Browsing by Autor "Carolina Guevara"

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Arboviral Etiologies of Acute Febrile Illnesses in Western South America, 2000–2007
(Public Library of Science, 2010) Brett M. Forshey; Carolina Guevara; V. Alberto Laguna-Torres; Manuel Céspedes; Jorge Vargas; Alberto Gianella; Efraín Vallejo; César Madrid; Nicolás Aguayo; Eduardo Gotuzzo
Our data provide a better understanding of the geographic range of arboviruses in South America and highlight the diversity of pathogens in circulation. These arboviruses are currently significant causes of human illness in endemic regions but also have potential for further expansion. Our data provide a basis for analyzing changes in their ecology and epidemiology.
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.
Novel Strain of Andes Virus Associated with Fatal Human Infection, Central Bolivia
(Centers for Disease Control and Prevention, 2012) Cristhopher D. Cruz; Brett M. Forshey; Efraín Vallejo; Roberto Agudo; Jorge Vargas; David L. Blazes; Carolina Guevara; V. Alberto Laguna-Torres; Eric S. Halsey; Tadeusz J. Kochel
To better describe the genetic diversity of hantaviruses associated with human illness in South America, we screened blood samples from febrile patients in Chapare Province in central Bolivia during 2008-2009 for recent hantavirus infection. Hantavirus RNA was detected in 3 patients, including 1 who died. Partial RNA sequences of small and medium segments from the 3 patients were most closely related to Andes virus lineages but distinct (<90% nt identity) from reported strains. A survey for IgG against hantaviruses among residents of Chapare Province indicated that 12.2% of the population had past exposure to >1 hantaviruses; the highest prevalence was among agricultural workers. Because of the high level of human exposure to hantavirus strains and the severity of resulting disease, additional studies are warranted to determine the reservoirs, ecologic range, and public health effect of this novel strain of hantavirus.
Primer aislamiento y caracterización de la cepa prototipo del virus SARS-CoV-2 a inicios de la pandemia de la COVID-19 en el Perú
(National University of San Marcos, 2023) María Mendoza; Miryam Palomino; Marcos Hernández; Pamela Rios; Maribel Huaringa; Carolina Guevara; Jannet Otárola; Carlos Padilla; Orson Mestanza; Ronnie G. Gavilán
Introduction: Currently, infections by the SARS-CoV-2 virus exceed 600 million cases in the world. Objective: Isolation and characterization of the SARS-CoV-2 virus causing COVID-19 at the beginning of the pandemic in Peru. Materials and methods: Twenty nasal and pharyngeal swab samples were isolated SARS-CoV-2 using two cell lines, Vero ATCC CCL-81 and Vero E-6; virus identification was performed by RT-PCR and the onset of cytopathic effect (CPE) was evaluated by indirect immunofluorescence and subsequent identification by genomic sequencing. One of the most widely circulating isolates was selected and named the prototype strain (PE/B.1.1/28549/2020). Then 10 successive passages were performed in Vero ATCC CCL-81 cells to assess mutation dynamics. Results: Results detected 11 virus isolates by cytopathic effect, and subsequently confirmed by RT-PCR and indirect immunofluorescence. Of these, six were sequenced and identified as the lineages B.1, B.1.1, B.1.1.1, and B.1.205 according to the Pango lineage nomenclature. The prototype strain corresponded to lineage B.1.1. The analysis of the strains from the successive passages showed mutations mainly at in the spike (S) protein of the virus without variation in the identity of the lineage. Conclusions: Four lineages were isolated in the Vero ATCC CCL-81 cell line. Subcultures in the same cell line show mutations in the spike protein indicating greater adaptability to the host cell and variation in pathogenicity in vitro, a behavior that allows it to have more survival success.
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.