Angiostrongylus cantonensis en Achatina fulica en la provincia del Napo, Ecuador y el riesgo incrementado de angiostrongiliasis / Angiostrongylus cantonensis in Achatina fulica in Napo province, Ecuador and the increased risk of angiostrongyliasis

Introducción: Angiostrongylus cantonensis es reconocido como uno de los principales patógenos causantes de la meningoencefalitis eosinofílica, fue identificado en Ecuador por primera vez en 2008. Métodos: se recolectaron 1476 ejemplares de Achatina fulica con el método de captura por unidad de esfuerzo durante 30 minutos, en 3 cantones de la provincia del Napo, con el fin de establecer la prevalencia de infección por A. cantonensis Resultados: el porcentaje total de caracoles infectados fue de 46,5% (687/1476). Conclusiones: Los resultados revelan una amplia distribución de A. fulica infectado con A. cantonensis, lo que, sumado a la gran cantidad de hospederos definitivos presentes, indica que un número considerable de personas tiene riesgo de adquirir angiostrongiliasis. Se necesita intervenciones educativas comunitaria orientadas a formación sanitaria, recalcando el riesgo de adquirir la infección parasitaria, principalmente por el consumo de A. fulica, crudos y/o con cocción inadecuada, principal forma de contagio. Además, se recomienda vigilancia rigurosa y control de los hospedadores involucrados, saneamiento ambiental, haciendo insistencia en factores relacionados con los hábitos biológico del caracol gigante africano, entre ello alimentos (vegetales), suelos y derivados del caracol de uso artesanal; para prevenir la aparición de casos esporádicos y de brotes de la enfermedad(AU)

Introduction: Angiostrongylus cantonensis is recognized as one of the main pathogens that cause eosinophilic meningoencephalitis, it was identified in Ecuador for the first time in 2008. Methods: 1476 specimens of Achatina fulica were collected using the capture method per unit of effort for 30 minutes, in 3 cantons of the Napo province, in order to establish the prevalence of infection by A. cantonensis Results: the total percentage of infected snails was 46.5% (687/1476). Conclusions: The results reveal a wide distribution of A. fulica infected with A. cantonensis, which, added to the large number of definitive hosts present, indicates that a considerable number of people are at risk of acquiring angiostrongyliasis. Community educational interventions aimed at health training are needed, emphasizing the risk of acquiring parasitic infection, mainly due to the consumption of A. fulica, raw and/or inadequately cooked, the main form of contagion. In addition, rigorous surveillance and control of the hosts involved, environmental sanitation, insisting on factors related to the biological habits of the giant African snail, including food (vegetables), soil and snail derivatives for artisanal use; to prevent the appearance of sporadic cases and outbreaks of the disease(AU)

Sterile Insect Technique: Successful Suppression of an Aedes aegypti Field Population in Cuba.

Dengue virus infections are a serious public health problem worldwide. Aedes aegypti is the primary vector of dengue in Cuba. As there is no vaccine or specific treatment, the control efforts are directed to the reduction of mosquito populations. The indiscriminate use of insecticides can lead to adverse effects on ecosystems, including human health. The sterile insect technique is a species-specific and environment-friendly method of insect population control based on the release of large numbers of sterile insects, ideally males only. The success of this technique for the sustainable management of agricultural pests has encouraged its evaluation for the population suppression of mosquito vector species. Here, we describe an open field trial to evaluate the effect of the release of irradiated male Ae. aegypti on a wild population. The pilot trial was carried out in a suburb of Havana and compared the mosquito population density before and after the intervention, in both untreated control and release areas. The wild population was monitored by an ovitrap network, recording frequency and density of eggs as well as their hatch rate. A significant amount of sterility was induced in the field population of the release area, as compared with the untreated control area. The ovitrap index and the mean number of eggs/trap declined dramatically after 12 and 5 weeks of releases, respectively. For the last 3 weeks, no eggs were collected in the treatment area, clearly indicating a significant suppression of the wild target population. We conclude that the sterile males released competed successfully and induced enough sterility to suppress the local Ae. aegypti population.

Detection of rotavirus and other enteropathogens in children hospitalized with acute gastroenteritis in Havana, Cuba.

