Survival of Phortica variegata experimentally and naturally infected with Thelazia callipaeda.

Knowledge of the effects that Thelazia callipaeda (Spirurida, Thelaziidae) infection has on the survival of its vector Phortica variegata (Drosophilidae, Steganinae) is scarce. The present study aimed to: (a) assess the rate of infection between experimentally infected (EI) and not experimentally infected (NEI) flies and (b) determine how T. callipaeda infection may affect the survival of P. variegata. In addition, fat composition was evaluated in flies that died during overwintering. Molecular analysis showed that T. callipaeda prevalence in flies that died before experimental infection, plus those from the NEI group, is 0.75% (i.e. 11 out of 1462 individuals). The EI group showed a significantly higher positivity to T. callipaeda (i.e. 51 out of 682 individuals; 7.48%) compared with the NEI group (i.e. 9 out of 750 individuals; 1.2%). Thelazia callipaeda DNA was detected until 147 days after experimental infection. This demonstrates that larvae of this eyeworm may survive in the fly for a significant period of the winter. Fat composition analysis showed that flies produced more unsaturated than saturated fatty acids during diapause, probably because unsaturated fatty acids remain in a liquid state at lower temperatures, providing anti-freeze properties to survive winter.

AMPK is activated early in cerebellar granule cells undergoing apoptosis and influences VADC1 phosphorylation status and activity.

The neurodegeneration of cerebellar granule cells, after low potassium induced apoptosis, is known to be temporally divided into an early and a late phase. Voltage-dependent anion channel-1 (VDAC1) protein, changing from the closed inactive state to the active open state, is central to the switch between the early and late phase. It is also known that: (i) VDAC1 can undergo phosphorylation events and (ii) AMP-activated protein kinase (AMPK), the sensor of cellular stress, may have a role in neuronal homeostasis. In the view of this, the involvement of AMPK activation and its correlation with VDAC1 status and activity has been investigated in the course of cerebellar granule cells apoptosis. The results reported in this study show that an increased level of the phosphorylated, active, isoform of AMPK occurs in the early phase, peaks at 3 h and guarantees an increase in the phosphorylation status of VDCA1, resulting in a reduced activity of this latter. However this situation is transient in nature, since, in the late phase, AMPK activation decreases as well as the level of phosphorylated VDAC1. In a less phosphorylated status, VDAC1 fully recovers its gating activity and drives cells along the death route.

Thioredoxin/thioredoxin reductase system involvement in cerebellar granule cell apoptosis.

The involvement of thioredoxin/thioredoxin reductase system has been investigated in cerebellar granule cells (CGCs), a cellular system in which neurons are induced in apoptosis by the physiological stimulus of lowering extracellular potassium. Clarifying the sequence of events that occur during apoptosis is a critical issue as it can lead to the identification of those key events that, if blocked, can slow down or reverse the death process. The results reported in this work show that TrxR is involved in the early phase of CGC apoptosis with an increase in activity that coincides with the increased expression of the TrxR1 isoform and guarantees the maintenance of adequate level of Trx in its reduced, active form. However, in late apoptosis, when about 50 % of cells are dead, partial proteolysis of TrxR1 by calpain occurs and the reduction of TrxR1 mRNA, together with the overall decrease in TrxR activity, contribute to increase the levels of the oxidized form of Trx. When the reduced form of Trx is externally added to apoptotic cultures, a significant reduction in cell death is achieved confirming that a well-functioning thioredoxin/thioredoxin reductase system is required for survival of CGCs.

Persistent organic pollutants (PCBs and DDTs) in small size specimens of bluefin tuna (Thunnus thynnus) from the Mediterranean Sea (Ionian Sea).

