Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Review
. 2021 Aug 19;15(8):e0009624.
doi: 10.1371/journal.pntd.0009624. eCollection 2021 Aug.

Changing epidemiology of dengue in Sri Lanka-Challenges for the future

Gathsaurie Neelika Malavige  1   2 , Chandima Jeewandara  1   2 , Azhar Ghouse  3 , Gayasha Somathilake  2 , Hasitha Tissera  3
Affiliations
Review

Changing epidemiology of dengue in Sri Lanka-Challenges for the future

Gathsaurie Neelika Malavige et al. PLoS Negl Trop Dis. .

Abstract

Background: Dengue infections are on the rise in Sri Lanka and are spreading to all areas in the country. Here, we discuss the changes in dengue epidemiology in Sri Lanka in relation to changes in age distribution, changes in seroprevalence rates over time, and possible reasons contributing to such changes.

Methods and findings: Although the incidence of dengue increased 20-fold from the year 2000 to 2012 and a further 3-fold from 2012 to 2019, this increase is not reflected in a similar increase in the age-stratified seropositivity rates for dengue. For instance, the annual seroconversion rates were 0.76% in 2013 and 0.91% in 2017. The annual seroconversion rates in the 6 to 17 age group were 1.5% per year in 2003, 3.9% in 2013, and 4.1% in 2017. In addition, although a 13-fold increase in dengue was seen in those who were <19 years of age, a 52.4-fold increase was seen in the 40- to 59-year age group. The case fatality rates (CFRs) have similarly changed, with 61.8% of deaths occurring in those <19 years of age in the year 2000, while in 2012 to 2018, the highest CFR were seen in those who were aged 20 to 39 years. Although there has been a marked increase in the number of cases, the vector densities did not change during a 4-year period. The proportion of adult individuals experiencing a secondary dengue infection has also remained between 65% and 75% between the years 2004 and 2018.

Conclusions: A change in the ratio of symptomatic to asymptomatic infections can give rise to changes in the reported incidence of dengue. In order to take an appropriate policy decision in dengue control activities, it would be important to study the changes in virus serotypes, vector dispersion, and densities. Further, the contribution of the rise in metabolic diseases to an increase in the symptomatic as well as more severe infections due to dengue is explored.

PubMed Disclaimer

Conflict of interest statement

The authors have declared that no competing interests exist.

Figures

Fig 1
Fig 1. Geographic spread and increase in the number of cases of dengue infection from 2006 to 2017 in Sri Lanka.
Each red dot denotes a reported case by each district. Colombo district is circled in black [15]. Source of the data: www.epid.gov.lk.
Fig 2
Fig 2. The increase in the prevalence of dengue cases from 2000 to 2018 in different age groups in Sri Lanka.
The number of dengue cases reported from 2000 to 2018 in each age group (A) and the fold rise of the number of cases from year 2000 to 2012 and 2018 (B).
Fig 3
Fig 3. The change in the CFRs in different age groups from the year 2000 to 2018. CFR, case fatality rate.
Fig 4
Fig 4. Age-stratified seroprevalence in the Colombo district in 2003, 2013, and 2017.
The age-stratified seroprevalence was determined in children aged 6 to 17 years in 2003, 2013, and 2017 (A) and in individuals aged 6 to 80 in 2013 and 2017 (B).
Fig 5
Fig 5. Changes in the circulating DENV serotypes in Colombo, Sri Lanka from 2015 to January 2020. DENV, dengue virus.
See this image and copyright information in PMC

References

    1. Bhatt S, Gething PW, Brady OJ, Messina JP, Farlow AW, Moyes CL, et al.. The global distribution and burden of dengue. Nature. 2013;496(7446):504–7. Epub 2013 Apr 9. doi: 10.1038/nature12060 ; PubMed Central PMCID: PMC3651993. - DOI - PMC - PubMed
    1. World Health Organization. Ten threats to global health in 2019. World Health Organization; 2019 [cited 2019]. Available from: https://www.who.int/emergencies/ten-threats-to-global-health-in-2019.
    1. Shepard DS, Undurraga EA, Halasa YA, Stanaway JD. The global economic burden of dengue: a systematic analysis. Lancet Infect Dis. 2016;16(8):935–41. doi: 10.1016/S1473-3099(16)00146-8 . - DOI - PubMed
    1. Thalagala N, Tissera H, Palihawadana P, Amarasinghe A, Ambagahawita A, Wilder-Smith A, et al.. Costs of Dengue Control Activities and Hospitalizations in the Public Health Sector during an Epidemic Year in Urban Sri Lanka. PLoS Negl Trop Dis. 2016;10(2):e0004466. doi: 10.1371/journal.pntd.0004466; PubMed Central PMCID: PMC4766086. - DOI - PMC - PubMed
    1. Epidemiology unit MoH, Sri Lanka. Epidemiological Bulletin, First quater 2018. Epidemiology Unit, 2018.

Publication types