RESUMEN
We examined the epidemiology of Cryptosporidium parvum in children aged 6 months to 13 years living in 1) colonias along the border (n = 105), 2) a clinic in an urban border community (n = 65), and 3) clinics in a large urban nonborder area (n = 109). Serum IgG and IgA anticryptosporidial antibodies were measured by enzyme-linked immunosorbent assay (ELISA). Overall, 70.2% (196/279) of subjects had detectable C. parvum antibodies. Prevalence rates were higher (93/105 [89%]) in the colonias and urban border community (53/65 [82%]) compared to the urban nonborder community (50/109 [46%]). Within colonias, independent risk factors for C. parvum infection included consumption of municipal water instead of bottled water, older age, and lower household income. Children living along the Texas-Mexico border have a higher rate of infection with C. parvum compared to children living in a large nonborder urban area. Within colonias, C. parvum infection was associated with source of water supply, age, and socioeconomic status.
Asunto(s)
Anticuerpos Antiprotozoarios/sangre , Criptosporidiosis/epidemiología , Cryptosporidium parvum/inmunología , Adolescente , Animales , Niño , Preescolar , Femenino , Humanos , Lactante , Masculino , México/epidemiología , Prevalencia , Factores de Riesgo , Población Rural , Encuestas y Cuestionarios , Texas/epidemiología , Población UrbanaRESUMEN
An initial retrospective study of 194 children demonstrated a high prevalence of hepatitis A but not hepatitis B or C infection among children living along the Texas-Mexico border. A larger prospective study of hepatitis A was conducted with 285 children (aged 6 months to 13 years) living in 3 sociodemographically dissimilar areas of South Texas. Children living in colonías along the border had a significantly higher prevalence of hepatitis A virus infection (37%) than children living in urban border communities (17%) or in a large metropolitan area (San Antonio [6%]). Independent risk factors for hepatitis A infection included increased age, colonía residence, and history of residence in a developing country. Use of bottled water (vs. municipal or spring/well water) and years of maternal secondary education were protective. Improved sanitation or routine hepatitis A vaccination in early childhood may reduce the prevalence of hepatitis A in these areas.
Asunto(s)
Hepatitis A/epidemiología , Anticuerpos Antihepatitis/sangre , Población Rural , Adolescente , Niño , Preescolar , Estudios Transversales , Anticuerpos de Hepatitis A , Hepatitis B/epidemiología , Hepatitis C/epidemiología , Hispánicos o Latinos , Humanos , Lactante , México , Prevalencia , Estudios Prospectivos , Factores de Riesgo , Encuestas y Cuestionarios , Texas/epidemiologíaRESUMEN
Gastric cancer is more than twice as common in Hispanics as in Anglos in Texas, while colorectal cancer is almost twice as common in Anglos as Hispanics. To test the hypothesis that mutations in the p53 tumour suppressor gene are involved in these differences, we examined 131 gastric and 138 colorectal cancers from Hispanic and Anglo patients from South Texas and Mexico using immunohistochemistry (IHC) as a screening assay for p53 mutations. The fraction of p53 positive cases was not significantly different in gastric cancers from Hispanics compared to Anglos (43% versus 61%, respectively, p = 0.13) or in colorectal cancer (57% versus 58%, respectively, p = 1.0), suggesting that p53 mutations are not involved in causing the different incidences of these cancers in these populations. In addition, the types of p53 mutations arising in gastric tumours from Hispanic patients were consistent with those reported in gastric tumours in other populations. Sequencing of mutations in five gastric cancers revealed two G:C to A:T transitions, two A:T to G:C transitions and one complex deletion. In contrast with findings in studies in other tumour types, neither stage nor survival was associated with p53 positive staining by IHC in either gastric or colorectal tumours in this study. Positive p53 immunostaining was associated with the diffuse histological subtype in gastric carcinoma (p = 0.05) and high histological grade in colorectal carcinoma (p = 0.04).
Asunto(s)
Neoplasias Colorrectales/genética , Genes p53 , Hispánicos o Latinos/genética , Mutación , Neoplasias Gástricas/genética , Secuencia de Bases , Codón , Neoplasias Colorrectales/química , Neoplasias Colorrectales/etnología , Exones , Femenino , Humanos , Inmunohistoquímica , Masculino , México , Datos de Secuencia Molecular , Neoplasias Gástricas/química , Neoplasias Gástricas/etnología , Texas , Proteína p53 Supresora de Tumor/análisis , Proteína p53 Supresora de Tumor/metabolismoRESUMEN
Data on cancer rates from West Indian populations are scarce, and to the authors' knowledge there are no published data on cancer rates and distributions among Haitians. Proportional distributions of cancers among three groups of patients living in Florida were compared: Haitian born blacks, United States born blacks, and non-Haitian Caribbean born blacks. The incidence rate of cancer of the cervix among the Haitian and United States born black groups was also compared. Increased rates of certain malignancies associated with viral infection or immunodeficiency were found in the Haitian group. These tumors were hepatocellular carcinoma, nasopharyngeal carcinoma, reticulum cell sarcoma, Kaposi's sarcoma, and carcinoma of the uterine cervix. The age-adjusted incidence rate of carcinoma of the cervix was especially high among Haitian women even with a liberal estimate of the female Haitian population from whom the cases were drawn. Except for cancer of the cervix, the numbers of cancers of interest were small, and age-adjusted incidence rates were not calculated. Continued epidemiological study of larger numbers of patients is needed to evaluate these findings further.