The concentration levels and pattern distribution of polychlorinated biphenyls (PCBs) and organochlorine pesticides (DDTs), were investigated in liver of small size specimens of bluefin tuna (Thunnus thynnus) from Mediterranean Sea (Ionian Sea). PCB concentrations (average: 526 ng g(-1) lipid wt) were comparable with DDT levels (average: 435 ng g(-1) lipid wt). The specific analysis of PCB congeners revealed a profile dominated by hexa-, penta- and heptachlorinated congeners, while among DDTs, the compounds with the higher concentration was p,p'-DDE, constituting 91.9% of the total DDT. The total 2,3,7,8-TCDD toxic equivalent (TEQs) of coplanar PCBs, including mono- and non-ortho congeners, was 0.55 pg g(-1) wet weight with. The congeners with highest TEQs values were non-ortho congeners followed by mono-ortho ones.

Score for pulmonary tuberculosis in patients with clinical presumption of tuberculosis in a low-prevalence area.

OBJECTIVES: To develop a diagnostic predictive model for the identification of patients with presumptive pulmonary tuberculosis (PTB) at high risk for active disease and those requiring nucleic acid amplification (NAAT) testing and/or preventive respiratory isolation in low-incidence, high-income countries. DESIGN: A 1:1 case-control study was conducted in consecutive immunocompetent patients with presumed PTB hospitalised between 2009 and 2012 in Paris, France. Cases were defined as individuals with culture-confirmed PTB, regardless of smear result. Those with presumed PTB and three smear- and culture-negative samples were selected as controls. A score was derived using conditional logistic regression. Internal validity of the score was assessed using the bootstrap method. RESULTS: A total of 354 patients were included in the analysis (177 cases, 177 controls). Among the 177 cases, 74 (42%) were smear-negative but culture-positive. Factors independently associated with PTB were age <50 years (adjusted OR [aOR] 4.7, 95%CI 1.8-12), diabetes (aOR 3.2, 95%CI 1.1-9.8), absence of cough with or without sputum (aOR 3.7, 95%CI 1.7-8.3), fever >15 days (aOR 3.5, 95%CI 1.3-9.5), apical infiltration without cavity (aOR 3.4, 95%CI 1.4-8.5) and cavitation or miliary pattern (aOR 19.7, 95%CI 7.6-51.1). Score C-index was 0.84 (95%CI 0.79-0.88). Calibration for the overall population (P = 0.770) and in smear-negative patients (P = 0.980) was appropriate. A score of 3.3 had 90% sensitivity, 50% specificity and 79% (IQR 28-95) median probability of PTB. CONCLUSIONS: This score could be used to build an algorithm to determine the need for respiratory isolation and/or NAAT use in PTB disease.

Deliberate drug poisonings admitted to an emergency department in Paris area - a descriptive study and assessment of risk factors for intensive care admission.

OBJECTIVE: Each year, approximately 165,000 poisonings are managed in the emergency departments (ED) in France. We performed a descriptive analysis of self-poisoned patients admitted to a university hospital ED in the Paris metropolitan area (France) aimed at investigating their outcome and the risk factors for transfer to the intensive care unit (ICU). PATIENTS AND METHODS: We retrospectively reviewed patients' records and performed multivariate logistic regression analysis to identify risk factors for ICU admission. RESULTS: During 4 years, 882 self-poisoned patients (median age, 38 years [IQR, 26-47]; sex-ratio, 1M/3F) were admitted to the ED, representing 0.7% of all referred patients. Poisonings mainly resulted from multidrug exposures (53%), including benzodiazepines (78%), serotonin reuptake inhibitors (17%), acetaminophen (13%), antipsychotics (9.5%), imidazopyridines (9.5%), antihypertensive drugs (3%), and polycyclic antidepressants (1.3%). Ethanol was involved in 20% of the exposures. Patients were briefly (<24h) monitored in the ED (55%), transferred to the psychiatric department (30%), medical ward (2%) or ICU (6%), and took an irregular discharge (7%). Among the patients transferred to the ICU, 25% were mechanically ventilated and only one died. Risk factors for ICU admission included antihypertensive (Odds ratio (OR), 40.6; 95%-confidence interval (CI), 7.5-221.9) or antipsychotic drug ingestion (OR, 5.3; CI, 2.0-14.4), male gender (OR, 3.3; CI, 1.30-8.8), and consciousness impairment (OR, 2.1; CI, 1.8-2.5 per point lost in Glasgow coma score). CONCLUSIONS: Deliberate drug exposure represents a frequent cause of ED admission. Psychotropic drugs are most commonly involved. Transfer to the ICU is rare and predicted by male gender, drug class, and coma depth.

