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Our objective was to assess the feasibility of integrating first void urine (FVU) specimens testing for Chlamydia trachomatis genitourinary infection into a general population sexual behaviour survey. A total of 752 randomly selected respondents aged 18 to 54 were enrolled into the survey. Face to face interviewing with self-administered sensitive questions was used. Overall survey response rate was 77.4%. A convenience sub-sample of 83 respondents were invited to provide FVU specimens for confidential testing for C. trachomatis genitourinary infection. Fifty-five complied. This resulted in 66% FVU specimen participation rate among targeted respondents. Two specimens tested positive by Amplicor polymerase chain reaction. High feasibility study overall response rate indicated good acceptability of the survey. It proved feasible to collect FVU specimens for C. trachomatis testing in the small sub-sample. Consequently, we proceeded with integration of testing for C. trachomatis into the ongoing main survey.

This paper describes the design and baseline results of a large and simple randomized controlled trial of the protection against tuberculosis of a dose of Bacillus Calmette Guerin (BCG) vaccination given to school children in a population with a high coverage of neonatal BCG (The Brazilian BCG-REVAC trial). The study started in 1996 and is a pair-matched and stratified-cluster randomized controlled trial with no placebo. The study population consists of children aged 7-14 years enrolled in 763 state schools from the cities of Salvador and Manaus, Brazil. Schools were the unit of randomization. Identifying information was collected for 354,708 school children. The final study population, after exclusions on the basis of age, BCG scar readings and absence from school on the day of the study visit, consists of 242,401 children, of whom 125,403 are in intervention schools. Follow-up relies on ascertainment of cases diagnosed at the health services and notified to the tuberculosis control program surveillance system. Blindness is guaranteed during linkage and validation of cases. Analysis is planned for the next 12 months, where efficacy will be estimated by calculating incidence of tuberculosis in the vaccine and control groups, taking into consideration the cluster design. The intervention studied, a second BCG vaccination, is widely used, although the World Health Organization does not recommend it on the basis of absence of evidence of protection or lack of protection. The results of the trial will make it possible for BCG revaccination practice to be informed by evidence. This is an example of a large simple and relatively inexpensive effectiveness trial, resulting from good collaboration between academia and health and education services enabling developing countries to define policies that are relevant for their reality., (Copyright 2002 Elsevier Science Inc.)

The HIV epidemic has greatly increased morbidity in many African cities and severe undernutrition is a prominent feature of the clinical presentation. However, there is little information about the relationship of morbidity or nutritional status to immune damage at a population level. We report a cross-sectional study of morbidity and nutritional status in relation to CD4 count in an impoverished urban community in Lusaka, Zambia, at enrollment into a longitudinal study. Over a 2 month period in 1999, 261 (52%) of 506 adults resident in one area were interviewed and examined. Of 186 adults who consented to testing, 33 (51%) of 65 who were HIV seropositive reported symptoms of disease compared to 39 (32%) of 121 who were HIV seronegative (OR 2.2, 95%CI 1.1-4.2; P=0.02). Peripheral blood CD4 counts in HIV seronegative individuals were broadly similar to norms in developed countries, but 8 (7%) had CD4 counts below 500 cells/microl. Morbidity in HIV seropositive adults was dominated by tuberculosis (n=11), other respiratory infections (5) or persistent diarrhoea (4), and affected individuals had a wide range of CD4 counts. Nutritional impairment was evident in HIV seropositive adults with clinical evidence of opportunistic infection (OI), not those with asymptomatic HIV infection. Unexpectedly, we also noted that systolic blood pressure was reduced progressively in HIV infection and in those with OI. In conclusion, HIV-related morbidity was dominated by a small number of treatable infectious diseases occurring over a wide range of CD4 count. Nutritional impairment was associated with OI.

When the hypothesis of a link between vaccination and a possible adverse outcome arises, further investigation is required to confirm or refute the suspicion. Given the rarity of most serious adverse effects, a case-control approach will often be chosen. This paper discusses aspects of the design, analysis and interpretation of case-control studies to evaluate vaccine adverse effects. Potential biases (and how to minimise such biases) in the selection of cases and assessment of vaccine exposure and the potential for confounding are discussed. Finally the increasing use of electronic databases in the evaluation of vaccine adverse effects is considered.

Background: In Brazil, there continues to be an excessive use of emergency services by patients with elective medical problems. Those patients who report having a primary care physician are less likely to utilize the emergency department for non-urgent consultations., Objective: The objective of this study was to compare patients who have a primary care physician with those who do not in relation to severity of their chief complaint at presentation in the emergency department., Methods: The study was carried out as a cross-sectional interview-based survey at the Conceição Hospital Emergency Service in Porto Alegre (Brazil). The sample was 553 patients selected through a systematic random sampling, and the response rate was 88%. The data entry and analysis were performed using the software Epi-info, EGRET and SPSS. The analysis included simple statistics to determine the prevalence of the conditions being investigated and the effect of independent variables (regular doctor) in relation to the dependent variable (severity of disease) through logistic regression., Results: The chief complaints were divided up as follows: 15% emergency cases, 46% urgent cases and 39% elective. The chief complaint was defined as urgent or emergency if it exhibited a significantly statistical association with the following independent variables, after being analysed by a logistic regression model: patients who reported having a primary care physician [odds ratio (OR) = 2.98, 95% confidence interval (CI) = 1.84-4.80] and patients who usually go to the emergency room by car (OR = 2.67, 95% CI = 1.75-4.05)., Conclusion: One strategy to reduce the number of non-urgent consultations at emergency rooms is to establish a close out-patient relationship between patients and physician. There is a need to optimize the health care of patients who have non-urgent problems but still seek the emergency department through strategies at the primary health care level-especially when continuous care is available-and where a comprehensive approach with an emphasis on prevention would stimulate better quality of care at a lower cost.

