# Comprehensive analysis of epidemiological and clinical features of Oropouche virus infection (1975 to 2025): a systematic review

## TL;DR

This study reviews Oropouche virus infections from 1975 to 2025, highlighting its symptoms, transmission, and recent severe cases in Latin America.

## Contribution

The study provides the first comprehensive systematic review of OROV epidemiology and clinical features over 50 years.

## Key findings

- Pooled seroprevalence in the general population was 7%, with higher rates in febrile patients.
- Common symptoms include fever, headache, and myalgia, with possible severe outcomes and vertical transmission.
- Infections were most common in individuals aged 20–39 years, with no significant sex bias.

## Abstract

Oropouche virus (OROV) has re-emerged since late 2023 with expanding urban transmission in Latin America. OROV causes an acute febrile illness with symptoms overlapping other arboviral infections, complicating diagnosis. Recent reports of fatalities and suspected vertical transmission have raised concerns regarding disease severity. This study aims to provide a comprehensive analysis of epidemiological and clinical features of OROV infection.

We conducted a PRISMA-compliant systematic review by searching major bibliographic databases and preprint servers. Observational studies reporting OROV infection in febrile patients or the general population were included, and pooled prevalence estimates were calculated.

59 studies were included. The pooled seroprevalence of anti-OROV antibodies in the general population was 7% (95% CI, 0–21%). Among febrile patients, pooled prevalence was 16% (95% CI, 10–24%) by virus detection and 24% (95% CI, 13–36%) by serology. Sex distribution was comparable (male 51% vs female 49%), while infections were most common among individuals aged 20–39 years (38%; 95% CI, 32–43%). The most frequent symptoms were fever (94%; 95% CI, 90–98%), headache (87%; 95% CI, 84–91%), and myalgia (73%; 95% CI, 67–80%), with gastrointestinal and ocular manifestations also common. Compilation of reported fatal cases showed a rapidly progressive clinical course. 17 pregnancy-associated cases suggested possible vertical transmission with heterogeneous outcomes, including congenital abnormalities and fetal loss.

OROV contributes to acute febrile illness in Latin America and presents as a multisystem disease. Emerging reports of fatal outcomes and pregnancy-associated adverse events warrant heightened clinical awareness, improved diagnostics, and strengthened surveillance.