Kinetics and sensitivity of ELISA IgG pertussis antitoxin after infection and vaccination with Bordetella pertussis in young children

Sera from 96 young children in a vaccine trial were analysed for kinetics of ELISA IgG anti‐pertussis toxin (anti‐PT) after a laboratory‐verified pertussis infection. The antibody decay curves after infection were biphasic and similar in shape to those after vaccination. The change from a rapid to a slower decay after the peak occurred about 4–5 months from the first day of cough. In a group of children given a two‐ or a five‐component acellular pertussis vaccine the proportion of sera above the tentative cut‐off values for anti‐PT of 20, 50 or 100 EU/ml 12 months after onset of the infection were 19%, 0% and 0% respectively. Corresponding figures for a whole‐cell or placebo vaccine group of infected children were significantly higher, 73%, 39% and 30%, i.e. the antibody decay after infection in young children depends on vaccination status as well as on the pertussis vaccine given. In a large group of non‐infected children vaccinated with the same five‐component acellular vaccine 13%, 0% and 0% had sera above 20, 50 and 100 EU/ml at 12 months after the third vaccine dose and all were below the minimum level of detection 2 years after vaccination. In conclusion, knowledge about anti‐PT kinetics is essential for the interpretation of seroepidemiological data but hardly offers the possibility to establish valid cut‐off values for anti‐PT in single sample serology. An option would be to identify a grey zone between the positive and negative ends of the distribution for follow‐up testing by a second serum.     

Seroprevalence of pertussis antitoxin (anti‐PT) in Sweden before and 10 years after the introduction of a universal childhood pertussis vaccination program

Hallander HO, Andersson M, Gustafsson L, Ljungman M, Netterlid E. Seroprevalence of pertussis antitoxin (anti‐PT) in Sweden before and 10 years after the introduction of a universal childhood pertussis vaccination program. APMIS 2009; 117: 912–22. The prevalence of IgG ELISA antibodies against pertussis toxin (anti‐PT) was studied in two Swedish seroepidemiological studies. One was performed in 1997 when the new pertussis vaccination program was 1 year old (n = 3420). In 2007, when Pa vaccines had been used countrywide for 10 years in the universal child vaccination program, this study was repeated to analyze the effect of vaccination on anti‐PT prevalence (n = 2379). Before the statistical analysis of seroprevalence, children vaccinated within the last 2 years before the serosurveys were excluded. The results indicate a reduced exposure to Bordetella pertussis in the population. The proportion of sera without measurable anti‐PT antibodies increased significantly, aggregated over all comparable age groups, from 3.8% in people sampled in 1997 to 16.3% in people sampled in 2007. For cord blood, 1% was without measurable anti‐PT antibodies in 1997 compared to a significantly higher level, 12%, in 2007. With anti‐PT concentrations of ≥50 and ≥100 EU/ml as cutoff points for ‘recent infection’ the proportion above the cutoff points for younger children was significantly higher in 1997 than in 2007 at both cutoff points. For all adults, 20 years of age and older, the difference in proportions above the lower cutoff point was close to statistically significant, comparing 1997 with 2007. This was not the case at 100 EU/ml. In the 1997 samples of children, there was a significant downward trend of ‘recent infections’ at both cutoff points for three sampled age groups between 5 and 15 years of age from 21% at 5.0–5.5 years of age to 7% at 14.7–15.7 years for the lowest cutoff. In the 2007 samples of children, on the contrary, there was a significant continuous upward trend of ‘recent infections’, at both cutoff points, for four sampled age groups between 4 and 18 years of age – from 4% at 4–5 years of age to 16% at 17–18 years at the lowest cutoff. The continuous increase, with age of children with high anti‐PT concentrations, supports the recent change in the general Swedish childhood vaccination program to include a pre‐school booster at 5–6 years and a school‐leaving booster at 14–16 years of age.     

