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PubMed1999

Serum concentrations of organochlorine compounds and the subsequent development of breast cancer.

A nested case-control study was conducted to examine the association between serum concentrations of 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE), the primary metabolite of 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT), and polychlorinated biphenyls (PCBs) and the development of breast cancer up to 20 years later. Cases (n = 346) and controls (n = 346) were selected from cohorts of women who donated blood in 1974, 1989, or both, and were matched on age, race, menopausal status, and month and year of blood donation. Analyses were stratified by cohort participation because median DDE and PCB concentrations among the controls were 59 and 147% higher in 1974 than 1989, respectively. Median concentrations of DDE were lower among cases than controls in both time periods [11.7% lower in 1974 (P = 0.06) and 8.6% lower in 1989 (P = 0.41)]. Median concentrations of PCBs were similar among cases and controls [P = 0.21 for 1974 and P = 0.37 for 1989 (Wilcoxon signed rank test)]. The risk of developing breast cancer among women with the highest concentrations of DDE was roughly half that among women with the lowest concentrations, whether based on concentrations in 1974 [odds ratio (OR), 0.50; 95% confidence interval (CI), 0.27-0.89; P(trend) = 0.02] or in 1989 (OR, 0.53; 95% CI, 0.24-1.17; P(trend) = 0.08). The associations between circulating concentrations of PCBs and breast cancer were less pronounced but still in the same direction (1974: OR, 0.68; 95% CI, 0.36-12.9; P(trend) = 0.2; and 1989: OR, 0.73; 95% CI, 0.37-1.46; P(trend) = 0.6). Adjustment for family history of breast cancer, body mass index, age at menarche or first birth, and months of lactation did not materially alter these associations. These associations remained consistent regardless of lactation history and length of the follow-up interval, with the strongest inverse association observed among women diagnosed 16-20 years after blood drawing. Results from this prospective, community-based nested case-control study are reassuring. Even after 20 years of follow-up, exposure to relatively high concentrations of DDE or PCBs showed no evidence of contributing to an increased risk of breast cancer.

Adult↗
PubMed1972

Studies on diarrhea in neonatal calves: the plasma proteins of normal and diarrheic calves during the first ten days of age.

The concentration of serum proteins and plasma fibrinogen were determined in 151 normal and 49 diarrheic calves at intervals from birth to ten days of age. There were significant differences in the concentrations of the various serum proteins in normal calves when the results were analysed at six age intervals. There was no significant relationship between the concentration of the various proteins and the season of the year. Of the diarrheic calves, those that died had significantly lower gamma globulin concentrations than the other calves. Severely diarrheic and dehydrated calves had significantly increased serum albumin and alpha glabulin concentrations and decreased gamma globulin concentrations. No significant variation occurred in total serum protein concentration. Plasma fibrinogen concentrations were similar in normal and diarrheic calves.

Alpha-Globulins↗
PubMed2006

Risk of congenital anomalies in pregnant users of non-steroidal anti-inflammatory drugs: A nested case-control study.

BACKGROUND: Many women take non-steroidal anti-inflammatory drugs (NSAIDs) during pregnancy but the risks for the infant remain controversial. We carried out a study to quantify the association between those women prescribed NSAIDs in early pregnancy and congenital anomalies. METHODS: A population-based pregnancy registry was built by linking data from three administrative databases in Quebec between 1997-2003. The inclusion criteria were mothers of live singleton infants, between 15-45 years of age, covered by the RAMQ drug plan > or =12 months before and during pregnancy, and prescribed an NSAID or other medications during pregnancy. We selected as cases infants with any congenital anomaly (ICD-9; 740-759) diagnosed in the first year of life. Up to 10 controls, defined as infants with no congenital anomalies detected were selected for each case. Adjusted odds ratios (OR) and 95% confidence intervals (CI) were estimated. RESULTS: Within the registry, 36,387 pregnant women met the inclusion criteria. We identified 93 births with congenital anomalies in 1056 women (8.8%) who filled prescriptions for NSAIDs in the first trimester of pregnancy, compared to 2478 in 35,331 (7%) women who did not. The adjusted OR for any congenital anomalies for women who filled a prescription for NSAIDs in the first trimester was 2.21 (95% CI = 1.72-2.85). The adjusted OR for the anomalies related to cardiac septal closure was 3.34 (95% CI = 1.87-5.98). There were no significant associations with anomalies of other major organ systems. CONCLUSIONS: Our study suggests that women prescribed NSAIDs during early pregnancy may be at a greater risk of having children with congenital anomalies, specifically cardiac septal defects.

