Clustering of Necropsy-Confirmed Porcine Cysticercosis Surrounding Taenia solium Tapeworm Carriers in Peru.

The pork tapeworm, Taenia solium, is among the leading causes of preventable epilepsy in the world and is common in rural areas of developing countries where sanitation is limited and pigs have access to human feces. Prior studies in rural villages of Peru have observed clusters of T. solium cysticercosis among pigs that live near human tapeworm carriers. Such spatial analyses, however, have been limited by incomplete participation and substandard diagnostic tests. In this study, we evaluated the association between necropsy-confirmed cysticercosis in pigs and their distance to T. solium tapeworm carriers in six villages in northern Peru. A total of six (1.4%) tapeworm carriers were detected using copro-antigen enzyme-linked immunosorbent assay and seven of 10 (70%) pigs belonging to the tapeworm carriers were found with viable cyst infection on necropsy. This was significantly greater than the prevalence of viable cyst infection among pigs living < 500 m (11%) and > 500 m (0.5%) from a tapeworm carrier (P < 0.001 for distance trend). Similar statistically significant prevalence gradients were observed after adjustment for possible confounders and for other pig-level outcomes including infection with > 10 viable cysts, degenerated cyst infection, and serological outcomes. This investigation confirms that porcine cysticercosis clusters strongly around tapeworm carriers in endemic rural regions of northern Peru and supports interventions that target these hotspots.

A qualitative socio-ecological characterization of the plague threat at Hermelinda Market, La Libertad, Peru

[ABSTRACT]. Objective. To identify 1) the main determinants of persistent Yersinia pestis circulation and the associated threat of plague at Hermelinda Market—a large farmers’ market in the city of Trujillo, La Libertad, Peru—and the main actions taken against it, as perceived by local stakeholders; 2) the level of plague risk perception among local actors; and 3) recommended actions to solve the plague threat at the market. Methods. A conceptual framework was developed combining a social determinants approach with a complex systems-thinking framework and a knowledge management perspective. A four-step qualitative protocol was carried out (literature review; stakeholder mapping; 37 semi-structured interviews; and coding/analysis). In the fourth step, the data collected in the semi-structured interviews were coded for eight social determinants of health (SDH) variables and analyzed with ATLAS.ti®, and an emerging category analysis was performed to identify risk perception levels. Results. Based on analysis by SDH variable, the three main determinants of the plague threat at Hermelinda Market were: 1) local (Trujillo City) governance, 2) infrastructure and basic services, and 3) local culture. According to the same analysis, actions most frequently undertaken against plague involved 1) infrastructure and basic services, 2) social vigilance, and 3) communication. The emerging category analysis indicated local risk perception levels were low, with most of the data pointing to “unhygienic” (“naturalized”) lifestyles and a general lack of awareness about the disease prior to plague-related health concerns at the market as the cause. Conclusions. The results indicate that the persistent circulation of Yersinia pestis at Hermelinda Market is not simply a technical matter but more of a managerial and cultural problem. As local governance was found to be a main factor in the persistence of this public health threat, future efforts against it should focus on sustainable inter-sectoral planning and education. Actions taken exclusively by the health sector and the improvement of infrastructure and basic services alone will not be enough to reduce the threat of plague at the market.

[RESUMEN]. Objetivo. Establecer: 1) los principales determinantes de la circulación persistente de Yersinia pestis y la amenaza asociada de peste en el mercado La Hermelinda, un gran mercado de agricultores en la ciudad de Trujillo, Departamento de La Libertad en Perú, y las medidas más adecuadas para combatir la bacteria, según la percepción de los interesados directos locales; 2) el grado de percepción del riesgo de peste entre los actores locales; y 3) las medidas recomendadas para resolver la amenaza de peste en el mercado. Métodos. Se elaboró un marco conceptual que combinaba un enfoque de determinantes sociales con un complejo marco de pensamiento sistémico y una perspectiva de gestión del conocimiento. Se llevó a cabo un protocolo cualitativo de cuatro pasos (revisión bibliográfica; mapeo de interesados directos; 37 entrevistas semiestructuradas y codificación y análisis). En el cuarto paso, los datos recopilados en las entrevistas semiestructuradas fueron codificados conforme a ocho variables de los determinantes sociales de la salud y analizados con el programa ATLAS.ti ®, y luego se realizó un análisis de las categorías emergentes para establecer los grados de percepción del riesgo. Resultados. Sobre la base del análisis de las variables de los determinantes sociales de la salud, los tres principales determinantes de la amenaza de peste en el mercado La Hermelinda fueron: 1) la gobernanza local (Ciudad de Trujillo), 2) la infraestructura y los servicios básicos y 3) la cultura local. Según el mismo análisis, las acciones emprendidas con mayor frecuencia contra la peste se vincularon con 1) la infraestructura y los servicios básicos, 2) la vigilancia social y 3) la comunicación. El análisis de las categorías emergentes indicó que los grados locales de percepción del riesgo fueron bajos y la mayoría de los datos apuntaron como causas a los modos de vida “antihigiénicos” (“naturalizados”) y a una falta general de concientización acerca de la enfermedad antes de la preocupación acerca de la salud relacionada con la peste en el mercado. Conclusiones. Los resultados indican que la circulación persistente de Yersinia pestis en el mercado La Hermelinda no es sencillamente un asunto técnico sino sobre todo un problema cultural y de gestión. Como se encontró que la gobernanza local era un factor importante en la persistencia de esta amenaza a la salud pública, las actividades futuras para combatirla deben centrarse en la planificación y la educación intersectoriales sostenibles. Las medidas adoptadas exclusivamente por el sector de la salud y el mejoramiento de la infraestructura y los servicios básicos por sí solos no serán suficientes para reducir la amenaza de la peste en el mercado.

