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Biomedical subjects

S M Pereira

Publications and source records attributed to S M Pereira.

At least 19 recordsLinked to original sources
PubMed2005

Neonatal BCG protection against tuberculosis lasts for 20 years in Brazil.

Bacille Calmette-Guérin (BCG) efficacy against pulmonary disease is highly variable; until very recently there was no evidence of protection after 10 years. In the control arm of a trial of efficacy of revaccination of schoolchildren in Brazil we found substantial protection (39%; 95%CI 9-58) of neonatal BCG against all forms of tuberculosis (TB) 15-20 years after vaccination, much longer than previously believed. This confirms recent findings from an earlier trial, and must be considered in the design of trials of new TB vaccines and in policy decisions based on assumed lack of neonatal BCG protection with time.

Adolescent↗
PubMed2003

A comparison of dual skin test with mycobacterial antigens and tuberculin skin test alone in estimating prevalence of Mycobacterium tuberculosis infection from population surveys.

SETTING: City of Manaus, Amazonas, Brazil. OBJECTIVE: To compare estimates of Mycobacterium tuberculosis infection prevalence obtained using traditional tuberculin skin test (TST) criteria and dual skin test (DST) data. METHODS: A total of 1070 schoolchildren received DST with tuberculin and four environmental mycobacteria sensitins. Responses were classified as sensitin-dominant, tuberculin-dominant or non-dominant. Positive predictive values (PPV) were defined using 'narrow' and 'wide' standards based on DST responses. These predictive values were derived for each category of tuberculin indurations, and were used to calculate the prevalence estimates. RESULTS: Using DST data, the estimates of M. tuberculosis prevalence for scar-negative children were 7.4% (M. avium) and 7.8% (M. scrofulaceum) using the 'narrow' standard, and 16.9% (M. avium) and 15.2% (M. scrofulaceum) using the 'wide' standard. The percentage with TST > or =10 mm was 11.5%. Scar-positive children had higher estimates using both the 10 mm cut-off and DST data. CONCLUSION: In settings with a relatively low prevalence of M. tuberculosis infection and high cross-reactivity with environmental mycobacteria, DST can help to assess the validity of traditional thresholds for estimating the prevalence of M. tuberculosis infection. DST data with environmental antigens and tuberculin do not distinguish BCG-induced cross-reactivity.

Adolescent↗
PubMed2001

Progression of cervical lesions in HIV-seropositive women: a cytological study.

It has been reported that cervical intraepithelial lesions have a more aggressive course in HIV-seropositive than in HIV-seronegative women. In the present investigation, the progression of these cervical lesions was studied in a group of HIV-seropositive women. Of 1,587 patients, 200 (12.6%) had a cytological diagnosis of squamous intraepithelial lesion (SIL) or invasive carcinoma. In 409 patients, more than one cytological smear was collected in 3(1/2) years. Progression occurred in 39 cases. In 24 (61.5%), the first diagnosis was benign cellular changes (BCC) and the second was low-grade SIL (LSIL) (1-yr interval in 21 cases); in 11 (28.2%), the first was BCC, and the second, high-grade SIL (HSIL) (1-yr interval in 9 cases); in 2 (5.0%), the first diagnosis was LSIL. and the second, HSIL (1-yr interval); in 2 (5.0%), the first was HSIL, and the second, invasive carcinoma (2-yr interval). These results point to the importance of cervical cytologic surveillance in HIV-seropositive patients.

AIDS-Related Opportunistic Infections↗
PubMed2001

Skin test reactivity to mycobacterial antigens parallels the phylogenetic structure of their genus.

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.

Adolescent↗
PubMed2001

Sensitivity and specificity of BCG scar reading in Brazil.

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.

BCG Vaccine↗
PubMed1998

Cervical intraepithelial neoplasia in adolescents: study of cytological findings between 1987 and 1995 in São Paulo State-Brazil.

The purpose of the present study was to ascertain the frequency of Pap smears abnormalities (SIL/carcinoma) in two populations in the State of S. Paulo (Brazil) who were screened for cervical cancer during the last nine years: adolescents (up to the age of 21) and adults (over 21). Statistical analysis showed a tendency to linear increase in frequency of abnormal Pap smears in both groups (adolescent: slope = 0.118 +/- 0.56; adult: slope = 0.079 +/- 0.021), being greater in the adolescent group (slope 0.039 +/- 0.038) than in the adult group. Between 1987 and 1995 the prevalence of abnormal smears tripled in the adult group (from 0.37 to 1.18) and almost quadruplicated in the adolescent group (from 0.64 to 2.10). Low grade squamous intraepithelial lesions (SIL) were the most frequent findings in cervical cytology in both groups: 92.3% in the adolescent group and 69.8% in the adult group. Few cases of high grade squamous intrapeithelial lesions (HSIL) (7.7%) and no cases of carcinoma were found in adolescent population. We suggested that sexually active adolescents should be included in cervical screening programs.

Adolescent↗
PubMed1997

Study of organizer nucleolar regions by the argyrophil technique in cervical intraepithelial neoplasias.