Abnormalities, Drug-Induced↗
PubMed2001

The Preterm Prediction Study: association between cervical interleukin 6 concentration and spontaneous preterm birth. National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network.

OBJECTIVE: The aim of this study was to determine the interrelationship between cervical concentration of interleukin 6 and detection of fetal fibronectin and other risk factors for spontaneous preterm birth. STUDY DESIGN: All patients with spontaneous preterm birth at <35 weeks' gestation (case patients; n = 125) and subjects matched for race, parity, and center delivered at > or = 37 weeks' gestation (n = 125; control subjects) were selected from women enrolled in the National Institute of Child Health and Human Development's Preterm Prediction Study. Interleukin 6 concentrations were determined by enzyme-linked immunosorbent assay in cervical swabs obtained at 22 weeks' to 24 weeks 6 days' gestation. Cutoffs to define an elevated interleukin 6 concentration included the 90th and 95th percentiles for control subjects (>305 and >538 pg/mL, respectively). RESULTS: The mean (+/-SD) interleukin 6 concentration was significantly higher in case patients than in control subjects (212 +/- 339 vs 111 +/- 186 pg/mL; P = .008). With either cutoff value elevated interleukin 6 concentration was significantly associated with spontaneous preterm birth (90th percentile, 20% vs 9.6%; P = .02; 95th percentile, 12% vs 4.8%; P = .04). Cervical interleukin 6 levels were highest within 4 weeks of delivery, and the trend continued until term. Elevated interleukin 6 concentration was not significantly associated with bacterial vaginosis, maternal body mass index <19.8 kg/m2, or a short cervix (< or = 25 mm), but it was significantly associated with a positive cervicovaginal fetal fibronectin test result (90th percentile, odds ratio, 5.5; 95% confidence interval, 2.6-11.9; 95th percentile, odds ratio, 5.3, 95% confidence interval, 2.1-12.9). The mean interleukin 6 concentration among women with a positive fibronectin test result was 373 +/- 406 pg/mL; that among women with a negative fetal fibronectin test result was 130 +/- 239 pg/mL (P = .001). In a regression analysis that adjusted for risk factors significantly associated with spontaneous preterm birth in this population (positive fetal fibronectin test result, body mass index <19.8 kg/m2, vaginal bleeding in the first or second trimester, previous spontaneous preterm birth, and short cervix) elevated cervical interleukin 6 concentration was not independently associated with spontaneous preterm birth (odds ratio, 1.8; 95% confidence interval, 0.8-4.3). CONCLUSIONS: At 24 weeks' gestation cervical interleukin 6 concentration in women who subsequently had a spontaneous preterm birth at <35 weeks' gestation was significantly elevated relative to those who were delivered at term. The association was particularly strong within 4 weeks of testing. A positive fetal fibronectin test result was strongly associated with elevated cervical interleukin 6 concentration, but bacterial vaginosis was not.

Case-Control Studies↗
PubMed1994

Renal function in preterm neonates.

