Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 11/12/2006
Publication Date: N/A
Interpretive Summary: None.
Technical Abstract: We established laboratory-based fever surveillance in the three clinics providing health care in Gonaives, Haiti following Hurricane Jeanne in 2004. Patients who were febrile (temperature > 38.5° C) at the time of presentation were asked to provide blood for a serum sample and thick and thin malaria smears. The attending physician completed a brief medical history, performed a physical examination of each of these patients, and indicated the discharge diagnosis and treatment. All patients were asked to return in two weeks so that a convalescent blood sample could be obtained. Malaria smears were stained and read using standard methods. To diagnose dengue, we used an IgM antibody-capture enzyme-linked immunosorbent assay (MAC ELISA) to detect anti-dengue IgM antibodies in all serum specimens. All serum specimens were also tested for the presence of anti-dengue IgG antibodies to determine previous exposure to dengue or another Flavivirus. In paired samples, a full titration of four-fold dilutions of serum specimen was used for the IgG ELISA and the end-point titration of these samples was used to assess seroconversion. To determine the presence of dengue viral RNA in acute serum samples (< 5 days post-onset of symptoms), we used both a nested polymerase chain reaction (PCR) and TaqMan assay. Because of the cross-reactivity of flavivirus antibody tests, we utilized a plaque reduction neutralization test (PRNT90) to determine the specificity of the antibody response to the infecting virus. The serum was tested against West Nile virus (WNV), St. Louis encephalitis and dengue 1-4 viruses. Of the 116 acutely febrile patients, three were diagnosed with malaria, two with acute dengue, and two with acute WNV infection. This is the first report of human WNV infections in Haiti.