Understanding and Managing Chikungunya Fever: Key Insights
Introduction
Chikungunya fever (CHIKF) is a debilitating mosquito-borne illness that has become a significant public health concern in recent years. The name “chikungunya” comes from the Makonde word meaning “he who walks bent” in reference to the arthritic symptoms of the disease.1–3 CHIKF is caused by the chikungunya virus (CHIKV), transmitted by the bite of infected Aedes aegypti and Aedes albopictus mosquitoes.1,2
The virus is classified as an arbovirus of the Alphavirus genus and can infect humans and various vertebrates.2,4 CHIKF has two primary transmission cycles: enzootic and sylvatic. Enzootic cycles occur in African tropical regions and involve arboreal mosquitoes and nonhuman primates, while sylvatic cycles are found in urban centers and involve human-to-human transmission via the Ae. aegypti and Ae. albopictus mosquitoes.2
The Spread and Impact of CHIKV
CHIKV was first isolated in Tanzania in 1953 and later spread across sub-Saharan Africa.6 Three distinct strains of CHIKV have been identified: West African, East-Central-South African (ECSA), and the Asian lineage.7 The ECSA strain re-emerged in the Kenyan coast and spread across the Indian Ocean islands, evolving into the Indian Ocean lineage (IOL).7
Major CHIKF outbreaks emerged in the Indian Ocean islands between 2004 and 2007, affecting over 272,000 people, with Reunion Island recording the highest number of cases at 270,000.8,9 These outbreaks had significant economic impacts, especially in developing countries.10 Since 2004, CHIKF has been documented in numerous countries worldwide, including North and South America, Europe, Asia, and the Pacific Islands.8
CHIKF Symptoms and Pathology
CHIKF symptoms typically appear within 3 to 7 days of infection, but can last up to 14 days. Studies show that 30-40% of infected individuals are asymptomatic, while the remaining 60-80% experience typical symptoms.14,15 The most common symptoms include high fever, joint pain, headache, muscle pain, and transient skin rash.13,14
Joint pain is a hallmark of CHIKF, often affecting wrists, hands, and knees. CHIKF is rarely fatal, with an acute phase lasting 1-2 weeks, followed by recovery. However, some survivors experience chronic joint pain and swelling that can last for months to years.3,8,9,15
Diagnosis of CHIKF
Diagnosis is typically made through molecular detection of the viral genome or identification of virus-specific antibodies in a laboratory setting.10,15 Reverse transcription–polymerase chain reaction (RT-PCR) is used to detect viral RNA from blood samples, while ELISA, immunofluorescence assay, and rapid immunochromatographic tests can detect virus-specific antibodies.6,10,16,17
Study Objectives
The primary objective of this study was to describe the acute clinical features of probable CHIKF cases and identify risk factors for persistent arthralgia.2
Study Design and Methodology
This was a prospective, descriptive cohort hospital-based study conducted at the Tesseney Community Hospital in Eritrea, serving a population of 87,992 individuals.2 The study included probable CHIKF cases with signs and symptoms of acute febrile illness who tested negative for malaria and dengue during an October 2018 outbreak.15
A convenience sampling method was used to include all probable cases of CHIKF based on clinical symptoms and epidemiological data. Serologic analysis wasn’t feasible, but 30 patients were randomly selected for.CHIKV analysis at a regional WHO virology laboratory in Kenya, which confirmed all samples as positive.6
Results
Out of 203 probable cases of CHIKF, a high male-to-female sex ratio (2.1:1) was observed, with a mean age of 39.2 years old. Most cases were between 25-35 years old, with 21% above 45 years old.2
The most common symptoms were polyarthralgia (97%), fever (96.1%), gastrointestinal symptoms (64.5%), headache (62%), and skin rash (56.7%).2 Joint pain was frequently reported, with the wrist, hands, and knees being the primary affected areas.2