Impact of a short exposure to levofloxacin on faecal densities and relative abundance of total and quinolone-resistant Enterobacteriaceae.

Emergence of resistant Enterobacteriaceae in the intestinal microbiota during antibiotic treatment is well documented but its early dynamic is not. Here, we compared the densities of total Enterobacteriaceae and relative abundance (RA) of quinolone-resistant Enterobacteriaceae (QRE) in the first stool passed by patients who had a short exposure to levofloxacin (levofloxacin, n=12) or not (control, n=8). Mean densities (SD) (log CFU/g stool) of total Enterobacteriaceae were lower in the levofloxacin group than in the control group-3.4 (1.6) versus 6.7 (1.7), respectively, p <0.001. Conversely, mean RA (SD) of QRE was significantly higher in the levofloxacin group than in the control group-49.7% (23.4) versus 0.1% (3.2), respectively, p <0.05). In conclusion, even a short exposure to levofloxacin has a profound impact on the densities of total Enterobacteriaceae and the QRE-RA.

Lipid peroxidation in rat liver microsomes. II. Response of hydroperoxide formation to iron concentration.

When rat liver microsomes were incubated with NADPH, the major products were hydroperoxides which increased with time indicating that endogenous iron content is able to promote lipid peroxidation. The addition of either 5 microM Fe2+ or Fe3+ ions strongly enhanced the hydroperoxide formation rate. However, due to the hydroperoxide breakdown, hydroperoxide concentration decreased with time in this case. Higher ferrous or ferric iron concentration did not change the situation much, in that both hydroperoxide breakdown and formation were similar to those when NADPH only was present in the incubation medium. After lipid peroxidation, analysis of fatty acids indicated that the highest amount of peroxidized PUFA occurred in the presence of 5 microM of either Fe2+ or Fe3+. This analysis also showed that after 8 min incubation with low iron concentration, PUFA depletion was about 77% of that observed after 20 min, whereas without any iron addition or in the presence of 30 microM of either Fe3+, PUFA decrease was only about 37% of that observed after 20 min. As far as the optimum Fe2+/Fe3+ ratio required to promote the initiation of microsomal lipid peroxidation in rat liver is concerned, the highest hydroperoxide formation was observed with a ratio ranging from 0.5 to 2. These results indicate that microsomal lipid peroxidation induced by endogenous iron is speeded up by the addition of low concentrations of either Fe2+ or Fe3+ ions, probably because free radicals generated by hydroperoxide breakdown catalyze the propagation process. In experimental conditions unfavourable to hydroperoxide breakdown the principal process is that of the initiation of lipid peroxidation.

A nosocomial outbreak of multidrug-resistant Mycobacterium bovis among HIV-infected patients. A case-control study.

