Economic analysis of CDC's culture- and smear-based tuberculosis instructions for Filipino immigrants.

SETTING: In 2007, the US Centers for Disease Control and Prevention (CDC) revised its tuberculosis (TB) technical instructions for panel physicians who administer mandatory medical examinations among US-bound immigrants. Many US-bound immigrants come from the Philippines, a high TB prevalence country. OBJECTIVE: To quantify economic and health impacts of smear- vs. culture-based TB screening. DESIGN: Decision tree modeling was used to compare three Filipino screening programs: 1) no screening, 2) smear-based screening, and 3) culture-based screening. The model incorporated pre-departure TB screening results from Filipino panel physicians and CDC databases with post-arrival follow-up outcomes. Costs (2013 $US) were examined from societal, immigrant, US Public Health Department and hospitalization perspectives. RESULTS: With no screening, an annual cohort of 35 722 Filipino immigrants would include an estimated 450 TB patients with 264 hospitalizations, at a societal cost of US$9.90 million. Culture-based vs. smear-based screening would result in fewer imported cases (80.9 vs. 310.5), hospitalizations (19.7 vs. 68.1), and treatment costs (US$1.57 million vs. US$4.28 million). Societal screening costs, including US follow-up, were greater for culture-based screening (US$5.98 million) than for smear-based screening (US$3.38 million). Culture-based screening requirements increased immigrant costs by 61% (US$1.7 million), but reduced costs for the US Public Health Department (22%, US$750 000) and of hospitalization (70%, US$1 020 000). CONCLUSION: Culture-based screening reduced imported TB and US costs among Filipino immigrants.

Syphilis Among U.S.-Bound Refugees, 2009-2013.

U.S. immigration regulations require clinical and serologic screening for syphilis for all U.S.-bound refugees 15 years of age and older. We reviewed syphilis screening results for all U.S.-bound refugees from January 1, 2009 through December 31, 2013. We calculated age-adjusted prevalence by region and nationality and assessed factors associated with syphilis seropositivity using multivariable log binomial regression models. Among 233,446 refugees, we identified 874 syphilis cases (373 cases per 100,000 refugees). The highest overall age-adjusted prevalence rates of syphilis seropositivity were observed among refugees from Africa (1340 cases per 100,000), followed by East Asia and the Pacific (397 cases per 100,000). In most regions, male sex, increasing age, and living in non-refugee camp settings were associated with syphilis seropositivity. Future analysis of test results, stage of infection, and treatment delivery overseas is warranted in order to determine the extent of transmission risk and benefits of the screening program.

Recurrent multistate outbreak of Salmonella Newport associated with tomatoes from contaminated fields, 2005.

Salmonella Newport causes more than an estimated 100,000 infections annually in the United States. In 2002, tomatoes grown and packed on the eastern shore of Virginia contaminated with a pan-susceptible S. Newport strain caused illness in 510 patients in 26 states. In July-November 2005, the same strain caused illness in at least 72 patients in 16 states. We conducted a case-control study during the 2005 outbreak, enrolling 29 cases and 140 matched neighbourhood controls. Infection was associated with eating tomatoes (matched odds ratio 9.7, 95% confidence interval 3.3-34.9). Tomatoes were traced back to the eastern shore of Virginia, where the outbreak strain was isolated from pond water used to irrigate tomato fields. Two multistate outbreaks caused by one rare strain, and identification of that strain in irrigation ponds 2 years apart, suggest persistent contamination of tomato fields. Further efforts are needed to prevent produce contamination on farms and throughout the food supply chain.

Influence of respiratory motor neurone activity on human autonomic and haemodynamic rhythms.

Although humans hold great advantages over other species as subjects for biomedical research, they also bring major disadvantages. One is that among the many rhythmic physiological signals that can be recorded, there is no sure way to know which individual change precedes another, or which change represents cause and which represents effect. In an attempt to deal with the inherent complexity of research conducted in intact human subjects, we developed and used a structural equation model to analyse responses of healthy young men to pharmacological changes of arterial pressure and graded inspiratory resistance, before and after vagomimetic atropine. Our model yielded a good fit of the experimental data, with a system weighted R2 of 0.77, and suggested that our treatments exerted both direct and indirect influences on the variables we measured. Thus, infusions of nitroprusside and phenylephrine exerted all of their direct effects by lowering and raising arterial pressure; the changes of R-R intervals, respiratory sinus arrhythmia and arterial pressure fluctuations that these drugs provoked, were indirect consequences of arterial pressure changes. The only direct effect of increased inspiratory resistance was augmentation of arterial pressure fluctuations. These results may provide a new way to disentangle and understand responses of intact human subjects to experimental forcings. The principal new insight we derived from our modelling is that respiratory gating of vagal-cardiac motor neurone firing is nearly maximal at usual levels of arterial pressure and inspiratory motor neurone activity.

Effect of weight loss on the ECG of normotensive morbidly obese patients.