The plasma creatinine concentration is elevated at birth and decreases concomitantly with the rapid increase in glomerular filtration rate that occurs in the first postnatal weeks. The velocity of these changes was assessed during the first 3 wk of life of 66 term and preterm infants. The plasma creatinine concentration, creatinine clearance, and sodium fractional excretion were measured serially at weekly intervals, starting 1-4 d after birth [mean = 1.5 +/- 0.8 (SD) d]. Premature infants were separated into three groups according to their birth weight: group 1, 1001 to 1500 g; group 2, 1501 to 2000 g; and group 3, 2001 to 2500 g. Group 4 included 28 term infants (mean birth weight = 3165 +/- 78 g). Mean gestational ages in the preterm groups were 31.3, 32.8, and 34.4 wk in groups 1, 2, and 3, respectively. The plasma creatinine concentration on d 1.5 was significantly higher in preterm (91 +/- 4 mumol/L) compared with term infants (66 +/- 3 mumol/L). The differences in plasma creatinine were still present during the second week of life, with values of 64 +/- 5, 58 +/- 7, 47 +/- 8, and 40 +/- 4 mumol/L in groups 1, 2, 3, and 4, respectively. The difference vanished by d 22-23. On d 1.5, creatinine clearance correlated positively with gestational age, amounting to 0.65 +/- 0.14, 0.92 +/- 0.19, 1.42 +/- 0.31, and 3.36 +/- 0.32 mL/min in groups 1, 2, 3, and 4, respectively. Creatinine clearance increased rapidly with postnatal age, the velocity of the maturation being less marked in the most premature infants.(ABSTRACT TRUNCATED AT 250 WORDS)

Birth Weight↗
PubMed1998

Population attributable fraction estimation for established breast cancer risk factors: considering the issues of high prevalence and unmodifiability.

Established breast cancer risk factors, in addition to being relatively unmodifiable, are highly prevalent among US women. Previous reports of population attributable fraction for the established risk factors have used definitions that resulted in 75-100% of women in the source population labeled exposed. The practical value of such estimates has not been discussed; further, the estimates have frequently been misinterpreted. In the context of examining the interpretation and public health value of such estimates, the authors demonstrate the sensitivity of the population attributable fraction to changes in exposure cutpoints. They use data from the Carolina Breast Cancer Study, a case-control study of breast cancer conducted in North Carolina between 1993 and 1996. For the four established risk factors (menarche before age 14 years, first birth at age 20 years or later/nulliparity, family history of breast cancer, and history of benign breast biopsy), the estimated population attributable fraction was 0.25 (95% confidence interval 0.06-0.48). Over 98% of the source population was exposed to at least one of these risk factors. The population attributable fraction estimate was reduced to 0.15 when more restrictive definitions of early menarche (less than age 12 years) and late age at first full-term pregnancy (30 years or more) were used (proportion exposed, 0.62). Population attributable fractions for established breast cancer risk factors probably have little public health value because of both the high proportions exposed and the relative unmodifiability of the risk factor distributions.

Adolescent↗
PubMed2000

Prevalence and clinical course of chronic hepatitis C virus (HCV) infection and rate of HCV vertical transmission in a cohort of 15,250 pregnant women.

The prevalence and natural course of chronic hepatitis C virus (HCV) infection was evaluated in 15,250 consecutive pregnant women. The rate of HCV vertical and perinatal transmission was also assessed. The presence of anti-HCV was tested by means of EIA III and confirmed by recombinant immunoblot assay III. Alanine transaminase (ALT), anti-human immunodeficiency virus (HIV), and HCV-RNA were tested during the first month and third trimester of pregnancy, and 6 months after delivery; the same tests were made in all of the newborns of anti-HCV-positive mothers at birth (on cord blood samples) and then at 4-month intervals. Anti-HCV positivity was found in 370 cases (2.4%), 72% of whom were also HCV-RNA-positive. The proportion of women with hypertransaminases decreased from 56.4% at the first examination during the first month of pregnancy to 7.4% in the last trimester, and then increased again after delivery (54. 5%), without any concomitant changes in the proportion of those with viremia. The proportion of anti-HCV- and HCV-RNA-positive newborns was 5.1% after 1 year (8 of 155), all of whom had the same genotype as their mother. The rate of HCV transmission was not affected by the type of delivery or feeding, or the HIV status of the mother. The results of this large-scale study confirm previous data in smaller series concerning the prevalence of HCV infection in pregnant women, and strongly support the hypothesis of a favorable (possibly immunomediated) effect of pregnancy on liver cell necrosis in anti-HCV-positive women.

Adult↗
PubMed1986

Colonisation of Haemophilus influenzae and Streptococcus pneumoniae in the upper respiratory tract of neonates in Papua New Guinea: primary acquisition, duration of carriage, and relationship to carriage in mothers.