OBJECTIVE: To identify risk factors in a nosocomial outbreak of multidrug-resistant Mycobacterium bovis (MDRMB) tuberculosis (TB) among HIV-infected patients. DESIGN: We evaluated the study period (from the first to the last MDRMB smear-positive patients hospitalized in the unit) using a case-control study with three control groups. Since MDRMB is extremely rare, we assumed that a single strain was responsible for all six cases. SETTING: A 19-bed infectious diseases unit in Paris, France. PATIENTS: The index case was an AIDS patient who was hospitalized in September 1989 because of MDRMB TB. The cases were five HIV-infected patients who developed MDRMB TB between January 1990 and October 1991. Controls were randomly selected from HIV-infected patients in our unit during the study period (case-control study 1, 15 patients), during the contact period (at least one MDRMB smear-positive patient hospitalized in the unit; case-control study 2,20 patients), and patients matched according to the length of contact (case-control study 3, 24 patients). INTERVENTIONS: After detecting the nosocomial outbreak, we took respiratory isolation precautions for all patients suspected of having active TB. MAIN OUTCOME MEASURES: Risk factors for MDRMB nosocomial transmission, and the occurrence of new cases of MDRMB infection in HIV-infected patients and health-care workers after the introduction of isolation precautions. RESULTS: The most important predictor of nosocomial transmission of MDRMB to HIV-infected patients was the (mean +/- s.d.) length of contact in days [cases, 22 +/- 15.8; study 1 controls, 11.2 +/- 18.9 (P = 0.07); study 2 controls, 14.6 +/- 8.5 (P = 0.043)]. Only one case of MDRMB TB resulted from exposure to MDRMB-smear-positive patient after the introduction of respiratory isolation measures. The incubation period in the single health-care worker who developed MDRMB TB was longer than in the cases. CONCLUSION: In a nosocomial outbreak of MDRMB TB, the contact time was the main risk factor of transmission to HIV-infected patients. Respiratory isolation measures appear to be effective.

A possible mechanism for initiation of lipid peroxidation by ascorbate in rat liver microsomes.

The mechanism by which lipid peroxidation progresses has been known for years, but there is disagreement regarding the mode of its initiation. The aim of this study was to examine: (a) the role of endogenous iron in the initiation of ascorbate-induced lipid peroxidation in microsomal and liposomal membranes; (b) the role of oxygen-free radicals in this process; and (c) the redox state of ascorbate during the course of lipid peroxidation. Ascorbate-induced lipid peroxidation was assessed by measuring hydroperoxide and thiobarbituric acid reactive substances (TBARS) formation in membranes after incubation in Tris-HCl buffer (pH 7.4) for 15 min. To confirm the role of endogenous iron and oxygen-free radicals, the effect of iron chelating agents (EDTA and thiourea) and radical scavengers (benzoate, mannitol, catalase and SOD) on lipid peroxidation was examined. Spectrophotometric measurements and ESR spectra have made it possible to determine ascorbate concentration and its redox state. Ascorbate promoted lipid peroxidation in both rat liver microsomes and liposomes without addition of exogenous iron. Iron chelating agents such as EDTA and thiourea inhibited lipid peroxidation, while SOD, catalase, mannitol and benzoate had no effect. The addition of 5 microM Fe2+ (or Fe3+) to the incubation mixture did not significantly alter hydroperoxide production, but that of TBARS was increased. Lipid peroxidation significantly altered the fatty acid profile in microsomes and liposomes, the most affected being the C20:4 and C22:6 species. Ascorbate in Tris-HCl buffer (pH 7.4) autoxidized very slowly. Its oxidation was catalyzed by Fe3+ ions at a rate determined by incubation time and iron concentration. In contrast, no ascorbate oxidation occurred in the presence of microsomes when lipid peroxidation was proceeding at a maximal rate. Under these conditions a typical ascorbyl radical ESR spectrum signal greater than that arising from ascorbate alone was obtained and the magnitude of this signal was unchanged by variations of microsome or ascorbate concentrations. A ferrous ion ascorbyl radical complex was responsible for this signal. These results suggest that an ascorbate-microsomal iron complex is responsible for the initiation of lipid peroxidation, and that during this process ascorbate remains in its reduced form.

Resting energy expenditure in human immunodeficiency virus-infected patients: comparison between patients with and without secondary infections.

Resting energy expenditure (REE) was measured in 165 malnourished patients with human immunodeficiency virus infection and compared with that of 31 control subjects. Of these patients, 129 had no symptoms of secondary infections (NI), whereas 36 had evolving secondary infection (I) despite a body temperature < 38 degrees C. Mean REE was 11% higher in the NI group than in the control group (P < 0.05); it was 34% higher in the I group than in the control group (P < 0.001) and 21% higher than in the NI group (P < 0.01). In all cases the best predictive variable for REE was the fat-free mass (FFM) (r = 0.77, P < 0.001 in NI; r = 0.70, P < 0.001 in I; r = 0.78 in the control group. The REE-FFM ratio was 152.5 +/- 1.2 and 207 +/- 5.4 kJ.kg-1.d-1 in the NI and I groups, respectively. A high energy expenditure may be a harbinger of secondary infection in acquired immunodeficiency syndrome and may participate in accelerated weight loss.

