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Biomedical subjects

L C Rodrigues

Publications and source records attributed to L C Rodrigues.

13 recordsLinked to original sources

Space time clustering of births in SIDS: do perinatal infections play a role?

The aetiology of sudden infant death syndrome (SIDS) remains uncertain; many causal pathways have been proposed. In this paper we have examined firstly the variation in the risk of SIDS with age, month of death and month of birth; and secondly the space time clustering of SIDS deaths, and, separately, space time clustering of their births. Data were obtained from the Office of Populations, Censuses and Surveys on all certified SIDS deaths in the period; children were assigned grid references for the address of birth and of death. Data on number of births were abstracted from published material. A log-linear modelling technique was used to investigate the separate effects of age, month of death and month of birth on the risk of SIDS. The Knox method was used to investigate space time clustering of deaths and of births of children who died of SIDS. Separate, statistically significant effects were found for age, month of death and month of birth. There was minor space time clustering of SIDS births and deaths at large time and space intervals, and a marked space time clustering of births in short space time intervals in the first quarter of the year. The finding of an effect of month of birth on the risk of SIDS, and of space time clustering of births suggest that a perinatal hazard--possibly of infectious origin--may play a role in the aetiology of SIDS.

Birth Intervals

Factors influencing childhood immunisation in an urban area of Brazil.

STUDY OBJECTIVE: The aim was to examine the factors associated with incomplete vaccination in an urban area in Sao Paulo, Brazil; and to explore whether differences in vaccine coverage in the catchment area of health centres remain after the demographic constitution of the population in these areas is controlled for. DESIGN: The children were selected as controls for a case-control study. 455 children were selected at random (but age matched) from the health centre registries. Data was collected from the health centre records and from home interviews. SETTING: All children were registered in FAISA, a municipal health service comprising a large network of health centres and hospitals. FAISA's services are free at the point of delivery, and over 85% of the city's children are registered. PARTICIPANTS: Participants were selected to represent, except in their age distribution, all children registered in the municipal health service. MEASUREMENTS AND MAIN RESULTS: Information was collected on subjects' vaccine history, year of birth, sex, birth order and birth weight, and health centre of registration; their mothers' age, education, and marital status; and the family's income per capita and history of migration. Analysis was undertaken to identify risk factors for vaccination and whether the differential coverage in health centres' catchment areas remained after demographic characteristics of the population were controlled for. The high coverage for DPT and polio vaccines suggests that low overall coverage was not simply a result of mothers failing to bring children for vaccination. The variable that best predicted vaccine coverage was year of birth. Children born to immigrant mothers or into large families had lower vaccine uptake. The characteristics of children and their mothers did not account for the variation in vaccination coverage in catchment areas of different health centres. CONCLUSIONS: It is likely that in this area vaccination completeness was associated mainly with the health centre's ability to deliver vaccination to the target population.

Brazil

Sudden infant death syndrome: does winter affect poor and rich babies equally?

STUDY OBJECTIVE: The aim was to investigate whether the winter increase in risk of sudden infant death was similar across social classes. DESIGN: This was an unmatched case-control study using routine data. SETTING: Cases and controls were selected from files holding routine birth and death certificate data for England and Wales for 1986. SUBJECTS: Cases were deaths in the first year of life occurring in the summer or the winter of 1986 with mention of sudden infant death or SIDS in the death certificate. Controls were a 1% random sample of all children born in the same year. Only children whose parents were married or living together at the time of birth registration were included. MAIN RESULTS: Data on age and season of death for cases, and on date of birth, social class of father, and birth weight were abstracted from the file. Season of birth and birth weight were treated as confounding variables. The increase in risk of SIDS in winter was calculated for each age group and social class. The winter increase in SIDS was more marked among the higher social classes for all ages, but not to a statistically significant degree: the p values for heterogeneity were 0.26 for age 0-3 months, 0.42 for 4-7 months, and 0.41 for 8-12 months. CONCLUSIONS: There is no direct association between seasonal variation in sudden infant death and social class.

