Prevalence of hepatitis C virus infection according to the year of birth: identification of risk groups

Hepatitis C virus (HCV) screening according to the year of birth is recommended is some countries based on epidemiological data. The aim of this study was to analyze anti-HCV prevalence among people born between 1905 and 2015 in Argentina. Patients attending a tertiary care hospital in Buenos Aires, Argentina, from 2001 to 2015, who had a determination of anti-HCV, were included. Of 22,079 patients analyzed, 1,152 (5.2%; 95% confidence interval [CI]: 4.9%-5.5%) patients showed positive anti-HCV and 729 (3.3%; 95% CI: 3.1%-3.5%) patients showed detectable viremia. Three risk groups were identified (HCV prevalence): low-risk group-outpatient clinics/emergencies (2.8%); intermediate-risk group-in-patients (8%); and high-risk group-dialysis/transplants (27.2%). In the low-risk group, being born in 1973 or before was identified as a cut-off value for the risk of anti-HCV acquisition (area under the receiver-operator characteristic curve: 75.1 [95% asymptotic CI: 0.732-0.770; p < 0.001]). Ninety-one patients born after 1973 (0.8%) showed positive anti-HCV versus 457 individuals born in 1973 or before (5.8%), p < 0.001. In this group, positive anti-HCV was observed in 252 females (2.1%) and 296 males (4.1%), p < 0.001. In a multivariate analysis adjusted for gender, alanine-aminotransferase levels and HIV coinfection, being born in 1973 or before was independently identified as a risk for positive anti-HCV (adjusted odds ratio: 14.234 [95% CI: 9.993-20.277]; p < 0.001). People born in 1973 or before without other risk factors should be included in screening programs to link the highest possible number of HCV-infected patients to appropriate care and treatment.

Study of the regional air quality south of Mexico City (Morelos state)

Results from the first study of the regional air quality in Morelos state (located south of Mexico City) are presented. Criteria pollutants concentrations were measured at several sites within Morelos in February and March of 2007 and 2009; meteorological data was also collected along the state for the same time periods; additionally, a coupled meteorology-chemistry model (Mesoscale Climate Chemistry Model, MCCM) was used to gain understanding on the atmospheric processes occurring in the region. In general, concentrations of almost all the monitored pollutants (O(3), NO(x), CO, SO(2), PM) remained below the Mexican air quality standards during the campaign; however, relatively high concentrations of ozone (8-hour average concentrations above the 60 ppb level several times during the campaigns, i.e. exceeding the World Health Organization and the European Union maximum levels) were observed even at sites with very low reported local emissions. In fact, there is evidence that a large percentage of Morelos vegetation was probably exposed to unhealthy ozone levels (estimated AOT40 levels above the 3 ppm h critical limit). The MCCM qualitatively reproduced ozone daily variations in the sites with an urban component; though it consistently overestimated the ozone concentration in all the sites in Morelos. This is probably because the lack of an updated and detailed emission inventory for the state. The main wind patterns in the region corresponded to the mountain-valley system (downslope flows at night and during the first hours of the day, and upslope flows in the afternoon). At times, Morelos was affected by emissions from surrounding states (Distrito Federal or Puebla). The results are indicative of an efficient transport of ozone and its precursors at a regional level. They also suggest that the state is divided in two atmospheric basins by the Sierras de Tepoztlán, Texcal and Monte Negro.

The roles of the glycosylphosphatidylinositol anchor on the production and immunogenicity of recombinant ookinete surface antigen Pbs21 of Plasmodium berghei when prepared in a baculovirus expression system

Malarial ookinetes express an immunodominant surface protein (P28) that is a priority candidate for the development of transmission-blocking vaccines. The full length P28 gene from Plasmodium berghei [Pbs21(1-213)] and a deletion construct [Pbs21(1-188)] encoding a protein that lacks the 25 C-terminal amino acids, including the glycosylphosphatidylinositol (GPI) anchor signal, were expressed in insect cells using baculovirus vectors. Pbs21(1-213) protein is strongly hydrophobic, found in the cytoplasm and on the surface of Spodoptera Sf21 cells, and in the culture medium. Pbs21(1-188) protein was largely found in the aqueous phase of the medium and in the cytoplasm of Sf21 cells, but was not detected on the cell surface. The presence of 25 C-terminal amino acids is therefore critical to the attachment of recombinant Pbs21 to the parasite plasma membrane. Mice were immunized subcutaneously or intramuscularly with affinity purified recombinant Pbs21(1-213), Pbs21(1-188) or native Pbs21 proteins. Following two immunizations, native Pbs21 induces higher titres when administered by either route, than the recombinant protein bearing an insect GPI anchor, which in turn is markedly more immunogenic than the recombinant polypeptide lacking a GPI anchor. When specific anti Pbs21 antibody titres exceeded 1 mg/ml all three antigens were capable of inducing transmission blockade > or = 90%, below 1 mg/ml blockade did not correlate with antibody concentration.