Biomedical subjects
Edward Hayes
Publications and source records attributed to Edward Hayes.
Texas lifestyle limits transmission of dengue virus.
Urban dengue is common in most countries of the Americas, but has been rare in the United States for more than half a century. In 1999 we investigated an outbreak of the disease that affected Nuevo Laredo, Tamaulipas, Mexico, and Laredo, Texas, United States, contiguous cities that straddle the international border. The incidence of recent cases, indicated by immunoglobulin M antibody serosurvey, was higher in Nuevo Laredo, although the vector, Aedes aegypti, was more abundant in Laredo. Environmental factors that affect contact with mosquitoes, such as air-conditioning and human behavior, appear to account for this paradox. We conclude that the low prevalence of dengue in the United States is primarily due to economic, rather than climatic, factors.
Immunohistochemical detection of Yersinia pestis in formalin-fixed, paraffin-embedded tissue.
Yersinia pestis infection usually is limited to lymph nodes (bubo); rarely, if bacteria are aerosolized, pneumonic plague occurs. We developed an immunohistochemical assay using a monoclonal anti-fraction 1 Y pestis antibody for formalin-fixed tissues. We studied 6 cases using this technique. Respiratory symptoms were prominent in 2 cases; histologically, one showed intra-alveolar inflammation, and the other had alveolar hemorrhage and edema. By using the immunohistochemical assay, we found intact Yersinia and granular bacterial antigen staining in alveoli, bronchi, and blood vessels. Of the remaining cases, 2 had septicemia and 2 had a bubo. Pathologic changes included lymphocyte depletion, necrosis, edema, and foamy macrophages in lymph nodes; multiple abscesses in the spleen; fibrin thrombi in glomeruli; and unremarkable lungs. By using the immunohistochemical assay, we identified intact bacteria inside monocytes and granular antigen staining in blood vessels. The immunohistochemical assay provided a fast, nonhazardous method for diagnosing plague. The immunohistochemical assay localizes bacteria, retaining tissue morphologic features, and can help define transmission mechanisms.