Modelling transmission and control of Mycobacterium avium subspecies paratuberculosis within Irish dairy herds with compact spring calving.

Paratuberculosis is a chronic bacterial infection of the intestine in cattle caused by Mycobacterium avium subspecies paratuberculosis (Map). To better understand Map transmission in Irish dairy herds, we adapted the French stochastic individual-based epidemiological simulation model to account for seasonal herd demographics. We investigated the probability of Map persistence over time, the within-herd prevalence over time, and the relative importance of transmission pathways, and assessed the relative effectiveness of test-and-cull control strategies. We investigated the impact on model outputs of calf separation from cows (calves grazed on pasture adjacent to cows vs. were completely separated from cows) and test-and-cull. Test-and-cull scenarios consisted of highly test-positive cows culled within 13 or 4 weeks after detection, and calf born to highly test-positive cows kept vs removed. We simulated a typical Irish dairy herd with on average 82 lactating cows, 112 animals in total. Each scenario was iterated 1000 times to adjust variation caused by stochasticity. Map was introduced in the fully naive herd through the purchase of a moderately infectious primiparous cow. Infection was considered to persist when at least one infected animal remained in the herd or when Map was present in the environment. The probability of Map persistence 15 years after introduction ranged between 32.2-42.7 % when calves and cows had contact on pasture, and between 18.9-29.4 % when calves and cows were separated on pasture. The most effective control strategy was to cull highly test-positive cows within four weeks of detection (absolute 10 % lower persistence compared to scenarios without control). Removing the offspring of highly test-positive dams did not affect either Map persistence or within-herd prevalence of Map. Mean prevalence 15 years after Map introduction was highest (63.5 %) when calves and cows had contact on pasture. Mean prevalence was 15 % lower (absolute decrease) when cows were culled within 13 weeks of a high test-positive result, and 28 % lower when culled within 4 weeks. Around calving, the infection rate was high, with calves being infected in utero or via the general indoor environment (most important transmission routes). For the remainder of the year, the incidence rate was relatively low with most calves being infected on pasture when in contact with cows. Testing and culling was an effective control strategy when it was used prior to the calving period to minimize the number of highly infectious cows present when calves were born.

[Cardiac myxoma. Surgical treatment. About 20 cases]. / Les myxomes cardiaques. Prise en charge chirurgicale. A propos de 20 cas.

INTRODUCTION: Cardiac myxoma is the commune cardiac tumors. Their clinical status depends in the anatomic type. The aim of this study is to evaluate our results and to compare them for literature. PATIENTS AND METHODS: From January 1990 to June 2004, 20 patients (8 males and 12 females) with mean age of 49 years underwent surgical treatment of cardiac myxoma. The tumors were in left atrium in 14 cases, in right atrium in 4 cases and biatrial in 2 cases. Surgical treatment consisted in complete resection of the tumor in all cases associated with partial atrial septal resection in 9 cases. RESULTS: There is not death in the postoperative outcome. The mean follow up is 50 months. The late mortality rate was 10%. All patients are asymptomatic and the echocardiography control showed no tumor recurrence. CONCLUSION: Cardiac myxoma is the communist primary tumor of the heart. Diagnosis is based upon echocardiography. Surgical management has well out come with low morbidity and mortality. Late results are satisfactory but regular screening is recommended although risk of recurrence is low.