Tierra Del Fuego: What Is Left from the Precolonial Male Lineages?

Similar to other South American regions, Tierra del Fuego has an admixed population characterized by distinct ancestors: Native Americans who first occupied the continent, European settlers who arrived from the late 15th century onwards, and Sub-Saharan Africans who were brought to the Americas for slave labor. To disclose the paternal lineages in the current population from Tierra del Fuego, 196 unrelated males were genotyped for 23 Y-STRs and 52 Y-SNPs. Haplotype and haplogroup diversities were high, indicating the absence of strong founder or drift events. A high frequency of Eurasian haplogroups was detected (94.4%), followed by Native American (5.1%) and African (0.5%) ones. The haplogroup R was the most abundant (48.5%), with the sub-haplogroup R-S116* taking up a quarter of the total dataset. Comparative analyses with other Latin American populations showed similarities with other admixed populations from Argentina. Regarding Eurasian populations, Tierra del Fuego presented similarities with Italian and Iberian populations. In an in-depth analysis of the haplogroup R-M269 and its subtypes, Tierra del Fuego displayed a close proximity to the Iberian Peninsula. The results from this study are in line with the historical records and reflect the severe demographic change led mainly by male newcomers with paternal European origin.

Seroprevalence of hepatitis E virus in Argentinean blood donors.

BACKGROUND: Hepatitis E virus (HEV) is the main cause of enteric acute viral hepatitis worldwide. In this epidemiological framework, it has become a threat to blood safety and a relevant issue for blood transfusions. However, there is a paucity of data regarding prevalence of HEV infection. The aim of this study was to determine HEV seroprevalence in blood donors from different regions from Argentina. MATERIAL AND METHODS: Serum samples from 391 individuals attending five blood donor centers located in different regions from Argentina were analyzed for anti-HEV IgG and anti-HEV IgM. RESULTS: Overall, anti-HEV IgG was detected in 44 out of 391 (11.3%) samples. HEV prevalence ranged from 5.1 to 20.0% among different country regions. A significant difference in blood donors' age was observed between anti-HEV IgG positive and negative individuals [44 (37-51) vs. 35 (27-43), P < 0.001, respectively]. Anti-HEV IgM was detected in 8 out of 44 (18.2%) anti-HEV IgG positive cases. CONCLUSION: Anti-HEV IgG was detected in blood donor samples from five analyzed Argentinean regions, highlighting the wide distribution of the virus in the country. HEV prevalence was variable among different regions and significantly higher in older donors. Given the evidence of anti-HEV IgM presence in blood donors, suggesting a potential risk of transfusion-transmitted HEV, screening for HEV in blood units to be used in vulnerable population would be desirable. Molecular studies for detection of viremic donors and donor-recipients follow-up are necessary to certainly determine the risk of transfusion-transmitted HEV in Argentina.

Hepatitis B surface antibodies seroprevalence among people born before and after implementation of universal HBV vaccination.

Universal vaccination is the most effective strategy to control hepatitis B virus (HBV) infection. In Argentina, vaccination against HBV was incorporated in year 2000 for newborns and in 2003 for 11 years old children. However, there is a paucity of data about protection levels against HBV infection. The aim of this work was to determine the prevalence of seroprotective anti-HBs antibodies (aHBs) in Argentina. Serum samples negative for HBsAg and anti-HBc from 132 children born after year 2000 and 762 blood donors, older than 18 years, from five centers across the country, were analyzed for aHBs. Titers ≥10 mIU/mL were observed in 74/132 children (56.1%) and 336/762 (44.1%) in blood donors. The median age for blood donors was 33.9 (23-43); from them, 210 (27.6%) were born after 1992 and, therefore, were catch-up by vaccine implementation at 11 years old age. Donors born in 1992 or before showed a significantly lower frequency of protection (32.2%) compared to donors born after 1992 (75.2%), p < 0.0001. In addition, significant differences were observed in the status of seroprotection between different participating centers (p = 0.024). Implementation of HBV vaccine in 2000 and 2003 implied an overall increase of the aHBs seroprotective rates, with a particularly adequate response in children vaccinated at 11 years old age. The observed results suggest that population born in 1992 or before is currently the most susceptible. Consequently, it would be advisable to become aware of the risk of transmission in this age group and to stress this population vaccination campaigns.

Reduced docosahexaenoic acid synthesis may contribute to growth restriction in infants born to mothers who smoke.

In newborn infants, progressive decrease in anthropometric values and impairment of the docosahexaenoic acid (DHA) status was associated with maternal smoking during pregnancy, with a parallel increase of the metabolic precursor of DHA, alpha-linolenic acid. Maternal smoking may impair DHA synthesis which may contribute to reduced fetal growth.