Virus Isolation for Diagnosing Dengue Virus Infections in Returning Travelers

Abstract

Dengue fever is recognized as one of the most frequent imported acute febrile illnesses affecting European tourists returning from the tropics. In order to assess the value of virus isolation for the diagnosis of dengue fever, 70 cases of dengue fever confirmed in German travelers during the period 1993-2001 were analyzed retrospectively. In 26 patients who had developed acute febrile illness within 2 weeks following their return from a trip to a dengue-endemic area, 9 of 13 attempts to isolate the virus were successful in sera drawn 1-5 days and 2 of 13 sera drawn 6-10 days after the onset of illness. DEN-1 was the most frequent serotype isolated. If performed early, virus isolation is a reliable tool for detecting dengue virus in returning travelers.

Evaluation of the use of RT-PCR for the early diagnosis of dengue fever

“…Keywords Candida albicans, Candida krusei, chlorhexidine, chloroxylenol, impregnated devices, rabbit model Candida spp. are recognised increasingly as important causes of infection associated with medical devices [1]. Recent surveillance data from 49 hospitals indicated that Candida spp.…”

“…Dengue fever (DF) is among the most important arthropod‐borne virus diseases in terms of human morbidity and mortality. The spectrum of this disease, caused by the four distinct dengue virus serotypes, DEN‐1 to DEN‐4, ranges from a self‐limiting febrile illness (DF) to dengue haemorrhagic fever/dengue shock syndrome (DHF/DSS) [1]. With c. 2.5 billion people living in endemic areas, there are 50–100 million cases of dengue fever and 250 000–500 000 cases of DHF/DS with 24 000 deaths, annually [2].…”

“…Travel destinations were South-east Asia (Thailand, n = 14; Indonesia, n = 1; Philippines, n = 1), the Indian subcontinent (India, n = 4; Sri Lanka, n = 1), Central America (El Salvador, n = 1; Nicaragua, n = 1), South America (Venezuela ⁄ Colombia, n = 1), Pacific Islands (Cook Islands, n = 1) and West Africa (Ghana, n = 1). Diagnosis of dengue fever was confirmed serologically by paired sera [1] in all cases. Table 1 summarises the RT-PCR results, grouped according to the day of illness when the diagnostic specimen was obtained.…”

“…Clinical observation is the key to case identification, but diagnosis by virus-specific antibody determination is crucial for confirmation and differentiation among the different dengue virus serotypes [1]. The existence of cross-reactive antigenic determinants shared by all four dengue virus serotypes and other flaviviruses means that the most precise serological diagnosis that can be offered by many laboratories is 'acute flavivirus infection', rather than 'acute dengue infection' [1]. It has been shown that direct detection and typing of dengue virus in serum using RT-PCR or culturing techniques yields the most reliable direct evidence of infection.…”

“…This approach cannot provide live virus for further biological characterisation, and its sensitivity appears to vary between serotypes and protocols [8]. However, although isolation and typing of dengue virus might be considered to be the reference standard, it also has a small window of opportunity for detection [1], and modified RT-PCR protocols have yielded better results than virus isolation in some settings [9]. With the possibility of using quantitative RT-PCR to estimate the risk of an individual progressing towards DHF, the role of this technique may increase in the future [10].…”