Sleep problems and internet addiction among children and adolescents: a longitudinal study

Although the literature has documented associations between sleep problems and internet addiction, the temporal direction of these relationships has not been established. The purpose of this study is to evaluate the bidirectional relationships between sleep problems and internet addiction among children and adolescents longitudinally. A four‐wave longitudinal study was conducted with 1253 children and adolescents in grades 3, 5 and 8 from March 2013 to January 2014. The sleep problems of the student participants were measured by parental reports on the Sleep Habit Questionnaire, which catalogues early insomnia, middle insomnia, disturbed circadian rhythm, periodic leg movements, sleep terrors, sleepwalking, sleep talking, nightmares, bruxism, snoring and sleep apnoea. The severity of internet addiction was measured by students’ self‐reports on the Chen Internet Addiction Scale. Based on the results of time‐lag models, dyssomnias (odds ratio = 1.31), especially early and middle insomnias (odds ratio = 1.74 and 2.24), sequentially predicted internet addiction, and internet addiction sequentially predicted disturbed circadian rhythm (odds ratio = 2.40), regardless of adjustment for gender and age. This is the first study to demonstrate the temporal relationship of early and middle insomnia predicting internet addiction, which subsequently predicts disturbed circadian rhythm. These findings imply that treatment strategies for sleep problems and internet addiction should vary according to the order of their occurrence.     

Should fimbriae be included in pertussis vaccines? Studies on ELISA IgG anti‐Fim2/3 antibodies after vaccination and infection

The anti‐Fim response and long‐term persistence after vaccination and infection may be of importance in understanding population immunity. Longitudinal serum samples (n = 1330) from 542 non‐infected children related to a Swedish vaccine trial showed that the post vaccination (DTPa5) antibody decay curve for pertussis ELISA IgG anti‐fimbriae2/3 (anti‐Fim2/3) was bi‐phasic. A slower one followed an initial rapid decay approximately 5–6 months after the third dose at 12 months of age. After 71 months, however, 60% still had concentrations above ≥5 EU/ml, a level that had been shown to correlate with decreased risk of disease. Booster responses after re‐vaccination with DTPa5 at 4, 5 and 6 years of age were strong and appeared within 1 week after vaccination, indicating immune memory. Ninety‐six young children with verified pertussis infection, for whom we had serum samples both before, during and after the infection, showed a high response if they had been primed with fimbriae (either DTPa5 or DTPwc). In contrast, 76% of infected children not primed with fimbriae (a DTPa2 or DT group) only had concentrations below the minimum level of detection in all samples taken during and after the infection. In two Swedish seroepidemiological surveys, one from 1997 just after reintroduction of universal childhood vaccination against pertussis and one from 2007, the proportion of children 2–3 years with anti‐Fim2/3 concentrations <5 EU/ml was similar and above 90%. This reflects that the two‐ or three‐component pertussis vaccines (DTPa2 and DTPa3) that were introduced in Sweden in 1996 do not induce anti‐Fim2/3 antibodies. In previous studies it was shown in multivariate analyses that levels of IgG anti‐Fim2/3 ≥ 5 EU/ml reduced short‐term risk of pertussis in small children. As the antibody response to Fim2/3 after infection is poor in children who have not been primed earlier in life, inclusion of immunogenic Fim2/3 in future pertussis vaccines should be considered.     

Assessment of IgA anti-PT and IgG anti-ACT reflex testing to improve Bordetella pertussis serodiagnosis in recently vaccinated subjects

ObjectivesQuantifying IgG antibodies to pertussis toxin (PT) is the most specific and sensitive method for the serodiagnosis of a Bordetella pertussis infection. Since PT is a component of acellular pertussis vaccines, anti-PT IgG is also induced by vaccination, precluding pertussis serodiagnosis based exclusively on anti-PT IgG in recently vaccinated subjects. Here, we aim to identify additional B. pertussis-specific serological markers that can discriminate between infection and recent vaccination.MethodsThe clinical usefulness of measuring IgA directed to the vaccine antigen PT and IgG directed to non-vaccine antigens (Fim2/3, LPS, ACT, CatACT) was evaluated in nine well characterized subject groups, aged 10–89 years (n = 390). Serum anti-PT IgG levels (>125 IU/mL) served as an indicator for a recent B. pertussis infection. Comparing symptomatic pertussis-infected subjects (n = 140) with recently vaccinated, non-infected subjects (n = 100) revealed the optimal cut-off, accuracy, sensitivity and specificity for each single parameter.ResultsFor pertussis diagnosis in recently vaccinated subjects, the measurement of anti-PT IgA (cut-off 15 IU/mL) and anti-ACT IgG (cut-off 15 U/mL) resulted in accuracies of 95% (91.5–97.1) and 87.5% (82.7–91.1), sensitivities of 92.9% (87.4–96.0) and 83.6% (76.5–88.8) and specificities of 98% (93.0–99.4) and 93% (86.3–96.6), respectively. Comparing anti-PT IgA levels between the youngest (10–19 years, n = 38) and oldest (70–89 years, n = 17) age groups revealed an age-dependent increase in antibody levels in pertussis-infected subjects (p < 0.0001).ConclusionsReflex testing of anti-PT IgA and anti-ACT IgG improves pertussis serodiagnosis in recently vaccinated symptomatic subjects with elevated anti-PT IgG levels. Furthermore, both markers can discriminate between vaccination and recent infection in pertussis serosurveillance studies.     

