Epidemiological profile of yellow fever, Guinea, 2017 to 2021
- Vector-borne
Background
Since 2017, Guinea has experienced three yellow fever’s outbreaks with 33 confirmed cases and 17 deaths, however its planned elimination by 2026 depends on outbreak control. This data analysis will identify high-risk areas, vulnerable populations to guide the Ministry of Health on the preventive measures to be taken to eliminate yellow fever.
Methods
A descriptive case incidence study was conducted. The DHIS2 database from 2017 to 2021 and WHO definitions of suspected, probable and confirmed cases were used. We assessed routine yellow fever vaccine coverage (VC). For entomological method, we used survey data seeking presence of the vector virus in larvae and nymphs of Aedes mosquitoes within a radius of 400 meters around the homes of the cases. Proportions, median, range and Bretau index (BI) were calculated with Epi Info 7.2.
Results
Of 978 suspected cases, 17(1.7%) were probable and 628 were tested. Among tested, 33(5.3%) were confirmed. Median age was 10 years old (2 to 55). Male: 26(52%) and children <10 years old: 24(48%) were the most represented. All cases had fever, 48(96%) jaundice but 3(6%) were vaccinated. The highest incidences per 100,000 inhabitant were 18 in Koundara in 2020 and 3 in Gaoual in 2017, two neighbors’ districts from Boke region. Routine national yellow fever VC varied from 100.2% in 2018 to 88% in 2021. Four entomological surveys were conducted and the highest BI was 17.25% in Koundara. Three outbreak were detected between 2017 and 2020, for wishes people aged 9 months and older were vaccinated reaching 95.6% in Koundara to 131.4% in Tanènè as VC.
Conclusion
Children <10 years old unvaccinated were most represented. The two district at high risk were Boke and Koundara from Boké region. We recommend setting up entomological surveillance and vector control in both districts and strengthening routine vaccination against yellow fever.
Since 2017, Guinea has experienced three yellow fever’s outbreaks with 33 confirmed cases and 17 deaths, however its planned elimination by 2026 depends on outbreak control. This data analysis will identify high-risk areas, vulnerable populations to guide the Ministry of Health on the preventive measures to be taken to eliminate yellow fever.
Methods
A descriptive case incidence study was conducted. The DHIS2 database from 2017 to 2021 and WHO definitions of suspected, probable and confirmed cases were used. We assessed routine yellow fever vaccine coverage (VC). For entomological method, we used survey data seeking presence of the vector virus in larvae and nymphs of Aedes mosquitoes within a radius of 400 meters around the homes of the cases. Proportions, median, range and Bretau index (BI) were calculated with Epi Info 7.2.
Results
Of 978 suspected cases, 17(1.7%) were probable and 628 were tested. Among tested, 33(5.3%) were confirmed. Median age was 10 years old (2 to 55). Male: 26(52%) and children <10 years old: 24(48%) were the most represented. All cases had fever, 48(96%) jaundice but 3(6%) were vaccinated. The highest incidences per 100,000 inhabitant were 18 in Koundara in 2020 and 3 in Gaoual in 2017, two neighbors’ districts from Boke region. Routine national yellow fever VC varied from 100.2% in 2018 to 88% in 2021. Four entomological surveys were conducted and the highest BI was 17.25% in Koundara. Three outbreak were detected between 2017 and 2020, for wishes people aged 9 months and older were vaccinated reaching 95.6% in Koundara to 131.4% in Tanènè as VC.
Conclusion
Children <10 years old unvaccinated were most represented. The two district at high risk were Boke and Koundara from Boké region. We recommend setting up entomological surveillance and vector control in both districts and strengthening routine vaccination against yellow fever.