In order to determine the age of acquisition and duration of carriage of the first strains of Haemophilus influenzae and Streptococcus pneumoniae in the upper respiratory tract of Papua New Guinea children, 25 babies were recruited at, or shortly after birth. Nasal secretions from mothers and children were cultured at 1- to 2-weekly intervals. H. influenzae and S. pneumoniae were acquired within the neonatal period by 60% of the infants, and all were colonised by both organisms within the first 3 months of life. Carriage periods for H. influenzae ranged from 6 to 221 days (mean, 74 days), and for S. pneumoniae from 5 to 290 days (mean, 96 days). Penicillin resistance was detected in 36% of the first acquired strains of pneumococci. Mothers, generally either did not carry H. influenzae or S. pneumoniae, or harboured types different to those first acquired by their infants. However, one-third of mothers subsequently became colonised with H. influenzae and S. pneumoniae types similar to those carried by their babies.

Carrier State↗
PubMed2003

Dual effect of parity on breast cancer risk in African-American women.

BACKGROUND: In the United States, breast cancer incidence is higher among African-American women than among white women before age 45 but lower at older ages. To explore whether differences in childbearing patterns can explain this observation, we assessed the relation of several childbearing variables to breast cancer risk in a large prospective cohort study of U.S. African-American women. METHODS: Black Women's Health Study participants were enrolled in 1995 and were followed by mailed questionnaires every 2 years (in 1997 and 1999). Of the 64,500 women enrolled, 56,725 (88%) completed at least one of the follow-up questionnaires. During 214,862 person-years of follow-up, participants reported 349 breast cancers, of which 128 were among women younger than 45 years and 221 were among women aged 45-70 years. Incidence rate ratios (IRRs) with 95% confidence intervals (CIs) were derived from age-stratified Cox regression models that adjusted for each of the childbearing variables (parity, age at first birth, and time since last birth). RESULTS: Compared with primiparity, high parity was associated with an increased risk of breast cancer among women younger than 45 years (IRR for four or more births = 2.4, 95% CI = 1.1 to 5.1) and a decreased risk among women aged 45 years and older (IRR = 0.5, 95% CI = 0.3 to 0.9). The IRR for late age at first birth compared with early age was 2.5 (95% CI = 1.1 to 5.8) among the younger women and was not elevated among older women. We found no statistically significant association of time since last birth with breast cancer risk among either younger or older women. CONCLUSIONS: Parity has a dual association with breast cancer risk in African-American women; among women younger than 45 years, parity is associated with an increased risk and among women 45 years and older it is associated with a decreased risk. This dual effect may explain some of the observed differences in breast cancer incidence rates among African-American and white women.

Adult↗
PubMed2002

Preeclampsia in the parous woman: who is at risk?

OBJECTIVE: The purpose of this study was to identify risk factors for preeclampsia in second pregnancies and to determine whether gestational age at delivery in the first pregnancy increases the risk of recurrent preeclampsia. STUDY DESIGN: We conducted a population-based, case-control study using birth certificate data from the Missouri maternally linked cohort. Data from women delivered of their first 2 singleton pregnancies between 1989 and 1997 (2332 cases with preeclampsia in the second pregnancy and 2370 control cases) were analyzed with logistic regression. RESULTS: Significant risk factors for preeclampsia in a second pregnancy include longer birth interval, previous preterm delivery, previous small-for-gestational-age newborn, renal disease, chronic hypertension, diabetes mellitus, obesity, black race, and inadequate prenatal care. Smoking and same paternity are protective. A history of preeclampsia confers the highest risk for preeclampsia in the second pregnancy; the risk is inversely proportional to gestational age at delivery of the first pregnancy: adjusted odds ratio, 15.0; 95% CI, 6.3-35.4 for 20 to 33 weeks; adjusted odds ratio, 10.2; 95% CI, 6.2-17.0 for 33 to 36 weeks; and adjusted odds ratio, 7.9; 95% CI, 6.3-10.0 for 37 to 45 weeks. CONCLUSION: The relative risk of recurrent preeclampsia increases with earlier gestational age at delivery of the first pregnancy that was complicated by preeclampsia.

