Dengue-specific serotype related to clinical severity during the 2012/2013 epidemic in centre of Brazil

• Published in: Infectious diseases of poverty Vol. 6; no. 1; p. 116
• Main Authors: Rocha, Benigno A M, Guilarde, Adriana O, Argolo, Angela F L T, Tassara, Marianna Peres, da Silveira, Lucimeire A, Junqueira, Isabela C, Turchi, Marília D, Féres, Valéria C R, Martelli, Celina M T
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 02-08-2017; BioMed Central; BMC
• Subjects: Adolescent; Adult; Aged; Brazil; Brazil - epidemiology; Care and treatment; Child; Child, Preschool; Coinfection - epidemiology; Coinfection - virology; Comparative analysis; Dengue; Dengue - epidemiology; Dengue - virology; Dengue fever; Dengue type 4; Dengue Virus - genetics; Development and progression; Disease Outbreaks; Epidemics; Female; Forecasts and trends; Health surveillance; Humans; Immune response; Infant; Infections; Laboratories; Male; Middle Aged; Odds Ratio; Pathogenesis; Polymerase chain reaction; Prospective Studies; Public health; Secondary infection; Serogroup; Severe dengue; Severe Dengue - epidemiology; Severe Dengue - virology; Viruses; Young Adult; Brazil; Brazil; Secondary infection; Severe dengue; Dengue type 4; Dengue
• ISSN: 2049-9957; 2095-5162; 2049-9957
• DOI: 10.1186/s40249-017-0328-9

Please see Additional file 1 for translations of the abstract into the five official working languages of the United Nations.
Currently, in Brazil, there is a co-circulation of the four dengue (DENV-1 to DENV-4) serotypes. This study aimed to assess whether different serotypes and antibody response patterns were associated with the severity of the disease during a dengue outbreak, which occurred in 2012/2013 in centre of Brazil.
We conducted a prospective study with 452 patients with laboratory confirmed dengue in central Brazil, from January 2012 to July 2013. The clinical outcome was the severity of cases: dengue, dengue with warning signs, and severe dengue. The patients were evaluated at three different moments. Blood sampling for laboratory testing and confirmatory tests for dengue infection were performed. We performed a multinomial analysis considering the three categories of the dependent variable, as outlined above. The odds ratios (ORs) were calculated. A multinomial logistic regression model was applied for variables with a P-value <0.20. Statistical analysis was performed with STATA 12.0 software.
Four hundred fifty-two patients (452/632, 71.5%) were diagnosed with dengue. The dengue virus (DENV) serotypes were identified in 243 cases. DENV-4 was detected in 135 patients (55.6%), DENV-1 in 91 (37.4%), DENV-3 in 13 (5.3%), and DENV-2 in 4 (1.6%). Patients with the DENV-1 serotype were more prone to present with several clinical and laboratory features as compared with DENV-4 patients, including spontaneous bleeding (P = 0.03), intense abdominal pain (P = 0.004), neurological symptoms (P = 0.09), and thrombocytopenia (P = 0.01). Secondary infection was more predominant among DENV-4 cases (80.0%) compared with DENV-1 cases (62.3%) (P = 0.03). The univariate analysis showed that females (OR = 2.12; 95% CI: 1.44-3.13; P < 0.01) had a higher risk of having dengue with warning signs. The multinomial analysis showed that severe dengue cases with secondary infection had an adjusted OR of 2.80 (95% CI: 0.78-10.00; P = 0.113) as compared with dengue fever with primary infection when adjusted for age and sex.
The current data show that 5.8% of patients recruited for treatment in healthcare centres and hospitals during the study period had severe dengue. DENV-4 was the predominant serotype, followed by DENV-1, in a large outbreak of dengue in central Brazil. Our findings contribute to the understanding of clinical differences and immune status related to the serotypes DENV-1 and DENV-4 in central of Brazil.