Prevalence and risk factors for encephalomyocarditis virus infection in Peru.

Although encephalomyocarditis virus (EMCV) infection has been commonly documented among domestic animals, less is known about EMCV transmission among humans. Recently, we described the isolation of EMCV from two febrile patients in Peru. To further investigate EMCV transmission in Peru, we screened febrile patients reporting to health clinics in Peru for serological evidence of recent EMCV infection. We also conducted a serological survey for EMCV-neutralizing antibodies in the city of Iquitos, located in the Amazon basin department of Loreto, Peru. Additionally, we screened serum from rodents collected from 10 departments in Peru for evidence of EMCV exposure. EMCV infection was found to be only rarely associated with acute febrile disease in Peru, accounting for <1% of febrile episodes analyzed. Despite the low acute disease burden associated with the virus, human exposure was quite common, as prevalence of EMCV-neutralizing antibodies ranged between 6.0% in the coastal city of Tumbes and >17% in cities in the tropical rainforest of northeastern Peru (Iquitos and Yurimaguas). On the basis of the serological survey conducted in Iquitos, risk factors for past infection include increased age, socioeconomic indicators such as residence construction materials and neighborhood, and swine ownership. Evidence from the rodent survey indicates that EMCV exposure is common among Murinae subfamily rodents in Peru (9.4% EMCV IgG positive), but less common among Sigmodontinae rodents (1.0% positive). Further studies are necessary to more precisely delineate the mode of EMCV transmission to humans, other potential disease manifestations, and the economic impact of EMCV transmission among swine in Peru.

Epidemiology of spotted fever group and typhus group rickettsial infection in the Amazon basin of Peru.

A seroprevalence study for IgG antibodies against spotted fever group (SFGR) and typhus group (TGR) Rickettsia among humans and domestic pets was conducted in the city of Iquitos, located in the Amazon basin of Peru. Of 1,195 human sera analyzed, 521 (43.6%) and 123 (10.3%) were positive for SFGR and TGR antibodies, respectively. District of residence and participant age were associated with antibody positivity for both groups, whereas rodent sightings in the home were associated with TGR antibody positivity. Of the 71 canines tested, 42 (59.2%) were positive for SFGR antibodies, and two (2.8%) were positive for TGR antibodies; one active SFGR infection was detected by polymerase chain reaction. An uncharacterized SFGR species was detected in 95.9% (71/74) of Ctenocephalides felis pools collected from domestic pets. These data suggest that rickettsial transmission is widespread in Iquitos. Rickettsia species should be further explored as potential causes of acute febrile illnesses in the region.

Venezuelan equine encephalitis virus in Iquitos, Peru: urban transmission of a sylvatic strain.

Enzootic strains of Venezuelan equine encephalitis virus (VEEV) have been isolated from febrile patients in the Peruvian Amazon Basin at low but consistent levels since the early 1990s. Through a clinic-based febrile surveillance program, we detected an outbreak of VEEV infections in Iquitos, Peru, in the first half of 2006. The majority of these patients resided within urban areas of Iquitos, with no report of recent travel outside the city. To characterize the risk factors for VEEV infection within the city, an antibody prevalence study was carried out in a geographically stratified sample of urban areas of Iquitos. Additionally, entomological surveys were conducted to determine if previously incriminated vectors of enzootic VEEV were present within the city. We found that greater than 23% of Iquitos residents carried neutralizing antibodies against VEEV, with significant associations between increased antibody prevalence and age, occupation, mosquito net use, and overnight travel. Furthermore, potential vector mosquitoes were widely distributed across the city. Our results suggest that while VEEV infection is more common in rural areas, transmission also occurs within urban areas of Iquitos, and that further studies are warranted to identify the precise vectors and reservoirs involved in urban VEEV transmission.

