Characterization of influenza infection in a high-income urban setting in Nairobi, Kenya
Abstract Background Influenza viruses are an important cause of respiratory infections across all age groups. Information on occurrence and magnitude of influenza virus infections in different populations in Kenya however remains scanty, compromising estimation of influenza disease burden. This stud...
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| Format: | Article |
| Language: | English |
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BMC
2022-09-01
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| Series: | Tropical Medicine and Health |
| Subjects: | |
| Online Access: | https://doi.org/10.1186/s41182-022-00463-y |
| _version_ | 1828148252233433088 |
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| author | Gabriel Miring’u Betty Muriithi Hisashi Shoji Samwel M. L. Symekher Ernest Apondi Wandera Claire Majisu Mitsuo Takei Koome Mwiraria Yukie Saito Satoshi Kaneko Issei Tokimatsu |
| author_facet | Gabriel Miring’u Betty Muriithi Hisashi Shoji Samwel M. L. Symekher Ernest Apondi Wandera Claire Majisu Mitsuo Takei Koome Mwiraria Yukie Saito Satoshi Kaneko Issei Tokimatsu |
| author_sort | Gabriel Miring’u |
| collection | DOAJ |
| description | Abstract Background Influenza viruses are an important cause of respiratory infections across all age groups. Information on occurrence and magnitude of influenza virus infections in different populations in Kenya however remains scanty, compromising estimation of influenza disease burden. This study examined influenza infection in an urban high-income setting in Nairobi to establish its prevalence and activity of influenza viruses, and evaluated diagnostic performance of a rapid influenza diagnostic test. Methodology A cross-sectional hospital-based study was conducted in six private health facilities located within high-income residential areas in Nairobi from January 2019 to July 2020. Patients of all ages presenting with influenza-like illness (ILI) were recruited into the study. Detection of influenza virus was conducted using rapid diagnosis and reverse transcription–polymerase chain reaction (RT–PCR). Data were summarized using descriptive statistics and tests of association. Sensitivity, specificity and area under receiver operating characteristics curve was calculated to establish diagnostic accuracy of the rapid diagnosis test. Results The study recruited 125 participants with signs and symptoms of ILI, of whom 21 (16.8%) were positive for influenza viruses. Of all the influenza-positive cases, 17 (81.0%) were influenza type A of which 70.6% were pandemic H1N1 (A/H1N1 2009). Highest detection was observed among children aged 5–10 years. Influenza virus mostly circulated during the second half of the year, and fever, general fatigue and muscular and joint pain were significantly observed among participants with influenza virus. Sensitivity and specificity of the diagnostic test was 95% (95% confidence interval 75.1–99.9) and 100% (95% confidence interval 96.5–100.0), respectively. Conclusions Findings of this study shows continuous but variable activity of influenza virus throughout the year in this population, with substantial disease burden. The findings highlight the need for continuous epidemiologic surveillance including genetic surveillance to monitor activity and generate data to inform vaccine introduction or development, and other interventions. |
| first_indexed | 2024-04-11T21:13:23Z |
| format | Article |
| id | doaj.art-e2edf1b74d75425d8d4c395f710c0824 |
| institution | Directory Open Access Journal |
| issn | 1349-4147 |
| language | English |
| last_indexed | 2024-04-11T21:13:23Z |
| publishDate | 2022-09-01 |
| publisher | BMC |
| record_format | Article |
| series | Tropical Medicine and Health |
| spelling | doaj.art-e2edf1b74d75425d8d4c395f710c08242022-12-22T04:02:56ZengBMCTropical Medicine and Health1349-41472022-09-015011810.1186/s41182-022-00463-yCharacterization of influenza infection in a high-income urban setting in Nairobi, KenyaGabriel Miring’u0Betty Muriithi1Hisashi Shoji2Samwel M. L. Symekher3Ernest Apondi Wandera4Claire Majisu5Mitsuo Takei6Koome Mwiraria7Yukie Saito8Satoshi Kaneko9Issei Tokimatsu10Institute of Tropical Medicine, Nagasaki University-Kenya Medical Research Institute ProjectInstitute of Tropical Medicine, Nagasaki University-Kenya Medical Research Institute ProjectEmbassy of JapanCenter for Virus Research, KEMRIInstitute of Tropical Medicine, Nagasaki University-Kenya Medical Research Institute ProjectLavington PediatricsForest Japan Medical CentreJ.G. Medical ClinicInstitute of Tropical Medicine, Nagasaki University-Kenya Medical Research Institute ProjectInstitute of Tropical Medicine, Nagasaki University-Kenya Medical Research Institute ProjectDivision of Clinical Infectious Diseases, Department of Internal Medicine, School of Medicine, Showa UniversityAbstract Background Influenza viruses are an important cause of respiratory infections across all age groups. Information on occurrence and magnitude of influenza virus infections in different populations in Kenya however remains scanty, compromising estimation of influenza disease burden. This study examined influenza infection in an urban high-income setting in Nairobi to establish its prevalence and activity of influenza viruses, and evaluated diagnostic performance of a rapid influenza diagnostic test. Methodology A cross-sectional hospital-based study was conducted in six private health facilities located within high-income residential areas in Nairobi from January 2019 to July 2020. Patients of all ages presenting with influenza-like illness (ILI) were recruited into the study. Detection of influenza virus was conducted using rapid diagnosis and reverse transcription–polymerase chain reaction (RT–PCR). Data were summarized using descriptive statistics and tests of association. Sensitivity, specificity and area under receiver operating characteristics curve was calculated to establish diagnostic accuracy of the rapid diagnosis test. Results The study recruited 125 participants with signs and symptoms of ILI, of whom 21 (16.8%) were positive for influenza viruses. Of all the influenza-positive cases, 17 (81.0%) were influenza type A of which 70.6% were pandemic H1N1 (A/H1N1 2009). Highest detection was observed among children aged 5–10 years. Influenza virus mostly circulated during the second half of the year, and fever, general fatigue and muscular and joint pain were significantly observed among participants with influenza virus. Sensitivity and specificity of the diagnostic test was 95% (95% confidence interval 75.1–99.9) and 100% (95% confidence interval 96.5–100.0), respectively. Conclusions Findings of this study shows continuous but variable activity of influenza virus throughout the year in this population, with substantial disease burden. The findings highlight the need for continuous epidemiologic surveillance including genetic surveillance to monitor activity and generate data to inform vaccine introduction or development, and other interventions.https://doi.org/10.1186/s41182-022-00463-yInfluenza virusPrevalenceDiagnosis |
| spellingShingle | Gabriel Miring’u Betty Muriithi Hisashi Shoji Samwel M. L. Symekher Ernest Apondi Wandera Claire Majisu Mitsuo Takei Koome Mwiraria Yukie Saito Satoshi Kaneko Issei Tokimatsu Characterization of influenza infection in a high-income urban setting in Nairobi, Kenya Tropical Medicine and Health Influenza virus Prevalence Diagnosis |
| title | Characterization of influenza infection in a high-income urban setting in Nairobi, Kenya |
| title_full | Characterization of influenza infection in a high-income urban setting in Nairobi, Kenya |
| title_fullStr | Characterization of influenza infection in a high-income urban setting in Nairobi, Kenya |
| title_full_unstemmed | Characterization of influenza infection in a high-income urban setting in Nairobi, Kenya |
| title_short | Characterization of influenza infection in a high-income urban setting in Nairobi, Kenya |
| title_sort | characterization of influenza infection in a high income urban setting in nairobi kenya |
| topic | Influenza virus Prevalence Diagnosis |
| url | https://doi.org/10.1186/s41182-022-00463-y |
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