Assessment of right ventricle function and pulmonary artery circulation by cine-MRI in patients with AIDS.

OBJECTIVE: To evaluate right ventricle (RV) anatomy and performance and its relationships with pulmonary circulation in AIDS patients. DESIGN: We conducted a prospective blinded study by using cine-MRI, a well-accepted method to assess RV and pulmonary circulation. SETTING: A university hospital. PARTICIPANTS: Ten healthy volunteers and 13 asymptomatic AIDS patients. MEASUREMENTS: RV end-diastolic and end-systolic volumes, RV ejection fraction (RVEF), pulmonary artery (PA) diameter, main pulmonary artery distensibility (MPAD), RV free wall diastolic thickness (RVWT), and RV mass were measured. The RVWT/left ventricular wall thickness index was calculated. RESULTS: AIDS patients had significantly increased RV end-diastolic and end-systolic volumes and decreased RVEF (50 +/- 10 vs 59 +/- 6; p < 0.03). Four AIDS patients had RV wall motion abnormalities; 5 (38%) had an RVEF under 45%. RVWT, the RVWT/left ventricular wall thickness index, and PA diameter were significantly increased in AIDS patients. RV mass was increased in 54% of AIDS patients. MPAD was significantly lower in AIDS patients (18.8 +/- 15 vs 26 +/- 4; p < 0.01). A significant relationship was found between RV mass and MPAD (r = 0.76; p = 0.02). CONCLUSIONS: RV function is frequently impaired in AIDS patients. Anatomic and functional abnormalities found in RV and PA parameters suggest a systolic overload on RV. Pulmonary circulation abnormalities may influence RV structure and function in AIDS patients.

Predictors of short- and long-term survival in HIV-infected patients admitted to the ICU.

STUDY OBJECTIVES: To evaluate the prognosis of HIV-infected patients admitted to ICUs and to identify factors predictive of short- and long-term survival. DESIGN: A prospective study from January 1, 1990, to December 31, 1992, including all consecutive HIV-infected patients admitted to our ICU for the first time. ICU survivors were followed up until January 1, 1994. SETTING: An 18-bed infectious diseases ICU in a 1,300-bed university hospital in Paris. PATIENTS: Four hundred twenty-one HIV-related admissions were recorded during the study period (33.5% of 1,258 admissions to ICU); 354 HIV-infected patients were first ICU admissions and were analyzed. MEASUREMENTS AND RESULTS: Predictive factors on univariate and multivariate analyses (logistic regression and Cox model) for short- and long-term mortality were performed. Respiratory failure was the main cause of admission (49.2%), followed by neurologic disorders (26.8%), sepsis (10.2%), heart failure (4.5%), and miscellaneous disorders (9.3%). For these groups, in-ICU and in-hospital mortality rates were as follows: 16.7% and 33.9%; 23.2% and 41.1%; 38.9% and 58.3%; 25% and 68.8%; and 12.1% and 24.2%, respectively. In-ICU and in-hospital mortality rates were significantly different across the groups (p=0.026 and 0.002, respectively). Multivariate analysis showed that the in-hospital outcome was significantly associated with functional status (p=0.05), time since AIDS diagnosis (p=0.04), HIV disease stage (0.016), simplified acute physiology score (SAPS I) (p=0.06), need for mechanical ventilation (p<0.000001), and its duration (p=0.0001). In the 281 patients who were discharged alive from the ICU, cumulative survival rates were 51%+/-38% at 6 months, 28%+/-38% at 12 months, and 18%+/-30% at 24 months. Median and crude mean+/-SD survival times were 199 days and 316+/-343 days. Multivariate analysis showed that the long-term outcome was significantly associated with functional status (p=0.000001), weight loss (p=0.00001), the CD4 count (p=0.00001), the HIV disease stage (p=0.01), the duration of AIDS (p=0.001), the admission cause group (p=0.03), and the SAPS I at admission (p=0.00001). CONCLUSIONS: The short-term (in-ICU and in-hospital) outcome of HIV-infected patients was mainly related to the severity of the acute illness (SAPS I, cause of admission, need for and duration of mechanical ventilation), and to the preadmission health status, based on functional status and weight loss. Some of these parameters, in particular the SAPS I and preadmission health status, also influenced the long-term outcome. Whereas HIV-related variables had little impact on the in-ICU outcome, they were closely related with the in-hospital outcome and even more strikingly with the long-term outcome. Thus, the life expectancy of HIV-infected patients, which depends primarily on the natural history of the HIV infection, is the most powerful determinant of the long-term prognosis. Our results confirm that ICU support for HIV-infected patients should not be considered futile.

