Viruses acquired abroad: what does the primary care physician need to know?

Abstract

Background: Viral infections are imported by travelers and immigrants from tropical or subtropical regions. The primary care physician should be able to include these diseases in the differential diagnosis of various clinical conditions.

Methods: This review is based on pertinent articles retrieved by a selective search of the literature, including guidelines from Germany and abroad.

Results: The available data on imported viral infections in Germany constitute low-level evidence, because most such infections are not reportable in this country. Useful data have, however, been collected by international surveillance networks. Imported viral infections usually present with fever, often also with a rash and elevated transaminases. An average of 230 cases occur in Germany each year; the most common diagnosis among them is dengue fever. An imported viral infection should also be included in the differential diagnosis of fever with arthralgia, as chikungunya virus causes an average of 38 such cases per year. On the other hand, in the past two years, there have been only five cases of imported viral infections causing encephalitis (West Nile virus and Japanese encephalitis virus).

Conclusion: The primary care physician should take a thorough history so that specifically targeted laboratory tests can be ordered as soon as possible. If the suspicion of an imported viral infection is confirmed, the patient should be transferred to a specialized treatment center.

Figure 1

Transmitted cases of dengue fever in Germany 2001–2011, according to the reference definition of the Robert Koch Institute; up to date as of 4 April 2012 (see www3.rki.de/SurvStat/)

Figure 2

Dermatographism in the rash of dengue fever

Figure 3

The course of serologic findings in dengue virus infection; NS1, NS1 antigen test

Figure 4

The main area of distribution of Japanese encephalitis (2)