Browsing by Autor "James G. Olson"

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Evidence of rickettsial spotted fever and ehrlichial infections in a subtropical territory of Jujuy, Argentina.
(American Society of Tropical Medicine and Hygiene, 1999) C.M. Ripoll; Carlos Remondegui; G Ordóñez; R Arazamendi; H Fusaro; M J Hyman; Christopher D. Paddock; Sherif R. Zaki; James G. Olson; Charles A. Santos-Buch
Between November 1993 and March 1994, a cluster 6 pediatric patients with acute febrile illnesses associated with rashes was identified in Jujuy Province, Argentina. Immunohistochemical staining of tissues confirmed spotted fever group rickettsial infection in a patient with fatal disease, and testing of serum of a patient convalescing from the illness by using an indirect immunofluorescence assay (IFA) demonstrated antibodies reactive with spotted fever group rickettsiae. A serosurvey was conducted among 16 households in proximity to the index case. Of 105 healthy subjects evaluated by IFA, 19 (18%) demonstrated antibodies reactive with rickettsiae or ehrlichiae: 4 had antibodies reactive with Rickettsia rickettsii, 15 with Ehrlichia chaffeensis, and 1 with R. typhi. Amblyomma cajennense, a known vector of R. rickettsii in South America, was collected from pets and horses in the area. These results are the first to document rickettsial spotted fever and ehrlichial infections in Argentina.
Hantavirus Pulmonary Syndrome in Santa Cruz, Bolivia: Outbreak Investigation and Antibody Prevalence Study
(Public Library of Science, 2012) Joel M. Montgomery; Patrick J. Blair; Darin S. Carroll; James N. Mills; Alberto Gianella; Naomi Iihoshi; Ana M. Briggiler; Vidal Felices; Milagros Salazar; James G. Olson
We report the results of an investigation of a small outbreak of hantavirus pulmonary syndrome in 2002 in the Department of Santa Cruz, Bolivia, where the disease had not previously been reported. Two cases were initially reported. The first case was a physician infected with Laguna Negra virus during a weekend visit to his ranch. Four other persons living on the ranch were IgM antibody-positive, two of whom were symptomatic for mild hantavirus pulmonary syndrome. The second case was a migrant sugarcane worker. Although no sample remained to determine the specific infecting hantavirus, a virus 90% homologous with Río Mamoré virus was previously found in small-eared pygmy rice rats (Oligoryzomys microtis) trapped in the area. An antibody prevalence study conducted in the region as part of the outbreak investigation showed 45 (9.1%) of 494 persons to be IgG positive, illustrating that hantavirus infection is common in Santa Cruz Department. Precipitation in the months preceding the outbreak was particularly heavy in comparison to other years, suggesting a possible climatic or ecological influence on rodent populations and risk of hantavirus transmission to humans. Hantavirus infection appears to be common in the Santa Cruz Department, but more comprehensive surveillance and field studies are needed to fully understand the epidemiology and risk to humans.
Molecular epidemiology of dengue virus type 3 in Northern South America: 2000–2005
(Elsevier BV, 2008) Tadeusz J. Kochel; Patricia Aguilar; Vidal Felices; Guillermo Comach; Cristhopher D. Cruz; Aracely Alava; Jorge Vargas; James G. Olson; Patrick J. Blair