Thirty three biopsies of the uterine cervix were studied by the AgNOR method, that identifies the nucleolar organizer regions. These comprised 9 cases of cervicitis (with or without squamous metaplasia), 9 cases of cervical intraepithelial neoplasia grade I (CIN I), 8 CIN II and 10 CIN III. A hundred cells were counted and classified according to the number of AgNOR dots. We use a more practical and fast method of AgNOR dots counting in cervical intraepithelial neoplasia, in that we exclude the two basal layers and count only cells with 4 or more dots. Statistically significant differences for AgNOR dots were found between cervicitis or CIN I and CIN II cases (p < 0.02) and between CIN II and CIN III cases (p < 0.001). No statistical difference was found between the cases of cervicitis and CIN I. It was concluded that this method of AgNOR counting can be useful in the identification and classification of individual cases intraepithelial neoplasia and their differentiation from eventual difficult cases of cervicitis.

Biopsy↗
PubMed1996

Role of viruses in acute gastroenteritis in infants and young children at Vellore, south India.

The aetiological contribution of viral agents in the causation of acute diarrhoea was studied prospectively in 915 infants and young children aged 1-35 months. This was a hospital-based study, selection being carried out by proportionate random sampling; 587 matched controls were also investigated simultaneously. Methods of detection included direct electron microscopy, ELISA for rotaviruses and immune electron microscopy. Rotaviruses emerged as the single most important cause with highest prevalence in the 6-11-month age group. The contribution of other agents was negligible. Electron microscopy, though a "catch-all' technique, is not a cost-effective diagnostic method for developing countries.

Acute Disease↗
PubMed1987

Aetiology and clinical features of acute childhood diarrhoea in an outpatient clinic in Vellore, India.

The aetiology of acute diarrhoea was investigated in 245 children less than 3 years old in a paediatric outpatient clinic in southern India. In 55% of the children organisms were found in the stools, and one quarter were infected with multiple organisms. Viruses, enteropathogenic E. coli, shigella and campylobacter species accounted for 75% of all isolates. Cholera and helminthiasis were rare, and no child had amoebiasis. Clinical findings were useful in the diagnosis of shigella and rotavirus infection only. Children with shigellosis had classical dysentery, and a greater number of stools; they were unlikely to be breast-fed, to be less than 6 months old, or to have watery stools. Rotavirus infections were characterized by vomiting. Only 20% of the 245 children had an infection which could be treated effectively with antimicrobials.

Campylobacter Infections↗
PubMed1987

Pyomyositis in south Indian children.

Thirty-two children with pyomyositis were studied. In 28 children, 23 boys and 5 girls, Staphylococcus aureus was the aetiological agent. The strains isolated were resistant to penicillin. The muscles of the thigh, back and upper arm were most frequently involved. Eight children had infections in other parts of the body, namely pneumonia, empyema, pericarditis, meningitis, osteomyelitis and arthritis. Two children died. At follow-up one child had chronic osteomyelitis. In four neonates, beta haemolytic streptococcus was the causative organism. All were septicaemic. One infant died.

Abscess↗
PubMed1987

The influence of illnesses on the food intake of young children.

The effect of illness on the food intake of 125 preschool children in a residential home was studied. The children had a mean of 6.8 episodes of illness per child per year. Upper respiratory infections, diarrhoeas and fevers depressed food intake by 15-20%. Measles resulted in prolonged and profound depression of appetite, and caused weight losses in the affected children. The number of days of depressed appetite due to illness had a cumulative effect on growth; poor increases in height and weight were seen in these children who had many days of reduced appetite due to illness. Measles vaccination is strongly recommended for improved growth and nutritional status of preschool children.

Appetite↗
PubMed1986

The growth of exclusively breastfed infants.

To determine the pattern of growth of exclusively breastfed babies and to establish their incremental weight gains, 329 babies attending a well baby clinic were studied. The weight gains were most rapid over the first 6 weeks and were of the order of 41.4 and 39.2 g/day in the boys and girls respectively. Underweight mothers did not produce lighter babies than mothers of desirable weight, nor did their nutritional status influence the weight gains of their infants over the first 6 weeks. Low birthweight infants doubled their weights by 9-10 weeks, while heavier babies took 15 to 18 weeks. The pattern of growth of exclusively breastfed infants appears to be different from that of artificially fed infants.

Birth Weight↗
PubMed1985

[Cold lymphocytotoxins in schistosomiasis mansoni].

The serum of 134 patients infected with Schistosoma mansoni, including both acute and chronic forms of the disease, were tested for the presence of cold lymphocytotoxins. These were found in 4.5% of acute forms of the disease, in 88.4% of chronic infections and in only 9.8% of the uninfected control group (blood donors). An analysis of the results suggests a probable role for cold lymphocytotoxins in the immune response of the different phases of human schistosomiasis.

Adolescent↗
PubMed1985

Latex agglutination: an appropriate technology for the diagnosis of bacterial meningitis in developing countries.

We evaluated prospectively the utility of a latex agglutination technique for the diagnosis of Haemophilus influenzae type b meningitis in a paediatric ward in India. Eight of 44 children had H. influenzae grown from cerebrospinal fluid. These proven cases plus four additional cases of H. influenzae meningitis were detected by the latex agglutination test. There were no cross reactions with other organisms. The high degree of sensitivity and specificity, combined with the speed and simplicity of this technique make it an appropriate method for developing countries.

Child↗