Risk factors for work-related injury among farm workers: a 1-year study.

A 1-year prospective study was carried out to look for risk factors of farm-related injuries in Egusquiza, Santa Fe (Argentina). Information on demographic characteristics and occupational accidents was collected on (N=110, n=78) farm workers by means of personal interviews using a structured questionnaire. Monthly telephone contact was then maintained with the workers for 1 year to document all farm-related injuries. Data analysis included incidence rate, χ2 and logistic regression. Sixty-nine farm-related injuries were reported during the study period, six injuries being the maximum number affecting one worker. A total of 46.3% of the workers suffered at least one injury during the year. The incidence rate was 7.5 injuries/100 individual-month at risk. Medical assistance was needed in 26.8% of the cases and 5.8% of the injuries caused at least 1 day off work. Hospitalization for at least 1 day was required for 2.9% of the injured workers. Previous work-related injury in the family (p=0.005) (odds ratio (OR)=4.6, 95% confidence interval (CI)=1.6-13.3) and worker's activity (p=0.021) (OR=3.7, 95%CI=1.2-11.6) were associated with the dependent variable work injury. Agricultural and livestock farming are of great importance for the national economy. Workers' training on farm safety may play a key role to prevent work-related injuries and diseases.

Enzyme-linked immunosorbent assay to diagnose human leptospirosis: a meta-analysis of the published literature.

We report an evaluation of the accuracy of ELISA for the detection of Leptospira-specific antibodies in humans. Eighty-eight studies published in 35 articles met all inclusion criteria and were submitted to meta-analysis. Pooled sensitivity and specificity were 0·779 (95% CI 0·770-0·789) and 0·913 (95% CI 0·908-0·917), respectively, and the area under the curve was 0·964. Heterogeneity across studies was statistically significant, but none of the sources of heterogeneity (disease stage, antigen used, antibody detected) could fully explain this finding. Although the convalescent stage of disease was significantly associated with higher diagnostic accuracy, IgM ELISA was the best choice, regardless of the stage of disease. Negative ELISAs (IgG or IgM) applied in the acute phase do not rule out leptospirosis due to the possibility of false-negative results. In this case it is advisable to request a second blood sample or to apply a direct method for leptospiral DNA.

Interventions to reduce verocytotoxigenic Escherichia coli in ground beef in Argentina: a simulation study.

A stochastic simulation model was used to assess the effects of measures implemented in the agri-food-chain to reduce the contamination of ground beef with verotoxigenic Escherichia coli (VTEC). A published risk assessment model developed in Argentina was used as baseline scenario. Control measures assessed were based on either a reduction in herd prevalence of infection due to vaccination, reduction in opportunity for cross-contamination in the slaughterhouses by the introduction of an on-line hide-wash cabinet, and control of storage temperature in slaughterhouses, retail and home. Additionally, the increase of feedlot production was modelled. Simulations suggested that the greatest potential impact was associated with hide-wash cabinet and vaccination, measures aimed to reduce the VTEC prevalence and concentration in the cattle hides at the beginning of the food-chain. Control of storage temperature was not effective if the carcasses cross-contamination with the pathogen was not prevented or reduced. An increase production (fattening) of cattle in feedlots may raise the risk of VTEC infection and its sequelae. This information can be used as a basis for measures of risk management.

Clinical characteristics and risk factors of human leptospirosis in Argentina (1999-2005).

There is scarce data on the burden of leptospirosis and its epidemiological characteristics in Argentina. This study aimed to evaluate distribution of leptospirosis cases and identify risk factors for the disease during national laboratory-based surveillance. From January 1999 to December 2005, 812 suspected cases were referred to the national reference laboratory, of which 182 and 463 had respectively, laboratory confirmed and unconfirmed diagnosis of leptospirosis. The diagnosis of leptospirosis was discarded in 167 cases. The most prevalent presumptive infecting serogroup was Icterohaemorrhagie followed by Pomona, Ballum and Canicola. The majority of cases occurred during the worm and rainy months. Confirmed cases were predominantly adults and males, who presented with fever, headache and myalgias. Severe clinical manifestations included jaundice and acute renal insufficiency. Conjunctival suffusion, a hallmark clinical sign of leptospirosis, was found in 55% of confirmed cases, and 43% of the cases with discarded diagnosis (p=0.036). After multivariate analyses, age >30 years (OR=2.16; 1.05-4.41), occupation in a rural setting (OR=3.41; 1.45-8.06), contact with contaminated surface water (OR=2.17; 1.01-4.68), and contact with floods (OR=4.49; 1.17-17.25) were significantly associated with leptospirosis. In conclusion, although activities associated with rural occupations remain important risk factors in Argentina, exposures occurring during flooding events have emerged to be the major risk factor for leptospirosis.