[RESUMO]. Objetivo. Identificar 1) os principais determinantes da circulação persistente de Yersinia pestis e o risco associado de ocorrência da peste no Mercado Hermelinda, um grande mercado de produtos agrícolas no município de Trujillo, La Libertad, Peru, e as principais medidas adotadas para enfrentar esta situação, segundo a percepção dos interessados diretos locais, 2) o nível de percepção do risco de ocorrência da peste entre os atores locais e 3) as ações recomendadas para eliminar o risco de ocorrência da peste no mercado. Métodos. Foi desenvolvida uma estrutura conceitual formada pela combinação de um enfoque de determinantes sociais, um enquadramento complexo de reflexão sistêmica e uma perspectiva de gestão do conhecimento. Foi conduzido um protocolo qualitativo de quatro etapas (revisão literária, mapeamento de interessados diretos, 37 entrevistas semiestruturadas e codificação/análise). Na quarta etapa, os dados coletados nas entrevistas semiestruturadas foram codificados para oito variáveis de determinantes sociais da saúde (DSS) e analisados com o programa ATLAS.ti®. Uma análise de categorias emergentes foi realizada para identificar os níveis de percepção de risco. Resultados. A partir da análise segundo as variáveis de DSS, os três principais determinantes do risco de ocorrência da peste no Mercado Hermelinda foram: 1) governança local (município de Trujillo), 2) infraestrutura e serviços básicos e 3) cultura local. Segundo a mesma análise, as medidas adotadas com maior frequência para evitar a peste foram: 1) infraestrutura e serviços básicos, 2) vigilância social e 3) comunicação. A análise de categorias emergentes indicou que o nível de percepção local do risco de ocorrência era baixo, sendo que a maioria dos dados apontou como causa hábitos de vida anti-higiênicos (“naturalizados”) e falta geral de consciência da doença anterior às preocupações de saúde relacionadas com a peste no mercado. Conclusões. Os resultados do estudo indicam que a circulação persistente de Yersinia pestis no Mercado Hermelinda não é simplesmente uma questão técnica, sendo mais um problema administrativo e cultural. Verificou-se que a governança local é um dos principais fatores para a persistência desta ameaça à saúde pública e os esforços futuros devem visar o planejamento intersetorial sustentável e a educação. Medidas adotadas exclusivamente pelo setor da saúde e a melhoria da infraestrutura e serviços básicos por si só não serão suficientes para reduzir o risco de ocorrência da peste no mercado.

Prevalence, Age Profile, and Associated Risk Factors for Hymenolepis nana Infection in a Large Population-Based Study in Northern Peru.

Hymenolepis nana, the dwarf tapeworm, is a common intestinal infection of children worldwide. We evaluated infection and risk factor data that were previously collected from 14,761 children aged 2-15 years during a large-scale program in northern Peru. We found that 1,124 of 14,761 children (7.61%) had H. nana infection, a likely underestimate given that only a single stool sample was examined by microscopy for diagnosis. The strongest association with infection was lack of adequate water (adjusted prevalence ratio [aPR] 2.22, 95% confidence interval [CI] 1.82-2.48) and sanitation infrastructure in the house (aPR 1.94, 95% CI 1.64-2.29). One quarter of those tested did not have a bathroom or latrine at home, which doubled their likelihood of infection. Similarly, one quarter did not have piped public water to the house, which also increased the likelihood of infection. Continued efforts to improve access to basic water and sanitation services will likely reduce the burden of infection in children for this and other intestinal infections.

