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Emerging viral pathogens in long‐term expatriates (II): dengue virus
Author(s) -
Jänisch Th.,
Preiser W.,
Berger A.,
Niedrig M.,
Mikulicz U.,
Thoma B.,
Doerr H. W.
Publication year - 1997
Publication title -
tropical medicine and international health
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.056
H-Index - 114
eISSN - 1365-3156
pISSN - 1360-2276
DOI - 10.1046/j.1365-3156.1997.d01-149.x
Subject(s) - dengue fever , dengue virus , virology , seroprevalence , virus , incidence (geometry) , antibody , flavivirus , viral disease , flaviviridae , immunology , biology , yellow fever , medicine , serology , physics , optics
Summary Dengue virus infections have been well known for many years; still dengue virus is regarded as an ‘emerging’ pathogen, as the disease profile is changing. Its geographical range and oveall incidence, and the incidence of the associated complications, dengue haemorrhagic fever (DHF) and dengue shock syndrome (DSS), are on the increse. Modern‐day travel and increasing urbanization seem to be the main contributing factors. In order to estimate the risk of infection during long‐term stays in dengue‐endemic countries, we tested sera obtained from 323 development aid workers and their family members who had spent on average 9.8 years in dengue‐endemic regions for the presence of dengue virus antibodies. 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 vaceination. We found seroprevalence rates of 4.3% with no significant differences related to gender or area of upbringing. Scroprevalence 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.