RESUMEN
Los Angeles and Orange Counties are known endemic areas for murine typhus in California; however, no recent reports of flea-borne rickettsioses are known from adjacent San Bernardino County. Sixty-five opossums (Didelphis virginiana) were trapped in the suburban residential and industrial zones of the southwestern part of San Bernardino County in 2007. Sixty out of 65 opossums were infested with fleas, primarily cat fleas, Ctenocephalides felis (Bouché, 1835). The flea minimum infection rate with Rickettsia felis was 13.3% in pooled samples and the prevalence was 23.7% in single fleas, with two gltA genotypes detected. In spite of historic records of murine typhus in this area, no evidence for circulation of R. typhi in fleas was found during the present study. Factors contributing to the absence of R. typhi in these cat fleas in contrast to its presence in cat fleas from Orange and Los Angeles Counties are unknown and need to be investigated further in San Bernardino County.
Asunto(s)
Ctenocephalides/microbiología , Didelphis/parasitología , Infestaciones por Pulgas/veterinaria , Insectos Vectores/microbiología , Infecciones por Rickettsia/veterinaria , Rickettsia felis/aislamiento & purificación , Animales , Proteínas Bacterianas/genética , California/epidemiología , Citrato (si)-Sintasa/genética , Femenino , Infestaciones por Pulgas/epidemiología , Infestaciones por Pulgas/parasitología , Genotipo , Masculino , Reacción en Cadena de la Polimerasa/veterinaria , Infecciones por Rickettsia/epidemiología , Infecciones por Rickettsia/microbiología , Rickettsia felis/genética , Análisis de Secuencia de ADN/veterinariaRESUMEN
BACKGROUND: Wilms' tumour is a common malignant neoplasm of the kidney and is ranked among the top six solid tumours in children in Kenya. Despite its rapid growth and therefore debilitating effects on its victims, it is one tumour that has shown good response to combined modality approach to its treatmentwith encouraging possibilities of survival even in resource poor settings. OBJECTIVE: To evaluate the management and outcome of patients with Wilms'tumour attended to at Moi Teaching and Referral Hospital (MTRH) during the period between January 2000 and December 2007. DESIGN: Retrospective Study. SETTING: The Paediatric Oncology Service (Oncology unit in the Paediatric Ward, the Paediatric Surgical Ward and the Outpatient Oncology Clinic) at the Moi Teaching and Referral Hospital, Eldoret, Kenya. RESULTS: Information of 45 patients diagnosed with Wilms' tumour was analysed. Forty two (93%) of the patients were referrals from various health facilities in the region. Twenty three (51%) were male and 34 (76%) were aged less than 48 months. Twenty five (56%) had the left kidney affected, 19 (42%) the right kidney and one (2%) bilateral. All the 45 (100%) had an abdominal ultrasound done but none had exhaustive investigations done to stage the disease. Only eight (18%) of the patients had a medical insurance cover. Fourty one (91%) of the patients received specific cancer treatment with 28 (62%) getting combined modality treatment. Nineteen (42%) were lost to follow up. Thirty (67%), 21 (47%), 15 (33%) and 13 (29%) patients were alive six months, one year, two years and three years respectively from the time of diagnosis. 29% survived beyond three years of diagnosis. CONCLUSION: Staging of Wilms tumour fell short of the expected. Neo-adjuvant chemotherapy reduced morbidity and mortality of patients managed for Wilms' tumour. Loss to follow up and cost of treatment had a negative impact on the outcome, a situation that requires to be improved.
Asunto(s)
Neoplasias Renales/diagnóstico , Neoplasias Renales/terapia , Tumor de Wilms/diagnóstico , Tumor de Wilms/terapia , Niño , Preescolar , Terapia Combinada , Manejo de la Enfermedad , Femenino , Hospitales de Enseñanza , Humanos , Lactante , Kenia , Masculino , Evaluación de Procesos y Resultados en Atención de Salud , Derivación y Consulta , Estudios RetrospectivosRESUMEN
Multiple blood feeding in field populations of Anopheles freeborni Aitken and Culex tarsalis Coquillet was detected using a histologic technique. Examination of 333 blood engorged An. freeborni and 41 Cx. tarsalis females revealed that 13 and 10% of these females imbibed multiple blood meals, respectively. Spatial and temporal distribution of multiple blood feeding events was evaluated against the percentage of blood fed females and the abundance of female mosquitoes. The percentage of blood fed An. freeborni females was higher among those collected in pasture and riparian habitats than those collected in rice field and mixed habitats. Conversely, spatial variation of multiple blood feeding in An. freeborni was not significantly associated with rice field, pasture, riparian, or mixed habitats. The decrease of multiple blood feeding for An. freeborni through the season was correlated inversely with the increase of the abundance of adult females; but not with the percentage of blood fed females. These results confirmed that multiple blood meals in An. freeborni, and perhaps in Cx. tarsalis, are a frequent phenomenon, and that the histologic procedure is an appropriate tool for longitudinal and region-wide detection of multiple blood feeding necessary in epidemiologic studies.