A qualitative socio-ecological characterization of the plague threat at Hermelinda Market, La Libertad, Peru.

OBJECTIVE: To identify 1) the main determinants of persistent Yersinia pestis circulation and the associated threat of plague at Hermelinda Market-a large farmers' market in the city of Trujillo, La Libertad, Peru-and the main actions taken against it, as perceived by local stakeholders; 2) the level of plague risk perception among local actors; and 3) recommended actions to solve the plague threat at the market. METHODS: A conceptual framework was developed combining a social determinants approach with a complex systems-thinking framework and a knowledge management perspective. A four-step qualitative protocol was carried out (literature review; stakeholder mapping; 37 semi-structured interviews; and coding/analysis). In the fourth step, the data collected in the semi-structured interviews were coded for eight social determinants of health (SDH) variables and analyzed with ATLAS.ti®, and an emerging category analysis was performed to identify risk perception levels. RESULTS: Based on analysis by SDH variable, the three main determinants of the plague threat at Hermelinda Market were: 1) local (Trujillo City) governance, 2) infrastructure and basic services, and 3) local culture. According to the same analysis, actions most frequently undertaken against plague involved 1) infrastructure and basic services, 2) social vigilance, and 3) communication. The emerging category analysis indicated local risk perception levels were low, with most of the data pointing to "unhygienic" ("naturalized") lifestyles and a general lack of awareness about the disease prior to plague-related health concerns at the market as the cause. CONCLUSIONS: The results indicate that the persistent circulation of Yersinia pestis at Hermelinda Market is not simply a technical matter but more of a managerial and cultural problem. As local governance was found to be a main factor in the persistence of this public health threat, future efforts against it should focus on sustainable inter-sectoral planning and education. Actions taken exclusively by the health sector and the improvement of infrastructure and basic services alone will not be enough to reduce the threat of plague at the market.

A qualitative socio-ecological characterization of the plague threat at Hermelinda Market, La Libertad, Peru / Caracterización socioecológica cualitativa de la amenaza de peste en el mercado La Hermelinda, Departamento de La Libertad Perú / Caracterização socioecológica qualitativa do risco de ocorrência da peste no Mercado Hermelinda, La Libertad, Peru

Objective To identify 1) the main determinants of persistent Yersinia pestis circulation and the associated threat of plague at Hermelinda Market—a large farmers' market in the city of Trujillo, La Libertad, Peru—and the main actions taken against it, as perceived by local stakeholders; 2) the level of plague risk perception among local actors; and 3) recommended actions to solve the plague threat at the market. Methods A conceptual framework was developed combining a social determinants approach with a complex systems-thinking framework and a knowledge management perspective. A four-step qualitative protocol was carried out (literature review; stakeholder mapping; 37 semi-structured interviews; and coding/analysis). In the fourth step, the data collected in the semi-structured interviews were coded for eight social determinants of health (SDH) variables and analyzed with ATLAS.ti®, and an emerging category analysis was performed to identify risk perception levels. Results Based on analysis by SDH variable, the three main determinants of the plague threat at Hermelinda Market were: 1) local (Trujillo City) governance, 2) infrastructure and basic services, and 3) local culture. According to the same analysis, actions most frequently undertaken against plague involved 1) infrastructure and basic services, 2) social vigilance, and 3) communication. The emerging category analysis indicated local risk perception levels were low, with most of the data pointing to "unhygienic" ("naturalized") lifestyles and a general lack of awareness about the disease prior to plague-related health concerns at the market as the cause. Conclusions The results indicate that the persistent circulation of Yersinia pestis at Hermelinda Market is not simply a technical matter but more of a managerial and cultural problem. As local governance was found to be a main factor in the persistence of this public health threat, future efforts against it should focus on sustainable inter-sectoral planning and education. Actions taken exclusively by the health sector and the improvement of infrastructure and basic services alone will not be enough to reduce the threat of plague at the market.

