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Biomedical subjects

S Prabha

Publications and source records attributed to S Prabha.

6 recordsLinked to original sources

Transplacental transfer of measles antibody in Delhi.

OBJECTIVE: To find out the patterns of and the factors, if any, affecting the transplacental transfer of measles antibody. DESIGN: Comparison of measles antibody titres in mothers with titres in cord blood samples. METHODS: Maternal and cord blood samples from 174 full-term pregnant women of middle socio-economic status were tested for hemagglutination inhibition (HI) antibody against measles in Delhi during October 1993 to January 1995. None of the mothers had been immunized against measles. RESULTS: Antibody were undetectable in both maternal and cord samples in only 4 (2.3%) pairs. Mean maternal titre was found to be 2.94 Log2. Transplacental concentration and dilution were respectively observed in 34% and 26% of the samples. Cord titres were more often higher than the maternal values only if the maternal values were low. Overall, cord/maternal ratio of mean titre (Log2) was found to be 1.06. Although the age of the mother and parity had had no significant bearing on the transplacental transfer of measles antibody, cord titres were significantly more often higher than the maternal values as the birth weight increased (Chi-square for linear trend = 5.4; p = 0.02). CONCLUSIONS: The study failed to show appreciable concentration of measles antibodies across the placenta.

Adolescent↗

Transplacental dilution of tetanus antitoxins in Delhi.

Maternal blood-cord samples from 171 women of middle socio-economic status who had been administered at least two doses of tetanus toxoid (TT), were assayed for tetanus antitoxins by passive haemagglutination (PHA) test. All the mother as well as cord samples had antitoxin titres > or = 0.015IU/ml, the generally accepted minimal protective level; 98 per cent of the mothers and 97 per cent of the newborns had levels > or = 0.125IU/ml. Transplacental dilution was observed in 45 per cent of the samples; the cord/maternal antitoxin ratio (C/M) of geometric mean titre (GMT) was found to be 0.72. The C/M ratio was not affected by the maternal age, parity, birth weight, and number of TT doses administered to mother. The study showed that tetanus antitoxins were diluted on the fetal side of circulation, but the protective levels of antitoxins were achieved in all the newborns as the mothers had received at least two doses of TT before delivery.

Adolescent↗

Immunity to diphtheria in women of childbearing age in Delhi in 1994: evidence of continued Corynebacterium diphtheriae circulation.

Blood samples from 171 full-term pregnant women (aged 18-38 years) of middle socioeconomic status from Delhi were tested for diphtheria antitoxins by indirect hemagglutination (IHA) test. History of primary immunization/clinical diphtheria during childhood was not ascertainable, but none had been revaccinated against diphtheria at any time. About 94% women had very high antitoxin titers (> or = 0.125 IU/ ml); none had antitoxin titer less than 0.015 IU/ml, the minimum protective level. The titers were uniformly high in all age groups. However, women having 2 or more children had significantly higher antitoxin titers than those having no or one child (p < 0.01). The results from this study and historical data on diphtheria in Delhi are compatible with continued transmission of C. diphtheriae in recent times in Delhi which is of sufficient magnitude to boost the antitoxin levels in adults, especially mothers having two or more children. The study highlights the need of increasing the immunization coverage with DPT among children to reduce the transmission of Corynebacterium diphtheriae.

Adolescent↗