Study Objectives: To determine if factors associated with HIV infection vary between subpopulations of women resident in Great Britain., Design: Case-control analyses on already existing datasets., Setting: Great Britain., Participants: 317 cases selected from a MRC Collaborative Study of HIV Infection in Women and 3635 controls selected from a National Survey of Sexual Attitudes and Lifestyles., Main Results: Factors associated with HIV infection varied among subpopulations of women. Among women heterosexually infected, factors associated with HIV infection were residence in London (odds ratio (OR) = 8.3; 95% confidence intervals (CI) 4.6 to 14.9), widowhood (OR = 47.6; CI 20.0 to 113.1), being black (OR = 25.2; CI 15.6 to 40.8) and particularly among white women, having 10 or more sexual partners (OR = 14.5; CI 5.1 to 41.3). Young age was important for black women heterosexually infected. Among women who shared needles, residence in London (OR = 19.0; CI 5.8 to 62.6) or Scotland (OR = 26.9; CI 8.0 to 90.4) and large numbers of sexual partners was important (OR = 19.6; CI 6.4 to 60.0); termination of pregnancy history was also important for those with fewer than 10 sexual partners (OR = 6.7; CI 3.4 to 13.1); and low social class was important for those with 10 or more sexual partners (OR = 4.1; CI 1.7 to 9.6)., Conclusions: Factors vary in importance and significance of association with HIV infection in different subpopulations of women resident in Great Britain. This diversity is also likely to occur in other populations. It is important to identify these differences between subpopulations. Prevention and control policies and activities for HIV/AIDS cannot treat all women as if they were the same.

Data from routine surveillance during two mass immunisation campaigns (MIC) with Measles-mumps-rubella (MMR)vaccine using Leningrad-Zagreb mumps strain in two states in Brazil were analysed to estimate the risk of vaccine-related meningitis and mumps. Increase in the incidence of the two diseases was observed in both states, 3 weeks after the vaccination campaigns. The estimated number of doses applied per one case of vaccine-related meningitis ranged from 6199 (95% CI: 4854-8058) to 19,247 (95% CI: 12,648-29,513) depending on the diagnostic criteria used and state. It was 300 doses (95% CI: 286-317) for each case of mumps. The implications for vaccination policy are discussed.

Background: The worldwide fall in the rate of detection of new cases of leprosy has been partly attributed to the introduction of multidrug therapy and other improvements in control programs. However, the rate of detection of new cases has not decreased in Brazil., Methods: An analysis was made of the temporal distribution of 18,872 newly reported leprosy cases in Bahia, Brazil, from 1974 to 1997. Population denominators for the annual detection rate were obtained from population estimates based on the national census. Trends were presented by sex, date of birth, date of diagnosis, date of release, clinical form and by residence in areas which had notified cases in the 5 years prior to the rise in detection rate., Results: There was a marked increase in the new case detection rate (NCDR) in the State of Bahia, from 0.19 to 1.43 cases per 10,000 inhabitants during the study period, an increment of nearly 7% to 8% per year. This increase was also observed in people aged 14 years and younger. During this period tuberculoid and indeterminate forms have become predominant among women and younger people. The average age of male cases has shifted toward younger ages., Conclusions: We interpret this pattern to mean that the increase in NCDR reflects a real increase in incidence of leprosy, whether or not accompanied by improved detection.

In a cross sectional survey within a community trial of BCG efficacy evaluation in Brazil, trained teams inspected children's upper arms and obtained information on BCG vaccination from guardian letters and vaccination cards. Nurses re-examined the sub-sample of children blindly. High agreement was found between the two scar readings (Kappa = 0.839). High sensitivity and low specificity was observed when guardian or card information was the gold standard. Sensitivity remained high when guardian and card information agreed. When disagreement occurred, sensitivity remained high and specificity was very low. BCG scar is a good indicator of BCG vaccination.

This is a case-control study aimed at identifying risk factors for intestinal infection with Campylobacter jejuni. Cases were defined as subjects with diarrhoea occurring in community cohorts or presenting to General Practitioners (GPs) with Campylobacter jejuni in stools. Controls were selected from GP lists or cohorts, matched by age, sex, and GP practice. Travel abroad and consumption of chicken in a restaurant were statistically significantly associated with being a case. There was no statistically significant risk associated with consumption of chicken other than in restaurants nor with reported domestic kitchen hygiene practices. Consumption of some foods was associated with a lower risk of being a case. Most cases remained unexplained. We suggest that infection with low numbers of micro-organisms, and individual susceptibility may play a greater role in the causation of campylobacter infection than previously thought. It is possible that in mild, sporadic cases infection may result from cross contamination from kitchen hygiene practices usually regarded as acceptable. Chicken may be a less important vehicle of infection for sporadic cases than for outbreaks, although its role as a source of infection in both settings requires further clarification in particular in relation to the effect of domestic hygiene practices. The potential effect of diet in reducing the risk of campylobacteriosis requires exploration.

The butyrylcholinesterase (BChE; EC 3.1.1.8) activities of two electrophoretic bands of the CHE2 C5+ phenotype--C5 and C(OF) (other forms)--were quantified by densitometry in 100 individuals. The activity data suggested that, in addition to determining C5, the CHE2*C5+ allele also increases the level of other BChE forms. Since the relative activity of C5 showed the highest correlation coefficient with weight when compared with the other BChE activity variables (total, absolute C5, and absolute C(OF)), its median activity level was used for the classification of CHE2 C5+ phenotypes (faint and intense). Mean body mass index (BMI) was compared among the CHE2 locus phenotypes-controlled by sex, age, and ethnic group. It was shown that the intense CHE2 C5+ phenotype presents a significantly lower (p < 0.001) mean BMI (23.2) than the other phenotypes (faint CHE2 C5+ = 25.2; CHE2 C5- = 25.4). It seems that the relative COF activity is positively associated with fat storage, since CHE2 C5- and faint CHE2 C5+ phenotypes showed higher mean BMI than the intense CHE2 C5+ phenotype. Our hypothesis is that the presence of C5 in a relatively high proportion leads to less fat storage.

