title: Potential Impact of Co-Infections and Co-Morbidities Prevalent in Africa on Influenza Severity and Frequency: A Systematic Review.
abstract: Infectious diseases and underlying medical conditions common to Africa may affect influenza frequency and severity. We conducted a systematic review of published studies on influenza and the following co-infections or co-morbidities that are prevalent in Africa: dengue, malaria, measles, meningococcus, Pneumocystis jirovecii pneumonia (PCP), hemoglobinopathies, and malnutrition. Articles were identified except for influenza and PCP. Very few studies were from Africa. Sickle cell disease, dengue, and measles co-infection were found to increase the severity of influenza disease, though this is based on few studies of dengue and measles and the measles study was of low quality. The frequency of influenza was increased among patients with sickle cell disease. Influenza infection increased the frequency of meningococcal disease. Studies on malaria and malnutrition found mixed results. Age-adjusted morbidity and mortality from influenza may be more common in Africa because infections and diseases common in the region lead to more severe outcomes and increase the influenza burden. However, gaps exist in our knowledge about these interactions.
authors.affiliation: Influenza Division, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America; Influenza Program, Centers for Disease Control and Prevention-South Africa, Pretoria, South Africa; United States Public Health Service, Rockville, Maryland, United States of America.
authors.forename: Adam L
authors.initials: AL
authors.lastname: Cohen
authors.affiliation: Influenza Division, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America; United States Public Health Service, Rockville, Maryland, United States of America.
authors.forename: Meredith
authors.initials: M
authors.lastname: McMorrow
authors.affiliation: Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases, Sandringham, South Africa; School of Public Health and Faculty of Health Science, University of the Witwatersrand, Johannesburg, South Africa.
authors.forename: Sibongile
authors.initials: S
authors.lastname: Walaza
authors.affiliation: Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases, Sandringham, South Africa; School of Public Health and Faculty of Health Science, University of the Witwatersrand, Johannesburg, South Africa.
authors.forename: Cheryl
authors.initials: C
authors.lastname: Cohen
authors.affiliation: Influenza Division, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America; Influenza Program, Centers for Disease Control and Prevention-South Africa, Pretoria, South Africa; Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases, Sandringham, South Africa.
authors.forename: Stefano
authors.initials: S
authors.lastname: Tempia
authors.affiliation: Division of Applied Research and Technology (DART), National Institute for Occupational Safety and Health (NIOSH), Centers for Disease Control and Prevention, Cincinnati, Ohio, United States of America; University of Illinois, Springfield, Illinois, United States of America.
authors.forename: Marissa
authors.initials: M
authors.lastname: Alexander-Scott
authors.affiliation: Influenza Division, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America.
authors.forename: Marc-Alain
authors.initials: MA
authors.lastname: Widdowson
mesh_terms: D000755:Anemia, Sickle Cell / Q000453:epidemiology / Q000473:pathology; D060085:Coinfection; D015897:Comorbidity; D003715:Dengue / Q000453:epidemiology / Q000473:pathology; D006453:Hemoglobinopathies / Q000453:epidemiology / Q000473:pathology; D006801:Humans; D007251:Influenza, Human / Q000453:epidemiology* / Q000401:mortality / Q000473:pathology; D008288:Malaria / Q000453:epidemiology / Q000473:pathology; D044342:Malnutrition / Q000453:epidemiology / Q000473:pathology; D008457:Measles / Q000453:epidemiology / Q000473:pathology; D012720:Severity of Illness Index