Abstract. Autochthonous dengue virus transmission has occurred in the continental United States with increased frequency during the last decade; the principal vector, Aedes aegypti, has expanded its geographic distribution in the southern United States. Dengue, a potentially fatal arboviral disease, is underreported, and US clinicians encountering patients with acute febrile illness consistent with dengue are likely to not be fully familiar with dengue diagnosis and management. Recently, investigators suggested that an outbreak of dengue likely occurred in Houston during 2003 based on retrospective laboratory testing of hospitalized cases with encephalitis and aseptic meningitis. Although certain aspects of the Houston testing results and argument for local transmission are doubtful, the report highlights the importance of prospective surveillance for dengue in Aedes-infested areas of the United States, the need for clinical training on dengue and its severe manifestations, and the need for laboratory testing in domestic patients presenting with febrile neurologic illness in these regions to include dengue.Dengue is an arboviral disease of major public health significance caused by four serologically related flaviviruses, dengue viruses (DENVs 1-4), with an expanding worldwide distribution.1 Although many DENV infections are asymptomatic, classic clinical dengue manifests as an acute febrile illness, with symptoms that include headache, retro-orbital pain, myalgia, arthralgia, and rash. Clinical dengue is usually a self-limited illness of about 1 week's duration, but severe illness can occur in both healthy persons and those with other underlying diseases. A relatively small percentage (approximately 10%) of persons with clinical dengue progresses to severe disease because of plasma leakage, which can lead to decompensated shock and death if not carefully managed with appropriate fluid therapy. Most patients requiring hospitalization for dengue have severe disease or complications related to underlying comorbid disease. DENVs seem to be less neurotropic than other flaviviruses, such as West Nile virus, St. Louis encephalitis virus, and Japanese encephalitis virus. DENV-associated neurologic disease, including neuroinvasive disease, has been rarely documented by isolation of virus and detection of DENV-specific immunoglobulin M (IgM) antibody in cerebrospinal fluid (CSF) or brain tissue. In Viet Nam, about 1% of patient hospitalizations with suspected dengue had encephalitis or aseptic meningitis syndromes.
2Another study in Viet Nam found that 0.5% of children admitted for dengue hemorrhagic fever (DHF), which is a subset of severe dengue, had serologically confirmed DENV infection with encephalopathy, although rates of dengue-associated neurologic diseases as high as 21% have been reported.
3,4The most efficient vector for DENV is Aedes aegypti, which is present in limited areas of the southern United States, but its current geographic distribution is not well-documented. Ae. albopictus is a less efficient tran...