RESUMEN Objetivo Establecer: 1) los principales determinantes de la circulación persistente de Yersinia pestis y la amenaza asociada de peste en el mercado La Hermelinda, un gran mercado de agricultores en la ciudad de Trujillo, Departamento de La Libertad en Perú, y las medidas más adecuadas para combatir la bacteria, según la percepción de los interesados directos locales; 2) el grado de percepción del riesgo de peste entre los actores locales; y 3) las medidas recomendadas para resolver la amenaza de peste en el mercado. Métodos Se elaboró un marco conceptual que combinaba un enfoque de determinantes sociales con un complejo marco de pensamiento sistémico y una perspectiva de gestión del conocimiento. Se llevó a cabo un protocolo cualitativo de cuatro pasos (revisión bibliográfica; mapeo de interesados directos; 37 entrevistas semiestructuradas y codificación y análisis). En el cuarto paso, los datos recopilados en las entrevistas semiestructuradas fueron codificados conforme a ocho variables de los determinantes sociales de la salud y analizados con el programa ATLAS.ti ®, y luego se realizó un análisis de las categorías emergentes para establecer los grados de percepción del riesgo. Resultados Sobre la base del análisis de las variables de los determinantes sociales de la salud, los tres principales determinantes de la amenaza de peste en el mercado La Hermelinda fueron: 1) la gobernanza local (Ciudad de Trujillo), 2) la infraestructura y los servicios básicos y 3) la cultura local. Según el mismo análisis, las acciones emprendidas con mayor frecuencia contra la peste se vincularon con 1) la infraestructura y los servicios básicos, 2) la vigilancia social y 3) la comunicación. El análisis de las categorías emergentes indicó que los grados locales de percepción del riesgo fueron bajos y la mayoría de los datos apuntaron como causas a los modos de vida "antihigiénicos" ("naturalizados") y a una falta general de concientización acerca de la enfermedad antes de la preocupación acerca de la salud relacionada con la peste en el mercado. Conclusiones Los resultados indican que la circulación persistente de Yersinia pestis en el mercado La Hermelinda no es sencillamente un asunto técnico sino sobre todo un problema cultural y de gestión. Como se encontró que la gobernanza local era un factor importante en la persistencia de esta amenaza a la salud pública, las actividades futuras para combatirla deben centrarse en la planificación y la educación intersectoriales sostenibles. Las medidas adoptadas exclusivamente por el sector de la salud y el mejoramiento de la infraestructura y los servicios básicos por sí solos no serán suficientes para reducir la amenaza de la peste en el mercado.

RESUMO Objetivo Identificar 1) os principais determinantes da circulação persistente de Yersinia pestis e o risco associado de ocorrência da peste no Mercado Hermelinda, um grande mercado de produtos agrícolas no município de Trujillo, La Libertad, Peru, e as principais medidas adotadas para enfrentar esta situação, segundo a percepção dos interessados diretos locais, 2) o nível de percepção do risco de ocorrência da peste entre os atores locais e 3) as ações recomendadas para eliminar o risco de ocorrência da peste no mercado. Métodos Foi desenvolvida uma estrutura conceitual formada pela combinação de um enfoque de determinantes sociais, um enquadramento complexo de reflexão sistêmica e uma perspectiva de gestão do conhecimento. Foi conduzido um protocolo qualitativo de quatro etapas (revisão literária, mapeamento de interessados diretos, 37 entrevistas semiestruturadas e codificação/análise). Na quarta etapa, os dados coletados nas entrevistas semiestruturadas foram codificados para oito variáveis de determinantes sociais da saúde (DSS) e analisados com o programa ATLAS.ti®. Uma análise de categorias emergentes foi realizada para identificar os níveis de percepção de risco. Resultados A partir da análise segundo as variáveis de DSS, os três principais determinantes do risco de ocorrência da peste no Mercado Hermelinda foram: 1) governança local (município de Trujillo), 2) infraestrutura e serviços básicos e 3) cultura local. Segundo a mesma análise, as medidas adotadas com maior frequência para evitar a peste foram: 1) infraestrutura e serviços básicos, 2) vigilância social e 3) comunicação. A análise de categorias emergentes indicou que o nível de percepção local do risco de ocorrência era baixo, sendo que a maioria dos dados apontou como causa hábitos de vida anti-higiênicos ("naturalizados") e falta geral de consciência da doença anterior às preocupações de saúde relacionadas com a peste no mercado. Conclusões Os resultados do estudo indicam que a circulação persistente de Yersinia pestis no Mercado Hermelinda não é simplesmente uma questão técnica, sendo mais um problema administrativo e cultural. Verificou-se que a governança local é um dos principais fatores para a persistência desta ameaça à saúde pública e os esforços futuros devem visar o planejamento intersetorial sustentável e a educação. Medidas adotadas exclusivamente pelo setor da saúde e a melhoria da infraestrutura e serviços básicos por si só não serão suficientes para reduzir o risco de ocorrência da peste no mercado.

High Prevalence of Asymptomatic Neurocysticercosis in an Endemic Rural Community in Peru.

