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Biomedical subjects

A Spanevello

Publications and source records attributed to A Spanevello.

At least 19 recordsLinked to original sources

Effect of methacholine challenge on cellular composition of sputum induction.

BACKGROUND: Induced sputum and methacholine inhalation challenge are routinely used for the assessment of airway inflammation and airway hyperresponsiveness, respectively. This study investigates whether a methacholine challenge performed one hour before sputum induction alters the cellular and biochemical constituents of sputum. METHODS: Sixteen stable asthmatic patients with lung function within the normal range underwent two sputum inductions within one week. One hour before one of the sputum inductions a methacholine challenge was performed. RESULTS: There were no significant differences in total cell count, macrophages, neutrophils, eosinophils, lymphocytes, epithelial cells, ECP, and albumin between the two challenges. The repeatability of cell counts was good for all cells, ECP and albumin, but poor for total cells. CONCLUSIONS: In patients with stable asthma a methacholine challenge carried out one hour before sputum induction does not significantly alter the cellular and biochemical constituents of sputum.

Adolescent

Airway responsiveness to methacholine: effects of deep inhalations and airway inflammation.

We determined the dose-response curves to inhaled methacholine (MCh) in 16 asthmatic and 8 healthy subjects with prohibition of deep inhalations (DIs) and with 5 DIs taken after each MCh dose. Flow was measured on partial expiratory flow-volume curves at an absolute lung volume (plethysmographically determined) equal to 25% of control forced vital capacity (FVC). Airway inflammation was assessed in asthmatic subjects by analysis of induced sputum. Even when DIs were prohibited, the dose of MCh causing a 50% decrease in forced partial flow at 25% of control FVC (PD(50)MCh) was lower in asthmatic than in healthy subjects (P < 0.0001). In healthy but not in asthmatic subjects, repeated DIs significantly decreased the maximum response to MCh [from 90 +/- 4 to 62 +/- 8 (SD) % of control, P < 0.001], increased PD(50)MCh (P < 0.005), without affecting the dose causing 50% of maximal response. In asthmatic subjects, neither PD(50)MCh when DIs were prohibited nor changes in PD(50)MCh induced by DIs were significantly correlated with inflammatory cell numbers or percentages in sputum. We conclude that 1) even when DIs are prohibited, the responsiveness to MCh is greater in asthmatic than in healthy subjects; 2) repeated DIs reduce airway responsiveness in healthy but not in asthmatic subjects; and 3) neither airway hyperresponsiveness nor the inability of DIs to relax constricted airways in asthmatic subjects is related to the presence of inflammatory cells in the airways.

Administration, Inhalation

Bronchoalveolar lavage causes decrease in PaO2, increase in (A-a) gradient value and bronchoconstriction in asthmatics.

The aims of this study were to (1) record the changes of (arterial oxygen partial pressure) PaO2, (arterial carbon dioxide partial pressure) PaCO2, (percentage saturation of haemoglobin with oxygen in arterial blood) SaO2 and alveolar-arterial (A-a) oxygen gradiant resulting from bronchoalveolar lavage (BAL) in asthmatic and normal subjects; (2) measure changes in forced expiratory volume in 1 s (FEV1), vital capacity forced (FVC) associated with BAL; and (3) assess possible predictive factors for the degree of hypoxaemia and impairment of spirometry resulting from BAL. Bronchoscopy and BAL (150 ml) were performed in 24 asthmatics and 15 healthy subjects. Serial arterial blood samples (radial artery) were obtained in all subjects: T1 and before T2 after local anaesthesia; T3 at end of bronchoscopy; T4 after BAL and 5 min, 15 min, 1 h, 2 h, 8 h and 24 h (T5-T10) after the procedure, FEV1 and FVC were measured immediately before and 5 min afer bronchoscopy. Baseline PaO2 was lower in asthmatics (10.2 +/- 0.8 kPa) than in healthy subjects (10.8 +/- 0.8). Both groups showed a significant decrease in PaO2, and a significant widening in (A-a) oxygen tension gradiant at T3-9, with respect to T1 (P < 0.05). PaO2 reached a significantly lower value in asthmatics (7.1 +/- 0.6 kPa) than in HS (7.7 +/- 0.5; P < 0.05). In asthmatics, FEV1, FVC and the ratio FEV1/FVC decreased significantly after BAL (P < 0.001). In healthy subjects, FEV1 and FVC decreased significantly (P < 0.001), whereas FEV1/FVC did not. The fall in FEV1 after BAL was significantly greater in asthmatics (32.4 +/- 10.0%) than in healthy subjects (17.7 +/- 4.6; P < 0.001). Severity of asthma, basline FEV1 or initial PaO2 did not predict the degree of hypoxaemia or the fall of FEV1. It is concluded that BAL causes more severe hypoxaemia and a greater decrease in FEV1 in asthmatics compared to healthy subjects, strongly supporting the recommendation of special caution and careful monitoring when BAL is undertaken in asthmatics.