Adolescent↗
PubMed1994

Comparison of first-trimester transvaginal amniocentesis with chorionic villus sampling and mid-trimester amniocentesis.

Between August 1989 and December 1991, 356 patients underwent first-trimester transvaginal amniocentesis (10-12 weeks). The same number of patients referred in the same period for mid-trimester amniocentesis (14-21 weeks) was matched also for maternal age and indication. A third group consisted of the first 356 cases in which chorionic villus sampling (CVS) was attempted. The overall success rate was 99.7 and 100 per cent for early and mid-trimester amniocentesis, respectively, and 97.2 per cent for CVS. The mean harvesting time was 12.8, 11, and 7.9 days, respectively. The percentage of patients rescheduled was 3.4 per cent in first-trimester amniocentesis, 1.7 per cent in mid-trimester amniocentesis, and 6.2 per cent in the CVS group. The early (less than 2 weeks) pregnancy loss was 1.7 and 0.6 per cent in early and mid-trimester amniocentesis, respectively, and 1.7 per cent in CVS. The total pregnancy loss was 3.2, 0.9, and 2.9 per cent, respectively. The rate of preterm birth was 6.0, 5.2 and 6.9 per cent, respectively. The results indicate that CVS has the shortest procedure-result interval, but the highest rescheduling rate. First-trimester amniocentesis has a higher procedure and laboratory success rate but, until otherwise proved, mid-trimester amniocentesis is the most efficient and safest procedure.

Abortion, Spontaneous↗
PubMed1986

Fetal surveillance in diabetic pregnancy. II. The nonstress test versus the oxytocin challenge test.

At the Department of Obstetrics and Gynecology, University of Lund, it has been the routine management in diabetic pregnancy to use both nonstress test (NST) and oxytocin challenge test (OCT) for fetal surveillance. The study material reported comprised 61 pregnant diabetics, 1,882 NSTs and 90 OCTs. Evaluations were made separately for the time interval 0-2 days antepartum, within 1 week antepartum, and all tests included. Predictive value, specificity and sensitivity were calculated for both the NSTs and the OCTs according to the following variables of neonatal outcome: Apgar scores at 1, 5 and 10 min, baby's first cry (or not) within 1 min of birth, pulmonary function, and metabolic balance. No perinatal deaths occurred. There were no statistically significant differences between the NSTs and OCTs in the antepartum time intervals 0-2 days and less than or equal to 1 week regarding any variable. When all tests were included, the OCT proved superior in that there were fewer falsely pathological tests, though biased by the fact that most of the NSTs evaluated were older than the oldest OCT in this context. Nevertheless, it is concluded that the OCT does not favor the NST for routine fetal surveillance in diabetic pregnancy.

Apgar Score↗
PubMed2005

When does mother to child transmission of hepatitis C virus occur?

OBJECTIVE: To investigate when hepatitis C virus (HCV) infection from mother to child occurs, and evaluate possible associated factors. DESIGN: Prospective cohort study. PATIENTS: Fifty four HCV infected children tested within three days of birth and their mothers. MAIN OUTCOME MEASURES: HCV RNA polymerase chain reaction (PCR) results. RESULTS: Seventeen of the children (31%, 95% confidence interval 19% to 46%) were positive in the first 3 days of life and could be assumed to have acquired infection in utero. Testing PCR positive was not associated with sex (53% v 49% boys; p=0.77) or mode of delivery (29% elective caesarean section in both groups; p=0.98). Children with evidence of intrauterine infection were significantly more likely to be of lower birth weight and infected with genotype 1 (58% v 12%, p=0.01). Although a higher proportion of infants born to HCV/HIV co-infected women were PCR positive in the first 3 days of life, this difference did not reach statistical significance; excluding infants born to co-infected women did not affect the results. Thirty seven of the children (68%) were negative in the first 3 days of life, 27 of whom were positive when tested again at 3 months, and nine were first PCR positive after 3 months (one child had no further tests). CONCLUSIONS: These results suggest that at least one third and up to a half of infected children acquired infection in utero. Although postpartum transmission cannot be excluded, these data suggest that it is rare. The role of HCV genotypes in the timing and mechanism of infection should be explored further.