Setting: City of Manaus, Amazonas, Brazil., Objective: To explore the relationship between positivity to tuberculin and other environmental mycobacteria sensitins, according to a range of criteria and presence of BCG scar., Design: Dual skin testing with tuberculin and four mycobacterial sensitins, and BCG scar recording of 1070 schoolchildren aged 7-14. Four criteria for positivity were used: simple and dominant, with 5 and 10 mm cut-off points., Results: The standardised prevalence of reactions > or = 5 mm for BCG scar negative children was 58.3% for Mycobacterium avium, 54.2% for M. scrofulaceum, 26.8% for M. fortuitum, 17.9% for M. tuberculosis and 7.6% for M. kansasii. Correlations between tuberculin and each sensitin, for BCG scar negative children, were 0.47 for M. avium, 0.53 for M. scrofulaceum, 0.60 for M. kansasii and 0.22 for M. fortuitum (all with P < 0.01). BCG effect was particularly significant for tuberculin (odds ratio = 3.44 for reactions > or = 5 mm, P < 0.001) and influenced the balance between dominant/non-dominant reactions for all sensitins., Conclusion: The correlation between tuberculin and each sensitin confirmed the separation of the rapidly (M. fortuitum) and slowly growing mycobacteria (M. tuberculosis, M. avium, M. scrofulaceum and M. kansasii). The influence of BCG on tuberculin reactions was more marked than on other mycobacterial sensitins.

Using a capture-recapture method, this study evaluates the completeness of the cutaneous leishmaniasis (CL) surveillance system in four districts of Santiago del Estero province, Argentina, for the period 1990-1993. Four reporting sources were evaluated: medical records kept by health facilities, interviews conducted during a case-control study, and the national and provincial levels of the leishmaniasis surveillance system (LSS). Using the capture-recapture method it was estimated that 210 cases (95% confidence interval [CI]: 202-218) of CL occurred in the four districts during the study period. Completeness of reporting to the leishmaniasis surveillance system at the national level was estimated to be 44.8% (95% CI: 43.2-46.4). The study results indicate that there is substantial underreporting within the LSS, although it did show the appropriate secular trends. The reasons for under-reporting and methods for addressing this problem are discussed.

Objective: To identify risk factors for infectious intestinal disease (IID) due to rotavirus group A in children aged under 16 years., Methods: Case-control study of cases of IID with rotavirus infection presenting to general practitioners (GPs) or occurring in community cohorts, and matched controls., Results: There were 139 matched pairs. In children under 16 years the following risk factors were significantly associated with rotavirus IID: living in rented council housing (adjusted OR = 3.78, P = 0.022), accommodation with more than five rooms (OR = 0.72, P = 0.002), contact with someone ill with IID (OR = 3.45, P < 0.001). Some foods were associated with decreased risk. In infants, bottle feeding with or without breast feeding was associated with increased risk (OR = 9.06, P < 0.05)., Conclusions: Contact with persons with IID, living in rented council housing and accommodation with fewer rooms, were significant risk factors for sporadic rotavirus IID in children whereas breast feeding is protective in infants.

Background: An association between mumps-measles-rubella (MMR) vaccination and the onset of symptoms typical of autism has recently been suggested. This has led to considerable concern about the safety of the vaccine., Methods: A matched case-control study using data derived form the United Kingdom General Practice Research Database. Children with a possible diagnosis of autism will be identified from their electronic health records. All diagnoses will be validated by a detailed review of hospital letters and by using information derived from a parental questionnaire. Ten controls per case will be selected from the database. Conditional logistic regression will be used to assess the association between MMR vaccination and autism. In addition case series analyses will be undertaken to estimate the relative incidence of onset of autism in defined time intervals after vaccination. The study is funded by the United Kingdom Medical Research Council., Discussion: Electronic health databases offer tremendous opportunities for evaluating the adverse effects of vaccines. However there is much scope for bias and confounding. The rigorous validation of all diagnoses and the collection of additional information by parental questionnaire in this study are essential to minimise the possibility of misleading results.

Bacillus Calmette-Guérin (BCG), the most common vaccine worldwide, has broad effects on the immune system. Hookworm infections are a major source of morbidity. In response to a preliminary report of BCG vaccination protection against nematodes in human immunodeficiency virus-infected adults, data from an ongoing prospective study were analyzed to determine the intensity (eggs per gram of stool), prevalence, and incidence of different helminths in children with and without a BCG vaccination scar. Adjusted prevalence and incidence ratios were estimated by using logistic regression. Children with a BCG vaccination scar were found to have statistically significantly lower hookworm prevalence (41%), incidence (37%), and mean egg counts (39%), after controlling for age, sex, and socioeconomic factors. There was no BCG association with incidence, prevalence, or intensity of infection with Schistosoma mansoni, Ascaris lumbricoides, or Trichuris trichiura. Such protection would have implications for public health and for research on mechanisms behind human immunological responses to hookworm.

Background: Most of the effort directed at understanding the role infections have in preventing allergy has focused on bacteria and viruses and their ability to divert the immune system towards T-helper-1 responses and away from proallergic T-helper-2 responses. However, helminth infections, highly prevalent in large parts of the developing world, where allergy is uncommon, stimulate strong T-helper-2 responses. We investigated the influence of chronic helminth infections on the prevalence of atopy and aimed to understand the relation at a detailed immunological level., Methods: 520 Gabonese schoolchildren were tested for skin reaction to house-dust mite and other allergens, for Schistosoma haematobium eggs in urine, and for microfilariae in blood samples. Total and mite-specific IgE antibodies were measured. A subsample selected on the basis of their skin test to house-dust mite received detailed immunological investigations., Findings: Children with urinary schistosomiasis had a lower prevalence of a positive skin reaction to house-dust mite than those free of this infection (odds ratio 0.32 [95% CI 0.16-0.63]). The degree of sensitisation to house-dust mite could not explain this difference in skin-prick positivity. Schistosome-antigen-specific concentrations of interleukin-10 were significantly higher in infected children, and higher specific concentrations of this anti-inflammatory cytokine were negatively associated with the outcome of skin-test reactivity to mite (0.53 [0.30-0.96]). No association between polyclonal IgE antibodies and skin-test results was found., Interpretation: The anti-inflammatory cytokine, interleukin-10, induced in chronic schistosomiasis, appears central to suppressing atopy in African children.