BACKGROUND: Neurocysticercosis is a common helminthic infection of the central nervous system and an important cause of adult-onset epilepsy in endemic countries. However, few studies have examined associations between neurologic symptoms, serology and radiographic findings on a community-level. METHODOLOGY: We conducted a population-based study of resident's ≥2 years old in a highly endemic village in Peru (pop. 454). We applied a 14 -question neurologic screening tool and evaluated serum for antibodies against Taenia solium cysticercosis using enzyme-linked immunoelectrotransfer blot (LLGP-EITB). We invited all residents ≥18 years old to have non-contrast computerized tomography (CT) of the head. PRINCIPAL FINDINGS: Of the 385 residents who provided serum samples, 142 (36.9%) were seropositive. Of the 256 residents who underwent CT scan, 48 (18.8%) had brain calcifications consistent with NCC; 8/48 (17.0%) reported a history of headache and/or seizures. Exposure to T. solium is very common in this endemic community where 1 out of 5 residents had brain calcifications. However, the vast majority of people with calcifications were asymptomatic. CONCLUSION: This study reports a high prevalence of NCC infection in an endemic community in Peru and confirms that a large proportion of apparently asymptomatic residents have brain calcifications that could provoke seizures in the future.

Elimination of Taenia solium Transmission in Northern Peru.

BACKGROUND: Taeniasis and cysticercosis are major causes of seizures and epilepsy. Infection by the causative parasite Taenia solium requires transmission between humans and pigs. The disease is considered to be eradicable, but data on attempts at regional elimination are lacking. We conducted a three-phase control program in Tumbes, Peru, to determine whether regional elimination would be feasible. METHODS: We systematically tested and compared elimination strategies to show the feasibility of interrupting the transmission of T. solium infection in a region of highly endemic disease in Peru. In phase 1, we assessed the effectiveness and feasibility of six intervention strategies that involved screening of humans and pigs, antiparasitic treatment, prevention education, and pig replacement in 42 villages. In phase 2, we compared mass treatment with mass screening (each either with or without vaccination of pigs) in 17 villages. In phase 3, we implemented the final strategy of mass treatment of humans along with the mass treatment and vaccination of pigs in the entire rural region of Tumbes (107 villages comprising 81,170 people and 55,638 pigs). The effect of the intervention was measured after phases 2 and 3 with the use of detailed necropsy to detect pigs with live, nondegenerated cysts capable of causing new infection. The necropsy sampling was weighted in that we preferentially included more samples from seropositive pigs than from seronegative pigs. RESULTS: Only two of the strategies implemented in phase 1 resulted in limited control over the transmission of T. solium infection, which highlighted the need to intensify the subsequent strategies. After the strategies in phase 2 were implemented, no cyst that was capable of further transmission of T. solium infection was found among 658 sampled pigs. One year later, without further intervention, 7 of 310 sampled pigs had live, nondegenerated cysts, but no infected pig was found in 11 of 17 villages, including all the villages in which mass antiparasitic treatment plus vaccination was implemented. After the final strategy was implemented in phase 3, a total of 3 of 342 pigs had live, nondegenerated cysts, but no infected pig was found in 105 of 107 villages. CONCLUSIONS: We showed that the transmission of T. solium infection was interrupted on a regional scale in a highly endemic region in Peru. (Funded by the Bill and Melinda Gates Foundation and others.).

An unforgettable event: a qualitative study of the 1997-98 El Niño in northern Peru.

During the 1997-98 El Niño, Tumbes, Peru received 16 times the annual average rainfall. This study explores how Tumbes residents perceived the impact of the El Niño event on basic necessities, transport, health care, jobs and migration. Forty-five individuals from five rural communities, some of which were isolated from the rest of Tumbes during the event, participated in five focus groups; six of these individuals constructed nutrition diaries. When asked about events in the past 20 years, participants identified the 1997-98 El Niño as a major negative event. The El Niño disaster situation induced a decrease in access to transport and health care and the rise in infectious diseases was swiftly contained. Residents needed more time to rebuild housing; recover agriculture, livestock and income stability; and return to eating sufficient animal protein. Although large-scale assistance minimized effects of the disaster, residents needed more support. Residents' perspectives on their risk of flooding should be considered in generating effective assistance policies and programmes.

Neurocysticercosis as a cause of epilepsy and seizures in two community-based studies in a cysticercosis-endemic region in Peru.

