Caries, gender and socio-economic change in the Xavante Indians from Central Brazil

Background: The oral health conditions of indigenous peoples in Amazonia are closely associated with ecological and dietary changes related to interaction with non-Indians. Aim: The study investigated the incidence of caries in an indigenous community from Central Brazil focusing on gender differences. Subjects and methods: The research was conducted among the Xavante Indians and was based on longitudinal data collected in two surveys (1999 and 2004). The study included 128 individuals, 63 (49.2%) males and 65 (50.8%) females, divided in four age brackets (6-12, 13-19, 20-34, 35-60 years of age). The DMFT (decayed, missing and filled teeth) index and incidences (difference between 1999 and 2004) were calculated for each individual. The proportion of incidence was also calculated. Differences in caries risk between gender and age brackets were compared by parametric and non-parametric tests. Results: There were statistically significant differences in relation to caries incidence between age brackets and gender. The greatest incidence was observed in the 20-34 age bracket, which presented 3.30 new decayed teeth, twice the risk of the 6-12 age bracket (p0.01), chosen as reference. While females in most age groups did not show higher risk for caries when compared to males, there was a 4.04-fold risk in the 20-34 age bracket (p0.01). Conclusion: It is concluded that factors related to the social functions of each sex (gender issues) and differential access to information, health services, and education may help to understand the differences observed in the incidence of caries.

Human papillomavirus type 16 variants in cervical cancer from an admixtured population in Brazil

Several studies indicate that molecular variants of HPV-16 have different geographic distribution and risk associated with persistent infection and development of high-grade cervical lesions. In the present study, the frequency of HPV-16 variants was determined in 81 biopsies from women with cervical intraepithelial neoplasia grade III or invasive cervical cancer from the city of Belem, Northern Brazil. Host DNAs were also genotyped in order to analyze the ethnicity-related distribution of these variants. Ninie different HPV-16 LCR variants belonging to four phylogenetic branches were identified. Among these, two new isolates were characterized. The most prevalent HPV-16 variant detected was the Asian-American B-2,followed by the European B-12 and the European prototype. Infections by multiple variants were observed in both invasive cervical cancer and cervical intraepithelial neoplasia grade III cases. The analysis of a specific polymorphism within the E6 viral gene was performed in a subset of 76 isolates. The E6-350G polymorphism was significantly more frequent in Asian-American variants. The HPV-16 variability detected followed the same pattern of the genetic ancestry observed in Northern Brazil, with European, Amerindian and African roots. Although African ancestry was higher among women infected by the prototype, no correlation between ethnical origin and HPV-16 variants was found. These results corroborate previous data showing a high frequency of Asian-American variants in cervical neoplasia among women with multiethnic origin.