Dengue Seroprevalence and Seroconversion in Urban and Rural Populations in Northeastern Thailand and Southern Laos

Abstract

Dengue is the most rapidly spreading mosquito-borne viral disease in the world. The detection of clinical cases enables us to measure the incidence of dengue infection, whereas serological surveys give insights into the prevalence of infection. This study aimed to determine dengue seroprevalence and seroconversion rates in northeastern Thailand and southern Laos and to assess any association of mosquito control methods and socioeconomic factors with dengue virus (DENV) infection. Cross-sectional seroprevalence surveys were performed in May and November 2019 on the same individuals. Blood samples were collected from one adult and one child, when possible, in each of 720 randomly selected households from two urban and two rural sites in both northeastern Thailand and southern Laos. IgG antibodies against DENV were detected in serum using a commercial enzyme-linked immunosorbent assay (ELISA) kit. Overall, 1071 individuals participated in the study. The seroprevalence rate was high (91.5%) across all 8 study sites. Only age and province were associated with seroprevalence rates. There were 33 seroconversions during the period from May to November, of which seven reported fever. More than half of the seroconversions occurred in the rural areas and in Laos. Dengue seroconversion was significantly associated with young age (<15 years old), female gender, province, and duration of living in the current residence. No socioeconomic factors or mosquito control methods were found to be associated with seroprevalence or seroconversion. Notably, however, the province with most seroconversions had lower diurnal temperature ranges than elsewhere. In conclusion, our study has highlighted the homogeneity of dengue exposure across a wide range of settings and most notably those from rural and urban areas. Dengue can no longer be considered to be solely an urban disease nor necessarily one linked to poverty.

Dengue Seroprevalence and Factors Associated with Dengue Seropositivity in Petaling District, Malaysia

“…The age-specific DENV seroprevalence in this study demonstrated a gradual increasing trend as age advanced. This was in line with other DENV seroprevalence studies conducted locally and internationally, which found an increment in DENV seropositivity rate with increasing age [ 1 , 11 , 13 , 26 , 36 , 40 ]. This observation was expected, as the longer a person resides in a dengue-endemic area, the greater the risk one is exposed to dengue infection coupled with the lifelong persistence of anti-DENV antibodies [ 1 , 13 , 34 ].…”

“…Population movement could have influenced the DENV seroprevalence results, lowering the seroprevalence rate if many migrants were coming from less dengue-prone areas [ 32 ]. Compared with other dengue-endemic Southeast Asian countries, the seroprevalence rate in this study was higher than that found in Singapore [ 33 , 34 ], while countries such as Thailand, Laos, and the Philippines reported even higher rates [ 35 , 36 ]. Compared to Latin American countries, which are also endemic with dengue, the DENV seroprevalence rate was comparable to two other cities, namely São Paulo, Brazil [ 37 ] and Maracay, Venezuela [ 38 ], but was lower than that of another community study conducted in Columbia [ 39 ].…”

“…Sociodemographic factors were seemingly more context-specific, as other studies had failed to show clear associations with DENV seropositivity [ 1 , 13 , 40 , 46 , 47 ]. Likewise, numerous other studies did not find significant associations between DENV seropositivity and preventive practices [ 29 , 36 , 46 , 47 , 48 ]. While having good knowledge on Aedes biting time may influence the adoption of effective preventive measures, no significant association between the knowledge and DENV seropositivity was found in two other studies [ 29 , 48 ].…”

Correction: Doum, D., et al. Dengue Seroprevalence and Seroconversion in Urban and Rural Populations in Northeastern Thailand and Southern Laos. Int. J. Environ. Res. Public Health 2020, 17, 9134

“…There was an error in the original article [ 1 ]: ethylenediamine tetraacetic acid (EDTA)-tubes was stated incorrectly.…”

A comparative study of dengue virus vectors in major parks and adjacent residential areas in Ho Chi Minh City, Vietnam

“…The dense human populations of urban areas increase vector-human contact, and dengue virus (DENV) circulates more efficiently [ 2 ]. However, recent seroprevalence studies showed that rural populations have been exposed to DENV as much as urban populations [ 4 , 5 ]. The high seropositive rate in rural areas is likely due to an increase of mobile populations infected with DENV from urban areas, and transitions of rural areas toward urban areas.…”