The aim of the study was to diagnose infections with rotavirus and other enteric pathogens in children under five years old with acute gastroenteritis and to identify the most common epidemiological and clinical characteristics of these pathogens. The study was conducted using 110 stool samples from the same number of children under five years old who were inpatients at three paediatric hospitals in Havana, Cuba, between October and December 2011. The samples were tested for rotavirus and other enteric pathogens using traditional and molecular microbiological methods. Pathogens were detected in 85 (77.3 %) of the children. Rotavirus was the most commonly found, appearing in 54.5 % of the children, followed by bacteria (29 %) and parasites (10.9 %). Other viral pathogens detected included adenovirus (6.4 %) and astrovirus (3.6 %). In rotavirus-positives cases, at least one other pathogen was detected, usually a bacterium (26.6 %). More than three episodes of watery diarrhea in 24 hours were observed in 78.3 % of the cases. Dehydration was found in 30 (50 %) rotavirus-positive children, of whom seven (11.6 %) were transferred to an intensive care unit due to complications of metabolic acidosis. Rotavirus was most commonly observed among children under 12 months old (65 %). The highest incidence of infection occurred in children who were under the care of a relative at home (78.3 %), had not been breastfed (65 %), or had been breastfed for less than six months (28.3 %). The genotype combinations most frequently found were G9P8 (28.3 %) and G1P8 (10 %). This study demonstrates the presence of rotavirus and other enteric pathogens as causes of gastroenteritis in hospitalized infants and young children in Cuba.

Large indoor cage study of the suppression of stable Aedes aegypti populations by the release of thiotepa-sterilised males

The sterile insect technique (SIT) is a promising pest control method in terms of efficacy and environmental compatibility. In this study, we determined the efficacy of thiotepa-sterilised males in reducing the target Aedes aegypti populations. Treated male pupae were released weekly into large laboratory cages at a constant ratio of either 5:1 or 2:1 sterile-to-fertile males. A two-to-one release ratio reduced the hatch rate of eggs laid in the cage by approximately a third and reduced the adult catch rate by approximately a quarter, but a 5:1 release drove the population to elimination after 15 weeks of release. These results indicate that thiotepa exposure is an effective means of sterilising Ae. aegypti and males thus treated are able to reduce the reproductive capacity of a stable population under laboratory conditions. Further testing of the method in semi-field enclosures is required to evaluate the mating competitiveness of sterile males when exposed to natural environmental conditions. If proven effective, SIT using thiotepa-sterilised males may be incorporated into an integrated programme of vector control to combat dengue in Cuba.

Large indoor cage study of the suppression of stable Aedes aegypti populations by the release of thiotepa-sterilised males.

The sterile insect technique (SIT) is a promising pest control method in terms of efficacy and environmental compatibility. In this study, we determined the efficacy of thiotepa-sterilised males in reducing the target Aedes aegypti populations. Treated male pupae were released weekly into large laboratory cages at a constant ratio of either 5:1 or 2:1 sterile-to-fertile males. A two-to-one release ratio reduced the hatch rate of eggs laid in the cage by approximately a third and reduced the adult catch rate by approximately a quarter, but a 5:1 release drove the population to elimination after 15 weeks of release. These results indicate that thiotepa exposure is an effective means of sterilising Ae. aegypti and males thus treated are able to reduce the reproductive capacity of a stable population under laboratory conditions. Further testing of the method in semi-field enclosures is required to evaluate the mating competitiveness of sterile males when exposed to natural environmental conditions. If proven effective, SIT using thiotepa-sterilised males may be incorporated into an integrated programme of vector control to combat dengue in Cuba.

Release of thiotepa sterilized males into caged populations of Aedes aegypti: life table analysis.

Successful SIT trials against mosquitoes in the 1960-70s were achieved by sterilizing male mosquitoes using chemosterilants. Their use was discontinued after concerns were raised about the effect of residues on non-target organisms, although scant evidence has been published. Irradiation is an expensive process; chemosterilization could be an affordable option for implementing SIT programs in developing countries. We compare life table parameters of three Aedes aegypti populations comprising different ratios of thiotepa-treated and non-treated males in order to identify the impact on reproductive potential of the presence of sterile males. No difference was observed in the survival of the treated and untreated males. The release of thiotepa sterilized males into caged Ae. aegypti populations had no effect on death or survival probability of the individuals in the cages but the fecundity of females was significantly reduced, as evaluated by hatch rate and stable age structure parameters. The significant decreases in net reproduction rate, finite rate of natural increase and intrinsic rate of natural increase in populations including sterile males are sufficient to indicate that such populations would not be able to proliferate in natural conditions. This suggests that release of Ae. aegypti thiotepa-treated males could be effective in reducing the reproductive capability of the target population and consequently contribute to vector control.

