Browsing by Autor "Patricia V. Aguilar"

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Genetic Characterization of Venezuelan Equine Encephalitis Virus from Bolivia, Ecuador and Peru: Identification of a New Subtype ID Lineage
(Public Library of Science, 2009) Patricia V. Aguilar; Alexandra Adams; Víctor Suárez; Luis Beingolea; Jorge Vargas; Stephen R. Manock; Juan Freire; Willan R. Espinoza; Vidal Felices; Ana María Díaz
Venezuelan equine encephalitis virus (VEEV) has been responsible for hundreds of thousands of human and equine cases of severe disease in the Americas. A passive surveillance study was conducted in Peru, Bolivia and Ecuador to determine the arboviral etiology of febrile illness. Patients with suspected viral-associated, acute, undifferentiated febrile illness of <7 days duration were enrolled in the study and blood samples were obtained from each patient and assayed by virus isolation. Demographic and clinical information from each patient was also obtained at the time of voluntary enrollment. In 2005-2007, cases of Venezuelan equine encephalitis (VEE) were diagnosed for the first time in residents of Bolivia; the patients did not report traveling, suggesting endemic circulation of VEEV in Bolivia. In 2001 and 2003, VEE cases were also identified in Ecuador. Since 1993, VEEV has been continuously isolated from patients in Loreto, Peru, and more recently (2005), in Madre de Dios, Peru. We performed phylogenetic analyses with VEEV from Bolivia, Ecuador and Peru and compared their relationships to strains from other parts of South America. We found that VEEV subtype ID Panama/Peru genotype is the predominant one circulating in Peru. We also demonstrated that VEEV subtype ID strains circulating in Ecuador belong to the Colombia/Venezuela genotype and VEEV from Madre de Dios, Peru and Cochabamba, Bolivia belong to a new ID genotype. In summary, we identified a new major lineage of enzootic VEEV subtype ID, information that could aid in the understanding of the emergence and evolution of VEEV in South America.
Guaroa Virus Infection among Humans in Bolivia and Peru
(American Society of Tropical Medicine and Hygiene, 2010) Patricia V. Aguilar; Amy C. Morrison; Claudio Rocha; Douglas M. Watts; Luis Beingolea; Víctor Suárez; Jorge Vargas; Cristhopher D. Cruz; Carolina Guevara; Joel M. Montgomery
Guaroa virus (GROV) was first isolated from humans in Colombia in 1959. Subsequent isolates of the virus have been recovered from febrile patients and mosquitoes in Brazil, Colombia, and Panama; however, association of the virus with human disease has been unclear. As part of a study on the etiology of febrile illnesses in Peru and Bolivia, 14 GROV strains were isolated from patients with febrile illnesses, and 3 additional cases were confirmed by IgM seroconversion. The prevalence rate of GROV antibodies among Iquitos residents was 13%; the highest rates were among persons with occupations such as woodcutters, fisherman, and oil-field workers. Genetic characterization of representative GROV isolates indicated that strains from Peru and Bolivia form a monophyletic group that can be distinguished from strains isolated earlier in Brazil and Colombia. This study confirms GROV as a cause of febrile illness in tropical regions of Central and South America.