Analysis of Variance

Inhaled corticosteroids reduce neutrophilic bronchial inflammation in patients with chronic obstructive pulmonary disease.

BACKGROUND: Airways inflammation is a feature of chronic obstructive pulmonary disease (COPD), but the role of corticosteroids in the management of clinically stable patients has yet to be established. A randomised controlled study was carried out to investigate the effect of high dose inhaled beclomethasone dipropionate (BDP) administered for two months to patients with stable, smoking related COPD. Sputum induction was used to evaluate bronchial inflammation response. METHODS: 34 patients (20 men and 14 women) were examined on three separate occasions. At the initial clinical assessment (visit 0), spirometry and blood gas analysis were performed. On visit 1 (within one week of visit 0) sputum induction was performed and each patient was randomised to receive either BDP 500 micrograms three times daily (treated group) or nothing (control group). After two months (visit 2), all patients underwent repeat clinical assessment, spirometry, and sputum induction. RESULTS: There were no differences in sputum cell counts between the groups at baseline. After two months of treatment, induced sputum samples from patients in the treated group showed a reduction in both neutrophils (-27%) and total cells (-42%) with respect to baseline, while the control group did not (neutrophils +9%, total cells +7%). Macrophages increased in the treated group but not in the control group. The mean final value of sputum neutrophils was 52% in the treated group and 73.3% in the control group (95% confidence interval (CI) -27.2 to -15.4). The mean final value of sputum macrophages was 35.8% in treated group and 19.3% in control group (95% CI 10.3 to 22.8). The differences between the treated and control groups for neutrophils (-21.3%), macrophages (+16.5%), and total cells (-65%) were significant. Spirometry and blood gas data did not change from baseline in either patient group. CONCLUSIONS: A two month course of treatment with high dose inhaled BDP reduces significantly neutrophil cell counts in patients with clinically stable, smoking related COPD. Further studies on the effectiveness of inhaled steroids in COPD are needed to confirm the clinical importance of this observation.

Administration, Inhalation

Dissociation between airway inflammation and airway hyperresponsiveness in allergic asthma.

In asthma, the acute increment of airway responsiveness caused by exposure to allergen is associated with influx of eosinophils into the airways. The relationship between chronic airway hyperresponsiveness and airway inflammation is unclear, as they do not change consistently following long-term anti-inflammatory treatments. We studied 71 patients with chronic asthma and allergic sensitization to perennial allergens. Airway responsiveness was determined by inhalation of methacholine, and airway inflammation was quantified by induced sputum (n = 28) or bronchoalveolar lavage (n = 43) and bronchial biopsy (n = 20). The relationships between airway responsiveness and the numbers of different inflammatory cells were assessed by multiple regression analysis. No significant correlations were found between the degree of airway responsiveness and the numbers of inflammatory cells in sputum or bronchoalveolar lavage or bronchial biopsy. By contrast, baseline lung function was inversely related to the numbers of eosinophils and directly related to the numbers of macrophages. The eosinophil cationic protein contents of either sputum or bronchoalveolar lavage were significantly correlated with the percentages of eosinophils but not with airway responsiveness. We suggest that other factors (e.g., airway wall remodeling or autonomic dysfunction) may be responsible for most of the interindividual variability of airway responsiveness in asthma.