The validity of medical history, classic symptoms, and chest radiographs in predicting pulmonary tuberculosis: derivation of a pulmonary tuberculosis prediction model.

STUDY OBJECTIVE: To improve the respiratory isolation policy for patients with suspected pulmonary tuberculosis (TB). DESIGN: Prospective, descriptive, French multicenter study. SETTING: Emergence of nosocomial outbreaks of TB. PATIENTS: All consecutive patients admitted with suspicion of pulmonary TB. MEASUREMENTS AND RESULTS: Medical history, social factors, symptoms, and chest radiograph (CXR) pattern (symptoms and CXR both scored as typical of pulmonary TB, compatible, negative, or atypical) were obtained on admission. Serial morning sputa were collected. Of the 211 patients, 47 (22.3%) had culture-proven pulmonary TB, including 31 (14.7%) with a positive smear. Mean age was 46.2 years; 52 patients were HIV positive (24.6%). The sensitivity of the respiratory isolation policy was 71.4%, specificity was 51.7%, negative predictive value (NPV) was 88.2%, and positive predictive value (PPV) was 26.3%. On univariate analysis, predictive factors of culture-proven pulmonary TB were CXR (p < 0.00001), symptoms (p = 0.0004), age (mean, 40.8 years for TB patients vs 47.5 years for non-TB patients; p = 0.04), absence of HIV infection (89.4% vs 71.3%; p = 0.01), immigrant status (72% vs 55%; p = 0.03), and bacillus Calmette-Guérin status (p = 0.025). On multivariate analysis, CXR pattern (p < 0.00001), HIV infection (p = 0.002), and symptoms (p = 0.009) remained independently predictive. Based on these data, a model was proposed using a receiver operating characteristics curve. In the derivation cohort, the sensitivity and NPV of the model in detecting smear-positive pulmonary TB would have been 100%. The specificity and PPV would have been 48.4% and 25%, respectively. The model performed less well when evaluated on two retrospective groups, but its sensitivity remained above that of the current respiratory isolation policy (91.1% and 82.4% for the retrospective groups vs 71.1% for the current policy). CONCLUSIONS: Improved interpretation of clinical and radiologic data available on patient admission could improve adequacy of respiratory isolation. A prediction model is proposed.

Persistent enhancement after treatment for cerebral toxoplasmosis in patients with AIDS: predictive value for subsequent recurrence.

PURPOSE: To determine the predictive imaging (CT and/or MR) features of brain toxoplasmosis recurrences in acquired immunodeficiency syndrome. METHODS: The imaging studies of patients with brain toxoplasmosis were retrospectively reviewed. Forty-three patients with significant decrease or disappearance of brain lesions under specific treatment on follow-up imaging examinations were included. MR examinations were performed using T2- and T1-weighted sequences, before and after intravenous administration of gadolinium-DOTA. RESULTS: A recurrence occurred in 11 (26%) of 43 cases. Ten (91%) of these 11 patients with recurrence showed focal persistent enhancement after the initial treatment of toxoplasmosis abscess. One of the 11 patients with recurrence showed no persistent enhancement; 3 patients showed persistent enhancement but had no recurrence. CONCLUSIONS: Recurrences of brain toxoplasmosis in our series correlated with persistent contrast enhancement. We hypothesize that demonstration of persistent areas of contrast enhancement after treatment for initial toxoplasmosis may be a valuable sign for identifying patients at risk for recurrence.

