IgG Antibodies In Serum Samples Research Articles

Risk Factors for Parvovirus B19 Infection in Pregnancy

ContextParvovirus B19 infection during pregnancy has been associated with fetal death. However, the incidence of and risk factors for infection in pregnant women have not been well studied.ObjectivesTo estimate a pregnant woman's risk of infection with parvovirus B19 in epidemic and endemic situations and to study risk factors for infection.DesignPopulation-based cohort study conducted between November 1992 and June 1994.SettingThree regions in Denmark.ParticipantsA total of 30,946 pregnant women from a consecutive and population-based screening.Main Outcome MeasuresSpecific IgG antibodies in serum samples obtained in the first trimester of pregnancy and from the newborn infant to assess past infection and seroconversion. Information on family structure, educational background, socioeconomic status, and pregnancy outcome was obtained from national registers.ResultsBased on 30,946 serum samples, 65.0% of pregnant women had evidence of past infection. Annual seroconversion rates among susceptible women during endemic and epidemic periods were 1.5% (95% confidence interval [CI], 0.2%-1.9%) and 13.0% (95% CI, 8.7%-23.1%), respectively. Baseline seropositivity was significantly correlated with increasing number of siblings, having a sibling of the same age, number of own children, and occupational exposure to children. Risk of acute infection increased with the number of children in the household as follows: 0 children odds ratio (OR), 1 (reference); 1 child OR, 3.17 (95% CI, 2.24-4.49); 2 children OR, 5.47 (95% CI, 3.55-8.45); 3 or more children OR, 7.54 (95% CI, 3.80-14.94). Having children aged 6 to 7 years resulted in the highest rate of seroconversion among mothers (6.8%; OR, 4.07; 95% CI, 1.89-8.73). Compared with other pregnant women, nursery school teachers had a 3-fold increased risk of acute infection (OR, 3.09; 95% CI, 1.62-5.89). Population-attributable risk of seroconversion was 55.4% for number of own children and 6.0% for occupational exposure.ConclusionsThe risk of infection is high for susceptible pregnant women during epidemics and associated with the level of contact with children. Nursery school teachers have the highest occupational risk, but most infections seem to be the result of exposure to the woman's own children.

Risk Factors for Parvovirus B19 Infection in Pregnancy

Parvovirus B19 infection during pregnancy has been associated with fetal death. However, the incidence of and risk factors for infection in pregnant women have not been well studied. To estimate a pregnant woman's risk of infection with parvovirus B19 in epidemic and endemic situations and to study risk factors for infection. Population-based cohort study conducted between November 1992 and June 1994. Three regions in Denmark. A total of 30946 pregnant women from a consecutive and population-based screening. Specific IgG antibodies in serum samples obtained in the first trimester of pregnancy and from the newborn infant to assess past infection and seroconversion. Information on family structure, educational background, socioeconomic status, and pregnancy outcome was obtained from national registers. Based on 30 946 serum samples, 65.0% of pregnant women had evidence of past infection. Annual seroconversion rates among susceptible women during endemic and epidemic periods were 1.5% (95% confidence interval [CI], 0.2%-1.9%) and 13.0% (95% CI, 8.7%-23.1 %), respectively. Baseline seropositivity was significantly correlated with increasing number of siblings, having a sibling of the same age, number of own children, and occupational exposure to children. Risk of acute infection increased with the number of children in the household as follows: 0 children odds ratio (OR), 1 (reference); 1 child OR, 3.17 (95% CI, 2.24-4.49); 2 children OR, 5.47 (95% CI, 3.55-8.45); 3 or more children OR, 7.54 (95% CI, 3.80-14.94). Having children aged 6 to 7 years resulted in the highest rate of seroconversion among mothers (6.8%; OR, 4.07; 95% CI, 1.89-8.73). Compared with other pregnant women, nursery school teachers had a 3-fold increased risk of acute infection (OR, 3.09; 95% CI, 1.62-5.89). Population-attributable risk of seroconversion was 55.4% for number of own children and 6.0% for occupational exposure. The risk of infection is high for susceptible pregnant women during epidemics and associated with the level of contact with children. Nursery school teachers have the highest occupational risk, but most infections seem to be the result of exposure to the woman's own children.

Antibodies to chlamydia trachomatis in semen and relationship with parameters of male fertility.

To screen for infection with Chlamydia trachomatis in semen samples from asymptomatic men in couples consulting for infertility and to determine the relationship of seminal chlamydial antibodies with clinically relevant parameters of male fertility, 197 randomly chosen patients were enrolled in a prospective study. The median duration of infertility was 4 years (range 1-18). Screening for C. trachomatis and chlamydial antibodies of the immunoglobulin (Ig) A and IgG classes were performed in ejaculates and, in parallel, endocervical material from the partners of the patients and serum samples from both partners were evaluated. A comprehensive examination of semen quality included sperm analyses, semen cultures, local antisperm antibody (ASA) testing, the determination of potential infection markers, and sperm-cervical mucus interaction testing in vitro (SCMPT) and in vivo (post-coital testing). Chlamydial IgA antibodies were found in the semen samples of 18.8% (37/197) of the patients, while chlamydial IgG antibodies were found in 8.1% (16/197) of the patients. Screening for C. trachomatis was negative in all semen and cervical specimens. Only 5.5% of men remembered a past genital infection. Chlamydia antibodies (IgA/Ig/G) in semen were significantly correlated with chlamydia IgG antibodies in serum samples (P < 0.001). No marked relationship was found between the presence of seminal chlamydial antibodies and the major parameters of sperm analysis, semen cultures, local ASA and sperm penetration testing as an indicator of functional capacity. Seminal chlamydial antibodies were not significantly associated with potential infection or inflammation markers in aliquots of the same ejaculates. However, a significant relationship of chlamydial antibodies in patients' semen with past genital infections of their female partners was found with clinical relevance for a tubal infertility factor. The results indicate that in asymptomatic patients the presence of chlamydial antibody IgA or IgG in semen is not associated with reduced semen quality, potential seminal infection markers or impaired functional capacity as important determinants of male fertility; however, seminal chlamydial antibodies suggesting a previous sexually transmitted disease are significantly related to a tubal infertility factor of female partners.

Significance of Chlamydia trachomatis for female fertility with special reference to prevalence in the endometrium

144 patients with longstanding infertility (mean duration of infertility 4.9 years) were screened for endometrial infection with Chlamydia trachomatis by means of endometrial biopsy and McCoy cell-culture. The same day blood was taken for detection of Chlamydia IgG antibodies in serum samples. During a 1 year's period, all new patients of a large infertility clinic without complaints or clinical symptoms of infection of the lower genital tract were consecutively submitted to the study. Elevated titers of IgG antibodies in serum samples (Chlam. AB greater than or equal to 1/256) revealed previous chlamydial infection of 26% of patients, but Chlamydia trachomatis was detected in endometrial biopsies in only 5/144 (3.5%). There was a strong correlation of previous chlamydial infection and reduced tubal patency (p 0.001) and a lower pregnancy rate after 6 months. The results suggested that infections with Chlamydia trachomatis, influenced by demographic and socio-economic aspects, are of minor importance as an actual infection in asymptomatic patients with longstanding infertility. Previous chlamydial infections, however, are of great importance because of their negative influence on tubal function.