient visits among children aged < 5 years were ARI and a high proportion of those required hospitalization. In 2015, Diene Sarr et al in Senegal found that influenza was most frequent among children aged less than 24 months [ 17 ]. In China, among < 5 year-olds, children aged 6 months to 4 years experienced the highest rates of influenza-associated ILI [ 18 ].…”

Epidemiology and molecular characterization of influenza viruses in Burkina Faso, sub‐Saharan Africa

“…Despite the burden of influenza infections worldwide, morbidity and mortality associated with influenza have been largely overlooked in sub‐Saharan Africa, likely due to previous lack of access to diagnostic tools. Misinterpretation of non‐pathognomonic influenza symptoms with those induced by various viral and bacterial respiratory infections or by malaria or Lassa fever also complicates the diagnosis . The implementation of the WHO Global Action Plan for Influenza Vaccines, strongly promoting seasonal influenza vaccination, remains challenging in (sub‐)tropical low‐income countries.…”