Molecular Virologic and Clinical Characteristics of a Chikungunya Fever Outbreak in La Romana, Dominican Republic, 2014

Abstract

Since emerging in Saint Martin in 2013, chikungunya virus (CHIKV), an alphavirus transmitted by the Aedes aegypti mosquito, has infected approximately two million individuals in the Americas, with over 500,000 reported cases in the Dominican Republic (DR). CHIKV-infected patients typically present with a febrile syndrome including polyarthritis/polyarthralgia, and a macropapular rash, similar to those infected with dengue and Zika viruses, and malaria. Nevertheless, many Dominican cases are unconfirmed due to the unavailability and high cost of laboratory testing and the absence of specific treatment for CHIKV infection. To obtain a more accurate representation of chikungunya fever (CHIKF) clinical signs and symptoms, and confirm the viral lineage responsible for the DR CHIKV outbreak, we tested 194 serum samples for CHIKV RNA and IgM antibodies from patients seen in a hospital in La Romana, DR using quantitative RT-PCR and IgM capture ELISA, and performed retrospective chart reviews. RNA and antibodies were detected in 49% and 24.7% of participants, respectively. Sequencing revealed that the CHIKV strain responsible for the La Romana outbreak belonged to the Asian/American lineage and grouped phylogenetically with recent Mexican and Trinidadian isolates. Our study shows that, while CHIKV-infected individuals were infrequently diagnosed with CHIKF, uninfected patients were never falsely diagnosed with CHIKF. Participants testing positive for CHIKV RNA were more likely to present with arthralgia, although it was reported in just 20.0% of CHIKF+ individuals. High percentages of respiratory (19.6%) signs and symptoms, especially among children, were noted, though it was not possible to determine whether individuals infected with CHIKV were co-infected with other pathogens. These results suggest that CHIKV may have been underdiagnosed during this outbreak, and that CHIKF should be included in differential diagnoses of diverse undifferentiated febrile syndromes in the Americas.

Chikungunya Outbreak in Bangladesh (2017): Clinical and hematological findings

“…Irrespective of sex, the combination of fever and severe arthralgia (present in 97.9% of cases) can be regarded as the cardinal hallmark of the Chikungunya 2017 outbreak in Bangladesh. This is consistent with the previous outbreak report (83.3 to 98%), though the values were less in case of the children [31, 43-45] ( Table 2, Table 3). However, in an Indian outbreak of the virus in Kerala in 2007, arthralgia was found to be the initial symptom in only ∼17% patients [33].…”

“…We were not able to document any significant drop in the lymphocyte counts nor any significant increase in platelets, leucocytes or neutrophils counts. These outcomes are atypical when compared to the reports from the Ahmedabad outbreak, the Caribbean outbreak in Trinidad in 2015, the La Romana outbreak in 2016 and the Kandy outbreak in Sri Lanka in 2006-07 [31, 44, 53-54]. However, the ESR values obtained through our analysis reports a very broad range with significantly elevated rates in most cases across age and sex (p <0.00001) ( Table 5).…”

Arboviroses reemergentes: perfil clínico-epidemiológico de idosos hospitalizados

“…The most frequent changes in laboratory exams were thrombocytopenia, high CRP and leukopenia, in agreement with a previous study (24) . In chikungunya fever, blood counts of patients commonly present leukopenia with lymphopenia (<1,000 cells/mm 3 ) and high erythrocyte sedimentation rate and CRP (5) .…”

“…All patients of the sample were clinically diagnosed and, for confirmation, only 18.2% were submitted to IgM serology for chikungunya and 15.2% to IgM serology for dengue. This reduced number of serology was also observed in other studies (18,24) . Regarding chikungunya fever, in typical cases, the diagnosis should be based on clinical epidemiological criteria, and serology only when required for differential diagnosis (22) .…”

Differential alphavirus defective RNA diversity between intracellular and encapsidated compartments is driven by subgenomic recombination events

“…Cleaned RNA was electroporated into Vero cells using a Neon electroporation device following manufacturer’s Vero protocol (Thermo Fisher Scientific, Waltham, MA). All viruses were amplified in C7/10 cells using MOI=0.1 to generate P1 stock virus; P0 and P1 stock titers were determined in vero or BHK21 cells using plaque assays as previously described (79).…”