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Updated: Oct 2, 2025
Multiplexed Isothermal Amplification Based Diagnostic Platform to Detect Zika, Chikungunya, and Dengue 1
Published on: March 13, 2018
Was It Chikungunya? Laboratorial and Clinical Investigations of Cases Occurred during a Triple Arboviruses' Outbreak
Thiara Manuele Alves de Souza1, Raquel Curtinhas de Lima1, Victor Edgar Fiestas Solórzano1
1Viral Immunology Laboratory, Oswaldo Cruz Institute, Rio de Janeiro 21040-360, Brazil.
Insights
Chikungunya virus (CHIKV) was the primary diagnosis in Rio de Janeiro arbovirus cases during a 2018 triple epidemic. Most suspected cases were confirmed CHIKV, with significant co-detection of dengue virus (DENV).
Area of Science:
- Arbovirology
- Epidemiology
- Clinical Medicine
Background:
- Rio de Janeiro faced a challenging triple epidemic of chikungunya virus (CHIKV), dengue virus (DENV), and Zika virus (ZIKV) in 2018.
- These arboviruses share similar clinical presentations and geographical distribution, complicating differential diagnosis.
Purpose of the Study:
- To investigate clinical and laboratory aspects of suspected chikungunya cases during the 2018 Rio de Janeiro outbreak.
- To differentiate chikungunya from dengue and Zika virus infections through diagnostic approaches.
Main Methods:
- Investigated 242 suspected arbovirus cases using molecular and serological diagnostic methods.
- Conducted RT-qPCR for viral detection and quantified cycle threshold (Ct) values.
- Performed phylogenetic analysis to identify the chikungunya virus genotype.
Main Results:
- 73.6% (178/242) of suspected cases were confirmed as chikungunya.
- No molecularly confirmed DENV or ZIKV infections were found, but serological evidence of DENV exposure was present in 9.5% of all cases and 42.7% of CHIKV-positive cases.
- CHIKV monoinfection showed a higher frequency of arthritis and limb edema compared to DENV or co-infection cases.
- Phylogenetic analysis identified the ECSA genotype of CHIKV.
Conclusions:
- Chikungunya was the predominant arbovirus diagnosed among patients with fever and arthralgia in Rio de Janeiro during the 2018 outbreak.
- A notable incidence of CHIKV/DENV co-detection was observed, exceeding previous reports.
- Differential diagnosis remains crucial for managing arboviral infections with overlapping symptoms.
Abstract:
The co-circulation of chikungunya virus (CHIKV), dengue virus (DENV) and Zika virus (ZIKV) in Rio de Janeiro (RJ), Brazil, caused a challenging triple epidemic, as they share similar clinical signs and symptoms and geographical distribution. Here, we aimed to investigate the clinical and laboratorial aspects of chikungunya suspected cases assisted in RJ during the 2018 outbreak, focusing on the differential diagnosis with dengue and zika. All suspected cases were submitted to molecular and/or serological differential diagnostic approaches to arboviruses. A total of 242 cases suspected of arbovirus infection were investigated and 73.6% (178/242) were molecular and/or serologically confirmed as chikungunya. In RT-qPCR confirmed cases, cycle threshold (Ct) values ranged from 15.46 to 35.13, with acute cases presenting lower values. Chikungunya cases were mainly in females (64%) and the most frequently affected age group was adults between 46 to 59 years old (27%). Polyarthralgia affected 89% of patients, especially in hands and feet. No dengue virus (DENV) and Zika virus (ZIKV) infections were confirmed by molecular diagnosis, but 9.5% (23/242) had serological evidence of DENV exposure by the detection of specific anti-DENV IgM or NS1, and 42.7% (76/178) of chikungunya positive cases also presented recent DENV exposure reflected by a positive anti-DENV IgM or NS1 result. A significantly higher frequency of arthritis (p = 0.023) and limb edema (p < 0.001) was found on patients with CHIKV monoinfection compared to dengue patients and patients exposed to both viruses. Lastly, phylogenetic analysis showed that the chikungunya cases were caused by the ECSA genotype. Despite the triple arboviruses' epidemic in the state of RJ, most patients with fever and arthralgia investigated here were diagnosed as chikungunya cases, and the incidence of CHIKV/DENV co-detection was higher than that reported in other studies.