Adult

Comparison of two methods of processing induced sputum: selected versus entire sputum.

Sputum analysis is increasingly used to assess airway inflammation in asthma. The analysis of sputum is currently performed with two techniques, i.e., analysis of selected sputum (plugs) and analysis of entire sputum. To investigate the diagnostic value of these two methods, we compared total and differential cell counts and supernatant eosinophil cationic protein (ECP) in selected and entire sputum collected on two occasions in a group of healthy and asthmatic subjects. We induced sputum with hypertonic saline in 18 asthmatics and in eight healthy subjects. On one occasion we analyzed selected sputum, and on another occasion we analyzed entire sputum. In each sample we measured total and differential cell counts and ECP concentration in supernatant. We found a higher percentage of eosinophils (15.3 versus 8.3%; p < 0.01), more viable nonsquamous cells (80.6 versus 71.8%; p < 0.01), and higher levels of ECP (548 versus 105 microg/L; p < 0.001) in selected sputum as compared with entire sputum, whereas the percentage of neutrophils was higher in the entire sputum (42.7 versus 33.3%; p < 0.05). The percentage of eosinophils and ECP concentration were significantly and similarly increased in both selected and entire sputum of asthmatic subjects, i.e., independent of the method of sputum analysis. In conclusion, the selected sputum method may indeed provide more viable cells, more eosinophils, and a higher concentration of ECP. However, both the selected sputum and the entire sputum method have the same diagnostic value in distinguishing asthmatics from healthy subjects.

Adult

Surveillance of tuberculosis treatment prescription in Italy. The Varese TB Study Group.

In industrialized countries, data on antituberculosis treatment are scanty. The aim of this study was to describe the tuberculosis (TB) treatment programme from diagnosis to drug intake in a model area of northern Italy, evaluating: 1) antiTB regimens prescribed and their adequacy; 2) dosage of drugs; 3) side-effects; and 4) drug resistance. Individual data on new TB cases from all the existing health facilities of the area were collected by means or a prospective surveillance system based on the systematic review of original clinical forms. Regimens were classified as adequate, potentially adequate and inadequate, based on published recommendations. Data on drug dosage, side effects and drug resistance were analysed. Out of 109 TB cases with regimen recorded on clinical records, 20.2% included more than four major drugs, 63.3% three drugs and 16.5% two drugs. The regimens were classified as 1.8% adequate, 85% potentially inadequate and 12.8% inadequate. The dosages prescribed (mean +/- SD in mg.kg body weight-1.day-1) were: isoniazid: 6.8 +/- 2.7: rifampicin: 10.2 +/- 2.5; ethambutol: 21.3 +/- 4.5; streptomycin: 17.4 +/- 4.0: and pyrazinamide: 15.2. Twelve per cent of cases required treatment modification due to side-effects. Resistance to one single drug was found in 9% of cases, but no case with multidrug-resistant TB. The description of the treatment programme revealed that: 1) the majority of regimens are potentially adequate; 2) they are at a proper dosage; 3) the side-effects are in agreement with the literature; and 4) drug-resistance rates are low.

Antitubercular Agents

Fibre types in skeletal muscles of chronic obstructive pulmonary disease patients related to respiratory function and exercise tolerance.