BACKGROUND: Morbid obesity produces a variety of ECG alterations, including leftward shifts of the P-wave, QRS, and T-wave axes; disproportionately high frequencies of low QRS voltage; left ventricular hypertrophy and left atrial abnormality; and a high frequency of T-wave flattening in the inferior and lateral leads. This study was designed to assess the effects of substantial weight loss on the ECG in morbid obesity. METHODS: We performed a resting 12-lead ECG on 60 normotensive patients (48 women and 12 men; mean +/- SD age, 37 +/- 7 years), whose body weight was twice their ideal body weight prior to and at the time of maximum weight loss after bariatric surgery. RESULTS: Mean weight decreased from 136 +/- 7 to 85 +/- 3 kg. Weight loss produced significant decreases in the frequencies of low QRS voltage; Romhilt-Estes point score > or = 5 points; SV(1) + RV(5) or V(6) > 35 mm; RV(5) or V(6) > 26 mm; RaVL > 11 mm; RaVL > or = 7.5 mm; SaVR > 14 mm; P-terminal force more negative than - 0.04 mm.s in lead V(1); and T-wave flattening in the inferior, lateral, and inferolateral leads. Weight loss significantly shifted the mean P-wave, QRS, T-wave axes rightward, and significantly reduced mean RaVL and mean SaVR voltage. CONCLUSION: Substantial weight loss is capable of reversing many of the ECG alterations associated with morbid obesity.

The electrocardiogram in morbid obesity.

Electrocardiographic variables that occurred with significantly higher frequency in morbidly obese patients than in lean controls were low QRS voltage, leftward shift of the P, QRS, and T axes and multiple electrocardiographic criteria for left ventricular hypertrophy and left atrial enlargement. P-terminal force, RaVL, SaVR, and R/S ratio in lead V1 values were significantly higher in morbidly obese than in lean subjects.

Atherosclerosis in angiographically "normal" coronary artery reference segments: an intravascular ultrasound study with clinical correlations.

OBJECTIVES: This study evaluated the magnitude, patterns and clinical correlates of atherosclerosis in angiographically "normal" reference segments in patients undergoing transcatheter therapy for symptomatic coronary artery disease. BACKGROUND: Pathologic studies indicate that the extent of coronary atherosclerosis is underestimated by visual analysis of angiographically normal coronary artery segments. Intravascular ultrasound allows detailed, high quality cross-sectional imaging of the coronary arteries in vivo. METHODS: Intravascular ultrasound was used to study angiographically normal coronary artery reference segments in 884 patients evaluated for transcatheter therapy for symptomatic native coronary artery disease. The reference segment was the most visually normal intravascular ultrasound cross section within 10 mm proximal to the target lesion but distal to any major side branch. Results are presented as mean value +/- 1 SD. RESULTS: Only 60 (6.8%) of 884 angiographically normal reference segments were normal by intravascular ultrasound. Reference segment percent cross-sectional narrowing measured 51 +/- 13% and correlated poorly with the target lesion percent cross-sectional narrowing (r = 0.166, p < 0.0001). Reference segments contained less calcific and dense fibrotic plaque and proportionately more soft plaque elements. Independent predictors of reference segment percent cross-sectional narrowing were male gender, patient age, diabetes mellitus, hypercholesterolemia and presence of multivessel disease. Independent predictors of reference segment calcification were patient age and serum creatinine levels. Reference segment percent cross-sectional narrowing in 723 patients undergoing transcatheter therapy was similar to that in patients studied for diagnostic purposes; however, reference segment arc of calcium was greater in treated patients (43 +/- 81 vs. 25 +/- 57, p = 0.015). Reference segment disease was not an independent predictor of subsequent angiographic restenosis or clinical events within 12 months of follow-up. CONCLUSIONS: Atherosclerosis is ubiquitous in angiographically normal coronary artery reference segments. Reference segment disease parallels the severity of target lesion disease and is associated with many of the conventional risk factors for coronary artery disease. Because of its sensitivity in detecting atherosclerosis in angiographically normal reference segments, intravascular ultrasound should enhance the study of risk factors for atherosclerosis and the results of therapies to control disease progression.

Analysis of electrocardiographic changes in status epilepticus.

The high mortality associated with status epilepticus (SE) has been hypothesized to result partially from neurologically induced changes in cardiac function. To test this hypothesis, we reviewed electrocardiograms of 60 patients presenting in status epilepticus. Sequential electrocardiograms before, during and after ictal episodes were compared to define changes from baseline studies. 58.3% of the SE patients (N = 35) exhibited significant abnormalities on electrocardiograms obtained within 24 h of status epilepticus. Specific electrocardiographic changes included arrhythmias, axis changes, conduction abnormalities and ischemic patterns. All of these abnormal ECG changes met generally accepted cardiologic standards for a high risk of myocardial dysfunction or ischemia. The association of ECG changes with mortality was statistically significant. These results indicate that a significant proportion of SE patients are at risk for cardiac dysfunction and that close monitoring of cardiac function is indicated during and after SE.

A possible role for the thyroid in reproductive inhibition in laboratory populations of the prairie deermouse (Peromyscus maniculatus).

Serum thyroxine concentrations were determined and found to be reduced in reproductively inhibited deermice selected from controlled growth laboratory populations. Daily injections of 1 microgram thyroxine in reproductively inhibited male deermice were shown to significantly increase testis weight and the number of spermatids with acrosome formation. Daily feeding of thyroxine to a controlled growth population promoted an increase in the mean weights of the reproductive organs of both sexes that was intermediate between reproductively inhibited and capable deermice. Also, two females in the population produced the first surviving young after 250 days of inhibition.