Birth Weight

BCG vaccination in the first year of life protects children of Indian subcontinent ethnic origin against tuberculosis in England.

STUDY OBJECTIVE: The aim was to assess the protection conferred by BCG given during the first year of life against tuberculosis among children of Asian ethnic origin born in England. DESIGN: This was a matched case-control study. SETTING: Cases were selected from notifications of tuberculosis and controls were selected from child health or school health records in 14 English health districts. PARTICIPANTS: 111 cases of childhood tuberculosis with Asian names were selected. For each case there were five controls with Asian names, matched for age, sex and district of birth. MEASUREMENTS AND MAIN RESULTS: Child health or school health records were searched to determine the proportions of cases and controls who had been vaccinated with BCG. Overall, BCG vaccination given in the first year of life was estimated to confer 49% protection against tuberculosis with 95% confidence interval 14-62%. CONCLUSIONS: BCG vaccination in infancy was found to be associated with a lower protective efficacy than has been found for the secondary school age BCG programme (80%) but nevertheless the protection is substantial and, in the United Kingdom, BCG vaccination of infants considered to be at relatively higher risk of tuberculosis is likely to reduce the incidence of childhood tuberculosis.

Asia, Western

Effectiveness of BCG vaccination against tuberculous meningitis: a case-control study in São Paulo, Brazil.

A case-control study was carried out in the Metropolitan Region of São Paulo, Brazil, to determine the protection against tuberculous meningitis conferred by BCG vaccination to children aged less than 5 years. The BCG vaccination coverage in the study area was about 88%. A total of 72 tuberculous meningitis patients were studied as well as 505 neighbourhood and 81 hospital controls. Analysis of the data using a conditional logistic regression for matched case-control studies indicated that the efficacy of BCG was similar for both groups of controls, that for neighbourhood controls (84.5%) being slightly greater than that for hospital controls (80.2%). No significant interactions were found between vaccination status and sex, age, or socioeconomic status.

BCG Vaccine

Evaluation of factors influencing vaccine uptake in Mozambique.

A pulse immunization project was started in Mozambique to compensate for the decrease in routine immunization caused by destabilization. A study was conducted to evaluate the project and identify determinants of vaccination in urban and rural areas of Mozambique. Vaccine coverage based on a documented record, the 'Road to Health' card, was 53% in urban and 60% in rural project areas, and 12% higher if a verbal history of vaccination was considered. A further 17% of children would have received effective vaccination if the correct schedule had been followed for all vaccines given and all preventive health services contacts had been used for vaccination. Factors relating to the individual mother and child and factors relating to the clusters were investigated for their association with vaccine uptake. Those which showed a strong negative association included vaccination on offer at the nearest vaccination post for only a small number of days per week; cancellation of an outreach session; knowing a child with a post-vaccination abscess; child born at home; at least five children in the family; mother's inability to speak Portuguese and her inability to name at least two target diseases. Improving the supervision of health services and immunizing at least three days per week at permanent immunization clinic sites may be the most important measures to improve coverage further.

Adult

Tuberculosis in developing countries and methods for its control.

Tuberculosis is a major cause of morbidity and mortality in developing countries. It is estimated that one-fifth of the world population is infected, 12-16 million people have the disease, every year 6-8 million develop tuberculosis and 2-3 million die from it. Four methods for the prevention of tuberculosis are available: improvement of socio-economic conditions, case-finding and treatment, chemoprophylaxis, and vaccination. Each of these methods is examined in relation to a model of the chain of transmission and development of disease. Improvement of socio-economic conditions, responsible for the decline of tuberculosis in the developed world, must be seen as a long-term solution. Case-finding and treatment is the only method expected to have an important short-term impact on transmission. A summary of the results of 35 studies shows the estimated efficacy of bacillus Calmette-Guérin (BCG) vaccination ranging from 96% to none. Follow-up results from 10 controlled trials are consistent with waning of BCG protective efficacy with time since vaccination. Chemoprophylaxis and vaccination are expected to protect the individual but not to have a significant short-term impact on transmission.

Antitubercular Agents