This study aimed to investigate the relationship between skeletal muscle, fibre type composition, functional respiratory impairment and exercise tolerance in patients with moderate to severe chronic obstructive pulmonary disease (COPD). A group of 22 COPD patients and 10 healthy control subjects were studied. In COPD patients, vital capacity (VC) and forced expiratory volume in one second (FEV1) were reduced to 79% and 51%, respectively. Diffusion indices (transfer factor of the lung for carbon monoxide (TL,CO) and carbon monoxide transfer coefficient (KCO)) were also reduced. Arterial oxygen tension (Pa,O2) was normal or slightly altered. A maximal exercise test was performed and anaerobic threshold was calculated. Muscle samples from vastus lateralis were obtained by needle biopsy. Myosin heavy chain (MHC) and light chain (MLC) isoforms were separated by gel electrophoresis and quantified by densitometry. MHC isoforms were considered as molecular markers of fibre types. The proportion of the fast MHC-2B isoform was increased in COPD patients. TL,CO, KCO, VC and FEV1 were positively correlated with slow MHC isoform content. TL,CO and KCO were also negatively correlated with the content of the fast MHC-2B isoform. No correlation was found between exercise parameters and MHC isoform composition. The co-ordinated expression between MHC and MLC isoforms was altered in COPD patients. We conclude that reduced oxygen availability, probably in combination with muscle disuse, may determine muscle alterations in chronic obstructive pulmonary disease patients. The altered correlations between myosin heavy chain and light chain isoforms suggest that co-ordinated protein expression is lost in chronic obstructive pulmonary disease muscles.

Adult

Induced sputum to assess airway inflammation: a study of reproducibility.

BACKGROUND: Infiltration of the airways mucosa with activated inflammatory cells appears to be a major factor in the pathogenesis of asthma and other airway diseases. Examination of sputum provides a direct method to investigate airway inflammation non-invasively. OBJECTIVES: The aim of the present study was to evaluate the reproducibility of cell counts on cytospins and fluid phase (eosinophil cationic protein, ECP) measurements in a selected portion of induced sputum. We aimed to confirm the validity of the tecnique by comparing measurements between stable asthmatics, allergic rhinithis and healthy subjects. METHODS: Sputum was induced with hypertonic saline (4.5%) twice within one week in 53 stable asthmatics, 16 subjects with seasonal rhinitis (out of the pollen season), and 19 healthy subjects. Reproducibility was examined within sample (two different plugs of the same sample) between sample (two specimens of induced sputum obtained within one week) and between examiners on stable subjects taking into account sample size, number of examinations per patients and Confidence Interval (CI) of the estimates. RESULTS: We have found that the method is highly reproducible within sample and between examiners for all types of cells and fluid phase measurements of ECP. It is reproducible between sample for eosinophils, macrophages, neutrophils and ECP, but not for lymphocytes and weakly for epithelial cells. Sputum from asthmatics, in comparison with the sputum of healthy subjects and subjects with rhinitis had higher eosinophils (asthmatics: 12.2% +/- 12.9, rhinitis: 0.4 +/- 0.8, normals: 0.4 +/- 0.7 (%) and ECP (asthmatics: 827 +/- 491 microg/L, rhinitis: 127 +/- 82 normals: 157 +/- 203). No significant differences were found between healthy subjects and subjects with rhinitis. Eosinophil counts were inversely correlated with FEV1 (r = -0.37) expressed as percentage of predicted, but not significantly correlated with PC20 methacholine (r = -0.28) or blood eosinophils (r = 0.26). CONCLUSIONS: The importance of this study is the confirmation, within important statistical guidelines for a study of reproducibility, that the methods examined are reproducible and valid.

Adult

AIDS and tuberculosis control programmes: an integrated approach at educational level.