Differences in coughing and other responses to intrabronchial infection with Bordetella pertussis among strains of rats.

Four strains of rats were each infected intrabronchially with approximately 10(8) CFU of Bordetella pertussis 18-323 encased in fine agarose beads. After 8 days, Sprague-Dawley rats developed the highest incidence of coughing paroxysms, as monitored with voice-activated tape recorders; Brown Norway, Lewis, and Hooded Lister rats coughed significantly less frequently. Marked leukocytosis, with counts up to four times the normal levels, and retardation of normal weight gain occurred in all four rat strains. Both coughing and leukocytosis were greater in animals that were infected at 4 weeks of age than in those infected at 6 weeks of age. Total serum immunoglobulin E (IgE) rose in all four rat strains 9- to 244-fold by day 8 after infection and returned to near preinfection levels at 6 weeks. Sprague-Dawley and Lewis rats, which had the lowest basal levels of total IgE in serum, showed the greatest degrees of elevation. All four rat strains had IgG to B. pertussis whole-cell sonicate and to filamentous hemagglutinin in 6-week-postinfection sera. However, the strains differed in production of IgG to pertussis toxin, with Sprague-Dawley rats having the highest titers and Hooded Lister and Lewis rats being nonresponders. These studies highlight the importance of rat strain as a variable in the coughing-rat model of pertussis and validate the choice of the Sprague-Dawley rats in previous studies.     

IL-10-592 polymorphism is associated with IL-10 expression and severity of enterovirus 71 infection in chinese children

BackgroundEnterovirus 71 (EV71) infection results in some severe complications with high mortality and disability in Hand, Foot and Mouth Disease (HFMD) in children. Recent studies have shown that cytokine genetic predispositions have associations with both the development of EV71 infection and severity of HFMD.ObjectiveThis study was designed to investigate whether the IL-10–592 polymorphism is associated with IL-10 levels and disease severity in Chinese children with EV71 infection.Study designIn patients selected, there were 378 cases with EV71 infection (including 291 mild cases, 70 severe cases and 17 critical cases), as well as 406 health controls. EV71 in serum was tested by RT-PCR, and IL-10-592 genotype was detected by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis techniques.ResultThe IL-10-592C allele was observed with higher frequency in patients with critical EV71 infection (70.59%) compared with severe EV71 infection (41.43%, P < 0.01), mild EV71 infection (43.81%, P < 0.01) and healthy children (44.46%, P < 0.01). The blood IL-10 levels of critical cases were significantly higher than severe cases, mild cases, and healthy children. Among all of the four groups, IL-10 levels in patients with genotype AA were significantly lower than those with genotypes AC + CC (t = 4.86, P < 0.05; t = 2.30, P < 0.05; t = 3.44, P < 0.05; t = 5.58, P < 0.05).ConclusionIL-10-592C allele is associated with IL-10 expressions and the severity of EV71 infection in Chinese patients.     

Seroprevalence of hepatitis B virus infection among children and adolescents in Singapore, 2008–2010

