High exposure of West Nile virus in equid and wild bird populations in Spain following the epidemic outbreak in 2020

A cross-sectional study was conducted to assess the circulation and risk factors associated with West Nile virus (WNV) exposure in equine and wild bird populations following the largest epidemic outbreak ever reported in Spain. A total of 305 equids and 171 wild birds were sampled between November 2020 and June 2021. IgG antibodies against flaviviruses were detected by blocking enzyme-linked immunosorbent assay (bELISA) in 44.9% (109/243) and 87.1% (54/62) of unvaccinated and vaccinated equids, respectively. The individual seroprevalence in unvaccinated individuals (calculated on animals seropositive by both bELISA and virus microneutralization test [VNT]) was 38.3% (95%CI: 33.1-43.4). No IgM antibodies were detected in animals tested (0/243; 0.0%; 95%CI: 0.0-1.5) by capture-ELISA. The main risk factors associated with WNV exposure in equids were age (adult and geriatric), breed (crossbred) and the absence of a disinsection programme on the facilities. In wild birds, IgG antibodies against flaviviruses were found in 32.7% (56/171; 95%CI: 26.8-38.6) using bELISA, giving an individual WNV seroprevalence of 19.3% (95%CI: 14.3-24.3) after VNT. Seropositivity was found in 37.8% of the 37 species analysed. Species group (raptors), age (>1-year old) and size (large) were the main risk factors related to WNV seropositivity in wild birds. Our results indicate high exposure and widespread distribution of WNV in equid and wild bird populations in Spain after the epidemic outbreak in 2020. The present study highlights the need to continue and improve active surveillance programmes for the detection of WNV in Spain, particularly in those areas at greatest risk of virus circulation.

The treatment of mice with Lactobacillus casei induces protection against Babesia microti infection

In this study, we report that administration of Lactobacillus casei confers protection to mice against the intracellular protozoan Babesia microti. Mice treated with L. casei orally or intraperitoneally were inoculated 7 days later with an infectious dose of B. microti. Mice treated with lactobacilli showed significant reduction in the percentage of parasitized erythrocytes (PPE) compared to untreated mice. When mice were inoculated intraperitoneally with L. casei 3 or 0 days before challenge with B. microti, the PPE was significantly lower compared to untreated mice and there were no differences between treated mice and mice immune to B. microti infection. When mice treated with live or dead L. casei were compared to mice inoculated with Freund Complete Adjuvant before a B. microti infection, a significant reduction of PPE was observed. These results show the protective effect of L. casei administered to mice against a B. microti infection and suggest that it might act by stimulating the innate immune system.

Qualitative and quantitative research in social epidemiology: is complementarity the only issue?

Although in recent years there has been a growing acceptance of qualitative research in social epidemiology, the role and scope of its use remain a contested terrain. We sketch some of the issues that have been the focus of the debate between supporters and critics of qualitative research in social epidemiology and adjacent public health disciplines. They include epistemological problems, such as the limitations of survey research to uncover social mechanisms, lack of background among epidemiologists to generate sound hypotheses for specific populations, and ontological problems such the idealism inherent in some of the qualitative research coming from anthropology. Next we review the urban ethnographies of Elliot Liebow's and a decade of population based research in African American and low income neighborhoods in the United States to expose another role for qualitative research in social epidemiology. Thus, we argue that qualitative research has been used in scientific debates that confront egalitarian researchers with institutions or peers with opposing economic interests and ideologies. Qualitative research is often a powerful tool to fuel alternative theoretical frameworks and measures to be included in quantitative population based surveys. We confine this use of qualitative research to the academic world and do not necessarily imply that communities benefit from it as in action research.

[Salmonella: comparison of methods for its detection in bird feed]

The Gene Trak colorimetric hybridization method (GENE TRAK Systems, 31 New York Avenue, Framingham, M.A.) was compared with conventional methodology proposed by International Commission for Microbiological Standard Foods (ICMSF) for the detection of Salmonella in samples of broiler feed and raw materials of vegetal and animal origin used in its formulation. In this study 249 samples which included inoculated samples and 9 uninoculated samples were studied. On 240 uninoculated samples, 62.9% resulted free of Salmonella, 27.9% were positive for both methods and 9.2% were positive by Gene Trak but it couldn't be confirmed by conventional methodology after five determinations. This methodology is presented as an interesting method of screening with important advantages in comparison to conventional methodology: facility for processing a big number of samples with few material expenses, less time to get results and high sensibility.