Uso de insecticidas: contexto y consecuencias ecológicas / Insecticide use: context and ecological consequences

Las restricciones de la sostenibilidad acerca del uso de insecticidas incluyen los efectos en la salud humana, los ecosistemas agrícolas (ejemplo, los insectos beneficiosos), el medio ambiente, en su sentido más amplio (por ejemplo, las especies que no son el objetivo, paisajes y comunidades) y la selección de los rasgos que confieren la resistencia a los insecticidas. Es posible encontrar ejemplos donde los insecticidas han tenido un impacto desastroso en todas aquellas variables y otros ejemplos donde los peligros que representaban han sido mitigados (por accidente o por diseño). En esta revisión examinamos lo que en la actualidad se puede concluir sobre el impacto de campo directo e indirecto y de largo plazo de los insecticidas en el medio ambiente. Proporcionamos ejemplos específicos, describimos los patrones actuales del uso de insecticidas, consideramos los contextos donde se usan los insecticidas y discutimos el papel de los reglamentos y leyes a fin de mitigar el riesgo. Discutimos cómo el uso de los insecticidas está cambiando como resultado de una mayor conciencia ambiental e inevitablemente, mientras discutimos las principales restricciones del uso de los insecticidas, también sugerimos por qué no se pueden descartar tan fácilmente.

Constraints to the sustainability of insecticide use include effects on human health, agroecosystems (e.g., beneficial insects), the wider environment (e.g., non-target species, landscapes and communities) and the selection of insecticide resistant traits. It is possible to find examples where insecticides have impacted disastrously on all these variables and others where the hazards posed have been (through accident or design) ameliorated. In this review, we examine what can currently be surmised about the direct and indirect long-term, field impacts of insecticides upon the environment. We detail specific examples, describe current insecticide use patterns, consider the contexts within which insecticide use occurs and discuss the role of regulation and legislation in reducing risk. We consider how insecticide use is changing in response to increasing environmental awareness and inevitably, as we discuss the main constraints to insecticide use, we suggest why they cannot easily be discarded.

Resultados postmórtem e infecciones oportunistas en pacientes VIH positivos de un hospitalpúblico del Perú / Postmortem findings and opportunistic infections in HIV-positive patients from a public hospital in Peru

Existen pocos estudios que reporten datos acerca de autopsias de pacientes con VIH en Sudamérica y ninguno que documente los resultados post mórtem en los pacientes con VIH/SIDA en el Perú. Objetivos: Determinar el espectro de las infecciones oportunistas y las causas de mortalidad en pacientes VIH-positivos en un hospital público en Lima. Asimismo, se revisa la información clínico-epidemiológica con respecto a la infección con VIH en el Perú. Materiales y métodos: Se incluyeron en este análisis retrospectivo, 16 autopsias relacionadas con VIH del Hospital Dos de Mayo, realizadas entre 1999-2004. Resultados: La causa primaria de la muerte fue establecida en 12 pacientes: uno murió de neoplasia y 11 de enfermedades infecciosas, incluyendo tres con infección pulmonar, siete con infección diseminada, y dos con infección del sistema nervioso central (un caso presentó patología dual). Las infecciones oportunistas fueron identificadas en 14 casos, incluyendo citomegalovirus, histoplasmosis, criptococcosis, toxoplasmosis, neumonía por Pneumocistis, aspergilosis, tuberculosis, virus de la varicela-zoster y criptosporidiosis. Catorce pacientes tenían por lo menos una enfermedad relacionada con el SIDA que no había sido sospechada clínicamente ni diagnosticada antes de la muerte. Por otra parte, 82% de los diagnósticos considerados de significancia clínica importante, no habían sido sospechados antes de la muerte. Conclusiones: El espectro y la frecuencia de ciertas infecciones oportunistas reportadas en el presente estudio lo diferencia de otros estudios de autopsias realizados en Sudamérica; destacando la importancia de realizar necropsias en VIH/SIDA en países de recursos limitados, con el fin de observar los patrones locales específicos de la enfermedad.

