Seroepidemiology of dengue in travellers: a paired sera analysis.

Abstract

BACKGROUND:

Dengue is a frequent cause of fever in travellers. The true extent is unknown as many infections are asymptomatic or undiagnosed.

METHODS:

We used paired sera, with pre- and post-travel specimens from Swiss travellers to tropical destinations, to evaluate the seroepidemiology of travel-related dengue. Post-travel specimens were tested for the presence of IgG and IgM antibodies to dengue antigen serotypes (1, 2, 3 and 4) using an indirect enzyme-linked immunosorbent assay (ELISA). All post-travel sera that screened as positive for dengue IgG or IgM antibodies were re-tested with the corresponding pre-travel sera as paired assays in order to detect seroconversion.

RESULTS:

There were 285 travellers with specimens available for analysis. Two hundred and fifty seven of the 285 individuals (90.2%) had negative dengue serology post-travel. Of the remaining 28 cases, 25 were dengue IgG positive and 3 had equivocal results. This corresponds to IgG seropositivity in 8.9%. Eighteen of these 25 individuals had a pre-travel specimen available for testing, of which 15 were positive for IgG consistent with possible past exposure. Three of the 18 had negative serology pre-travel, indicating possible recent infection. This corresponds to an attack rate of possible dengue of 1.1% and an incidence rate of 6.7 per 1000 person-months (95% CI 0-60.0). Two of these three individuals had received yellow fever vaccine for their trip, raising the potential of cross-reactivity. The confirmed dengue attack rate therefore was 0.23% with a corresponding incidence rate of 2.2 per 1000 person-months (95% CI-0-33.1).

CONCLUSIONS:

Seroepidemiology provides additional evidence of an appreciable risk of acute dengue infection among travellers to tropical destinations.

• Authors: Karin Leder, Margot Mutsch, Patricia Schlagenhauf, Christine Luxemburger, Joseph Torresi
• Journal: Travel medicine and infectious disease (Travel Med Infect Dis) 2013 Jul-Aug Vol. 11 Issue 4 Pg. 210-3 ISSN: 1873-0442 [Electronic] Netherlands
• PMID: 23890678 (Publication Type: Journal Article)
• Copyright: Copyright © 2013. Published by Elsevier Ltd.

Chemical References

• Antibodies, Viral
• Immunoglobulin G
• Immunoglobulin M

Topics

• Adolescent
• Adult
• Aged
• Aged, 80 and over
• Antibodies, Viral (blood)
• Cohort Studies
• Dengue (epidemiology, immunology)
• Dengue Virus (immunology, isolation & purification)
• Enzyme-Linked Immunosorbent Assay
• Female
• Humans
• Immunoglobulin G (blood)
• Immunoglobulin M (blood)
• Male
• Middle Aged
• Prospective Studies
• Risk
• Seroepidemiologic Studies
• Switzerland (epidemiology)
• Travel
• Vaccination
• Young Adult