Concurrent multi-serotypic dengue infections in various body fluids

Abstract number: O82

Kulwichit W., Krajiw S., Chansinghakul D., Suwanpimolkul G., Prommalikit O., Suandork P., Pupaibool J., Arunyingmongkol K., Pancharoen C., Thisyakorn U.

Objectives: Dengue virus infection is one of the rapidly-spreading emerging diseases worldwide. The virus is divided into 4 distinct serotypes with limited cross-protective immunity; therefore, one can be reinfected with different serotypes. While each episode is usually caused by a single serotype, an individual can occasionally be infected by concurrent multiple ones. Our group has previously detected dengue virus from urine and oral specimens of some patients. In this study, we sought to determine the characteristics of multi-serotype infections when analysing beyond the patients' blood compartments.

Methods: During 2003–2007, paediatric and adult patients suspected of dengue infections were enrolled. Plasma, peripheral blood mononuclear cells (PBMC), urine pellets, buccal brushes, and saliva were collected during and after the febrile episode. Only specimens from patients with both positive dengue serology and pan-dengue-specific RT-PCR were included. Serotype-specific RT-PCR was then performed on the aforementioned various specimens of each patient.

Results: 95 patients met the above criteria. Serotyping was successful in 85 patients. DEN-4 was the most common serotype, accounting for half of the cases. 20 of these 85 (23.5%) demonstrated multi-serotypic infections when combining data from all specimen types in each individual. Serotyping using single, conventional serum/plasma specimens, however, would detect only half of the cases. The phenomenon of concurrent multi-serotypic infections was present in all examined specimen types, including urine pellets, buccal brushes, and saliva. The most frequent combinations were DEN-1 + DEN-4 and DEN-2 + DEN-4 (5 cases each). Two patients were simultaneously infected by serotypes 1, 2, and 4 and one by serotypes 1, 3, and 4. There was no demonstrable significant difference in clinical severity between single- and multi-serotypic infections.

Conclusion: In a dengue-hyperendemic country with simultaneous circulation of all four serotypes, the phenomenon of concurrent multi-serotypic infections are more common than previously demonstrated by traditional serotyping on single serum/plasma specimens. This may be explained by the sensitivity limitation of the detection method or by biological behaviour of the virus. Our findings have an implication for potentially more accurate epidemiologic studies in the future, and for further exploratory investigations regarding dengue virus in various secretions and excretions.

Session Details

Date: 16/05/2009
Time: 00:00-00:00
Session name: 19th European Congress of Clinical Microbiology and Infectious Diseases
Location: Helsinki, Finland, 16 - 19 May 2009
Presentation type:
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