Asymptomatic infection and risk factors for leptospirosis in Nicaragua.

As part of an investigation of a 1995 outbreak of leptospirosis in Nicaragua, a cross-sectional serologic survey was conducted in the town of El Sauce. Of 566 persons, 85 (15%) were positive for IgM anti-Leptospira antibodies, indicating recent leptospirosis infection. Asymptomatic leptospirosis infection was common, with only 25 (29.4%) of the 85 seropositive inhabitants reporting a febrile illness in the 2 months before the survey. Multivariable analysis revealed that having an indoor water source remained independently protective against leptospirosis. Gathering wood was independently associated with infection. These findings suggest that asymptomatic infection with Leptospira is common in endemic areas of Leptospira transmission. Improvement in water sanitation and behavioral modifications to reduce environmental exposure may reduce the risk of leptospirosis in endemic regions.

Utilization of three maturities of alfalfa by dairy cows fed rations that contain similar concentrations of fiber.

The effect of alfalfa maturity on ration utilization and lactation performance by high producing dairy cows was measured in a 13-wk lactation study. Eighteen multiparous Holsteins were fed one of three rations containing first crop alfalfa hay harvested at early vegetative (36.1% NDF), late bud (51.7% NDF), or full bloom (51.7% NDF) maturity. Forage to concentrate ratios were 68:32, 53:47, and 45:55 for early vegetative, late bud, and full bloom rations, respectively. As offered, the late bud ration was higher in fiber (34.6% NDF) than either the early vegetative (31.8% NDF) or full bloom (30.6% NDF) rations. Cows fed the ration with early vegetative hay produced as much 4% FCM (32.5 kg) as cows fed the ration containing more fiber (late bud, 32.9 kg) or the later maturity hay (full bloom, 32.2 kg). Milk fat and protein composition were not affected by ration fiber concentration or forage maturity. Average dry matter intake per day and body weight change were similar across treatments. Time spent ruminating was similar for the three rations (6.8 h/d), but eating time was affected by forage maturity (early vegetative, 4.4 h/d vs. full bloom, 5.7 h/d). Cows receiving the higher fiber diet (late bud, 6.2 h/d) spent more time eating than cows receiving the lower fiber diets. Fiber concentration and forage maturity did not affect milk production, milk composition, or body weight change of high producing dairy cows in early lactation.

Spontaneous abortion after midtrimester amniocentesis.

Of 371 consecutive patients who underwent midtrimester diagnostic amniocentesis, 8 subsequently aborted spontaneously (2.2%), and 1 had a stillbirth at 24 weeks of gestation (0.17%). In 3 of the 9 patients who suffered fetal loss, infection appears to have played a significant role. Whereas midtrimester diagnostic amniocentesis is widely considered to be a safe and accurate procedure, the possibility of hazard to the patient and her fetus remains and should be considered during the preliminary counseling session.