Assessment of Dengue and Chikungunya Infections among Febrile Patients Visiting Four Healthcare Centres in Yaounde and Dizangue, Cameroon

Dengue and chikungunya are now widely distributed in Cameroon, but there is still not enough information on their prevalence in different epidemiological settings. This study was undertaken to assess the prevalence of dengue and chikungunya in both urban and rural settings in Cameroon using three diagnostic tools. From December 2019 to September 2021, willing febrile (temperature >38 degrees C) outpatients visiting four healthcare facilities in the cities of Yaounde and Dizangue were screened for dengue, and chikungunya. Clinical features of patient were recorded in a form, and their blood samples were analysed using real-time reverse transcriptase-polymerase chain reaction (rtRT-PCR), rapid diagnostic tests (RDTs) and enzyme-linked immuno-sorbent assays (ELISA). Odds ratios were used to determine the level of association between socio-demographic factors, clinical features, and infection status. The Kappa coefficient permitted to assess the level of agreement between RDTs and ELISA. Overall, 301 febrile patients were recruited in the study: 198 in Yaounde and 103 in Dizangue. The prevalence of infection varied with the diagnostic tool used. For dengue diagnostics, 110 patients were positive to rtRT-PCR: 90 (45.45%) in Yaounde, and 20 (19.42%) in Dizangue. The prevalence of dengue IgM using ELISA varied from 22.3% in Dizangue to 30.8% in Yaounde. Dengue IgM rate using RDTs was 7.6% in Yaounde and 3.9% in Dizangue. For chikungunya, one (0.5%) patient (Yaounde, suburb) was positive to rtRT-PCR. The prevalence of chikungunya IgM according to ELISA varied from 18.4% in Dizangue to 21.7% in Yaounde, while it was 4.5% in Yaounde and 12.6% in Dizangue with RDTs. Only abdominal and retro-orbital pains were significantly associated with acute dengue infection. All four dengue serotypes were recorded, with a predominance of DENV-3 (35.45%) and DENV-4 (25.45%). Rapid Diagnostic Tests for either chikungunya or dengue displayed very poor sensitivity. This study further confirms the high endemicity of both dengue and chikungunya in Yaounde and Dizangue. These data stress the need for active surveillance and the implementation of vector control measures to prevent the occurrence of outbreaks across the country.

Automated summary

This study assessed the prevalence of dengue and chikungunya in urban and rural settings in Cameroon using three diagnostic tools. The results showed a high prevalence of these diseases in Yaounde and Dizangue, with variations depending on the diagnostic tool used.