Prevalence of pulmonary tuberculosis among respiratory symptomatic subjects in an out-patient primary health unit.

SETTING: Out-patient primary health unit (OPHU) in Rio de Janeiro City, Brazil. OBJECTIVE: To evaluate the impact on the detection of tuberculosis (TB) cases of reducing the time of respiratory symptoms from 'cough > or = 3 weeks' to 'cough > or = 1 week' as a criteria for TB case finding among individuals visiting an OPHU for any other reason. DESIGN: Cross-sectional study. RESULTS: During the period of the study, 10.7% (765/ 7174) of subjects reported cough > or = 1 week. Among 542 subjects enrolled in the study with cough > or = 1 week, 15 (2.7%) cases were diagnosed with pulmonary tuberculosis (PTB, 2767/100000). The probability of detecting TB in the OPHU setting among subjects seeking care for respiratory symptoms was significantly higher than among those presenting to the OPHU for other reasons (OR 31.5, 95% CI 4.1-241.9; P < 0.0001). The probability of identifying TB among patients seeking care due to respiratory symptoms was not influenced by the duration of cough (P = 0.7). CONCLUSION: These findings suggest that the screening criteria for TB case finding of cough for less than the usual 3 weeks among patients who attend a health facility due to respiratory symptoms in settings with a high prevalence of TB may significantly improve the proportion of TB cases diagnosed.

Attack cone avoidance during predator inspection visits by wild finescale dace (Phoxinus neogaeus): the effects of predator diet.

When confronted by potential predators, many prey fishes engage in predator inspection behavior. Previous authors have argued that by selectively avoiding the predator's head during an inspection visit (attack cone avoidance), individual inspectors may reduce their local risk of predation. In field trials, we investigated the effects of predator diet cues on the presence of 'attack cone avoidance' during predator inspection visits. Wild, free-ranging finescale dace (Phoxinus neogaeus) were exposed to the combined cues of a model predator and a distilled water control or the odor of a yellow perch (Perca flavescens) fed dace (with alarm pheromone), swordtail (Xiphophorus helleri) (lacking Ostariophysan alarm pheromone), or perch that were food deprived for four days. Finescale dace modified their predator inspection behavior following exposure to the odor of a perch fed dace (fewer dace present, reduced frequency of inspections, and an increased per capita inspection rate) compared to those exposed to the odor of a perch fed swordtails, perch that were food deprived, or a distilled water control. In addition, dace inspected the tail region more often only when the model predator was paired with the odor of a perch fed dace. In all other treatments, dace inspected the head region of the model predator more often. These data suggest that attack cone avoidance of inspecting prey fishes may be more likely to occur in high-risk situations, such as in the presence of conspecific alarm pheromones in the diet of potential predators.