Pulmonary tuberculosis: computed tomography and high-resolution computed tomography patterns in patients who are either HIV-negative or HIV-seropositive.

To compare findings of active pulmonary tuberculosis on computed tomography (CT) and high-resolution computed tomography (HRCT) scans in patients without the human immunodeficiency virus (HIV) and patients with HIV, and to define the spectrum of pulmonary tuberculosis in patients with HIV according to the CD4 T cell status, 76 patients (47 patients without HIV and 29 patients with HIV) with newly diagnosed pulmonary tuberculosis were studied retrospectively. The diagnosis of active pulmonary tuberculosis was based on acid-fast bacilli (AFB) in sputum culture. All patients underwent CT within 1 month of diagnosis. Patients with HIV demonstrated significantly less cavitation and bronchial wall thickening (24% vs. 49% [p < 0.05]; and 14% vs. 45% [p < 0.01], respectively) than the combined group of patients with HIV. Centrilobular nodules were significantly less common in patients without HIV (14% vs. 45%, p < 0.05). Lymphadenopathy with low attenuation centers was significantly less frequent in the patients with HIV (3% vs. 15%, p < 0.05). In patients with HIV, cavitation, lymphadenopathy, as well as the the number of nodules and the number of lobes involved correlated well with the CD4 levels. Two patients with less than 50 CD4 T cells/mm3 had normal chest CT results. Atypical chest CT patterns are frequently encountered in patients with HIV. Knowledge of these CT patterns may assist in the diagnosis and follow-up of patients with HIV with known or suspected pulmonary tuberculosis.

[Development of a predictive model for respiratory isolation of patients suspected of having pulmonary tuberculosis]. / Proposition d'un score décisionnel d'isolement respiratoire précoce des patients suspects de tuberculose pulmonaire.

INTRODUCTION: As numerous nosocomial outbreaks of pulmonary tuberculosis have been reported during the last two decades, prompt identification and effective isolation of contagious patients should be made a priority in tuberculosis control policies. There is a need to develop a predictive model which would allow prompt recognition and isolation of smear-positive patients. CURRENT KNOWLEDGE AND KEY POINTS: Various authors have attempted to improve the respiratory isolation policies for patients suspected of having pulmonary tuberculosis. A French multicenter prospective study of 211 patients suspected of having pulmonary tuberculosis established that: 1) the current respiratory isolation policy of suspected pulmonary tuberculosis needs improvement (sensitivity = 71.4%; i.e., 28.6% of smear-positive patients are admitted without isolation) and 2) better interpretation of clinical and radiological data available on patient admission could improve the adequacy of respiratory isolation. Univariate analysis showed that predictive factors of pulmonary tuberculosis were chest X-rays (P < 0.00001), symptoms (P = 0.0004), age (mean: 40.8 years for TB vs. 47.5 for non-TB, P = 0.04), HIV infection (10.6% vs. 28.7%, P = 0.01), immigrant (72% vs. 55%, P = 0.03) and BCG status (P = 0.025), while multivariate analysis demonstrated that chest X-ray pattern (P < 0.00001), HIV infection (P = 0.002) and symptoms (P = 0.009) were independent predictive factors. FUTURE PROSPECTS AND PROJECTS: From these data, a model was proposed and evaluated in the derivation cohort using the receiver operating characteristics (ROC) curve. We retrospectively studied the predictive model in two populations different from the one from which it was derived. The model would have improved sensitivity of the respiratory isolation policy from 71.4% (current respiratory isolation policy) to 82.4% and 91.1%, respectively. Prospective, multicenter studies are requested to establish the value of such a predictive model in improving the respiratory isolation policy for patients suspected of having pulmonary tuberculosis.