Clinical signs predictive of influenza virus infection in Cameroon

Chavely Gwladys Monamele; Cyprien Kengne-Nde; Hermann Landry Munshili Njifon; Mohamadou Ripa Njankouo; Sebastien Kenmoe; Richard Njouom

doi:10.1371/journal.pone.0236267

Clinical signs predictive of influenza virus infection in Cameroon

PLoS One. 2020 Jul 23;15(7):e0236267. doi: 10.1371/journal.pone.0236267. eCollection 2020.

Authors

Chavely Gwladys Monamele¹, Cyprien Kengne-Nde², Hermann Landry Munshili Njifon¹, Mohamadou Ripa Njankouo¹, Sebastien Kenmoe¹, Richard Njouom¹

Affiliations

¹ Virology Department, Centre Pasteur of Cameroon, Yaounde, Cameroon.
² Evaluation and Research Unit, National AIDS Control Committee, Yaounde, Cameroon.

Abstract

Influenza virus accounts for majority of respiratory virus infections in Cameroon. According to the World Health Organization (WHO), influenza-like illnesses (ILI) are identified by a measured temperature of ≥38°C and cough, with onset within the past 10 days. Other symptoms could as well be observed however, none of these are specific to influenza alone. This study aimed to determine symptom based predictors of influenza virus infection in Cameroon. Individuals with ILI were recruited from 2009-2018 in sentinel sites of the influenza surveillance system in Cameroon according to the WHO case definition. Individual data collection forms accompanied each respiratory sample and contained clinical data. Samples were analyzed for influenza using the gold standard assay. Two statistical methods were compared to determine the most reliable clinical predictors of influenza virus activity in Cameroon: binomial logistic predictive model and random forest model. Analyses were performed in R version 3.5.2. A total of 11816 participants were recruited, of which, 24.0% were positive for influenza virus. Binomial logistic predictive model revealed that the presence of cough, rhinorrhoea, headache and myalgia are significant predictors of influenza positivity. The prediction model had a sensitivity of 75.6%, specificity of 46.6% and AUC of 66.7%. The random forest model categorized the reported symptoms according to their degree of importance in predicting influenza virus infection. Myalgia had a 2-fold higher value in predicting influenza virus infection compared to any other symptom followed by arthralgia, head ache, rhinorrhoea and sore throat. The model had a OOB error rate of 25.86%. Analysis showed that the random forest model had a better performance over the binomial regression model in predicting influenza infection. Rhinorrhoea, headache and myalgia were symptoms reported by both models as significant predictors of influenza infection in Cameroon. These symptoms could be used by clinicians in their decision to treat patients.

Publication types

Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

Adolescent
Adult
Age Factors
Aged
Cameroon / epidemiology
Child
Child, Preschool
Female
Humans
Infant
Influenza, Human / diagnosis
Influenza, Human / epidemiology*
Logistic Models
Male
Middle Aged
Young Adult

Grants and funding

This work received grant fom the U.S. Department of Health and Human Services, DHHS (grant number 6 DESP060001-01-01). This work also benefited from the WHO PIP Implementation project in Cameroon. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.