Breast Feeding↗
PubMed1997

Mortality within the first 2 years in infants exposed to cocaine, opiate, or cannabinoid during gestation.

OBJECTIVE: To determine the mortality rate, during the first 2 years of life, in infants who were exposed to cocaine, opiate, or cannabinoid during gestation. METHODS: For a period of 11 months, a large group of infants were enrolled and screened at birth for exposure to cocaine, opiate, or cannabinoid by meconium analysis. Death outcome, within the first 2 years after birth, was determined in this group of infants using the death registry of the Michigan Department of Public Health. RESULTS: A total of 2964 infants was studied. At birth, 44% of the infants tested positive for drugs: 30. 5% positive for cocaine, 20.2% for opiate, and 11.4% for cannabinoids. Compared to the drug negative group, a significantly higher percentage (P < .05) of the drug positive infants had lower weight and smaller head circumference and length at birth and a higher percent of their mothers were single, multigravid, multiparous, and had little to no prenatal care. Within the first 2 years of life, 44 infants died: 26 were drug negative (15.7 deaths per 1000 live births) and 18 were drug positive (13.7 deaths per 1000 live births). The mortality rate among cocaine, opiate, or cannabinoid positive infants were 17.7, 18.4, and 8.9 per 1000 live births, respectively. Among infants with birth weight </=2500 g, infants who were positive for both cocaine and morphine had a higher mortality rate (odds ratio = 5.9, confidence interval [CI] = 1.4 to 24) than drug negative infants. Eleven infants died from the sudden infant death syndrome (SIDS); 58% were positive for drugs, predominantly cocaine. The odds ratio for SIDS among drug positive infants was 1.5 (CI = 0.46 to 5.01) and 1.9 (CI = 0.58 to 6.2) among cocaine positive infants. CONCLUSION: We conclude that prenatal drug exposure in infants, although associated with a high perinatal morbidity, is not associated with an overall increase in their mortality rate or incidence of SIDS during the first 2 years of life. However, a significantly higher mortality rate was observed among low birth weight infants (</=2500 g) who were positive for both cocaine and opiate.

Birth Weight↗
PubMed1994

Human milk as a source of methylmercury exposure in infants.

As methylmercury is excreted in human milk and infants are particularly susceptible to toxicity due to this compound, the purpose of this study was to evaluate the possible transfer of methylmercury to infants via breast-feeding. In a community with a high intake of seafood, 583 children from a birth cohort were followed. The duration of nursing was recorded, and hair samples were obtained for mercury analysis at approximately 12 months of age. The hair mercury concentrations increased with the length of the nursing period, and those nursed throughout the first year showed the highest geometric mean (9.0 nmol/g or 1.8 microg/g). Human milk therefore seems to be an important source of methylmercury exposure in infants. An increasing time interval from weaning to hair sample collection was not associated with any detectable decrease in mercury concentrations. A slow or absent elimination of methylmercury during the first year after birth could explain this finding. In certain fishing communities, infants nursed for long periods may be at increased risk of developing methylmercury toxicity.

Cohort Studies↗
PubMed2001

Evidence of a dose-response relationship between urbanicity during upbringing and schizophrenia risk.

