Neutralising antibodies for West Nile virus in horses from Brazilian Pantanal

Despite evidence of West Nile virus (WNV) activity in Colombia, Venezuela and Argentina, this virus has not been reported in most South American countries. In February 2009, we commenced an investigation for WNV in mosquitoes, horses and caimans from the Pantanal, Central-West Brazil. The sera of 168 horses and 30 caimans were initially tested using a flaviviruses-specific epitope-blocking enzyme-linked immunosorbent assay (blocking ELISA) for the detection of flavivirus-reactive antibodies. The seropositive samples were further tested using a plaque-reduction neutralisation test (PRNT90) for WNV and its most closely-related flaviviruses that circulate in Brazil to confirm the detection of specific virus-neutralising antibodies. Of the 93 (55.4%) blocking ELISA-seropositive horse serum samples, five (3%) were seropositive for WNV, nine (5.4%) were seropositive for St. Louis encephalitis virus, 18 (10.7%) were seropositive for Ilheus virus, three (1.8%) were seropositive for Cacipacore virus and none were seropositive for Rocio virus using PRNT90, with a criteria of > four-fold antibody titre difference. All caimans were negative for flaviviruses-specific antibodies using the blocking ELISA. No virus genome was detected from caiman blood or mosquito samples. The present study is the first report of confirmed serological evidence of WNV activity in Brazil

Preexisting Japanese Encephalitis Virus Neutralizing Antibodies and Increased Symptomatic Dengue Illness in a School-Based Cohort in Thailand

Dengue viruses (DENVs) and Japanese encephalitis virus (JEV) have significant cross-reactivity in serological assays, but the possible clinical implications of this remain poorly understood. Interactions between these flaviviruses are potentially important for public health because wild-type JEV continues to co-circulate with DENV in Southeast Asia, the area with the highest burden of DENV illness, and JEV vaccination coverage in this region is high. In this study, we examined how preexisting JEV neutralizing antibodies (NAbs) influenced the clinical severity of subsequent DENV infection using data from a prospective school-based cohort study in Thailand that captured a wide range of clinical severities, including asymptomatic, non-hospitalized, and hospitalized DENV infections. We found that the prior existence of JEV NAbs was associated with an increased occurrence of symptomatic versus asymptomatic DENV infection. This association was most notable in DENV-naives, in whom the presence of JEV NAbs was also associated with an illness of longer duration. These findings suggest that the issue of heterologous flavivirus immunity and DENV infection merits renewed attention and interest and that DENV vaccine developers might incorporate detailed assessments of preexisting immunity to non-DENV flaviviruses and histories of vaccination against non-DENV flaviviruses in evaluating DENV vaccine safety and efficacy

Gender differences in the use of cardiovascular interventions in HIV-positive persons; the D:A:D Study

Peer reviewe

Mitochondrial DNA corroborates the species distinctiveness of the Planalto (Thamnophilus pelzelni Hellmayr, 1924) and the Sooretama (T. ambiguus Swainson, 1825) Slaty-antshrikes (Passeriformes: Thamnophilidae)

The Thamnophilus punctatus complex has been recently reviewed on the basis of morphological and vocal characters, and is divided in six different species. Two of the new species, although well defined on the basis of morphological differences, could not be unambiguously distinguished through their loudsongs. The Planalto Slaty-antshrike (Thamnophilus pelzelni) and the Sooretama Slaty-antshrike (T. ambiguus) are most easily distinguished by subtle and localized changes in plumage colors of males and females. In the present study we used sequences of the control region, Cytochrome b, and ND2 genes, of the mitochondrial DNA (mtDNA) to evaluate the levels of molecular differentiation between these two species. The mean pairwise distance between the two species was 3.8%, while it varied from 2.7% to 4.9% for each mtDNA region. Although extensive variation was also detected among haplotypes within species, especially for T. ambiguus, we suggest that the genetic divergence found between T. ambiguus and T. pelzelni is high enough to corroborate the separate species status of these two antbird taxa

Re-examining policies for food security in Asia

In the wake of recent food price spikes, plus growing demands for food in emerging Asia and for biofuels in Europe and the United States, governments are re-examining their strategies for dealing with both short-term and long-term food security concerns. This paper argues that long-run trends in real agricultural prices have policy implications for food security that are at least as important as those related to short-lived spikes around trend prices. The paper therefore summarizes recent projections of markets to 2030 under various scenarios, and then reviews evidence on how trade policy restrictions typically are altered to insulate domestic markets from short-run fluctuations in international prices around their long-run trends. That provides a firm empirical basis for re-examining the effectiveness and efficiency of various policy options for ensuring food security in Asia and elsewhere. Those options include boosting agricultural productivity growth rates to deal with long-run concerns, and using more-appropriate domestic policy measures rather than trade policies to cope with price volatility.Kym Anderson & Shikha Jha & Signe Nelgen & Anna Strut