The World Health Organization suggested that the prevalence of Schistosoma mansoni among 7- to 14-year-olds be used to guide treatment strategies in endemic areas. This study explores how well the prevalence in that age group predicted the overall prevalence in the community in data from stool examinations (Kato-Katz method) from 180,000 people in 3 municipalities in Brazil in 1984 and 1985. The median prevalence was higher in 1984, before community treatment was introduced. There was a strong relationship between the prevalence among 7- to 14-year-olds and the overall prevalence in the community. We present sensitivities and positive predictive values for the use of prevalence in the indicator group to select communities for mass treatment as recommended by WHO. For a range of assumptions sensitivity and positive predictive value were never both above 80 %. We suggest that the estimates of validity presented in this paper inform future evaluations of strategies for S. mansoni control.

This study firstly describes the epidemiology of malaria in Roraima, Amazon Basin in Brazil, in the years from 1991 to 1993: the predominance of plasmodium species, distribution of the blood slides examined, the malaria risk and seasonality; and secondly investigates whether population growth from 1962 to 1993 was associated with increasing risk of malaria. Frequency of malaria varied significantly by municipality. Marginally more malaria cases were reported during the dry season (from October to April), even after controlling for by year and municipality. Vivax was the predominant type in all municipalities but the ratio of plasmodium types varied between municipalities. No direct association between population growth and increasing risk of malaria from 1962 to 1993 was detected. Malaria in Roraima is of the "frontier" epidemiological type with high epidemic potential.

Background: Compliance with outpatient treatment can reduce the use of psychiatric inpatient services by people with severe mental disorders. In developing countries, socio-economic factors may be associated with compliance with outpatient treatment., Methods: A 2-year prospective cohort study was conducted of 99 patients with non-affective functional psychoses who were discharged from hospital. Standardized assessments were used for psychopathology, social functioning and use of psychiatric services., Results: Forty-two patients (42.4%) missed all outpatient appointments for at least 2 consecutive months. Household crowding was the only variable associated with poor compliance, patients living in very crowded homes being more than twice as likely to show poor compliance as those living in less crowded homes., Conclusions: In large urban centres in developing countries, strategies to improve compliance with outpatient treatment targeted towards those living in overcrowded households may reduce use of psychiatric beds.

background Verbal autopsy (VA) is used to ascertain causes of death using information obtained from bereaved relatives. Causes of death can be ascertained from VA questionnaires by a panel of physicians or from predefined algorithms. In a previous study, we developed data-derived algorithms using VA data from 796 adult deaths in hospitals in Tanzania, Ethiopia, and Ghana (primary sites). These computerized algorithms accurately estimated the cause-specific mortality fractions (CSMFs) for deaths due to injuries, meningitis, TB/AIDS and diarrhoeal diseases in the primary sites. Since the same data were used to generate and to validate the algorithms, the accuracy of our algorithms may have been overestimated. We report here on the validity of the algorithms when they were applied to VA data from two secondary sites in Ghana and Tanzania. Here, 'validity' is taken to mean the degree to which the algorithms replicated the physician-generated CSMF for major causes of death, when applied to the same VA data. methods VA interviews were conducted in two secondary sites: in Navrongo, Ghana, on 406 adult deaths, where three local physicians independently reviewed the questionnaires and assigned a cause of death. In Morogoro, Tanzania, VA interviews were conducted on 209 adult deaths, and a panel of physicians independently reviewed the VA questionnaires together with the hospital death certificates or hospital records to determine the cause of death. The CSMF obtained using each algorithm was compared with the CSMF obtained using physician review. results For injuries and meningitis, the algorithms and physician review estimated a similar CSMF in the Morogoro and Navrongo data. For TB/AIDS, the algorithm estimated a similar CSMF as the physicians in Morogoro. The algorithm for diarrhoeal diseases did not agree closely with the physicians in Morogoro or Navrongo. conclusions In general, our data-derived algorithms for assigning causes of death due to injuries, meningitis, and TB/AIDS estimated a similar CSMF as the physicians in the secondary sites. Recommendations for further validation and refinement are discussed. Computerized algorithms offer a potentially quick, affordable, and feasible method for assigning causes of death in mortality surveillance or studies using VA.

Background: Continued medical care (including having a personal doctor) is regarded as an essential aspect of a good health service., Objectives: The objectives of the present study were to investigate the reasons for not having a personal doctor, and the satisfaction with the care received by patients with and without a personal doctor., Methods: We conducted a cross-sectional study with data collected during 20 days over 6 months in the Emergency Service of the Conceição Hospital, the busiest emergency service in Porto Alegre. The subjects were 553 patients selected through systematic random sampling. The main outcome measure was having a personal doctor. Patients who reported usually to see the same doctor and remembered their physician's name were regarded as having a personal doctor., Results: Patients who usually use primary care service represented 23% of the sample, and were four times more likely to have a personal doctor (OR = 3.83, CI 95% = 2.41-6.11). Independent, statistically significant variables associated with having a personal physician were: usually receiving care from a primary health care service (OR = 3.8, CI 95% = 2.39-6.00) and from a physician in the private sector (OR = 2.16, CI 95% = 1.15-4.00). Patients who had a personal doctor reported higher satisfaction with their access to health care. The personal doctors' specialties were: internal medicine (37%), cardiologist (17%), gynaecologist-obstetrician (13%), family physician (8%) and pneumologist (6%)., Conclusions: For patients who attend emergency services in Brazil, primary health care and private medical care provide better access to continuity of patient care. Patients with personal doctors report higher satisfaction with access to consultations.

Background: The verbal autopsy (VA) is used to collect information on cause-specific mortality from bereaved relatives. A cause of death may be assigned by physician review of the questionnaires, or by an algorithm. We compared the diagnostic accuracy of physician review, an expert algorithm, and data-derived algorithms., Methods: Data were drawn from a multicentre validation study of 796 adult deaths that occurred in hospitals in Tanzania, Ethiopia, and Ghana. A 'gold standard' cause of death was assigned using hospital records and death certificates. The VA interviews were carried out by trained fieldworkers 1-21 months after the subject's death. A cause of death was assigned by physician review and an expert algorithm. Data-derived algorithms that most accurately estimated the cause-specific mortality fraction (CSMF) for each cause of death were identified using logistic regression., Results: The most common causes of death were tuberculosis/AIDS (CSMF = 18.6%), malaria (CSMF = 10.7%), meningitis (CSMF = 8.3%), and cardiovascular disorders (CSMF = 8.2%). The CSMF obtained using physician review was within +/-20% of the gold standard value for 12 causes of death including the four common causes. The CSMF obtained using the expert algorithm was within +/-20% of the gold standard for eight causes of death, including tuberculosis/AIDS, malaria, and meningitis. The CSMF obtained using the data-derived algorithms was within +/-20% of the gold standard for seven causes of death, including tuberculosis/ AIDS, meningitis, and cardiovascular disorders. All three methods yielded a specificity of at least 80% for all causes of death, and a sensitivity of at least 80% for deaths due to injuries and rabies., Conclusions: For those settings where physician review is not feasible, expert and data-derived algorithms provide an alternative approach for assigning many causes of death. We recommend that the algorithms proposed herein are validated further.