Persistent joint pain was observed in 21.7% of cases at six months post-infection. Age above 41, working in health or administrative jobs, and having an O-type blood group were associated with increased risk of persistent joint pain.2
Discussion
CHIKV has re-emerged in many tropical and subtropical regions due to its genetic variability, increasing vector susceptibility, and globalization.13,17 The first confirmed CHIKF outbreak in Eritrea occurred in the Tesseney subzone in October 2018.2 Recent studies suggest that persistent arthralgia affects only a minority of CHIKF cases, usually those over 41 years old.2,22
Conclusion and Recommendations
Our findings indicate that polyarthralgia, fever, and skin rash are key symptoms during the acute phase of CHIKF, often accompanied by gastrointestinal disturbances, lymphadenopathy, and ocular symptoms.2 Persistent joint pain affects a subset of cases, with older age and certain occupations being associated risk factors.2
Mosquito-based surveillance and control are essential strategies for preventing and controlling CHIKF. Individuals can reduce their risk by wearing long-sleeved clothing, using mosquito repellents, and sleeping under mosquito bed nets. Further research is needed to understand the immunological basis of chronic arthralgia and to develop effective treatments.28
Abbreviations
WHO, World Health Organization; CHIKF, chikungunya fever; CHIKV, chikungunya virus; ELISA, Enzyme-linked immunosorbent assay; RT-PCR, Reverse-transcription polymerase chain reaction; ESCA, East-Central-South African; IOL, Indian Ocean lineage; GI, Gastrointestinal; CI, confidence interval.
Data Sharing Statement
All available information is included in the manuscript.
Ethical Approval
Ethical approval was obtained from the zonal branch of the Ministry of Health and Ethics Review Committee, and informed consent was obtained from all participants.
Consent
Written informed consent was taken from all patients, and data confidentiality was ensured.
Acknowledgment
Author Contributions
Funding
The research did not have any source of funding.
Disclosure
The authors do not have any conflict of interest to disclose for this work.
References
1. Khongwichit S, Chansaenroj J, Thongmee T, et al. Large-scale outbreak of CHIKFFungunya virus infection in Thailand, 2018-2019. PLoS One. 2021;16(3):e0247314. doi:10.1371/journal.pone.0247314
2. Fini R, Dos S MIC, Carvalho DO, et al. CHIKFFungunya Fever: Biology and Epidemiological Aspects. Vector-Borne Diseases & Treatment:p1–22.
3. De ADC, Jean S, Clavelou P, Dallel R, Bouhassira D. Chronic pain associated with the CHIKFFungunya fever: long lasting burden of an acute illness. BMC Infect Dis. 2010;10(31):1–6.
4. Lakshmi V, Neeraja M, Subbalaxmi MVS, et al. Clinical features and molecular diagnosis of CHIKFFungunya fever from south India. Clin Infect Dis. 2008;46(9):1436–1442. doi:10.1086/529444
5. Kularatne SAM, Weerasinghe SC, Gihan C, et al. Epidemiology, clinical manifestations, and long-term outcomes of a major outbreak of CHIKFFungunya in a hamlet in Sri Lanka, in 2007: a longitudinal cohort study. J Trop Med. 2012;2012:1–6. doi:10.1155/2012/639178
6. de Lima Cavalcanti TYV, Pereira MR, de Paula SO, Franca RFDO. A review on CHIKFFungunya virus epidemiology, pathogenesis and current vaccine development. Viruses. 2022;14:969. doi:10.3390/v14050969
7. Kril V, Aïqui-reboul-paviet O, Briant L, Amara A. New insights into CHIKFFungunya virus infection and pathogenesis. Annu Rev Virol. 2021;8:327–347. doi:10.1146/annurev-virology-091919-102021
8. Gutierrez-rubio AK, Magbitang AD, Penserga EG. A three-month follow up of musculoskeletal manifestions in CHIKFFungunya fever. Philipp J Intern Med. 2014;52(1):1–5.
9. Virology H. CHIKFFungunya association with different presentation at tertiary care centre. J Hum Virol Retrovirology. 2017;6(1):6–9.
10. Atalay T, Kaygusuz S, Azkur AK. A study of the CHIKFFungunya virus in humans in Turkey.