Short report: neonatal screening pilot study of Toxoplasma gondii congenital infection in Mexico.

Congenital toxoplasmosis is an obstetric problem in Mexico, but its actual frequency is unknown. Using a network for screening of non-infectious disorders, we performed a pilot study to determine the frequency of IgM antibodies to Toxoplasma gondii in 1,003 infants (53.1% male, mean +/- SD age = 18.3 +/- 13.0 days, birth weight = 3.116 +/- 0.453 kg) in Mexico City from March to April 2003. Blood samples embedded in filter paper were assayed for IgM antibodies using a capture enzyme-linked immunosorbent assay and results were confirmed by Western blot. Two asymptomatic newborns, one of them premature, had IgM and IgG antibodies in a serum sample taken from both the infant and the mother and were clinically followed. Our data suggest a frequency of approximately two cases of congenital T. gondii infection per 1,000 newborns in Mexico City.

[Epidemiology of congenital hypothyroidism in Mexico]. / Epidemiología del hipotiroidismo congénito en México.

OBJECTIVE: To describe the epidemiological characteristics of congenital hypothyroidism (CH) in newborns (NB) detected by the Ministry of Health of Mexico (SSA). MATERIAL AND METHODS: A cross-sectional study was conducted. Thyroid stimulating hormone (TSH) was quantified in 1,379,717 blood samples of NB (from umbilical cord or heel prick), collected in Guthrie cards, between January 2001 and December 2002, in medical units of the SSA. The samples with TSH > or = 15 microUI/ml for cord blood and > or = 10 microUI/ml for heel blood were considered suspicious and were submitted for confirmation by thyroid hormone profile and/or scintigraphy. When the results were positive, the case was registered as confirmed CH and the clinical and demographic data were recorded in specific formats. Statistical analysis was performed using descriptive statistics. RESULTS: The prevalence of CH was 4.12 x 10,000 NB, with female predominance (66.84%). Regional variations in the prevalence were observed, the highest in Quintana Roo (8.13 x 10,000 NB) and the lowest in Sinaloa (0.62 x 10,000 NB). Abnormalities included 57.46% of ectopic glands, 35.91% of athyrosis, and 6.63% abnormal thyroid function conditions. The main clinical features were umbilical hernia (43.73%) and jaundice (41.58%). A total of 151 (17.12%) suspicious NB were not confirmed because of incomplete or inaccurate identification data, death of the NB, parent refusal, and change of address. CONCLUSIONS: CH was present in 1:2,426 NB, with a female predominance (2:1); an ectopic thyroid was the most common finding, and its prominent clinical features were umbilical hernia and jaundice.

Epidemiología del hipotiroidismo congénito en México / Epidemiology of congenital hypothyroidism in Mexico

OBJETIVO: Describir las características epidemiológicas del hipotiroidismo congénito en recién nacidos en unidades médicas de la Secretaría de Salud de México. MATERIAL Y MÉTODOS: Estudio transversal en el cual se cuantificó tirotropina en 1 379 717 muestras de sangre de recién nacidos (de cordón umbilical o de talón), recolectadas en papel filtro, de enero de 2001 a diciembre de 2002, en unidades médicas de la Secretaría de Salud. Las muestras con tirotropina >15 æUI/ml para sangre de cordón, y > 10 æUI/ml para talón, se consideraron sospechosas, y se notificaron para realizar el perfil tiroideo y gammagrafía. Cuando los resultados fueron positivos, el caso se registró como hipotiroidismo congénito confirmado, y se anotaron los datos clínicos y demográficos en formatos específicos. Se utilizó estadística descriptiva estándar. RESULTADOS: Se encontró una prevalencia de 4.12 x 10 000 recién nacidos, con predominancia del sexo femenino (66.84 por ciento). Se observaron variaciones estatales en la prevalencia, máxima en Quintana Roo (8.13 x 10 000 recién nacidos) y mínima en Sinaloa (0.62 X 10 000). Se encontraron 57.46 por ciento tiroides ectópicas, 35.91 por ciento agenesias tiroideas y 6.63 por ciento defectos de la función de las hormonas tiroideas. Los principales datos clínicos fueron hernia umbilical (43.73 por ciento) e ictericia (41.58 por ciento). A 151 (17.12 por ciento) sospechosos no se les realizó estudio confirmatorio debido a datos incompletos o falsos en la ficha de identificación, fallecimiento del recién nacido, renuencia de los padres y cambio de domicilio. CONCLUSIONES: El hipotiroidismo se presentó en 1:2 426 recién nacidos, con predominio femenino (2:1), siendo la ectopia tiroidea su forma más común, y la hernia umbilical y la ictericia sus datos clínicos prominentes.

[Hyperthyrotropinemia in Mexican newborns]. / Hipertirotropinemia en recién nacidos mexicanos.

OBJECTIVE: To assess the differences in the blood concentration levels of the thyroid stimulating hormone and their possible use as an indicator of iodine sufficiency, in a sample of Mexican newborns. MATERIAL AND METHODS: A cross-sectional study was conducted from September 1999 to August 2000, among 25,427 Mexican newborns in the Ministry of Health clinics from 5 states. A total of 8,095 heel-prick and 17,332 umbilical cord blood samples were analyzed. Blood samples were collected in filter paper and processed by enzyme-linked immunosorbent assay. The Mann-Whitney U test and the Kruskal-Wallis test were used for statistical analyses. RESULTS: Hyperthyrotropinemia was found in 9.95% of heel samples and in 24.27% of umbilical cord samples (TSH > 5 microUl/ml). CONCLUSIONS: The percentage of hyperthyrotropinemia observed in this study was higher than that expected in a population with sufficient iodine intake; these findings could be due to poor maternal iodine intake.

Hipertirotropinemia en recién nacidos mexicanos / Hyperthyrotropinemia in Mexican newborns

OBJETIVO: Comunicar las diferencias encontradas en los niveles de concentración sanguínea de la hormona estimulante de la tiroides y su posible uso como indicador del estado de suficiencia de yodo en una muestra de recién nacidos mexicanos. MATERIAL Y MÉTODOS: De septiembre de 1999 a agosto de 2000 se estudiaron 25 427 recién nacidos en unidades asistenciales de la Secretaría de Salud de cinco estados de la República Mexicana. Se analizaron 8 095 muestras de sangre de talón y 17 332 de cordón umbilical. La sangre fue recolectada en papel filtro y procesada mediante ensayo inmunoenzimático. Para el análisis estadístico se emplearon las pruebas U de Mann-Wittney, y de Kruskal-Wallis. RESULTADOS: Se observó que 9.95 por ciento de las muestras de talón y 24.27 por ciento de las de cordón presentaron hipertirotropinemia (TSH>5 æUI/ml). CONCLUSIONES: El porcentaje de muestras de hipertirotropinemia observado es mayor del esperado para una población con aporte suficiente de yodo. Este hallazgo pudiera deberse a una deficiencia en la ingesta materna de yodo