The Committee on the Microbiological Safety of Food, set up in 1989 by the Department of Health in response to national epidemics of foodborne infection, considered the available evidence and commissioned a study of infectious intestinal disease (IID) in England. Seventy practices (with 489,500) patients overall) recruited from the Medical Research Council's General Practice Research Framework between August 1993 and January 1995 collected data for one year. The practice populations were representative of practices in England by area and urban/rural location, but with fewer small and affluent practices. There were five main components. i) A population cohort of 9776 (40% of those eligible) were enrolled to estimate the incidence and aetiology of IID in the community, and a large proportion were followed up. A median of 10% of patients on practice age-sex registers had moved away or died. ii) A nested case control component based on cases ascertained in the cohort was used to identify risk factors for IID in the community. iii) In a case control component used to identify risk factors and to estimate the incidence and aetiology of IID presenting in 34 general practices 70% of the 4026 cases returned risk factor questionnaires, 75% submitted stools, and matched controls were found for 75% of cases. iv) An enumeration component was used to estimate the incidence of IID presenting to general practitioners (GPs) in 36 practices and the proportion of specimens sent routinely for microbiological examination. v) In a socioeconomic costs component used to estimate the burden of illness of IID in the community and presenting to GPs 63% of those who returned a risk factor questionnaire also returned a socioeconomic questionnaire and were representative by age, sex, and social class. Despite variable enrolment and compliance the study sample had sufficient power for the multivariable analysis. The characteristics associated with low enrollment and compliance must be considered in the interpretation of the main study results.

Objective: To establish the incidence and aetiology of infectious intestinal disease in the community and presenting to general practitioners. Comparison with incidence and aetiology of cases reaching national laboratory based surveillance., Design: Population based community cohort incidence study, general practice based incidence studies, and case linkage to national laboratory surveillance., Setting: 70 general practices throughout England., Participants: 459 975 patients served by the practices. Community surveillance of 9776 randomly selected patients., Main Outcome Measures: Incidence of infectious intestinal disease in community and reported to general practice., Results: 781 cases were identified in the community cohort, giving an incidence of 19.4/100 person years (95% confidence interval 18.1 to 20.8). 8770 cases presented to general practice (3.3/100 person years (2.94 to 3.75)). One case was reported to national surveillance for every 1.4 laboratory identifications, 6.2 stools sent for laboratory investigation, 23 cases presenting to general practice, and 136 community cases. The ratio of cases in the community to cases reaching national surveillance was lower for bacterial pathogens (salmonella 3.2:1, campylobacter 7.6:1) than for viruses (rotavirus 35:1, small round structured viruses 1562:1). There were many cases for which no organism was identified., Conclusions: Infectious intestinal disease occurs in 1 in 5 people each year, of whom 1 in 6 presents to a general practitioner. The proportion of cases not recorded by national laboratory surveillance is large and varies widely by microorganism. Ways of supplementing the national laboratory surveillance system for infectious intestinal diseases should be considered.

Background: One of the aims of the Study of Infectious Intestinal Disease (IID) in England is to estimate the incidence of IID presenting to general practice. This sub-study aims to estimate and correct the degree of under-ascertainment in the national study., Methods: Cases of presumed IID which presented to general practice in the national study had been ascertained by their GP. In 26 general practices, cases with computerized diagnoses suggestive of IID were identified retrospectively. Cases which fulfilled the case definition of IID and should have been ascertained to the coordinating centre but were not, represented the under-ascertainment. Logistic regression modelling was used to identify independent factors which influenced under-ascertainment., Results: The records of 2021 patients were examined, 1514 were eligible and should have been ascertained but only 974 (64%) were. There was variation in ascertainment between the practices (30% to 93%). Patient-related factors independently associated with ascertainment were: i) vomiting only as opposed to diarrhoea with and without vomiting (OR 0.37) and ii) consultation in the surgery as opposed to at home (OR 2.18). Practice-related factors independently associated with ascertainment were: i) participation in the enumeration study component (OR 1.78), ii) a larger number of partners (OR 0.3 for 7-8 partners); iii) rural location (OR 2.27) and iv) previous research experience (OR 1.92). Predicted ascertainment percentages were calculated according to practice characteristics., Conclusion: Under-ascertainment of IID was substantial (36%) and non-random and had to be corrected. Practice characteristics influencing variation in ascertainment were identified and a multivariate model developed to identify adjustment factors which could be applied to individual practices. Researchers need to be aware of factors which influence ascertainment in acute epidemiological studies based in general practice.

Objective: Women suffer from minor psychiatric disorders (MPM) more frequently than men. Most of the studies were conducted in England and in the United States and some reported the higher occurrence of MPM among women to be modified by marital status and others by sociodemographic variables. The present study intends to address this question in a developing country., Method: A population based case-control study was conducted in three important urban centers in Brazil. Two hundred seventy-six individuals diagnosed as new cases of MPM and 261 controls were selected to investigate the role of a set of sociodemographic variables in the association between gender and MPM using logistic regression models., Results: Univariate analysis showed that women were more likely than men to suffer from MPM (OR = 3.34; 2.27-4.91). After controlling for other sociodemographic variables, female gender was still positively associated with MPM, but not in a homogeneous way. A multiplicative interaction of gender with age group was found (LRT = 6.01; 2 df; p = 0.05) suggesting an increment in the magnitude of the association among those older than thirty years. Odds-ratios were 2.33 (1.19-4.55), 6.85 (2.86-16.41), and 7.47 (2.90-19.22) for age groups of fourteen to twenty-nine; thirty to forty-four; forty-five or more, respectively. There was no evidence of interaction of gender with marital status or other sociodemographic variables., Conclusions: The findings are consistent with the modification of the association between gender and MPM being mediated by social factors.

