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Meta-Analysis
. 2022 Dec 29;15(1):92.
doi: 10.3390/v15010092.

Clinical Landscape and Rate of Exposure to Ilheus Virus: Insights from Systematic Review and Meta-Analysis

Vivaldo Gomes da Costa  1 , Marielena Vogel Saivish  2 , Nikolas Alexander Borsato Lino  1 , Cíntia Bittar  1 , Marília de Freitas Calmon  1 , Maurício Lacerda Nogueira  2 , Paula Rahal  1
Affiliations
Meta-Analysis

Clinical Landscape and Rate of Exposure to Ilheus Virus: Insights from Systematic Review and Meta-Analysis

Vivaldo Gomes da Costa et al. Viruses. .

Abstract

Ilheus fever is a mosquito-borne, poorly known tropical disease. We aimed to report the pooled rate of exposure to the Ilheus virus (ILHV) and clinical outcomes of infection to determine the epidemiological patterns of ILHV. We conducted a meta-analysis of 37 studies (n = 17,722 individuals) from Latin America. The common clinical characteristics of ILHV infection were fever (82.3%), headache (52.9%), and myalgia (52.9%). Encephalitis complicated the course of the infection in 29.4% cases. Monotypic serological reactions detected a pooled rate of exposure of 2% to ILHV (95% CI: 1-2). Studies were mainly conducted in Brazil, with a pooled proportion of ILHV positivity of 8% (95% CI: 3-14). Males (12%) had higher rates of seropositivity than females (7%) and had high chances of ILHV infection (OR: 1.7, 95% CI: 1.2-2.5). Seropositivity increased with age, from 2% (95% CI: 2-3) among people aged 0-14 years to 8% (95% CI: 6-10) among people aged 15-64 years. Our analysis indicated a low and relatively constant burden of ILHV in Latin America. More research is needed to evaluate and innovate serological assays for ILHV to better estimate the burden and dynamics of epidemiological changes in ILHV infection in different regions.

Keywords: Ilheus virus; arbovirus; meta-analysis; neglected disease; sero-epidemiology.

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Conflict of interest statement

The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript; or in the decision to publish the results.

Figures

Figure 1
Figure 1
Map illustrating the geographical distribution of the included studies. (a) Color intensity represents the number of studies from each region. (b) Pooled estimated frequency of ILHV seropositivity. At the upper right of (b), the monotypic reaction data, which are samples that were only positive for ILHV (antibody against ILHV) and negative for at least one pair of tested flaviviruses, are shown.
Figure 2
Figure 2
Clinical manifestations of ILHV infection [5,6,7,8,9,10,11,12,13,14].
Figure 3
Figure 3
Forest plot of the proportion of laboratory confirmed ILHV infection according to the type of serological reaction (heterotypic vs monotypic) [8,36,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71]. The black diamonds in gray squares indicate the mean of the ratio of ILHV positivity, while the size of the grey square represents the weight (population size) contributed by each study in the meta-analysis. The horizontal lines in blue represent their 95% confidence intervals (CI). The red diamond represents the pooled ratio of positives and its 95% CI, while dashed purple line represents the mean of the pooled estimate. id = identification of the study; Events = ILHV infection; CI = confidence interval; ES = effect size.
Figure 4
Figure 4
Distribution of ILHV seropositivity according to the year in which the samples were obtained. The values represent the mean with their respective 95% CI.
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