BACKGROUND: The prevalence of epilepsy added to inadequate treatment results in chronic morbidity and considerable mortality in poor populations. Neurocysticercosis (NCC), a helminthic disease of the central nervous system, is a leading cause of seizures and epilepsy in most of the world. METHODS: Taking advantage of a cysticercosis elimination program, we performed two community-based cross-sectional studies between 2006 and 2007 in 58 rural communities (population 20,610) to assess the prevalence and characteristics of epilepsy and epileptic seizures in this endemic region. Serological and computed tomography (CT) data in individuals with epilepsy were compared to previous surveys in general population from the same region. PRINCIPAL FINDINGS: In two surveys, 17,450 individuals were evaluated. Lifetime prevalence of epilepsy was 17.25/1000, and prevalence of active epilepsy was 10.8/1000 inhabitants. The prevalence of epilepsy increased after age 25 years and dropped after age 45. Only 24% (45/188) of patients with active epilepsy were taking antiepileptic drugs, all at sub-therapeutic doses. Antibodies to cysticercosis were found in approximately 40% of individuals with epilepsy in both studies. In one survey only individuals presenting strong antibody reactions were significantly associated with having epilepsy (OR 5.74; p<0.001). In the second, the seroprevalence as well as the proportion presenting strong antibody reactions were both significantly higher in individuals with epilepsy (OR 2.2 and 4.33, respectively). Brain CT showed NCC-compatible images in 109/282 individuals with epilepsy (39%). All individuals with viable parasites on CT were seropositive. CONCLUSION: The prevalence of epilepsy in this cysticercosis endemic region is high and NCC is an important contributor to it.

Effect of urbanisation on the relationship between total serum IgE and asthma.

It is unclear if the relationship of total serum IgE with asthma varies with degree of urbanisation. We hypothesised that the relationship of total serum IgE to asthma is more pronounced in an urban versus a rural environment. We enrolled 1441 children aged 13-15 years in a peri-urban shanty town in Lima, Peru (n=725) and 23 villages in rural Tumbes, Peru (n=716). We asked participants about asthma and allergy symptoms, environmental exposures and sociodemographics; and performed spirometry, and exhaled nitric oxide and allergy skin testing. We obtained blood for total serum IgE in 1143 (79%) participants. Geometric means for total serum IgE were higher in Lima versus Tumbes (262 versus 192 kU·L(-1); p<0.001). The odds of asthma increased by factors of 1.6 (95% CI 1.3-2.0) versus 1.4 (95% CI 0.9-2.1) per log unit increase in total serum IgE in Lima versus Tumbes, respectively. Atopy was an effect modifier of the relationship of total serum IgE on asthma. Among atopics and non-atopics, the odds of asthma increased by a factor of 2.0 (95% CI 1.5-2.7) and 1.0 (95% CI 0.7-1.4) per log unit increase in total serum IgE, respectively. Total serum IgE was associated with atopic asthma but not with non-atopic asthma. Urbanisation did not appear to be an effect modifier of this relationship.

The Peru Urban versus Rural Asthma (PURA) Study: methods and baseline quality control data from a cross-sectional investigation into the prevalence, severity, genetics, immunology and environmental factors affecting asthma in adolescence in Peru.

OBJECTIVES: According to a large-scale international survey, Peru has one of the highest prevalences of asthma worldwide; however, data from this survey were limited to participants from urban Lima. The authors sought to characterise the epidemiology of asthma in Peru in two regions with disparate degrees of urbanisation. In this manuscript, the authors summarise the study design and implementation. DESIGN: A cross-sectional study. PARTICIPANTS: Using census data of 13-15-year-old adolescents from two communities in Peru, the authors invited a random sample of participants in Lima (n=725) and all adolescents in Tumbes (n=716) to participate in our study. PRIMARY AND SECONDARY OUTCOME MEASURES: The authors asked participants to complete a questionnaire on asthma symptoms, environmental exposures and socio-demographics and to undergo spirometry before and after bronchodilator, skin allergy testing and exhaled nitric oxide testing. The authors obtained blood samples for haematocrit, total IgE levels, vitamin D levels and DNA in all participants and measured indoor particulate matter concentrations for 48 h in a random subset of 70-100 households at each site. RESULTS: Of 1851 eligible participants, 1441 (78%) were enrolled and 1159 (80% of enrolled) completed all physical tests. 1283 (89%) performed spirometry according to standard guidelines, of which 86% of prebronchodilator tests and 92% of postbronchodilator tests were acceptable and reproducible. 92% of allergy skin tests had an adequate negative control. The authors collected blood from 1146 participants (79%) and saliva samples from 148 participants (9%). Overall amounts of DNA obtained from blood or saliva were 25.8 µg, with a 260/280 ratio of 1.86. CONCLUSIONS: This study will contribute to the characterisation of a variety of risk factors for asthma, including urbanisation, total IgE levels, vitamin D levels and candidate genes, in a resource-poor setting. The authors present data to support high quality of survey, allergic, spirometric and genetic data collected in our study.