This report presents data from a study carried out in three African countries to assess the validity of verbal autopsies--based on information about symptoms and signs observed antemortem by relatives or associates of deceased individuals--for determining the causes of institutional maternal death. The validity of the verbal autopsy was assessed for each cause of death; and for groups of "direct" and "indirect" maternal causes, by comparing the verbal autopsy diagnoses with the reference diagnoses and calculating their sensitivity, specificity, and positive predictive value. Verbal autopsies were found to be highly specific (98 percent specificity for all causes of maternal death) but not very sensitive (< or = 60 percent sensitivity for all causes except ante/postpartum hemorrhage). Verbal autopsy estimates of cause-specific mortality were comparable to expected values for most of the causes. The study shows that certain direct causes of hospital-based maternal mortality can be determined by means of verbal autopsies with a reasonable level of confidence.

Objectives: To examine the implications of variation in maternal infectivity on the timing of mother-to-child HIV transmission through breastfeeding., Design and Methods: A mathematical model of mother-to-child HIV transmission was developed that incorporates two main features: (i) the fetus/child potentially experiences a series of exposures (in utero, intrapartum, and via breastmilk) to HIV; and (ii) variation in maternal infectivity. The model was estimated from different sources of epidemiological data: a retrospective cohort study of children born to HIV-1-infected women in Sao Paulo State, Brazil, the International Registry of HIV-Exposed Twins, and the AIDS Clinical Trials Group 076 trial, which assessed the effectiveness of zidovudine in preventing mother-to-child HIV transmission., Results: Variation in maternal infectivity results in higher average risk of breastfeeding-related transmission in the early stages of breastfeeding than in the late stages, even in the absence of a direct relationship between transmission risk and the age of the child. However, the available data were unable to resolve the quantitative importance of this mechanism., Conclusions: Our model has helped identify a previously unrecognized determinant of the timing of breastfeeding-related HIV transmission, which may have adverse implications for the effectiveness of certain interventions to reduce mother-to-child HIV transmission such as maternal antiretroviral therapy in breastfeeding populations and the early cessation of breastfeeding.

Although vertical transmission of HIV-1 can occur through breast-feeding, little is known about the effect of colostrum, duration of breast-feeding, mixing feeding, and nipple pathology. We used retrospective cohort data to examine the association between breast-feeding-related factors and transmission of HIV-1 from mother to child in São Paulo State, Brazil. Information on maternal and postnatal factors was collected by medical record review and interview. Infection status was determined for 434 children by anti-HIV-1 tests performed beyond 18 months of age or diagnosis of AIDS at any age. Among 168 breast-fed children, the risk of transmission of HIV-1 was 21%, compared with 13% (p = .01) among 264 children artificially fed. Breast-feeding was independently and significantly associated with mother-to-child transmission of HIV-1 after controlling for stage of maternal HIV-1 disease (odds ratio [OR] = 2.2; 95% confidence interval [CI], 1.3-3.8). A trend was shown toward an increased risk of transmission with longer duration of breast-feeding, a history of bleeding nipples, and introduction of other liquid food before weaning, but these associations were not statistically significant. History of colostrum intake or cracked nipples without bleeding were not associated with transmission. Most of the women who breast-fed were unaware of their HIV-1 infection status at the time of delivery. Avoidance of mixed feeding and withholding of breast-feeding in the presence of bleeding nipples should be considered in further research as strategies to reduce postnatal transmission of HIV-1 in settings in which safe and sustainable alternatives for breast-feeding are not yet available.

Background: Verbal autopsy (VA) has been widely used to ascertain causes of child deaths, but little is known about the usefulness of VA for adult deaths. This paper describes the process used to develop a VA tool for adult deaths and the results of a multicentre validation of this tool., Methods: A mortality classification was developed by including causes of death that might be arrived at by VAs and causes that are responsive to public health interventions. An algorithm was designed for each cause in the classification, based on classifying symptoms into essential, supportive and differential. A structured questionnaire designed to elicit information on these symptoms was developed in English translated into the local languages. The tool was validated on deaths occurring at hospitals in Tanzania (315 deaths), Ethiopia (249) and Ghana (232). Hospital records of all adult deaths occurring at the study hospitals from June 1993 to April 1995 were collected prospectively. Non-medical interviewers with at least 12 years of formal education conducted VA interviews. Causes of death were diagnosed by a panel of physicians and by a computerized algorithm. The validity of the VA was assessed by comparing the VA diagnoses with hospital diagnoses., Results: Specificity of VAs by physicians fell below 95% only for acute febrile illness (AFI) and TB/AIDS. Sensitivity and positive predictive value (PPV), however, varied widely both across the sites and between causes. Sensitivity was > 75% for tetanus, rabies, direct maternal causes, injuries and TB/AIDS and ranged between 60% and 74% for diarrhoea, acute abdominal conditions and AFI. The PPV was > 75% for tetanus, rabies, hepatitis and injuries and ranged between 60 and 74% for meningitis, AFI, TB/AIDS and direct maternal causes. When the communicable diseases were combined in a single group, the sensitivity was 82%, specificity 78% and PPV 85%. For the group of noncommunicable diseases the corresponding sensitivity, specificity and PPV were 71%, 87% and 67%, respectively. Use of an algorithm resulted in lower sensitivity, specificity and PPV than the VAs by physician., Conclusion: VAs by a panel of physicians performed better than an opinion-based algorithm. The validity of VA diagnosis was highest for AFI, direct maternal causes, TB/AIDS, tetanus, rabies and injuries.

