title: Molecular Characterisation of Chikungunya Virus Infections in Trinidad and Comparison of Clinical and Laboratory Features with Dengue and Other Acute Febrile Cases.
abstract: Local transmission of Chikungunya virus (CHIKV) was first documented in Trinidad and Tobago (T&T) in July 2014 preceding a large epidemic. At initial presentation, it is difficult to distinguish chikungunya fever (CHIKF) from other acute undifferentiated febrile illnesses (AUFIs), including life-threatening dengue disease. We characterised and compared dengue virus (DENV) and CHIKV infections in 158 patients presenting with suspected dengue fever (DF) and CHIKF at a major hospital in T&T, and performed phylogenetic analyses on CHIKV genomic sequences recovered from 8 individuals. The characteristics of patients with and without PCR-confirmed CHIKV were compared using Pearson's χ2 and student's t-tests, and adjusted odds ratios (aORs) and 95% confidence intervals (CIs) were determined using logistic regression. We then compared signs and symptoms of people with RT-qPCR-confirmed CHIKV and DENV infections using the Mann-Whitney U, Pearson's χ2 and Fisher's exact tests. Among the 158 persons there were 8 (6%) RT-qPCR-confirmed DENV and 30 (22%) RT-qPCR-confirmed CHIKV infections. Phylogenetic analyses showed that the CHIKV strains belonged to the Asian genotype and were most closely related to a British Virgin Islands strain isolated at the beginning of the 2013/14 outbreak in the Americas. Compared to persons who were RT-qPCR-negative for CHIKV, RT-qPCR-positive individuals were significantly more likely to have joint pain (aOR: 4.52 [95% CI: 1.28-16.00]), less likely to be interviewed at a later stage of illness (days post onset of fever--aOR: 0.56 [0.40-0.78]) and had a lower white blood cell count (aOR: 0.83 [0.71-0.96]). Among the 38 patients with RT-qPCR-confirmed CHIKV or DENV, there were no significant differences in symptomatic presentation. However when individuals with serological evidence of recent DENV or CHIKV infection were included in the analyses, there were key differences in clinical presentation between CHIKF and other AUFIs including DF, which can be used to triage patients for appropriate care in the clinical setting.
authors.affiliation: Department of Preclinical Sciences, Faculty of Medical Sciences, The University of the West Indies, St. Augustine, Republic of Trinidad and Tobago.
authors.forename: Nikita
authors.initials: N
authors.lastname: Sahadeo
authors.affiliation: Public Health England, HIV & STI Department, London, United Kingdom.
authors.forename: Hamish
authors.initials: H
authors.lastname: Mohammed
authors.affiliation: Department of Preclinical Sciences, Faculty of Medical Sciences, The University of the West Indies, St. Augustine, Republic of Trinidad and Tobago.
authors.forename: Orchid M
authors.initials: OM
authors.lastname: Allicock
authors.affiliation: Institute for Human Infections and Immunity and Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, United States of America.
authors.forename: Albert J
authors.initials: AJ
authors.lastname: Auguste
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, Texas, United States of America.
authors.forename: Steven G
authors.initials: SG
authors.lastname: Widen
authors.affiliation: Department of Preclinical Sciences, Faculty of Medical Sciences, The University of the West Indies, St. Augustine, Republic of Trinidad and Tobago.
authors.forename: Kimberly
authors.initials: K
authors.lastname: Badal
authors.affiliation: Adult Emergency Department, Eric Williams Medical Sciences Complex, Mt. Hope, Republic of Trinidad and Tobago.
authors.forename: Krishna
authors.initials: K
authors.lastname: Pulchan
authors.affiliation: Department of Preclinical Sciences, Faculty of Medical Sciences, The University of the West Indies, St. Augustine, Republic of Trinidad and Tobago.
authors.forename: Jerome E
authors.initials: JE
authors.lastname: Foster
authors.affiliation: Institute for Human Infections and Immunity and Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, United States of America.
authors.forename: Scott C
authors.initials: SC
authors.lastname: Weaver
authors.affiliation: Department of Preclinical Sciences, Faculty of Medical Sciences, The University of the West Indies, St. Augustine, Republic of Trinidad and Tobago.
authors.forename: Christine V F
authors.initials: CV
authors.lastname: Carrington
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D065632:Chikungunya Fever / Q000175:diagnosis* / Q000453:epidemiology* / Q000473:pathology; D002646:Chikungunya virus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D003715:Dengue / Q000175:diagnosis* / Q000453:epidemiology* / Q000473:pathology; D003937:Diagnosis, Differential; D005260:Female; D005335:Fever of Unknown Origin / Q000175:diagnosis / Q000453:epidemiology / Q000473:pathology; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D025202:Molecular Diagnostic Techniques / Q000379:methods*; D008969:Molecular Sequence Data; D010802:Phylogeny; D012367:RNA, Viral / Q000235:genetics; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D014300:Trinidad and Tobago / Q000453:epidemiology; D055815:Young Adult
chemical_list: D012367:RNA, Viral