A national pediatric survey was undertaken to determine the prevalence of hepatitis B virus markers in Singapore. The aim was to assess the impact of the national childhood immunization program against hepatitis B implemented for all newborns since 1987. The survey involved prospective collection of residual sera from Singapore residents aged 1–17 years attending inpatient services or day surgery in two public hospitals between August 2008 and July 2010. A total of 1,200 sera were collected comprising 400 in each of the three age groups of 1–6, 7–12, and 13–17 years. The sera were tested for hepatitis B surface antigen (HBsAg) and antibody to HBsAg (anti‐HBs). Four of the 1,200 samples tested positive for HBsAg, giving an overall prevalence of 0.3%. One and three in the 7–12 years and 13–17 years age groups, respectively, were positive for HBsAg. About 40% possessed anti‐HBs (≥10 mIU/ml); the antibody prevalence decreased significantly from 63.8% in children aged 1–6 years to 32.8% in 7–12 year olds, and 23.5% in 13–17 year olds (P < 0.0005). The successful implementation of the national childhood hepatitis B immunization program over the last two decades has resulted in a low prevalence of HBsAg among children and adolescents. Singapore has achieved the World Health Organization Western Pacific Region's goal in reducing the prevalence of chronic HBV infection to below 2% among children aged 5 years and older by 2012 and to below 1% by 2017. J. Med. Virol. 85:583–588, 2013. © 2013 Wiley Periodicals, Inc.     

The relationship of character strengths to sexual behaviors and related risks among African American adolescents

Background: Relatively few studies have examined positive character traits that are associated with lower HIV/STD risks.Purpose: In the present study, the relationships of character strengths with sexual behaviors and attitudes were assessed among 383 African-American adolescents.Method: Character strengths were measured using the Values in Action Inventory of Strengths. Because the strengths were highly inter-correlated, stepwise discriminant function analyses were utilized to assess their independent associations with sexual behaviors and attitudes.Results: Greater Love of Learning was related to self-reported abstinence from sexual intercourse for boys and self-reported abstinence from drug use for boys and girls. Greater Love of Learning and Curiosity were related to the belief in no premarital sex for boys, whereas only Curiosity was significant for girls. Prudence was related to reported abstinence from sexual intimacy (e.g., touching or kissing). Judgment was related to sexual initiation efficacy for girls and boys, whereas Leadership was only significant for girls.Conclusions: The findings suggest that character strengths may be associated with lower levels of sexual behaviors and sex-related beliefs among a sample of African-American adolescents. The data for the present study were collected at Jackson State University. This research was supported by grants from the Values in Action Institute of the Mayerson Foundation and the National Institute of Child Health & Human Development (5R01HD039122-03).     

Urinary levels of kidney injury molecule-1 (KIM-1) and interleukin-18 (IL-18) in children and adolescents with hyperuricemia

PurposeHyperuricemia may lead to silent tissue damage and increase the risk of some diseases, including kidney diseases. Increased serum uric acid concentration induces inflammatory pathways and promotes kidney damage. This study aimed to determine whether hyperuricemia influences the levels of urinary kidney injury markers in children and adolescents with hyperuricemia, assessed by the urinary concentrations of interleukin-18, a biomarker of inflammation, and kidney injury molecule-1 (KIM-1), a biomarker of kidney injury.Material and methodsThe study included 73 children and adolescents (32 males and 41 females) aged 2–18 years. They were divided into two groups: hyperuricemia (HU) group (n ?= ?48) and normouricemia – reference group (R) (n ?= ?25). The concentrations of urinary interleukin-18 and KIM-1 were measured using an ELISA kit and were normalized for urinary creatinine (cr.) concentration.ResultsThe median interleukin-18/cr. Levels in the HU group were significantly higher than in the R group (median, Q1-Q3) 21.83 (11.32–35.96) and 12.68 (7.11–24.04), respectively, (p ?< ?0.05). The KIM-1/cr. in the HU group and the R group were (median, Q1-Q3) 0.79 (0.45–1.03) and 0.81 (0.59–1.01), respectively, and the difference was not significant. KIM-1/cr. did not differ between the groups. Interleukin-18/cr. ratio correlated positively with serum uric acid concentration (r ?= ?0.24, p ?< ?0.05).ConclusionsInterleukin-18/cr., but not KIM-1/cr. was higher in children with hyperuricemia. Hyperuricemia results in increased IL-18 in urine, in absence of other markers of kidney injury, suggesting inflammation in the kidney. Additional studies on the adults should be done, to confirm this hypothesis.     

