Emerging viral pathogens in long-term expatriates (II): dengue virus
Dengue virus antibody screening was done by a commercially available immunofluorescence test (IF). Reactive samples were re-tested by an in-house IF and also tested for cross-reactivity to yellow fever virus using yellow fever IF and neutralization test (NT). Evaluation of the results revealed that the screening test has a specificity of at least 63.2%. In 12 of 19 initially positive cases crossreacting antibodies against yellow fever virus could be ruled out. Three cases remained indeterminable, whereas four of the reactive and 10 (out of 12) of the borderline reactive cases showed crossreactivity with yellow fever virus, probably due to previous vaccination.
We found seroprevalence rates of 4.3% with no significant differences related to gender or area of upbringing. Seroprevalence rates were evaluated according to region of suspected or confirmed infection. In two cases the dengue infection had taken a classical clinical course; in another three cases an extraordinary febrile illness was reported in the history. None of the other seropositive individuals had a history of an illness possibly attributable to dengue virus infection. Our results show that there definitely is a risk for long-term expatriates to acquire (mostly non- or oligo-symptomatic) dengue infection, which might be important especially in the light of the supposed aetiology of DHF or DSS as a secondary infection with another dengue virus serotype.
Document Type: Original Article
Affiliations: 1: Institut für Medizinische Virologie, Zentrum der Hygiene, Klinikum der J. W. Goethe-Universität, Paul Ehrlich-Straße 40, 60596 Frankfurt am Main, Germany, 2: Robert Koch-Institut, Berlin, Germany, 3: Tropenmedizinische Untersuchungsstelle, Gesellschaft für Technische Zusammenarbeit (GTZ), Eschborn, Germany
Publication date: 1997-10-01