Ilheus Virus Infection in Human, Bolivia
(Centers for Disease Control and Prevention, 2012) Erika A. Venegas; Patricia V. Aguilar; Cristhopher D. Cruz; Carolina Guevara; Tadeusz J. Kochel; Jorge Vargas; Eric S. Halsey
To the Editor: Ilheus virus (ILHV) was first isolated from mosquitoes of the genera Ochlerotatus and Psorophora near Ilheus, Bahia, Brazil, in 1944 (1). After its discovery, the virus was also isolated from other mosquito species, including the genera Culex, Sabethes, Haemagogus, and Trichoprosopon, and from a variety of birds in different countries in Latin America (2). Only a few reports describe isolation of this virus from humans in Central and South America with symptoms ranging from subclinical to severe febrile disease (2–6). In mild cases, patients often reported gastrointestinal or respiratory symptoms lasting ≈1 week. In severe cases, either the central nervous or cardiac system can be affected. However, long-term sequelae or deaths have not been described. No epidemics attributed to ILHV have been reported. In November 2005, a 15-year-old boy (farmer) sought medical attention in a health clinic in Magdalena, Bolivia, after having fever for 5 days. The patient’s symptoms included malaise, asthenia, conjunctival injection, vesicular rash, facial edema, arthralgia, myalgias, bone pain, abdominal pain, headache, and earache. Signs of cardiac, neurologic, or renal damage were not detected. A blood specimen was obtained during the clinic visit, and a convalescent-phase sample was obtained 24 days after onset of symptoms. At that follow-up visit, the patient reported a full recovery from his symptoms. Both samples were sent to the Naval Medical Research Unit No. 6 in Lima, Peru, for processing as part of a clinic-based study to determine the etiology of febrile illnesses in Bolivia (7). The study was approved by the Naval Medical Research Unit No. 6 Institutional Review Board (Navy Medical Research Center Detachment 2000.0008) and conducted in collaboration with the Bolivia Ministry of Health. Serologic analyses showed a 64-fold IgM seroconversion between the acute-phase (<100) and convalescent-phase samples (6,400) by using an IgM ELISA as described (8). Samples were also tested by ELISA for the following arboviruses: West Nile virus, dengue virus, Oropouche virus, Guaroa virus, Rocio virus, St. Louis encephalitis virus, yellow fever virus, Venezuelan equine encephalitis virus, and Mayaro virus. All test results were negative for these viruses. Virus isolation was attempted on the acute-phase serum sample by using Vero and C6/36 cells, but the culture did not yield any virus. Attempts to isolate virus by intracranial inoculation in suckling mice were also unsuccessful (University of Texas Medical Branch, Institutional Animal Care and Use Committee protocol 9505045). Viral RNA was extracted from the acute-phase sample and reverse transcription PCR specific for a portion of the nonstructural protein 5 gene was performed by using a described method (9). A 189-bp PCR product was obtained, purified, and sequenced by using flavivirus primers FU1 and cFD2 (9) and further analyzed by using BLAST (www.ncbi.nlm.nih.gov/blast), resulting in ≈95% homology to ILHV. Phylogenetic analysis with neighbor-joining and parsimony methods grouped the nucleotide sequence of the ILHV virus from Bolivia with ILHV strains from Ecuador and Peru (Figure). Figure Phylogenetic analysis of the nonstructural protein 5 (NS5) gene region of 7 Ilheus virus isolates and a 189-bp nt sequence (FMB 202 Bolivia). Alignments were analyzed by using the neighbor-joining method with the Kimura 2-parameter algorithm in MEGA5 ... Magdalena is a tropical city in northern Bolivia that borders Brazil. The city is surrounded by rivers and chestnut fields, and agriculture and fishing are the main sources of employment. Despite having ecoepidemiologic conditions similar to those in other locations with a history of ILHV transmission, the virus had not been detected in the area. The patient had no travel history in the 30 days preceding his illness, indicating that the virus is probably endemic to the area. Mild unspecific symptoms, a short viremic period, and lack of advanced confirmatory laboratory techniques in situ are some of the barriers impeding the diagnosis of ILHV in disease-endemic areas. High levels of antibody cross-reactivity among flaviviruses, which are also endemic to the area, might render diagnosis even more difficult. The presence of the main ILHV vector, Psorophora sp. mosquitoes, in the city suggests that much of the population that labors outdoors may be at risk for ILHV infection.
Reemergence of Bolivian Hemorrhagic Fever, 2007–2008
(Centers for Disease Control and Prevention, 2009) Patricia V. Aguilar; Wilfredo Camargo; Jorge Vargas; Carolina Guevara; Yelin Roca; Vidal Felices; V. Alberto Laguna-Torres; Robert B. Tesh; Thomas G. Ksiazek; Tadeusz J. Kochel
age.In particular, suspected childhood TB patients without an identifiable TB contact and with normal immune status were subjected to further investigations.Multidisciplinary management, including enhanced laboratory diagnosis of atypical bony lesions in infants and children, is recommended for any suspected TB infection.Once BCGrelated infection is confirmed, medical treatment has to be consistent.