13～15岁壮族青少年年龄、身高、体质量与肺活量的相关性

目的:建立广西壮族13~15岁青少年肺活量正常参考值及其与身高、体质量和年龄之间的相关性,为临床应用提供参考。方法:以常住广西百色地区13~15岁正常壮族青少年为研究对象,采用肺活量计测量肺活量和人体成分分析仪测量体质,采用马丁顿测高仪测量身高。结果:13~15岁壮族男女青少年肺活量与年龄、身高均呈正相关,体质量是男女性肺活量的主要影响因素。13岁壮族女生平均身高和体质量均显著低于同龄男生,13岁女生的肺活量值低于同龄男生,但14岁女生的肺活量值显著提高。结论:肺活量随着体质量、身高和年龄的增加逐渐增加,随着青春期的启动而显著地增加,青春期是肺活量迅速增加的一个关键时期。     

The significance of IgG subclasses and mannan-binding lectin (MBL) for susceptibility to infection in apparently healthy adults with IgA deficiency.

The aim of this study was to investigate the significance of IgG subclasses and MBL for susceptibility to infection in association with IgA deficiency. The study population consisted of 139 apparently healthy adult blood donors with IgA deficiency and normal serum levels of IgG and IgM, and an increased susceptibility to infection demonstrated at a population level. Additionally, 216 controls matched for age and sex were investigated. IgG4 deficiency was more common and the mean level of IgG4 lower in persons with IgA deficiency than in the controls. No significant associations could be demonstrated between overt IgG subclass deficiencies and increased susceptibility to infection. However, when the mean concentrations of IgG subclasses were analysed with regard to medical history, that of IgG1 was lower in persons who reported recurrent viral respiratory infections, that of IgG3 in persons who had episodes of severe infection in their history, and that of IgG4 in persons who had recurrent mild respiratory infections, compared with those who had no particular history of infections. In contrast, MBL deficiency-alone or combined with that of the IgG subclass-was not associated with increased susceptibility to infection in persons with IgA deficiency. The results indicate that the proneness to infections observed in a population of otherwise healthy persons with IgA deficiency can only for a small part be accounted for by concomitant deficiencies of IgG subclasses. Contrary to expectations, no synergism between the deficiencies of IgA and MBL could be demonstrated.     

瘦素和脂联素在儿童肥胖相关性高血压发病中的作用

目的探讨瘦素和脂联素在儿童肥胖相关性高血压发病中的作用。方法基于北京市儿童青少年代谢综合征研究项目的现况调查结果,非随机选择3502名6-18岁学龄儿童（其中男1784名,女1718名）为研究对象,按照超重（包括肥胖）和高血压状态将研究对象分为4组,正常体重正常血压组（对照组,1497名）、正常体重高血压组（HBP组,125名）、超重但血压正常组（OB组,1349名）和超重合并高血压组（OB＋HBP组,531名）。通过比较4组人群血清瘦素和脂联素水平,以及瘦素和脂联素与血压之间的相关回归分析,探讨其与肥胖和血压之间的关系。结果超重肥胖人群BMI、血压、胰岛素和瘦素水平显著升高,脂联素水平降低。HBP组与对照组BMI、瘦素、脂联素水平差异无统计学意义。OB组和OB＋HBP组与对照组比较,BMI、SBP、DBP、胰岛素和瘦素水平升高,脂联素水平降低,与HBP组比较仍可见BMI、胰岛素和瘦素水平升高,脂联素水平降低。与OB组比较,OB＋HBP组BMI和胰岛素水平及男性的瘦素水平明显升高。血压与年龄、BMI、胰岛素、瘦素均呈显著正相关（r=0.260-0.643,P〈0.01）,与脂联素呈显著负相关（r=-0.171--0.332,P〈0.01）。但在调整胰岛素或BMI后,瘦素、脂联素与血压的相关性减弱或消失。结论超重人群血压、胰岛素及瘦素水平均高于对照人群,脂联素水平低于对照人群。瘦素、脂联素可能通过肥胖或胰岛素抵抗与血压相关。     

Parenting styles, regimen adherence, and glycemic control in 4- to 10-year-old children with diabetes

OBJECTIVE: To examine relationships among parenting styles, regimen adherence, and glycemic control for preschool and elementary school children who have Type I diabetes. METHODS: Parents of 55 children with diabetes completed parenting style and regimen adherence questionnaires. Glycosylated hemoglobin results were collected by chart review. RESULTS: Parental warmth was associated with better adherence ratings. Regression analyses showed that parental warmth explained 27% of the variance in adherence ratings. Parental restrictiveness was associated with worse glycemic control in univariate analyses. However, only Black ethnicity, not adherence or parenting variables, predicted glycemic control. Black ethnicity and lower socioeconomic status (SES) were associated with more parental restrictiveness and worse glycemic control. CONCLUSIONS: These results suggest that authoritative parenting, characterized by support and affection, may be advantageous for the regimen adherence and glycemic control of school-age and younger children with diabetes. Demographic characteristics are important and require further study in this context.     

