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R O Suara

Publications and source records attributed to R O Suara.

8 recordsLinked to original sources

Seroprevalence of antibodies to group B streptococcal polysaccharides in Gambian mothers and their newborns.

In developing countries, little is known about the relationship between group B streptococcal (GBS) colonization in pregnant women and serum antibody levels to capsular polysaccharide antigens of these organisms. This study examined the prevalence of antibodies to two polysaccharides of GBS, Ia and III, in 124 Gambian women with known GBS colonization at delivery and their newborns. Mean antibody levels in maternal-cord serum pairs were 4.06 +/- 0.25 micrograms/mL and 2.64 +/- 0.20 micrograms/mL for type Ia GBS, and 1.1 +/- 0.52 microgram/mL and 0.78 +/- 0.43 microgram/mL for type III GBS. Women colonized with type V GBS had significantly higher antibody levels to type III GBS than did noncolonized women, but no difference was found when these groups were compared for antibody levels to type Ia GBS. Women > or = 20 years had significantly higher antibody levels to type III GBS compared with younger women and those colonized by other GBS serotypes. Maternal antibodies to types la and III GBS were transferred across the placenta to newborns. The rarity of GBS disease in Gambia and other developing countries may be due to the prevalence of maternally derived GBS antibodies, the low prevalence of colonization with serotype III strains, or other undefined factors.

Adult↗

Maternal immunization with Haemophilus influenzae type b polysaccharide-tetanus protein conjugate vaccine in The Gambia.

OBJECTIVE: To evaluate maternal responses to Haemophilus influenzae type b (Hib) polysaccharide-tetanus protein conjugate (polyribosylribitol phosphate-tetanus or PRP-T) given to pregnant Gambian women, the transplacental transfer of antibody, and the effect of maternal immunization on infant responses to the vaccine. DESIGN: An open, randomized immunogenicity study. SETTING: A busy urban health center in The Gambia. STUDY PARTICIPANTS: A total of 451 pregnant women enrolled during the third trimester of pregnancy. INTERVENTION: Study participants were randomized to three groups. In one group, mothers were given PRP-T during the third trimester and their infants were given PRP-T at 2, 3, and 4 months of age. In the second group, mothers received PRP-T and infants were given inactivated poliovirus vaccine. In the third group, mothers received meningococcal A and C vaccine, and their infants received PRP-T. MAIN OUTCOME MEASURES: Anti-PRP antibody measurements of maternal cord, and infant blood. RESULTS: Vaccinated women had a marked increase in total anti-PRP antibody (geometric mean titer 9.0 micrograms/mL), which was greatest in women in their first or second pregnancy. Previous tetanus vaccination during the same pregnancy and high concentrations of antitetanus antibody were associated with lower anti-PRP responses. In infants of PRP-T recipients, cord blood anti-PRP IgG concentrations were 61% of simultaneous maternal concentrations. In vaccinated infants of vaccinated mothers, geometric mean anti-PRP antibody concentrations at birth, 2 months of age, and 5 months of age were 1.92, 0.35 and 2.84 micrograms/mL, respectively, while in vaccinated infants of unvaccinated mothers, the corresponding concentrations were 0.29, 0.12, and 3.91 micrograms/mL. At 2 months of age, 60% of infants of vaccinated mothers and 26% of infants of unvaccinated mothers had anti-PRP antibody concentrations considered to be protective (>0.15 micrograms/mL). CONCLUSIONS: In areas where much invasive Hib disease occurs in infants younger than 6 months, maternal immunization may help to reduce the risk of Hib disease in infants too young for immunization.

Antibodies, Bacterial↗

Prevalence of neutralizing antibody to respiratory syncytial virus in sera from mothers and newborns residing in the Gambia and in The United States.

The prevalence of maternal respiratory syncytial virus (RSV)-neutralizing antibodies has been documented in developed countries, but there is little information from developing countries. We assessed the prevalence of RSV-neutralizing antibody in sera from Gambian women and their newborns and compared them with their American counterparts during a similar period. The geometric mean titers of maternal antibodies to RSV subgroup A in the two populations were similar, while titers of antibodies to RSV subgroup B in Gambian mothers were significantly higher (8.7 +/- 1.4 versus 7.9 +/- 1.3 [mean +/- standard deviation], P < 0.001). The titers of neutralizing antibody in newborns in both populations correlated with the neutralizing-antibody titers of their mothers. Thus, the status of neutralizing antibody to both major RSV subgroups was comparable among infants and mothers in a developing country, The Gambia, and those in a developed country, the United States.

Antibodies, Viral↗

Carriage of group B Streptococci in pregnant Gambian mothers and their infants.

The prevalence of group B streptococcal (GBS) colonization was studied in 136 pregnant women and their newborn infants by collecting vaginal and rectal swabs from the mothers and throat, rectal, and umbilical swabs from their infants. Maternal and infant colonization rates were 22% and 23%, respectively. One-third of infants born to colonized mothers and 15% of infants born to noncolonized mothers had GBS isolated. Of GBS-colonized infants, 50% remained colonized at the mean age of 2 months. Type V was the commonest serotype among GBS isolates from mothers and infants; type III strains were uncommon. The rarity of GBS disease in Gambian infants may be due to low rates of maternal carriage with the more virulent GBS serotypes.

Adult↗