Geographic correlation between tapeworm carriers and heavily infected cysticercotic pigs.

BACKGROUND: Neurocysticercosis is a leading cause of preventable epilepsy in the developing world. Sustainable community-based interventions are urgently needed to control transmission of the causative parasite, Taenia solium. We examined the geospatial relationship between live pigs with visible cysticercotic cysts on their tongues and humans with adult intestinal tapeworm infection (taeniasis) in a rural village in northern Peru. The objective was to determine whether tongue-positive pigs could indicate high-risk geographic foci for taeniasis to guide targeted screening efforts. This approach could offer significant benefit compared to mass intervention. METHODS: We recorded geographic coordinates of all village houses, collected stool samples from all consenting villagers, and collected blood and examined tongues of all village pigs. Stool samples were processed by enzyme-linked immunosorbent assay (ELISA) for presence of Taenia sp. coproantigens indicative of active taeniasis; serum was processed by enzyme-linked immunoelectrotransfer blot for antibodies against T. solium cysticercosis (EITB LLGP) and T. solium taeniasis (EITB rES33). FINDINGS: Of 548 pigs, 256 (46.7%) were positive for antibodies against cysticercosis on EITB LLGP. Of 402 fecal samples, 6 (1.5%) were positive for the presence of Taenia sp. coproantigens. The proportion of coproantigen-positive individuals differed significantly between residents living within 100-meters of a tongue-positive pig (4/79, 5.1%) and residents living >100 meters from a tongue-positive pig (2/323, 0.6%) (p = 0.02). The prevalence of taeniasis was >8 times higher among residents living within 100 meters of a tongue-positive pig compared to residents living outside this range (adjusted PR 8.1, 95% CI 1.4-47.0). CONCLUSIONS: Tongue-positive pigs in endemic communities can indicate geospatial foci in which the risk for taeniasis is increased. Targeted screening or presumptive treatment for taeniasis within these high-risk foci may be an effective and practical control intervention for rural endemic areas.

Effect of urbanisation on asthma, allergy and airways inflammation in a developing country setting.

BACKGROUND: Asthma is a growing public health problem in developing countries. However, few studies have studied the role of urbanisation in this phenomenon. It was hypothesised that children living in a peri-urban setting in Peru have higher rates of asthma and allergy than rural counterparts. METHODS: 1441 adolescents aged 13-15 years were enrolled from two settings: a peri-urban shanty town in Lima (n = 725) and 23 rural villages in Tumbes (n = 716). Participants filled in questionnaires on asthma and allergy symptoms, environmental exposures and sociodemographics, and underwent spirometry, and exhaled nitric oxide (eNO) and allergy skin testing. Indoor particulate matter (PM) concentrations were measured in 170 households. RESULTS: Lima adolescents had higher rates of lifetime wheezing (22% vs 10%), current asthma symptoms (12% vs 3%) and physician-diagnosed asthma (13% vs 2%; all p <0.001). Current rhinitis (23% vs 12%), eczema (12% vs 0.4%), atopy (56% vs 38%), personal history of cigarette smoking (7.4% vs 1.3%) and mean indoor PM (31 vs 13 µg/m(3)) were also higher in Lima (all p < 0.001). The peri-urban environment of Lima was associated with a 2.6-fold greater odds (95% CI 1.3 to 5.3) of asthma in multivariable regression. Forced expiratory volumes were higher and FEV(1)/FVC (forced expiratory volume in 1 s/forced vital capacity) ratios were lower in Lima (all p < 0.001). Higher eNO values in Lima (p < 0.001) were attributable to higher rates of asthma and atopy. CONCLUSIONS: Peri-urban adolescents had more asthma, atopy and airways inflammation and were exposed to more indoor pollution. The findings provide evidence of the risks posed to lung health by peri-urban environments in developing countries.

Epidemiología y control de la cisticercosis en el Perú / Epidemiology and control of cysticercosis in Peru

La neurocisticercosis, infección del sistema nervioso humano por el estadio larvario de la Taenia solium, es una causa importante de epilepsia y otras manifestaciones neurológicas en el Perú y en la mayoría de países en desarrollo. Desde 1987, el Grupo de Trabajo en Cisticercosis en Perú ha desarrollado una serie de estudios epidemiológicos que han llevado a estimar el impacto y entender la transmisión de la Taenia solium, y que posteriormente se aplicaron al diseño y ejecución de un programa de control en Tumbes, en la costa norte del país. En este artículo se revisan los principales hallazgos epidemiológicos, así como las líneas generales del programa de eliminación y las herramientas utilizadas. Los avances en el control de la teniasis/cisticercosis en nuestro país abren el camino hacia su eliminación y eventual erradicación.