In developing countries with a high prevalence of individuals co-infected by human immunodeficiency virus (HIV) and tuberculosis (TB), urgent public health measures should be implemented to prevent the spread of both diseases. This study was performed by a combined acquired immune deficiency syndrome (AIDS)-TB health team with the following aims: 1) to assess knowledge, attitudes and practice towards AIDS; 2) to identify target groups for health education (HE); 3) to evaluate HE impact; 4) to circulate correct information on AIDS and TB through target groups; and 5) to evaluate integration of AIDS and control TB activities. Secondary school students of Arua District, Uganda, participated in a standardized HE session (covering the key-points of AIDS and TB control) preceded by a pretest (multiple choice) questionnaire and followed 3 months later by the same questionnaire (post-test). The impact of HE on AIDS control was evaluated by comparing answers to pre- and post-test questionnaires and its influence on the TB programme by evaluating case-finding performances in the period preceding and following the survey. We analysed 1,478 questionnaires. The results of our study gave information on knowledge about AIDS, identified females and students < 16 yrs of age as good targets for HE, revealed that the impact of HE was significantly associated with improved knowledge, contributed to improved TB case-finding and offered suggestions for the integration of programmes. The survey represented an opportunity to create a stable AIDS/TB health team at district level.

Acquired Immunodeficiency Syndrome

Computerized patient record for a department of respiratory rehabilitation.

A computerized patient record (CPR) system plays an essential support role in the efficient functioning of the clinical and research services of a medical centre. We report the experience gained in developing a CPR for the Respiratory Rehabilitation Department (RRD) of the Tradate Medical Center of the Salvatore Maugeri Foundation, with specific reference to Out-patient (OP) and In-patient (IP) Units. The CPR was developed locally under the guidance of the Bioengineering Department. Several items implemented and strategies adopted are described and grouped in relation to broader objectives, such as the improvement of health-care quality, the enhancement of personnel productivity and reduction in costs, the support of clinical and health service research and the accommodation of future developments. In particular, we describe the design and implementation of anamnestic, physical and admission data collection, specifically orientated to respiratory diseases. Daily use of the CPR in the OP and IP units and its potential outcome for research and management support are also studied in detail. On the basis of our experience (1,251 out-patient examinations, 650 in-patient clinical admission cards), the computerized patient record seems a useful way of providing better health-care and a more comprehensive coverage of the rehabilitation process of patients in a Respiratory Rehabilitation Department.

Delivery of Health Care

Evaluation of the impact of guidelines on tuberculosis control in Italy. National AIPO "Tuberculosis" Study Group. Associazione Italiana Pneumologi Ospedalieri.

This study was performed in Italy, where a central tuberculosis (TB) unit and national guidelines on TB control are lacking. The objectives of the study were: 1) to design comprehensive guidelines on TB control; 2) to discuss them within the scientific community and to present them to administrators and politicians: and 3) to evaluate their impact from a public health perspective. The ultimate goal was to improve TB control nationwide through a consensus-based initiative. The steps taken in planning were as follows: 1) an assessment of control activities operating in the country was made by means of three surveys: 2) guidelines on TB control were designed, presented, discussed and approved during three Consensus Conferences involving representatives of organizations operating in TB control and services; and 3) their impact was evaluated by means of objectively verifiable indicators (availability of TB case definition, regional control programmes, surveillance reports, guidelines on treatment, staff training). Regional TB control programmes were implemented in three major regions (30% of the national population), and are in advanced process in other four regions (29% of the national population). The protocol approved during the three Consensus Conferences benefited from the co-ordinated action of governmental and nongovernmental organizations. Its impact on tuberculosis control was positive, particularly at the regional level.

Consensus Statements as Topic

Economic analysis of two structured treatment and teaching programs on asthma.