Intramammary infections during the periparturient period in Argentine dairy heifers.

Prevalence of intramammary infections at prepartum and postpartum in primigravid heifers from five dairy herds located in the central dairy area of Argentina was determined. Mammary secretion samples from 140 heifers (560 mammary quarters) were obtained 14 days prior to the expected calving day and within 7 days after parturition and subjected to bacteriological analysis. No clinical mastitis cases were detected during the study. The number of infected heifers in at least one mammary quarter at pre and postpartum was 87 (62.2%) and 53 (37.8%), respectively. The most prevalent mastitis pathogens at prepartum among samples yielding a positive bacteriological culture were coagulase-negative staphylococci (69.07%), Staphylococcus aureus (12.71%) and Streptococcus uberis (4.42%). A decrease on isolation frequency of coagulase-negative staphylococci (53.41%) and S. uberis (2.27%) was observed at postpartum, while that of S. aureus showed an increase (21.59%). Presence of intramammary infections appeared to be associated with some management conditions. These results highlighted the need to improve diagnosis and control measures in replacement heifers.

Intramammary infections during the periparturient period in Argentine dairy heifers / Infecciones intramamarias durante el periparto en vaquillonas en Argentina

Prevalence of intramammary infections at prepartum and postpartum in primigravid heifers from five dairy herds located in the central dairy area of Argentina was determined. Mammary secretion samples from 140 heifers (560 mammary quarters) were obtained 14 days prior to the expected calving day and within 7 days after parturition and subjected to bacteriological analysis. No clinical mastitis cases were detected during the study. The number of infected heifers in at least one mammary quarter at pre and postpartum was 87 (62.2%) and 53 (37.8%), respectively. The most prevalent mastitis pathogens at prepartum among samples yielding a positive bacteriological culture were coagulasenegative staphylococci (69.07%), Staphylococcus aureus (12.71%) and Streptococcus uberis (4.42%). A decrease on isolation frequency of coagulase-negative staphylococci (53.41%) and S. uberis (2.27%) was observed at postpartum, while that of S. aureus showed an increase (21.59%). Presence of intramammary infections appeared to be associated with some management conditions. These results highlighted the need to improve diagnosis and control measures in replacement heifers.

Se determinó la prevalencia al preparto y posparto de infecciones intramamarias causadas por organismos patógenos de mastitis en vaquillonas primíparas de cinco establecimientos lecheros ubicados en la cuenca central santafesina. Se tomaron muestras de secreción mamaria de 140 vaquillonas (560 cuartos mamarios) aproximadamente 14 días antes de la fecha probable de parto y dentro de los 7 días posparto, y se procesaron bacteriológicamente. No se detectaron casos de mastitis clínicas durante el estudio. El número de vaquillonas infectadas en al menos un cuarto mamario al preparto y posparto fue de 87 (62,2%) y 53 (37,8%), respectivamente. Los organismos patógenos más prevalentes al preparto entre las muestras con cultivo bacteriológico positivo fueron estafilococos coagulasa negativos (69,07%), Staphylococcus aureus (12,7%) y Streptococcus uberis (4,42%). Al posparto se observó un descenso en la frecuencia de aislamiento de estafilococos coagulasa negativos (53,41%) y S. uberis (2,27%), mientras que la de S. aureus mostró un aumento (21,59%). La presencia de infecciones intramamarias pareció estar asociada con algunas prácticas de manejo. Estos resultados ponen de manifiesto la importancia de hacer extensivo el diagnóstico y control de la enfermedad a las vaquillonas de reemplazo antes de su ingreso al rodeo en ordeño.

Microbiological screening test validation for detection of tylosin excretion in milk of cows with low and high somatic cell counts.

Antibiotic residues in milk above tolerance levels interfere with dairy product processing and pose potential health risks to consumers. Residue avoidance programmes include, among other components, the observance of withdrawal times indicated in label instructions. Persistence of antibiotics in milk following treatment is influenced by drug, dosage, route of administration, body weight and mammary gland health status. Compositional changes that take place during intramammary infection (IMI) can affect antibiotic excretion in milk, thus modifying milk withdrawal time. The objectives of this study were to validate sensitivity and specificity of a qualitative microbiological method (Charm AIM-96) to detect tylosin in bovine composite milk and to determine the influence of subclinical IMI in tylosin excretion following intramuscular administration. For test validation, two groups of approximately 120 cows were used; one received a single intramuscular injection of tylosin tartrate at a dose of 20 mg/kg, while the other group remained as untreated control. Test sensitivity and specificity were 100% and 94.1% respectively. To determine the influence of subclinical IMI in tylosin excretion, two groups of seven cows, one with somatic cell counts (SCC) < or =250 000 cells/ml and the other with SCC > or =900 000, were administered a single intramuscular injection of tylosin tartrate at a dose of 20 mg/kg. Milk samples were obtained every 12 h for 10 days following treatment. Milk tylosin excretion averaged between 5 and 9 days for cows with low and high SCC respectively (P < 0.0001). Compositional changes in cows with high SCC most likely affect the pharmacokinetic characteristics of tylosin, extending the presence of the antibiotic in milk, thus influencing milk withdrawal times.