Características epidemiológicas y microbiológicas en casos confirmados de enfermedad meningocócica en Cuba, 1998-2007 / Epidemiological and microbiological features of 86 confirmed meningococcal disease cases in Cuba, 1998-2007

En la presente investigación se describió el comportamiento de la enfermedad meningocócica en 86 casos notificados con aislamiento de Neisseria meningitidis en Cuba, entre 1998-2007, a través de la distribución espacial y temporal de los casos, la caracterización fenotípica de las cepas aisladas y la identificación de algunos factores de riesgo del hospedero que pudieran incidir en su cambio fenotípico. Se calcularon los porcentajes y el índice de cambio de la estructura fenotípica del meningococo con diferentes criterios. Predominó el grupo de pacientes menores de un año (30,2%) y la forma clínica meningítica (76,7%). La letalidad fue de 15,1%. Enfermó con el mismo fenotipo de la cepa vacunal (B:4:P1.19,15) el 58,1% de los casos. Se detectaron cambios fenotípicos en el 41,9% de las cepas aisladas, principalmente en niños entre 5-9 años (2001 y 2007), residentes en la región occidental y central del país. Los que enfermaron en julio, septiembre, diciembre y abril y residían en las provincias de Matanzas, La Habana y Villa Clara, se asociaron con el cambio fenotípico de las cepas(AU)

En la presente investigación se describió el comportamiento de la enfermedad meningocócica en 86 casos notificados con aislamiento de Neisseria meningitidis en Cuba, entre 1998-2007, a través de la distribución espacial y temporal de los casos, la caracterización fenotípica de las cepas aisladas y la identificación de algunos factores de riesgo del hospedero que pudieran incidir en su cambio fenotípico. Se calcularon los porcentajes y el índice de cambio de la estructura fenotípica del meningococo con diferentes criterios. Predominó el grupo de pacientes menores de un año (30,2%) y la forma clínica meningítica (76,7%). La letalidad fue de 15,1%. Enfermó con el mismo fenotipo de la cepa vacunal (B:4:P1.19,15) el 58,1% de los casos. Se detectaron cambios fenotípicos en el 41,9% de las cepas aisladas, principalmente en niños entre 5-9 años (2001 y 2007), residentes en la región occidental y central del país. Los que enfermaron en julio, septiembre, diciembre y abril y residían en las provincias de Matanzas, La Habana y Villa Clara, se asociaron con el cambio fenotípico de las cepas(AU)

Community acquired bacterial meningitis in Cuba: a follow up of a decade.

BACKGROUND: Community acquired Bacterial Meningitis (BM) remains a serious threat to global health. Cuban surveillance system for BM allowed to characterize the main epidemiological features of this group of diseases, as well as to assess the association of some variables with mortality. Results of the BM surveillance in Cuba are presented in this paper. METHODS: A follow up of BM cases reported to the Institute "Pedro Kourí" by the National Bacterial Meningitis Surveillance System from 1998 to 2007 was completed. Incidence and case-fatality rate (CFR) were calculated. Univariate analysis and logistic regression were used to elucidate associated factors to mortality comparing death versus survival. Relative Risk (RR) or odds ratio and its 95% confidence interval (CI 95%) were estimated, using either a Chi-squared Test or Fisher's Exact Test as appropriate. A Holt-Winters model was used to assess seasonality. RESULTS: 4798 cases of BM (4.3 per 100,000 population) were reported, with a decreasing trend of the incidence. Highest incidence was observed in infants and elderly. Overall CFR reached 24.1% affecting mostly older adults. S. pneumoniae (23.6%), N. meningitidis (8.2%) and H. influenzae type b (6.0%) were the main causative agents. Males predominate in the incidence. Highest incidence and CFR were mainly clustered in the centre of the island. The univariate analysis did not show association between delayed medical consultation (RR = 1.20; CI = 1.07-1.35) or delayed hospitalization (RR = 0.98; CI = 0.87-1.11) and the fatal outcome. Logistic regression model showed association of categories housewife, pensioned, imprisoned, unemployed, S. pneumoniae and other bacteria with mortality. Seasonality during September, January and March was observed. CONCLUSIONS: The results of the National Program for Control and Prevention of the Neurological Infectious Syndrome evidenced a reduction of the BM incidence, but not the CFR. Multivariate analysis identified an association of mortality with some societal groups as well as with S. pneumoniae.

Community acquired bacterial meningitis in Cuba: a follow up of a decade

Community acquired Bacterial Meningitis (BM) remains a serious threat to global health. Cuban surveillance system for BM allowed to characterize the main epidemiological features of this group of diseases, as well as to assess the association of some variables with mortality. Results of the BM surveillance in Cuba are presented in this paper...(AU)