Dengue in Thailand and Cambodia: An Assessment of the Degree of Underrecognized Disease Burden Based on Reported Cases

Abstract

BackgroundDisease incidence data are needed to guide decision-making for public health interventions. Although dengue is a reportable disease in Thailand and Cambodia, the degree that reported incidence underrecognizes true disease burden is unknown. We utilized dengue incidence calculated from laboratory-confirmed outpatient and inpatient cases in prospective cohort studies to estimate the magnitude of dengue underrecognition and to establish more accurate disease burden estimates for these countries.Methods and FindingsCohort studies were conducted among children aged <15 years by members of a dengue field site consortium over at least 2 dengue seasons. Age-group specific multiplication factors (MFs) were computed by comparing data from three cohort studies to national surveillance data in the same province and year. In Thailand, 14,627 person-years of prospective cohort data were obtained in two provinces and 14,493 person-years from one province in Cambodia. Average annual incidence of laboratory-confirmed dengue was 23/1,000 and 25/1,000 in Thailand, and 41/1,000 in Cambodia. Calculated MFs in these provinces varied by age-group and year (range 0.4–29). Average age-group specific MFs were then applied to country-level reporting data and indicated that in Thailand a median 229,886 (range 210,612–331,236) dengue cases occurred annually during 2003–2007 and a median 111,178 (range 80,452–357,135) cases occurred in Cambodia in children <15 years of age. Average underrecognition of total and inpatient dengue cases was 8.7 and 2.6-fold in Thailand, and 9.1 and 1.4-fold in Cambodia, respectively. During the high-incidence year 2007, >95,000 children in Thailand and >58,000 children in Cambodia were estimated to be hospitalized due to dengue.ConclusionCalculating MFs by comparing prospective cohort study data to locally-reported national surveillance data is one approach to more accurately assess disease burden. These data indicate that although dengue is regularly reported in many countries, national surveillance data significantly underrecognize the true burden of disease.

Burden of Dengue Infection and Disease in a Pediatric Cohort in Urban Sri Lanka

“…Recent studies in Southeast Asia have estimated expansion factors of 8.9 and 9.6 when comparing national data with true disease incidence for Thailand and Cambodia, respectively. 7,32 Moreover, a recent study of the global burden of dengue estimated that there are three times as many infections and dengue cases compared with cases reported to the World Health Organization. 4 For most regions in the world with endemic dengue transmission, we do not have accurate estimates of infection and disease because of the cost and infrastructure required to conduct cohort studies.…”

Quantifying the added value of climate information in a spatio-temporal dengue model

“…From 2003 to the present, the reported data from the national surveillance system (DF, DHF, DSS using the 1997 WHO case definition) have been available on both the electronic and the hardcopy of the Weekly Bulletin of Epidemiology, Ministry of Public Health of Thailand (http://www.boe.moph.go.th/). Despite the unknown degree of under-reporting, this national surveillance system is thought to provide a good estimation, albeit underestimated, of the real disease burden in the country (Wichmann et al, 2011).…”

“…Dengue remains a disease of children and young adults in Thailand, with most cases occurring in individuals aged between 5 years and 24 years, who represent one third of the population (Limkittikul et al, 2014). The incidence rate appears to be declining from its peak in the 1970s and 1980s, but remains high at 20 per 1,000 for children <15 years old (Wichmann et al, 2011). The small temporal decline has been linked to a reduced estimated force of infection and the changing demography (reduced birth and death rates) may have contributed to this ).…”

Indonesian strategy in reducing Aedes aegypty diseases in ASEAN economic community era

“…But, there are many things underlie the difficulty of eradicating Aedes aegypty in Indonesia, including lack of knowledge and awareness of society to behave in a healthy life and pay attention to the environment, particularly the environment of mosquito breeding sites. 6 This is due to lack of community involvement in tackling the issue of Aedes aegypty and dissemination of government to the public about how to eradicate the Aedes aegypty and prevention appropriate and in accordance with the state of the surrounding environment.…”

“…However, it is associated with the environment and people behavior. 6 Therefore, to control and manage the environment and change the people behavior are needed.…”