Associations between leptospiral infection and seropositivity in rodents and environmental characteristics in Argentina.

Our objective was to look for associations between leptospiral infection in rodents and selected environmental and rodent characteristics in Santa Fe, Argentina. Rodents (n = 214) were trapped alive from January 1998 to December 1999 in three environmental settings. Kidneys from 118 rodents were cultured and serum samples from 201 were processed by enzyme-linked immunosorbent assay (ELISA). Logistic regression was performed with ELISA seropositivity as the dependent variable and rodent characteristics were offered as independent variables. Overall prevalence of positive ELISA reactions was 42% (84/201). In urban areas, leptospiral isolations belonged to the Ballum serogroup; in natural corridors, they belonged to the Icterohaemorragiae serogroup. M. musculus (house mouse) was the most-frequently captured species and the predominant one in urban areas. Most isolates and seropositivity results were obtained on this species. Adults and subadults had higher seroprevalences than juvenile rodents. Oligoryzomys flavescens had higher seroprevalence than Akodon azarae, Mus musculus, Rattus rattus and Rattus norvegicus.

Associations between farmers' personal characteristics, management practices and farm performance.

A survey was carried out in a random sample of 123 dairy farms from the east of Ireland. The monthly mean production per cow was 315 l of milk and 11.5 kg of fat. The mean log herd somatic cell count was 5.45 (arithmetic mean = 372,573 cells/ml), with almost 50% of the monthly counts over 300,000 cells/ml in a 12-month period. Bivariate and multivariate analysis was performed to assess the relative impact of the personal characteristics of the farmer and the management policies he applied on the amount and quality of the milk produced. In five out of six models the group of variables related to farmers' attitudes, values, and sociodemographic profile explained a similar or greater amount (between 14.44 and 34.35%) of the variation of farm performance than the group of management variables (between 14.33 and 25.99%) as measured by the R2. These results stress the importance of the human factors in explaining variation in farm performance.

Vaccination with Anaplasma centrale: response after an experimental challenge with Anaplasma marginale.

The haematological and clinical responses to vaccination with Anaplasma centrale and to subsequent challenge with Anaplasma marginale were evaluated. Twenty Holstein steers 14 to 16 months of age were divided into two groups of 12 and eight animals respectively (groups I and II). Group I was inoculated on day zero with 10(7) A. centrale-infected erythrocytes and group II was kept as a control. On day 125 both groups were challenged with 5 X 10(7) A. marginale-infected erythrocytes. A. centrale inoculation produced low parasitaemias (maximum mean 2.7%), moderate packed cell volume (PCV) falls (minimum mean 20.5%) and no clinical symptoms. After the challenge group I had significantly lower parasitaemia (maximum mean 2.3%) and higher PCV (minimum mean 20.1%) than group II (7.5% and 14.5% respectively). Four steers from group II developed acute anaplasmosis and required treatment.

[Eperythrozoon teganodes infection in splenectomized calves in the province of Santa Fe, Argentina]. / Infección por Eperythrozoon teganodes en terneros espelenectomizados de la provincia de Santa Fe, Argentina.

The finding of Eperythrozoon teganodes in splenectomized calves from the Santa Fe province, Argentina, is reported. The morphology of the agent and the clinical characteristics of the infection are described.

Infeccion por Eperythrozoon teganodes en terneros esplenectomizados de la provincia de Santa Fe, Argentina. / Infection due to Esperythrozoon teganodes in splenectomized calves of the province of Santa Fe, Argentina

Se comunica el hallazgo de Eperythrozoon teganodes en la provincia de Santa Fe, describiendo su morfologia y las caracteristicas clinicas que presento la infeccion en terneros esplenectomizados

Infección por Eperythrozoon teganodes en terneros espelenectomizados de la provincia de Santa Fe, Argentina. / [Eperythrozoon teganodes infection in splenectomized calves in the province of Santa Fe, Argentina]

The finding of Eperythrozoon teganodes in splenectomized calves from the Santa Fe province, Argentina, is reported. The morphology of the agent and the clinical characteristics of the infection are described.