The Chikungunya virus: A reemerging cause of acute febrile illness in the high jungle of northern Peru

BackgroundThe Chikungunya virus (CHIKV) is an emerging arthropod-borne virus (arbovirus) that causes undifferentiated acute febrile illness. Cases of CHIKV may be under-reported in Peru, given the various difficulties in diagnosing it, such as lack of diagnostic tests in remote areas, the passive nature of epidemiological surveillance, and co-circulation of other arthropod-borne pathogens. Therefore, a study was conducted in the high jungle of northern Peru to determine the prevalence of CHIKV among febrile patients and describe their clinical characteristics.MethodsA cross-sectional study was conducted in the province of Jaen, Cajamarca, located in the high jungle of northern Peru. Patients attending primary healthcare centers within Cajamarca's Regional Health Directorate were enrolled. The study took place from June 2020 through June 2021. Patients were eligible if they sought outpatient healthcare for a clinical diagnosis of acute febrile illness (AFI). Serum samples were collected from all patients, and the diagnosis of CHIKV was determined using real-time RT-PCR, as well as the detection of IgM antibodies by ELISA. A logistic regression model was employed to identify the risk factors for CHIKV, and the odds ratios (ORs) were calculated, along with their corresponding 95% confidence intervals (95% CI).ResultsA total of 1 047 patients with AFI were included during the study period. CHIKV was identified in 130 patients of 1 047 (12.4%). Among the CHIKV positive cases, 84 of 130 (64.6%) were diagnosed by RT-PCR, 42 of 130 (32.3%) by IgM ELISA detection, and 4 of 130 (3.1%) by both assays. The majority of patients with CHIKV infection fell within the 18-39 years age group (50.0%), followed by the 40-59 years age group (23.9%) and those with 60 years or older (10.8%). The most common clinical symptoms observed in patients with CHIKV infection were headache (85.4%), myalgias (72.3%), and arthralgias (64.6%). The highest number of positive CHIKV cases occurred in May (23.1%), followed by March (20.0%) and February (13.8%) of 2021.ConclusionThe study reports a considerable frequency of CHIKV infections among patients with AFI from the high jungle of northern Peru. These findings highlight the importance of recognizing CHIKV as an ongoing pathogen with continuous transmission in various areas of Peru. It is crucial to enhance epidemiological surveillance by implementing reliable diagnostic techniques, as the clinical symptoms of CHIKV infection can be nonspecific. The Chikungunya virus (CHIKV) has been one of the most challenging pathogens to affect humanity in recent years. Since its first major outbreak in 2004 in Africa, this virus has caused a series of epidemics worldwide, leading the scientific community and health systems to face a threat to public health. The authors conducted a study in the northern jungle of Peru to better understand the CHIKV situation. They determined that the most frequently infected were those in the age group of 18 to 39 years and the most common symptoms were headache, muscle aches and joint pain. It is highlighted that making an etiological diagnosis can be difficult in some remote areas, and that the clinical presentation overlaps with other mosquito-borne diseases. This research emphasizes the importance of epidemiological surveillance and scientific research in disease control, particularly acute febrile CHIKV illness.

Automated summary

The study conducted in the high jungle of northern Peru reveals a significant prevalence of CHIKV infections among febrile patients. The findings underscore the importance of improving epidemiological surveillance and implementing reliable diagnostic techniques due to the nonspecific clinical symptoms of CHIKV infection.