The aims of the present study were as follows: 1) to evaluate the medical outcomes of two treatment and educational asthma programs 2) to determine by cost-analysis both cost and economic outcome of the programs 3) to perform a cost-benefit analysis (determining the net cost-benefit) and a cost-effectiveness analysis (determining the cost per unit of effect and the incremental cost-effectiveness ratio) from the perspective of health program policy makers (HPP; indirect costs, i.e., loss of productivity, excluded) and of society as a whole (SaW, all costs included). Patients were randomly assigned to a complete (CP; n = 32) or reduced (RP; n = 33) program: the RP group received a reduced education (self-reading of an educational booklet on asthma), while the CP group attended an "asthma school", consisting of six lessons based on the same booklet and including educational videotapes. Both programs included peak-flow monitoring and treatment according to international guidelines, and follow-up. The outcome variables (asthma attacks, urgent medical examinations, admission days, working days lost) did not differ significantly between CP and RP. Morbidity savings were $1894.70 (CP) and $1697.80 (RP) according to SaW, and $1349.50 and $1301.80, respectively, according to HPP. The net cost-benefit was $1181.50 for CP and $1028.00 for RP, and the cost-benefit ratio per dollar spent was 1:2.6 for CP and 1:2.5 for RP, according to SaW. One day of admission prevented had a cost of $110.20 (CP) and $94.10 (RP). CP gave slightly better results and was slightly more cost-effective than RP in improving patients' welfare. It cannot be excluded that the retrospective analysis used to determine baseline costs might have inflated differences for both groups. Sensitivity analysis was slightly in favor of RP when the outcome variables were tested at their upper and lower 95% CI.

Adult

Effects of intradermal injection of atrial natriuretic peptide.

Atrial natriuretic peptide (ANP) causes mast cell degranulation in rats in vivo and in vitro but is bronchodilator in humans. The aim of this study was to investigate the wheal and flare dose-response to intradermal injection of alpha-human ANP in normal humans. Eight normal subjects received five 30 microliters injections containing 1, 10, 39, 78, 117 pmol ANP and one each of normal saline, histamine 675 pmol and substance P 30 pmol. Maximum ANP flare response was greater but not significantly than that to saline at 1.55 +/- 0.6 (mean +/- s.e. mean) compared with 0.42 +/- 0.17 cm2, but much less than to histamine 9.86 +/- 0.97 or to substance P 12.5 +/- 1.2. Maximum ANP wheal response was significantly greater than that to saline at 0.38 +/- 0.08 compared with 0.18 +/- 0.05 cm2 (difference between means 0.20, 95% CI 0.05, 0.35), but much less than to histamine 0.75 +/- 0.06 or to substance P 1.05 +/- 0.08 cm2. No dose-response to ANP was demonstrated, though responses to the highest dose differed significantly from those to the lowest dose studied. We conclude that human cutaneous responses to ANP differ from those of animals and that the skin is less responsive than other tissues in humans.

Adult

Validation of the surveillance system for new cases of tuberculosis in a province of northern Italy. Varese Tuberculosis Study Group.

In Italy tuberculosis (TB) surveillance is hampered by several problems (inconsistency of data and underreporting). A tuberculosis surveillance system was established in Varese Province (VSS) in 1992. The aim of the present study was, using VSS, to estimate: 1) coverage and validity of data collected by the national Compulsory Surveillance System (CSS); 2) validity of diagnosis and risk factors for tuberculosis; 3) tuberculosis incidence. A specifically designed form, including the same items as the CSS form and 10 more questions on risk factors and diagnostic issue, was completed in all the existing health facilities in the province for each new tuberculosis case diagnosed, collected by the study co-ordinator during monthly supervision after a review of clinical records, and stored in a database at the co-ordinating centre. Routine notifications collected at national level by CSS for the province were nominally linked with VSS data. To evaluate coverage and data validity, a comparison was made between VSS and CSS data after removal of duplicates. Quality of data, risk factors and incidence were evaluated on VSS data (gold standard). CSS coverage was 63% with a significant underreporting of extrapulmonary cases. Within CSS, 20% of data were missing (particularly diagnostic information: 42-72%). According to VSS, smear was performed on 88% of cases and culture on 66%. Half of the cases had no risk factors. The overall incidence of tuberculosis in Varese Province was 15 per 100,000. We estimated the coverage and validity of the data collected by CSS, validity of diagnosis, risk factors for and incidence of tuberculosis and proposed several suggestions to improve CSS nationwide.