Neurocysticercosis, the infection of the human central nervous system by the larval stage of the cestode Taenia solium, is an important cause of epilepsy and other neurological manifestations in Peru and most developing countries. Since 1987, the Cysticercosis Working Group in Peru has performed a series of epidemiological studies which led to estimate the impact and to better understand the transmission of Taenia solium. This information was later applied to the design and execution of a control program in Tumbes, in the Northern Coast of Peru. This paper reviews the main epidemiological findings, as well as the conceptual framework of the elimination program and the tools used. Advances in the control of taeniasis/cysticercosis in our country open the road towards its elimination and potential eradication.

[Epidemiology and control of cysticercosis in Peru]. / Epidemiología y control de la cisticercosis en el Perú.

Neurocysticercosis, the infection of the human central nervous system by the larval stage of the cestode Taenia solium, is an important cause of epilepsy and other neurological manifestations in Peru and most developing countries. Since 1987, the Cysticercosis Working Group in Peru has performed a series of epidemiological studies which led to estimate the impact and to better understand the transmission of Taenia solium. This information was later applied to the design and execution of a control program in Tumbes, in the Northern Coast of Peru. This paper reviews the main epidemiological findings, as well as the conceptual framework of the elimination program and the tools used. Advances in the control of taeniasis/cysticercosis in our country open the road towards its elimination and potential eradication.

Epilepsy and neurocysticercosis: an incidence study in a Peruvian rural population.

BACKGROUND: Epilepsy is a serious neurological disorder and neurocysticercosis (NCC), the central nervous system infection by the larvae of Taenia solium, is the main cause of acquired epilepsy in developing countries. NCC is becoming more frequent in industrialized countries due to immigration from endemic areas. Previously reported epilepsy incidences range from 30 to 50/100,000 people in industrialized countries and 90 to 122/100,000 people in developing countries. OBJECTIVES: To determine the incidence of epilepsy in a cysticercosis endemic area of Peru. METHODS: A screening survey for possible seizure cases was repeated biannually in this cohort for a period of 5 years (1999-2004) using a previously validated questionnaire. All positive respondents throughout the study were examined by a trained neurologist in the field to confirm the seizure. If confirmed, they were offered treatment, serological testing, neuroimaging (CT scans and MRI) and clinical follow-up. RESULTS: The cohort study comprised 817 individuals. The overall epilepsy incidence rate was 162.3/100,000 person-years, and for epileptic seizures, 216.6/100,000 person-years. Out of the 8 individuals who had epileptic seizures, 4 had markers for NCC (neuroimaging and/or serology). CONCLUSION: The incidence of epilepsy in this area endemic for cysticercosis is one of the highest reported worldwide.

"Can it be that god does not remember me": a qualitative study on the psychological distress, suffering, and coping of Dominican women with chronic filarial lymphedema and elephantiasis of the leg.

The psychological states of Dominican women with chronic lymphedema and elephantiasis of the leg and the coping strategies they used to ameliorate the negative psychological effects of this condition were explored using modified precepts of grounded theory method. Qualitative data were gathered through in-depth interviewing and focus group discussions held in the Dominican Republic. Thematic results found that compounding their physical disfigurement, functional limitations, and social losses were feelings of depression, embarrassment, social isolation, and despair. Adaptive problem solving and emotion-focused coping strategies that emerged during analysis also are discussed. It is recommended that management of psychological distress should be a significant component of lymphedema management programs in developing countries.

Strategies for the elimination of taeniasis/cysticercosis.

Advances in the field of neurocysticercosis continue to shape our understanding of the disease and our efforts to control it. Several attempts have been made to eradicate the disease with active interventions such as changing domestic pig-raising practices, mass chemotherapy of porcine cysticercosis and taeniasis, selective detection and treatment of taeniasis, and community health education. Moreover, ongoing progress in the diagnosis of taeniasis and the development of a porcine vaccine against cysticercosis in Australia, Mexico and Peru has yielded at least one effective vaccine that is currently available. Thus far, however, attempted interventions have only been successful in temporarily disrupting transmission of the disease. Controlled data on the efficacy and acceptability of the different interventions is urgently needed to provide a base-line schematic for intervention which could later be tailored to each particular endemic scenario.