Identification of estuarine fish Dormitator latifrons as an intermediate host and Eleotris picta as a paratenic host for Gnathostoma binucleatum in Sinaloa, Mexico.

Gnathostomosis is a typical fish-borne zoonotic parasitosis and is currently a serious public health issue in Mexico. Among several Gnathostoma species present in wild animals in Mexico, Gnathostoma binucleatum is the only proven species responsible for human diseases, and the advanced third stage larvae (AL3) of G. binucleatum have been found in over 20 species of fish in this country. In Sinaloa State, two fish species, Dormitator latifrons and Eleotris picta, were heavily contaminated with G. binucleatum AL3. When we analyzed the relationship between the size of the fish and the density of infection with G. binucleatum AL3, the distribution patterns of AL3 were markedly different between these two fish species. Apparent size-dependent accumulation was observed in E. picta but not in D. latifrons, suggesting that E. picta is a paratenic host whereas D. latifrons is a second intermediate host.

Acute outbreak of gnathostomiasis in a fishing community in Sinaloa, Mexico.

An increasing number of human cases of gnathostomiasis have been reported in Sinaloa, Mexico, most of whom have a custom of eating of raw fish dishes such as 'cebiche'. Here we report five adult patients, three women and two men, having an acute episode of vomiting and abdominal pain a few minutes after eating a dish of cebiche prepared from a spotted sleeper perch (Eleotris picta) fished from a nearby lake in southern Sinaloa. All five patients experienced acute throat pain, chest and joint pains, headache and fever. One patient, a 55-year-old male, was hospitalized with suspected pancreatitis and pneumonia. By 8-9 days later, all five patients developed between three and 12 edematous, migrating skin lesions on the back, abdomen, upper and lower extremities, face, eye and scalp. By ELISA, all of them were sero-positive to Gnathostoma doloresi antigen and had elevated IgE levels. Eosinophilia was found in two patients. These patients lived in an agricultural and fishing community. In this community we carried out a sero-epidemiological survey and study of living conditions in a random sample of 309 individuals distributed in 74 households. Frequent consumption of raw fish was reported in 36% of households, and 12 individuals had a clinical history of migrating skin lesions. The sero-prevalence to Gnathostoma antigens was 34.95%. Five fish species and four species of ichthyophagous birds collected from three lakes in the village and a nearby estuary were infected with the advanced third-stage larvae of G. binucleatum, a species found in Ecuador and Mexico. The results describe the first known outbreak of acute gnathostomiasis on the American continent.

Estudio de pacientes con parasitosis intestinal: mediante algoritmos / Test of ratients with intestinal parasitosis based on olgorithms

Se efectuó el estudio sistematizado de pacientes con probable parasitosis intestinal, por medio de procedimientos diagnósticos basadoas en algoritmos. Se diseño un formato de datos para orientar el diagnóstico y algoritmos con las rutas diagnósticas de las diferentes parasitosis intestinal. Se incluyeron 475 pacientes en edad pediátrica, de la consulta del Servicio de Parasitología del Instituto nacional de Pediatría S.S., Centro de Salud Manuel González e Instituto Nacional de diagnóstico y Referencias Epidemiológica, con sospecha de padecer parasitosis intestinal, sin exámenes de laboratorio. Se les realizó historia clínica incluyéndose en el algoritmo correspondiente de los 475 pacientes; se excluyeron 12 por diferentes motivos, quedando solamente 463 de éstos; en 291 se confirmó la presencia de parásitosis por diferentes métodos de laboratorio. En 117 se demostró parasitosis mixta y en 174 parasitosis única; 277 fueron sintomáticoas y 14 asintomáticos. Cuando de tomó en cuenta únicamente coproparasitoscópicos sin otros exámenes especiales, se diagnosticó el 86.95 por iento de parasitos, el 13.05 por ciento restante requirió de exámenes especiales. En el control postratamiento se encontró que en 243 pacientes fue efectivo un solo tratamiento, en 38 se necesitaron dos, y en 10 se tuvo que administrar más de dos tratamientos. Los datos obtenidos, muestran que es necesario una metodología sistematizada para abarcar el mayor número de posibilidades diagnósticas en pacientes con diagnóstico presuncional de parasitosis intestinal, representando los algoritmos un procedimiento útil para elaborar diagnósticos de certeza, en una forma sencilla y rápida.