BACKGROUND: Many studies have demonstrated that an urban birth or upbringing increases schizophrenia risk, but no studies have been able to distinguish between these effects. The objectives of this study were to discriminate the effect of urbanicity at birth from an effect of urbanicity during upbringing, and to identify particularly vulnerable age periods and a possible dose-response relationship between urbanicity during upbringing and schizophrenia risk. METHODS: Using data from the Danish Civil Registration System, we established a population-based cohort of 1.89 million people, which included information on place of birth, place of residence during upbringing, and the accumulated number of years lived in each category of the 5-level degree of urbanization during upbringing. Schizophrenia in cohort members and mental illness in a parent or sibling were identified by linkage with the Danish Psychiatric Central Register. RESULTS: Individuals living in a higher degree of urbanization than 5 years earlier had a 1.40-fold (95% confidence interval, 1.28-1.51) increased risk, while individuals living in a lower degree of urbanization than 5 years earlier had a 0.82-fold (95% confidence interval, 0.77-0.88) decreased risk of schizophrenia. For fixed urbanicity at the 15th birthday, risk increased with increasing degree of urbanization at birth. Furthermore, the more years lived in the higher the degree of urbanization, the greater the risk. Individuals who lived their first 15 years in the highest category of the 5-level urbanicity had a 2.75-fold (95% confidence interval, 2.31-3.28) increased risk of schizophrenia. CONCLUSION: Continuous, or repeated, exposures during upbringing that occur more frequently in urbanized areas may be responsible for the association between urbanization and schizophrenia risk.

Age Distribution↗
PubMed2003

Vaccinations and risk of central nervous system demyelinating diseases in adults.

BACKGROUND: Several case reports of the onset or exacerbation of multiple sclerosis or other demyelinating conditions shortly after vaccination have suggested that vaccines may increase the risk of demyelinating diseases. OBJECTIVE: To evaluate the association between vaccination and onset of multiple sclerosis or optic neuritis. DESIGN: Case-control study involving cases of multiple sclerosis or optic neuritis among adults 18 to 49 years of age. Data on vaccinations and other risk factors were obtained from computerized and paper medical records and from telephone interviews. SETTING: Three health maintenance organizations. PARTICIPANTS: Four hundred forty case subjects and 950 control subjects matched on health maintenance organization, sex, and date of birth. INTERVENTIONS: None. MAIN OUTCOME MEASURES: Onset of first symptoms of demyelinating disease at any time after vaccination and during specified intervals after vaccination (<1 year, 1-5 years, and >5 years). RESULTS: Cases and controls had similar vaccination histories. The odds ratios (95% confidence intervals), adjusted for potential confounding variables, of the associations between ever having been vaccinated and risk of demyelinating disease (multiple sclerosis and optic neuritis combined) were 0.9 (0.6-1.5) for hepatitis B vaccine; 0.6 (0.4-0.8) for tetanus vaccination; 0.8 (0.6-1.2) for influenza vaccine; 0.8 (0.5-1.5) for measles, mumps, rubella vaccine; 0.9 (0.5-1.4) for measles vaccine; and 0.7 (0.4-1.0) for rubella vaccine. The results were similar when multiple sclerosis and optic neuritis were analyzed separately. There was no increased risk according to timing of vaccination. CONCLUSION: Vaccination against hepatitis B, influenza, tetanus, measles, or rubella is not associated with an increased risk of multiple sclerosis or optic neuritis.

Adolescent↗
PubMed2000

Differences in the epidemiology of theileriosis on smallholder dairy farms in contrasting agro-ecological and grazing strata of highland Kenya.

A prospective cohort study was conducted in five purposively-sampled agro-ecological zone (AEZ)-grazing system strata in Murang'a District, Kenya, between March 1995 and June 1996. The study strata were selected based on a preliminary characterization study to represent the widest range of risks to East Coast fever (ECF) in the District and included zero-grazing and open-grazing farms. In total, 225 calves from 188 smallholder farms were examined from birth to 6 months of age and visited within the first 2 weeks of life and thereafter at bi-weekly intervals for up to 14 visits. The purpose of the study was to characterize the differences in epidemiology (risks of infection, morbidity and mortality) and potential control of ECF between the selected strata. Evidence of Theileria parva infection was assessed by increased antibody levels as measured in an indirect ELISA assay by the percent positivity (PP) of serum samples relative to a strong positive reference serum. Sero-conversion risks of T. parva were highest in the open-grazing strata. Antibody prevalence in adult cattle and ECF morbidity and mortality risks were also highest in open-grazing strata. While different, all five AEZ-grazing strata were considered to be endemically unstable for ECF. East Coast fever challenge was low in all zero-grazing strata and this challenge is likely to remain low due to continuing intensification of smallholder farming in the central highlands. In the open-grazing strata, there was higher challenge and a greater impact of ECF.

Animals↗