Welfare issues and potential solutions for laying hens in free range and organic production systems: A review based on literature and interviews.

In free-range and organic production systems, hens can make choices according to their needs and desires, which is in accordance with welfare definitions. Nonetheless, health and behavioral problems are also encountered in these systems. The aim of this article was to identify welfare challenges observed in these production systems in the EU and the most promising solutions to overcome these challenges. It is based on a review of published literature and research projects complemented by interviews with experts. We selected EU specific information for welfare problems, however, the selected literature regarding solutions is global. Free range use may increase the risk of infection by some bacteria, viruses and parasites. Preventive methods include avoiding contamination thanks to biosecurity measures and strengthening animals' natural defenses against these diseases which can be based on nutritional means with new diet components such as insect-derived products, probiotics and prebiotics. Phytotherapy and aromatherapy can be used as preventive and curative medicine and vaccines as alternatives to antibiotics and pesticides. Bone quality in pullets and hens prevents keel deviations and is favored by exercise in the outdoor range. Free range use also lead to higher exposure to variable weather conditions and predators, therefore shadow, fences and guard animals can be used to prevent heat stress and predation respectively. Granting a free range provides opportunities for the expression of many behaviors and yet many hens usually stay close to the house. Providing the birds with trees, shelters or attractive plants can increase range use. Small flock sizes, early experiences of enrichment and personality traits have also been found to enhance range use. Severe feather pecking can occur in free range production systems, although flocks using the outdoor area have better plumage than indoors. While many prevention strategies are facilitated in free range systems, the influence of genetics, prenatal and nutritional factors in free range hens still need to be investigated. This review provides information about practices that have been tested or still need to be explored and this information can be used by stakeholders and researchers to help them evaluate the applicability of these solutions for welfare improvement.

Increased efficiency in evaluating patients with suspected tuberculosis by use of a dedicated airborne infection isolation unit.

BACKGROUND: The resurgence of tuberculosis (TB) in the 1980s and early 1990s in the United States was also accompanied by numerous hospital outbreaks of TB and nosocomial transmission to health care workers. OBJECTIVE: To determine whether a dedicated airborne infection isolation (AII) unit improves efficiency in "ruling-out" patients suspected of having pulmonary TB. This is important because, to prevent nosocomial transmission of TB, the number and ratio of patients isolated who are subsequently found to have TB is much higher than those "ruled out" and have TB excluded. METHODS: A prospective cohort study was conducted of all patients 18 years and older admitted to respiratory isolation during 3 separate time periods before and after opening of an 26-bed AII unit in a 1000-bed, public, university-affiliated, innercity hospital. RESULTS: A total of 879 patients were admitted during the 3 study periods. Most were black and males (87%, 72%, respectively). The median age was 42 years, and 70% of patients included in the study were HIV positive. Among patients who "ruled out," ie, TB was excluded by having 3 negative AFB smears of respiratory specimens for TB, there was a significant decrease in time from 5.0 days in period I to 3.3 days in period III (P < .0001). In period III, patients who were admitted to rule out TB in areas outside of the AII unit in other wards of the hospital required a significantly longer period to have TB excluded: 5.9 days compared with 3.5 on the AII unit (P = .0015). CONCLUSION: The decrease in isolation time after the opening of the dedicated AII unit demonstrates that a concerted effort to rule patients out by having nurses and respiratory therapists trained in tuberculosis control is efficacious and efficient and results in significant cost savings.

Risk of tuberculin skin test conversion among health care workers: occupational versus community exposure and infection.

A prospective observational cohort study to assess rates of and risk factors for tuberculin skin test (TST) conversion among health care workers (HCWs) was conducted at an urban hospital located in a high tuberculosis-incidence area in 1994-1998. All hospital employees undergoing required testing every 6 months were included. A total of 69 (1.2%) of 5773 susceptible employees had a documented TST conversion (overall rate, 0.38 per 100 person-years worked). No significant difference existed in conversion rates among employees with frequent, limited, or no patient contact. HCWs with a TST conversion lived in zip codes with higher tuberculosis case rates (P< or =.05). In multivariate analysis, TST conversion was associated with history of bacille Calmette-Guérin vaccination (relative risk [RR], 11.63), annual salary <$20,000 (RR, 3.67), and increasing age. In the setting of an effective tuberculosis infection-control program, TST conversion rates were low, and risk of conversion among HCWs was associated most strongly with nonoccupational factors.