-One hundred and seven fattening pig units randomly selected in Catalonia (Spain) were surveyed during 2001−2003, in order to determine the frequency of the prophylactic use of antimicrobials and mass treatments against respiratory and enteric disease outbreaks. Logistic regression and regression tree analysis were done to determine the factors associated with the on-farm mass antimicrobial usage. Fifty-eight per cent of the surveyed farms used mass antimicrobial prophylaxis; among them, 39% used two or more antimicrobials. The more frequently administered drugs were colistin, beta-lactams and tetracyclines. Fattening units from strict finishing farms were more likely to use antimicrobials than farrow-to-finish farms (Odds Ratio = 11.7) and farms with changing facilities were less likely to use these compounds (OR = 0.17). In the event of a respiratory disease outbreak, most farms applied mass treatment and 46% used two or more compounds, with tetracyclines, beta-lactams and sulphonamides being the most popular ones. Mass treatment with several compounds in case of respiratory problems was significantly related to the use of growth promoters on the farm (OR = 4.3). If an outbreak of an enteric disease occurred, most farms resorted also to a mass treatment and 48% used two or more drugs. The most frequent antimicrobial agent for the treatment of enteric disease was colistin. Fattening farms (OR = 6.9) and operations that perform routine antimicrobial prophylaxis (OR = 2.0) were more likely to use more than one antimicrobial agent for enteric diseases.antimicrobial agents / fattening pig units / prophylactic usage / regression tree

Pulsed-field gel electrophoresis, plasmid profiling, and phage typing were used to characterize and determine possible genetic relationships between 48 Salmonella enterica subsp. enterica isolates of pig origin collected in Catalonia, Spain, from 1998 to 2000. The strains were grouped into 23 multidrug-resistant fljB-lacking S. enterica serovar 4,5,12:i:؊ isolates, 24 S. enterica serovar Typhimurium isolates, and 1 S. enterica serovar 4,5,12:؊:؊ isolate. After combining the XbaI and BlnI macrorestriction profiles (XB profile), we observed 29 distinct subtypes which were grouped into seven main patterns. All 23 of the 4,5,12:i:؊ serovar strains and 10 serovar Typhimurium isolates were found to have pattern AR, and similarities of >78% were detected among the subtypes. Three of the serovar Typhimurium DT U302 strains (strains T3, T4, and T8) were included in the same 4,5,12:i:؊ serovar cluster and shared a plasmid profile (profile I) and a pattern of multidrug resistance (resistance to ampicillin, chloramphenicol, streptomycin, sulfonamide, tetracycline, gentamicin, and trimethoprim-sulfamethoxazole) commonly found in monophasic isolates. This led us to the conclusion that strains of the S. enterica 4,5,12:i:؊ serovar might have originated from an S. enterica serovar Typhimurium DT U302 strain.

No abstract

One hundred and thirteen finishing pig units and 74 sow units in Catalonia, Spain, were examined to determine the prevalence of salmonella infections and the factors that could be associated with them. Pooled faecal samples were taken from the finishing units, and samples of faeces were collected from individual sows. The Salmonella isolates were serotyped, phage typed and examined for their antimicrobial susceptibility to 18 common antimicrobial drugs. In addition, blood samples from pigs on 141 farms were analysed by ELISA. In both the bacteriological and serological surveys, a questionnaire with 84 questions was completed for each farm. Salmonella species were isolated from 20 per cent of the finishing units and 24 per cent of the sow units; 14 serotypes were detected in the finishing pigs and 11 in the sows. More than 30 per cent of the strains were resistant to tetracycline, sulphonamides, ampicillin or streptomycin, and 69 per cent of the strains were resistant to three or more agents up to 10 compounds. Seventy-seven per cent of the farms had at least one seropositive animal, and 26 per cent of these farms had an individual seroprevalence of 50 per cent or more. The factors associated (P<0.05) with the excretion of Salmonella species in the finishing units were the practice of raising livestock other than pigs (odds ratio [OR]=6.18), the herd size (OR=5.87), and a past history of clinical salmonellosis (OR=4.97). For the sows, the factors associated (P<0.05) with the excretion of Salmonella species were having open-flushed drainage of sewage (OR=34.48), a lack of rodent control measures (OR=0.05) and the number of sows in the unit (OR=9.26). Factors associated with seropositivity in the finishing units were a lack of bird-proof nets (OR=0.30) and the use of water from private wells (OR=3.64).

No abstract

No abstract

Background Since the late twentieth century, Chagas disease gained global attention to suppress the vector burden as a main control strategy in endemic countries. In Central America, multi-national initiative successfully achieved significant reduction in the estimated disease prevalence as well as elimination of the region’s principal vector species at the time in 2012. While the last decade has witnessed significant changes in ecosystem—such as urbanization and replacement of the main vector species—that can possibly affect the vector’s habitation and residual transmission, the up-to-date vector burden in the region has not been evaluated thoroughly due to the cessation of active vector surveillance. The aim of this study was to update the risk of vector-borne Trypanosoma cruzi infection in El Salvador, the top Chagas disease-endemic country in Central America. Methods A nationwide vector survey was conducted in the domestic environment of El Salvador from September 2018 to November 2020. The selection of the houses for inspection was based on expert purposeful sampling. Infection for T. cruzi was examined by microscopic observation of the insects’ feces, followed by a species confirmation using PCR. The data were analyzed using R software version 4.1.3. Proportion estimates with 95% confidence intervals were inferred using the Jeffrey’s method provided under the epiR package. Results A total of 1529 Triatoma dimidiata was captured from 107 houses (infestation rate, 34.4%; 107/311) in all the fourteen departments of the country visited within the period; prevalence of T. cruzi infection was as high as 10% (153/1529). In the country, domestic T. dimidiata infestation was distributed ubiquitously, while T. cruzi infection rates varied across the departments. Five out of fourteen departments showed higher infection rates than the average, suggesting sporadic high-risk areas in the country. Conclusions Our comprehensive study revealed substantial T. cruzi infection of T. dimidiata across the country, indicating potential active transmission of the disease. Therefore, strengthened surveillance for both vector and human infection is required to truly eliminate the risk of T. cruzi transmission in Central America.

No abstract