There is a paucity of HIV autopsy data from South America and none that document the postmortem findings in patients with HIV/AIDS in Peru. Objectives: The purpose of this autopsy study was to determine the spectrum of opportunistic infections and the causes of mortality in HIV-positive patients at a public hospital in Lima. Material and methods: Clinico-epidemiological information regarding HIV infection in Peru is also reviewed. Sixteen HIV-related hospital postmortems, performed between 1999-2004, were included in this retrospective analysis. Results: The primary cause of death was established in 12 patients: one died of neoplasia and 11 of infectious diseases, including 3 from pulmonary infection, 7 from disseminated infection, and 2 from central nervous system infection (one case had dual pathology). Opportunistic infections were identified in 14 cases, comprising cytomegalovirus, histoplasmosis, cryptococcosis, toxoplasmosis, Pneumocystis pneumonia, aspergillosis, tuberculosis, varicella zoster virus and cryptosporidiosis. Fourteen patients had at least one AIDS-related disease that had been neither clinically suspected nor diagnosed premortem. Moreover, 82% of the diagnoses deemed of important clinical significance, had not been suspected antemortem. Conclusions: The spectrum and frequency of certain opportunistic infections differed from other South American autopsy studies, highlighting the importance of performing HIV/AIDS postmortems in resource-limited countries where locallyspecific disease patterns may be observed.

Postmortem findings and opportunistic infections in HIV-positive patients from a public hospital in Peru.

There is a paucity of HIV autopsy data from South America and none that document the postmortem findings in patients with HIV/AIDS in Peru. The purpose of this autopsy study was to determine the spectrum of opportunistic infections and the causes of mortality in HIV-positive patients at a public hospital in Lima. Clinico-epidemiological information regarding HIV infection in Peru is also reviewed. Sixteen HIV-related hospital postmortems, performed between 1999 and 2004, were included in this retrospective analysis. The primary cause of death was established in 12 patients: one died of neoplasia and 11 of infectious diseases, including 3 from pulmonary infection, 7 from disseminated infection, and 2 from central nervous system infection (one case had dual pathology). Opportunistic infections were identified in 14 cases, comprising cytomegalovirus, histoplasmosis, cryptococcosis, toxoplasmosis, Pneumocystis pneumonia, aspergillosis, tuberculosis, varicella zoster virus, and cryptosporidiosis. Fourteen patients had at least one AIDS-related disease that had been neither clinically suspected nor diagnosed premortem. Moreover, 82% of the diagnoses considered to be of important clinical significance had not been suspected antemortem. The spectrum and frequency of certain opportunistic infections differed from other South American autopsy studies, highlighting the importance of performing HIV/AIDS postmortems in resource-limited countries where locally specific disease patterns may be observed.

Helicobacter pylori-associated chronic atrophic gastritis involving the gastric body and severe disease by Vibrio cholerae.

Evidence has associated chronic infection by Helicobacter pylori with chronic gastritis, low gastric acid production and an increased risk of life-threatening cholera. However, the relationship of specific patterns of histological damage in the gastric mucosa associated with H. pylori infection and the occurrence of cholera has not been described. The purpose of this study was to compare the gastric pH and histopathological findings in gastric biopsies taken from patients with severe diarrhoeal disease due to Vibrio cholerae with those taken from a control (cholera-negative) population. Thirty-five H. pylori-positive patients who had severe dehydration from culture-confirmed cholera (cases) and 40 patients with H. pylori but with no history of cholera (controls) were recruited. Gastric pH was measured and multiple biopsies were taken from the gastric antrum and body for histopathological examination. The results revealed that patients with severe cholera had a significantly higher prevalence of hypochlorhydria at endoscopy compared with controls. Furthermore, cases had significantly more chronic atrophic gastritis (45.7% vs. 12.5%; P=0.002) and intestinal metaplasia (37.1% vs. 2.5%; P<0.01) in the gastric body than controls. Our findings suggest that the nature and location of these gastric lesions may predispose a subset of H. pylori-infected individuals to severe disease by V. cholerae.