Asunto(s)
Anopheles/fisiología , Culex , Conducta Alimentaria , Animales , Anopheles/ultraestructura , FemeninoRESUMEN
The objective of this study was to determine whether abundance, blood feeding rates, and sex ratios of adult Anopheles freeborni Aitken and Culex tarsalis Coquillett were associated significantly with either rice field, pasture, riparian, or mixed habitats found within the rice culture agroecosystem of northern California. Significantly higher numbers of adult An. freeborni occurred in riparian and mixed habitats compared with rice and pasture habitats. Such a pattern was not evident for Cx. tarsalis. Riparian and pasture habitats contained significantly higher proportions of blood fed An. freeborni females than did rice and mixed habitats; however, the proportions of blood fed Cx. tarsalis females did not vary significantly among habitat types. The proportions of blood fed An. freeborni and Cx. tarsalis females in riparian habitats decreased with increasing abundance. There was no correlation between blood feeding rates and abundance for An. freeborni and Cx. tarsalis females in the other habitat types. The sex ratio of An. freeborni in pasture and riparian habitats was significantly female biased, unlike the other habitats which did not differ significantly from unity (1:1). Overall, riparian and mixed habitats contained greater numbers of adults mosquitoes; therefore, surveillance and control efforts of these mosquito species should be focused on such habitats.
Asunto(s)
Anopheles , Culex , Oryza , Agricultura , Animales , California , Demografía , Ecosistema , Femenino , Mordeduras y Picaduras de Insectos , Masculino , Razón de MasculinidadRESUMEN
The frequency of multiple blood feeding in field populations of Anopheles freeborni was determined. Fifty-six laboratory-reared mosquitoes, all known to have taken two blood meals, were used to define the limits of the histologic procedure we used. Seventy-eight percent of known double meals were detected when the interval between meals was from 1 to 24 hr, and the time from the second meal until fixation ranged from 0 to 24 hr. At intervals outside this range, 50% of multiple meals were detected. In field-collected An. freeborni, the most important histologic parameters for determination of multiple feeding were the amount of heme that developed around each meal, the peritrophic membrane, partially digested blood meals, and physical blood meal separation. Examination of 134 blood-engorged An. freeborni collected in the field showed that 9.7% had imbibed multiple blood meals. These results suggest that multiple blood meals in An. freeborni are more frequent than previously thought, perhaps with significant epidemiologic implications.
Asunto(s)
Anopheles/fisiología , Sangre , Mordeduras y Picaduras de Insectos , Insectos Vectores/fisiología , Animales , Conducta Alimentaria , Femenino , HumanosRESUMEN
Feeding behavior was compared between infected and uninfected field-collected groups of Anopheles gambiae sensu lato and An. funestus from western Kenya. A significantly greater percentage (81%) of Plasmodium falciparum-infected An. gambiae s.l. females probed on experimental hosts (hamsters) than did uninfected females (38%). Among those females that initiated probing, there was no effect of infection status on the ability to take a bloodmeal. Plasmodium falciparum-infected An. gambiae s.l. probed more often (mean = 4.0) and for a longer time (mean = 277 sec) than did their uninfected counterparts (mean = 2.4 probes and mean probing time = 214 sec). Results for the small number of An. funestus that fed followed the same trend. Among infected An. gambiae s.l. females, there was no effect of sporozoite density on either the number of probes made or the total probing time. Among uninfected females, there was no difference in feeding behavior between nulliparous and parous females. In laboratory experiments, female age had no effect on blood-feeding behavior. Our findings provide evidence that natural malaria infection modifies the feeding behavior of Anopheles females.