Adolescent

Sputum induction: a method to assess airway inflammation in asthma.

In recent studies, sputum cell counts have been used to examine the cell and molecular markers of airway inflammation. In this paper, we describe three different technical methods of analysing sputum samples: the first using smears, the second using cytocentrifugation after selection of a mucous plug, and the third using cytocentrifugation to analyse the entire sputum sample. These last two techniques have been used in a pilot study to compare the differential cell counts in sputum and bronchoalveolar lavage (BAL). The results show a significant correlation between the percentage of the eosinophils in sputum and bronchial sample of the BAL. Previous results on the study of airway inflammation with the analysis of sputum and the preliminary data on the relationship between sputum and BAL confirm the usefulness of this noninvasive technique in the understanding of the pathogenesis of asthma.

Asthma

The effects of a cognitive behavioural intervention in asthmatic patients.

There is evidence that educational programmes may improve patient's compliance with asthma treatment and control symptoms. Whilst medical parameters have been thoroughly studied, few data are available concerning psychological intervention. The aim of our open pilot study was to verify whether any difference in perceived illness and response style to asthma existed in the patients enrolled in an Asthma Rehabilitation Group (ARG) and in a Control Group (CG). Forty consecutive asthmatics were randomly enrolled, all of whom were diagnosed, treated and followed-up according to the International Guidelines. Both groups underwent a psychological assessment at baseline and after one year. A battery of questionnaires was used to obtain data relating to baseline characteristics (anxiety, depression, psychophysiological disorders), emotional reactions to asthma attacks (panic-fear, etc,) and cognitive variables (external control, psychological stigma, internal beliefs, external chance, etc.) involved in the perceived illness. In addition, the Asthma Rehabilitation Group patients underwent an educational programme and a cognitive-behavioural intervention. In both groups, a reduction of anxiety and depression scores was observed, as well as a significant improvement of the medical parameters evaluated. Only the Asthma Rehabilitation Group reported lower scores on the Psychophysiological Questionnaire and on the External Control Subscale after 1 year. The Control Group reported higher score on the External Chance Scale. The data of our study seem to confirm the effectiveness of psychological intervention on the cognitive skills involved in the perception and management of asthma. Larger scale studies on this topic are suggested.

Asthma

Risk of infection and estimated incidence of tuberculosis in northern Uganda.

The main goals of our study were to evaluate: 1) the annual risk of tuberculosis infection (ARTI) and its annual decrease in Uganda; 2) the expected incidence of new tuberculosis cases and the notification rate; and 3) the role of incentives given to children tested in increasing compliance with the survey procedures. The methodology is based on performing the standard World Health Organization (WHO) tuberculin test on children of the same age groups at intervals of 10-15 yrs, identifying infected persons by induration distribution analysis, and converting the prevalence rates detected into risk rates according to the ARTI model. Two thousand six hundred and twenty one school children aged 10 yrs old and bacilli Calmette-Guérin (BCG) nonvaccinated, in six study areas, were injected with two tuberculin units (TU) of purified protein derivative (PPD) RT 23 Copenhagen. The detected prevalence was 14 +/- 1.4% (prevalence +/- 95% confidence interval (95% CI)) and the ARTI value 1.2 +/- 0.9%, with an estimated annual decrease of 0.83% from 1958 to 1970 and 2.9% in the 1970-1987 period. The estimated expected incidence of new cases in Uganda was 59 smear positive and 75 smear negative/extrapulmonary cases per 100,000 population in 1987, and 53 and 65, respectively, in 1990, with an overall 68% notification coverage. No significant improvement in children returning for reading was observed in the group receiving incentives. We conclude that the average decrease (2.9%) probably represents the natural decline of tuberculosis in Uganda. The coverage appears encouraging, although the ARTI detected could be underestimated, since the existing ARTI model was developed and validated before the human immunodeficiency virus (HIV) era.(ABSTRACT TRUNCATED AT 250 WORDS)

BCG Vaccine