Seroprevalence of dengue antibodies, annual incidence and risk factors among children in southern Vietnam

Abstract

SummaryDengue is highly endemic in southern Vietnam and all four serotypes of dengue virus have already been identified. To determine the age-specific prevalence of dengue and associated risk factors, we conducted a serological study at two primary schools and assessed risk factors by analysing children's questionnaires and household surveys. Sera were collected from 961 primary schoolchildren in Binh Thuan Province and tested for the presence of dengue virus serum antibodies using an indirect immunoglobulin G (IgG) enzyme-linked immunosorbent assay (ELISA). The antibody prevalence of the total population was 65.7% (n ¼ 631) which increased from 53.0 to 88.2% with age. The annual incidence of a first dengue infection, estimated by binary regression of the seroprevalence by age, was 11.7%. Interestingly, the prevalence of dengue IgG antibodies was significantly higher in children who confirmed using a pit latrine (RR 1.467, 95% CI: 1.245-1.730) and whose domestic environment contained discarded cans (RR 1.238, 95% CI: 1.042-1.470) and pigs (RR 1.228, 95% CI: 1.002-1.504). The epidemiology of dengue in southern Vietnam is stable with a constantly high annual incidence of first infections. Transmission occurs mainly peri-domestically, which has important public health implications.

Seroprevalence of Neutralizing Antibodies Against Dengue Virus in Two Localities in the State of Morelos, Mexico

“…17,18 However, for the 5-to 9-year-old group, the seroprevalence found in this study is lower compared with SEA countries. 33,34 This difference can probably be explained by the higher intensity of dengue transmission in SEA compared with that in Latin America-endemic countries. 16 In general, studies have shown an increase in seroprevalence with age as a result of a longer period of exposure to the DENV circulating in endemic regions.…”

High potential risk of dengue transmission during the hot-dry season in Nha Trang City, Vietnam

“…Although a seroprevalence survey has not been carried out in Nha Trang City, we assumed 33% immunity to be a sensitive threshold to detect a dengue outbreak in the city on the basis of a study conducted in South Vietnam (Thai et al, 2005). Transmission thresholds for 29.0 o C and 25.2 o C were not listed in the reference table, and the threshold values for these temperatures were calculated linearly.…”

Seroprevalencia en una zona de hiperendemia por dengue, en Barranquilla, Colombia

“…Con respecto a los grupos etarios, a medida que se avanza en edad se incrementa la seroprevalencia, lo que refleja una tendencia lineal (21,30,31,36) que afecta preferencialmente a las mujeres (21,23). Estos hallazgos coinciden con el estudio realizado por Restrepo (38) en el Urabá antioqueño, donde la seroprevalencia para IgG fue del 59,1 %, con prevalencias por encima del 50 % para los grupos etarios; se encontraron tasas de 88,9 % en mayores de 55 años y tasas más bajas en menores de 5 años.…”

“…Resultados: a soroprevalência para IgG foi 88,2 % (IC 95 % =85,2-91,1) e para IgM de 11,8 % (IC 95%= 8,80-14,75). Constatouse associação estatística em idades de 30 a 49 e 50 a 69 anos (OR=7,09 [2,[6][7][8][9][10][11][12][13][14][15][16][17][18][19]3] e OR= 8,93 [2,[9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27],0] respectivamente), pertencer ao sistema de saúde subsidiado (OR=2,56 [1,53]) e ocupação do lar (OR= 3,38 [1,67]. Conclusões: a alta soroprevalência para IgG é explicada pela circulação dos quatro sorotipos no país, os surtos epidêmicos a cada dois ou três anos e os comportamentos e práticas desfavoráveis relacionados com o uso da água.…”

“…Además, posibilitan entender la dinámica poblacional de transmisibilidad, el patrón de difusión del dengue a nivel poblacional y el acumulado de antecedente de exposición (2,4,6,7,10,13,(18)(19)(20)(21)(22)(23)(24)(25).…”