Objectives: To evaluate the effect of maternal, obstetric, neonatal and post-natal factors on the risk of vertical transmission of HIV-1., Design: Multicentre retrospective cohort study., Setting: Obstetric and paediatric clinics in four cities in Sao Paulo State, Brazil., Main Outcome: Child's HIV-1 infection status., Methods: Data were collected by standardized record abstraction and interview on 553 children born to women identified as HIV-1-infected before or at delivery. Paediatric infection was determined by immunoglobulin G anti-HIV-1 tests at age 18 months or by AIDS diagnosis at any age. Multivariate logistic regression was used to assess the effect of potential risk factors on vertical transmission of HIV-1., Results: HIV-1 infection status was determined for 434 children (follow-up rate of 78%); 69 were classified as HIV-1-infected [transmission risk, 16%; 95% confidence interval (CI), 13-20%]. In multivariate analysis, advanced maternal HIV-1 disease [odds ratio (OR), 4.5; 95% CI, 2.1-9.5], ever breastfed (OR, 2.2; 95% CI, 1.2-4.2), child's negative Rhesus blood group (OR, 2.5; 95% CI, 1.2-5.5), third trimester amniocentesis (OR, 4.1; 95% CI, 1.2-13.5) and black racial group (OR, 0.3; 95% CI, 0.1-0.9) were independently and significantly associated with mother-to-child transmission of HIV-1. Transmission was increased marginally with prematurity, more than 10 lifetime sexual partners and prolonged duration of membrane rupture. No association was found between child's HIV-1 infection and mode of delivery or serological evidence of syphilis during pregnancy., Conclusion: These findings support the importance of severity of maternal HIV-1 disease in the risk of vertical transmission of HIV-1, indicate measures to reduce transmission by avoiding amniocentesis and breastfeeding and suggest that race and Rhesus blood type may be markers for genetic susceptibility to infection.

Objective: To investigate whether the protective efficacy of bacille Calmette-Guérin (BCG) against tuberculosis decreases with time since vaccination., Design: A quantitative review of all 10 randomized trials of BCG against tuberculosis in purified protein derivative (PPD)-negative individuals, that presented data for discrete periods. For each trial, we derived log rate ratios for the annual change in the efficacy of BCG. We also compared efficacy in the first two years, and the first 10 years, to that in the rest of the trial., Results: There was considerable heterogeneity between trials in the annual change in the efficacy of BCG. In seven efficacy decreased overtime, while in three it increased. Average annual change in efficacy was not related to overall efficacy. Efficacy also varied between trials in the first two years after vaccination, at more than two years after vaccination and in the first ten years after vaccination. However the variation in efficacy between trials more than 10 years after vaccination was not statistically significant (P = 0.26). We therefore calculated that the average efficacy more than 10 years after vaccination was 14% (95% confidence interval -9% to 32%)., Conclusion: BCG protection can wane with time since vaccination. There is no good evidence that BCG provides protection more than 10 years after vaccination.

BACKGROUND: Restenosis, or ÒAchilles heelÓ of balloon angioplasty, remains in a range near 30% and cannot be predicted with certainty. To find adequate methods for its foresight is a challenge. OBJECTIVES: To determine risk factors and an angiographic score to predict the appearance of restenosis after one-site percutaneous transluminal coronary angioplasty (PTCA). METHODS: We restudied prospectively 315 (239 men, 76 women, age range from 29 to 78, 53.6 +/- 9.5 years) of 360 patients who underwent PTCA to a native coronary artery. The study didnÕt include patients with left main disease, total occlusion, side-branch involvement, ostial stenosis, acute phase of myocardial infarction or those who repeat PTCA. Two-hundred twenty-eight patients underwent PTCA of the left anterior descending artery, 56 of the right coronary artery and 31 of the left circumflex artery. RESULTS: Restenosis, defined as a luminal renarrowing > 50% at follow-up, was present in 82 (26%) patients between 1 and 8 months after the procedure. Univariate and multivariate analysis revealed four vascular factors related to restenosis (p < 0.05): a) lesion length and; b) irregularity of the lesion borders before PTCA; c) perivascular and/or endovascular haziness and; d) intensity of residual stenosis after PTCA. To construct the score, a zero was given to a lesion length < 8 mm; to smooth lesion borders; to residual stenosis up to 20%; and to absence of haziness after PTCA. A one was given to a lesion length between 8 and 10 mm; and to a lesion with irregular borders. A two was given to a lesion length > 10 mm. A three was given to a residual stenosis > 20%; and to the presence of haziness after PTCA. The sum of all terms was considered the final score. So, it could oscillate from 0 to 9. Calculated score from 0 to > 5 showed respective restenosis rates of (%): 5.2; 15.1; 24.0; 39.4; 44.8; 60.8; and 84.2. The calculated correlation coefficient (0.98) among the scored values and the correspondent restenosis rates was highly significant (p < 0.001). CONCLUSIONS: It is concluded that restenosis is primarily a multifactorial problem based on vascular factors and may be predicted with a high degree of probability by the proposed score.

The human immunodeficiency virus (HIV) infection has both a direct and an indirect effect on the incidence of tuberculosis. The direct effect is due to the increased number of cases among HIV-infected individuals because of their enhanced susceptibility to the disease. The indirect effect is increased transmission of Mycobacterium tuberculosis infection in a community with high levels of dual infection, as a consequence of infectious cases occurring in HIV-infected persons. The risk of infection by M. tuberculosis in the population will then increase, as will the number of tuberculosis cases in the general population. According to the World Health Organization, over 4 million people are estimated to be dually infected with HIV and M. tuberculosis world-wide. In 1990, it was estimated that 300,000 new TB cases (4% of total new cases) were attributable to HIV infection; around 1.4 million cases are expected per year by 2000 (equivalent to about 14% of expected cases), thus increasing the reservoir of tuberculosis patients capable of transmitting the infection to others, and increasing the burden on the already overstretched National Tuberculosis Control Programmes, especially in resource-poor countries. This paper is a review of methods suggested to quantify the effect of the interaction between HIV infection and tuberculosis at population level, and more particularly the effect of HIV on the risk of tuberculosis infection.