A study of problem behaviors in 10- to 15-year-old biologically related and unrelated international adoptees

Genetic and environmental influences on problem behaviors were studied in a sample of international adoptees. Parental ratings of childrens' problem behaviors were obtained with the Child Behavior Checklist (CBCL). The sample (mean age, 12.4 years) comprised a group of biological siblings (111 pairs), a group of nonbiological siblings (221 pairs), and a group of singletons (94). Nonshared environmental influences were most important for problem behaviors studied in this paper. Genetic influences were substantial for Externalizing behaviors but unimportant for Internalizing behaviors. For the CBCL total problem score, Attention Problems, and Externalizing behaviors, the results of the present study were in agreement with findings from twin studies. The lack of genetic influences on Internalizing behaviors contrasts with results from twin studies. For the total problem score, the Externalizing grouping, Delinquent Behavior, and Aggressive Behavior, variances for singletons were significantly smaller than for siblings. Model fit indices indicated that these differences in variances are better attributed to smaller effects of factors associated with sibship size than to active influences of siblings on each other. Significant sex differences were found for 8 of the 10 scales. The larger variances for boys on the Externalizing grouping and Aggressive Behavior could be explained by genetic influences.     

Preoperative and perioperative risk factors,and risk score development for prosthetic joint infection due to Staphylococcus aureus: a multinational matched case-control study

ObjectivesWe aim to identify the preoperative and perioperative risk factors associated with post-surgical Staphylococcus aureus prosthetic joint infections (PJI) and to develop and validate risk-scoring systems, to allow a better identification of high-risk patients for more efficient targeted interventions.MethodsWe performed a multicenter matched case-control study of patients who underwent a primary hip and knee arthroplasty from 2014 to 2016. Two multivariable models by logistic regression were performed, one for the preoperative and one for perioperative variables; predictive scores also were developed and validated in an external cohort.ResultsIn total, 130 cases and 386 controls were included. The variables independently associated with S. aureus-PJI in the preoperative period were (adjusted OR; 95% CI): body mass index >30 kg/m² (3.0; 1.9 to 4.8), resident in a long-term care facility (2.8; 1.05 to 7.5), fracture as reason for arthroplasty (2.7; 1.4 to 5.03), skin disorders (2.5; 0.9 to 7.04), previous surgery in the index joint (2.4; 1.3 to 4.4), male sex (1.9; 1.2 to 2.9) and American Society of Anesthesiologists index score 3 to 4 (1.8; 1.2 to 2.9). The area under the receiver operating characteristic curve was 0.73 (95% CI 0.68 to 0.78). In perioperative model, the risk factors were the previous ones plus surgical antibiotic prophylaxis administered out of the first 60 minutes before incision (5.9; 2.1 to 16.2), wound drainage for >72 hours after arthroplasty (4.5; 1.9 to 19.4) and use of metal bearing material versus ceramic (1.9; 1.1 to 3.3). The area under the receiver operating characteristic curve was 0.78 (95% CI 0.72 to 0.83). The predictive scores developed were validated in the external cohort.DiscussionPredictive scores for S. aureus-PJI were developed and validated; this information would be useful for implementation of specific preventive measures.     

Significance of maternal and infant serum antibodies to hepatitis B core antigen in hepatitis B virus infection of infancy

The significance of IgM and IgG class antibodies to hepatitis B virus (HBV) core component (anti-HBc) was investigated in a study of maternal-fetal HBV transmission. An IgM anti-HBc response was lacking in the majority (49/53) of HBV-infected infants. This antibody thus cannot be used as an indicator of transplacental infection. However, most infants who became HBsAg positive during the first 6 months of life acquire infection in the perinatal period rather than transplacentally. Passively transferred maternal IgG anti-HBc in the infant and additional IgM anti-HBc positively in the carrier mother have no modulating influence on HBV infection of infants born to HBV carrier women.