A systematic review and meta-analysis of Toxoplasma gondii infection among the Mexican population.

BACKGROUND: Toxoplasmosis is a disease caused by Toxoplasma gondii and at least one-third of the world's population has detectable T. gondii antibodies. The seroprevalence of T.gondii ranges from 15% to 50% among the Mexican general population. The aim of this work was to determine the mean prevalence and weighted mean prevalence of T. gondii infection, and to evaluate the epidemiological transition of infection in Mexico. METHODS: Pub Med, Lilacs, Medline, Latindex, Google Scholar data bases were searched to retrieve reports from 1951 up to 2012 regarding prevalence data, diagnostic tests and risk factors of infection among the adult population. Data collection and criteria eligibility was established in order to determine the crude prevalence (proportion of positive cases) of each study, together with weighted population prevalence according to individual research group categories to limit the bias that may impose the heterogeneous nature of the reports. A Forest Plot chart and linear regression analysis were performed by plotting the prevalence of infection reported from each study over a period of sixty years. RESULTS: A total of 132 studies were collected from 41 publications that included 70,123 individuals. The average mean prevalence was 27.97%, and weighted mean prevalence was 19.27%. Comparisons among different risk groups showed that the weighted prevalence was higher in women with miscarriages (36.03%), immunocompromised patients (28.54%), mentally-ill patients (38.52%) and other risk groups (35.13%). Toxoplasma infection among the Mexican population showed a downward trend of 0.1%/year over a period of sixty years that represents a 5.8% reduction in prevalence. CONCLUSIONS: This analysis showed a downward trend of infection; however, there are individuals at high risk for infection such as immunocompromised patients, mentally-ill patients and pregnant women. Further research is required to provide better prevention strategies, effective diagnostic testing and medical management of patients. Educational efforts are required to avoid the transmission of infection in populations that cannot be controlled by drugs alone.

Prevalence of toxoplasma infection in Mexican newborns and children: a systematic review from 1954 to 2009.

Introduction. Recent studies in Mexico have shown that from 20/10,000 to 58/10,000 newborns with Toxoplasma infection could be undetected. The aim of this study was to determine the weighed prevalence of T. gondii infection and describe the epidemiological transition of infection in newborns. Methods. Research literature reporting Toxoplasma infection prevalence in Mexican newborns and children were searched in five international databases. Weighted prevalence was calculated by inverse variance-weighted method in asymptomatic and symptomatic study groups, and the epidemiological transition was estimated by a lineal regression analysis. Results. The weighed prevalence in 4833 asymptomatic newborns was 0.616%, CI95% (0.396%-0.835%) (P < 0.001), whereas, among 895 symptomatic newborns, the weighed prevalence was 3.02%, CI 95% (1.91%-4.1%) (P < 0.001). A downward trend of 0.25%/year represented an accumulated decrease of -13,75% in the prevalence in the symptomatic newborns throughout 55 years, whereas, in the asymptomatic children, the prevalence was similar over the course of the years. Conclusion. The high-weighted prevalence of congenital Toxoplasma infection in newborns justifies that Toxoplasma gondii testing be included in the screening programs for women during pregnancy and newborns in Mexico. A rapid diagnosis and treatment strategy could aid in limiting a potential damage to the newborns.

Entamoeba histolytica and Entamoeba dispar: differentiation by Enzyme-Linked Immunosorbet Assay (ELISA) and its clinical correlation in pediatric patients

Studies were carried out at a mexican pediatric hospital to determine the ratio between the pathogenic species Entamoeba histolytica and non-pathogenic species E. dispar using an enzyme-linked immunosorbent assay (ELISA) to detect the lectin (1 galactose N-acetyl D-galactosamine) of E. histolytica in feces. A close correlation was noted between the presence of the E. histolytica lectin and clinical symptoms. In the study, amebas were detected by microscopy in 120 children (either E. histolytica or E. dispar). But while almost all (13/14) of the children with E. histolytica had clinical symptoms, dysentery-feces with mocus and blood, diarrhea, cramping abdominal pain, tenesmus rectal, flatulence, vomiting and headache, almost none (1/106) of the children infected with the non-pathogenic ameba E. dispar had signs and symptoms. This suggests that much of the amebiasis diagnoses made in Mexico are, in fact, due to non-pathogenic E. dispar.

Protozoos emergentes. Comparación de tres métodos de identificación / Emergent protozoos. Comparison between three identification methods

Se realizó un estudio comparativo-prospectivo en 541 muestras de heces blanda, muy blandas y líquidas, de niños de un año a 14 años de edad. Se procesaron tres técnicas coproparasitoscópicas (CPS): CPS directo, CPS de concentración por flotación Ferreira y tinción de Kinyoun, para la identificación de Cryptosporidium parvum, Cyclospora cayetanensis, Isospora belli y Blastocystis hominis. Los cuatro protozoarios patógenos emergentes fueron identificados en 158 muestras de heces (29.2 por ciento). Dentro de los positivos el 25.9 por ciento correspondió a C. parvum, 11.4 por ciento a C. cayetanensis, 62.0 por ciento a B. hominis y sólo un caso de I. belli. La sensibilidad de la tinción de Kinyoun para C. parbun y C. cayetanensis fue de 100 por ciento y la especificidad de 98.8 por ciento, comparada con CPS Ferreira (p<0.05). La sensibilidad del CPS Ferreira en B. hominis fue 100.0 por ciento y la especificidad de 84.9 por ciento comprada con el CPS directo (p<0.05). Se sugiere que a todas las muestras de heces alteradas en su consistencia se les realice la búsqueda intencionada de estos cuatro patógenos emergentes, mediante CPS convencionales y la tinción de Kinyoun