A case-control study of 712 Brazilian mother-baby pairs was performed to assess maternal nutritional factors, more specifically low or marginal concentrations of vitamin A, folate and iron, as risk factors for intrauterine growth retardation (IUGR). Newborns were classified as being IUGR according to the Lubchenco classification. The gestational age of the newborns was evaluated by the Capurro method. Vitamin A, folate, ferritin and haemoglobin were measured by high-performance liquid chromatography, radioimmunoassay, immunoenzymetric assay and by the cyanmethaemoglobin method respectively. The relationship between maternal nutritional status and IUGR was investigated using stratification and logistic regression. According to the final logistic regression model, the risk factors for IUGR were: maternal body weight, per capita income, cigarette smoking, maternal weight gain, prior history of low birthweight, high maternal ferritin, beer intake and coffee intake. Specific interventions likely to have the major short-term impact in this region are not directly related to nutritional factors, but to efforts to reduce or eliminate toxic exposures. Over the long term, improvement in maternal nutritional status and socioeconomic conditions would be expected to produce important benefits.

A prospective cohort study of schizophrenia was carried out in Sao Paulo, Brazil, in order to investigate clinical and social outcomes in schizophrenia and related psychoses after hospitalization. A sample of 124 individuals who were living in a defined catchment area and had been consecutively admitted to psychiatric hospitals in that area with clinical diagnoses of non-affective functional psychoses was followed up for 2 years. Assessments of clinical status and social adjustment at inclusion and at 2-year follow-up were carried out by means of standardized instruments, the PSE and the DAS. At the end of the follow-up period, 120 subjects (96.8%) were traced, and 103 (83.1%) were re-assessed. At the second assessment, the proportion of subjects with a nuclear syndrome of schizophrenia had halved (from 68.3% to 32.7%), 23.8% were symptom free and 60.2% showed at least one psychotic symptom. Presence of psychotic symptoms at follow-up was best predicted by educational level (less than 4 years of formal education) and an initial DSM-III-R diagnosis of schizophrenia. The distribution of global social adjustment levels at 2-year follow-up was similar to that observed at the outset, with approximately one third of subjects showing good, one third showing intermediate and one third showing poor global social adjustment. Social disability was best predicted by longer duration of illness, worse social adjustment levels at inclusion and lower educational level.

HIV prevalence estimates for pregnant women from unlinked anonymous surveys are becoming increasingly available and can be used to determine the prevalence of HIV in women in the same population. The ratio of prevalence in pregnant women to that in all women is influenced by HIV-related risk behaviours that are different for pregnant and nonpregnant women and also by differences in fertility level among infected and uninfected women. This ratio is affected by biases that are likely to be culturally and socially specific. A model is proposed for the qualification and quantification of these biases and hence the estimation of general female population prevalence from serosurveillance data on pregnant women.

Background: Friend controls in matched case-control studies can be a potential source of bias based on the assumption that friends are more likely to share exposure factors. This study evaluates the role of selection bias in a case-control study that used the snowball sampling method based on friendship for the selection of cases and controls., Methods: The cases selected fro the study were drug abusers located in the community. Exposure was defined by the presence of at least one psychiatric diagnosis. Psychiatric and drug abuse/dependence diagnoses were made according to the Diagnostic and Statistical Manual of Mental Disorders (DSM-III-R) criteria. Cases and controls were matched on sex, age and friendship. The measurement of selection bias was made through the comparison of the proportion of exposed controls selected by exposed cases (p1) with the proportion of exposed controls selected by unexposed cases (p2). If p1 = p2 then, selection bias should not occur., Results: The observed distribution of the 185 matched pairs having at least one psychiatric disorder showed a p1 value of 0.52 and a p2 value of 0.51, indicating no selection bias in this study., Conclusions: Our findings support the idea that the use of friend controls can produce a valid basis for a case-control study.

Objective: To examine the association between coffee consumption in pregnancy and foetal growth., Design: Retrospective unmatched case-control study., Setting: Maternidade de Campinas, Universidade Estadual de Campinas, Pontificia Universidade Católica de Campinas, Hospital Albert Sabin., Subjects: 356 mother/baby pairs who had interauterine growth retardation (IUGR) and 356 mother/baby pairs who were appropriate for gestational age (AGA)., Interventions: Newborns were classified as being IUGR according to the Lubchenco classification. Gestational age of the newborns was evaluated by the Capurro method. Coffee consumption in pregnancy was assessed by a food frequency questionnaire. Coffee consumption and a range of risk factors for IUGR were stratified and entered into a logistic regression model. The final results were expressed by the attributable risk percent (AR%)., Results: More IUGR mothers (85.4%) than AGA mothers (70.5%) ingested coffee in pregnancy (OR = 2.45; P < 0.001). The proportion of mothers who delivered IUGR babies increased as the average consumption of coffee increased (test for trend = 31.76; P < 0.001). The tendency for heavy coffee drinkers to deliver IUGR babies remained after controlling for alcohol intake and cigarette smoking (P < 0.001). According to the logistic regression model and to the attributable risk percent (AR% = 28.0%), coffee consumption, (independent of average coffee consumption) was an important preventable cause of IUGR in this Brazilian population., Conclusions: We recommend moderation in the consumption of coffee in pregnancy, since intrauterine growth retardation increases the risk of perinatal and neonatal morbidity and mortality. Further large prospective studies evaluating the content of caffeine in the coffee consumed by this population is advised.

Objective: To validate a method for salivary testing for HIV infection in children older than 12 months., Methods: Oral fluid samples were collected via sponge foam swabs from children born to HIV-positive mothers and were tested for antibodies to HIV-1 and HIV-2 with an IgG antibody capture enzyme-linked immunosorbent assay and a modified Western blot for confirmation. In each child serum antibody status was the standard used to validate the salivary antibody test., Results: We obtained 331 oral fluid samples from children born to HIV-positive mothers. The specificity and sensitivity of salivary testing compared with results on sera were both 100% (297 of 297 (95% confidence interval 98.8 to 100%) and 34 of 34 (95% confidence interval 89.7 to 100%), respectively). Compliance in the study population increased from 91% to 97% when mothers were offered the opportunity to provide oral fluid from their children instead of blood specimens., Conclusion: Salivary testing provides an accurate and acceptable noninvasive method for assessing the HIV infection status of children born to infected mothers by using IgG antibody capture enzyme-linked immunosorbent assay alone with a strategy of duplicate retesting of reactive specimens.