O-36 What we can Learn for Older Adults from the 2014 Chikungunya Outbreak in the French West Indies
Author(s):
M Dramé, F Najioullah, S Bartholet-Gazeuse, L Godaert
Year of Presentation:
2023
Objective: The aim of the study was to highlight particularities concerning older adults infected by CHIKV compared to younger counterparts, and to propose an adaptation of the clinical forms for older adults.
Methods: A single centre cohort was built from retrospective cases. Eligible patients were aged 65 years or older, who underwent biological testing using RT-PCR. For the purpose of comparison, a random sample of young adults was selected. Patients who’s clinical and/or biological data were missing in their medical records were excluded.
Results: In all, 687 older adults constituted the cohort (467 positive, and 220 negative RT-PCR). Performance indicators of the Mayotte and the Reunion Island scores in our cohort were poor: Youden’s index ranged from 1% to 30%. In contrast, a new score derived from our cohort had better metrological performances (Youden’s index=57% (95% CI: 54%-60%). Misdiagnosis rate of CHIKV infection was higher in the older adults (31%) than in the younger ones (6%), (p<0.001). According to the WHO definitions 43% of older adults could not be classified in any category (vs. 17% in youngers ones). After adaptation of the WHO definitions, the 114 unclassifiable patients were reclassified as follows: eight were reclassified as typical cases, 50 as atypical, 42 as severe, and 14 remained unclassifiable.
Conclusion: The most frequent clinical presentation of CHIKV infection in aged adults differs from that most commonly observed in younger adults. This leads to more misdiagnosis rates in older patients. Adapted definitions appear to be more appropriate, and could help improve management of older patients with CHIKV infection.