Chronic medical conditions as risk factors for herpes zoster

OBJECTIVE

To determine the degree to which chronic conditions might contribute to the unexplained burden of herpes zoster.

METHODS

We conducted a case-control study using MarketScan data from January 1, 2007, through December 31, 2007, to investigate chronic conditions as risk factors for herpes zoster among persons 20 to 64 years old. Cases were enrollees with a herpes zoster diagnosis (International Classification of Diseases, Ninth Revision, Clinical Modification codes 053.xx), and controls were those without a herpes zoster diagnosis, matched by age groups and insurance plan. We selected 10 chronic conditions based on their prevalence in the general population. We calculated the attributable fraction and created a comorbidity composite score by summing the significant coefficient of regression of chronic conditions. We used logistic regression to evaluate the associations between herpes zoster and chronic conditions.

RESULTS

We identified a total of 59,173 cases and 616,177 controls for the analysis. Risk of herpes zoster was significant for 8 of the 10 study conditions (odds ratios, 1.06-1.52). Herpes zoster risk also increased as a function of comorbidity composite score. The attributable fractions for these 8 significant conditions ranged from 0.24% to 2.89%.

CONCLUSION

The risk of herpes zoster may be increased in people with chronic conditions. However, this risk may not contribute substantially to the burden of herpes zoster in the population. The causes for most cases of herpes zoster remain unknown.

Breast-feeding among women attending women, infants, and children clinics in Georgia, 1987

Breast-feeding is an important determinant of the health and nutritional status of children, particularly in lower socioeconomic populations. A major goal of the Georgia Special Supplemental Food Program for Women, Infants, and Children (WIC) is to increase the practice of breast-feeding among the women it serves. Breast-feeding practices were determined among a random sample of 404 women from a cohort of 2010 who attended WIC prenatal clinics in Georgia in 1986 and were expected to deliver in February 1987. Respondents were interviewed 6 months postpartum. Of these women, 24% initially breast-fed, but only 6% continued for 6 months or longer. The initiation of breast-feeding was associated with greater maternal education and with being married. The adjusted odds of breast-feeding for mothers who were married or living as married were 3.0 (95% confidence interval, 1.7 to 5.3) times greater than for mothers who were not married or living as married. Mothers with more than 12 years, 12 years, or 10 to 11 years of education were 5.2 (1.8 to 15.3), 2.7 (1.0 to 6.9), and 2.5 (0.9 to 6.9) times more likely, respectively, to breast-feed than mothers with 9 or fewer years of education. After adjustment was made for marital status and education, the remaining variables (ethnicity, parity, age, and employment status) did not influence the initiation of breast-feeding in this low-income population. The need for vigorous promotion of breast-feeding by the Georgia WIC program is emphasized by the low rate of initiation and short duration of breast-feeding in this low-income population.

Sex partner recruitment as risk factor for STD: clustering of risky modes

Nine hundred and fourteen heterosexual persons who requested care at STD clinics in South Carolina responded to self-administered questions on STD history, socio-demographic characteristics, number of sexual partners, and sexual partner choice. These data and the current STD diagnosis were analysed using multivariate techniques. Sexual behaviors of men and women were different. Men reported greater number of partners and less discriminating sex partner recruitment patterns. Age, rural/urban residence, race, and number of sex partners were independent predictors of gonorrhea infection among men. Among women, age, rural/urban residence, and not knowing the most recent sex partner very well emerged as independent predictors of infection.

Recurrence of low birth weight in siblings

The recurrence of low birth weight (LBW, less than 2500 g) in full siblings was studied in 3286 singleton infants born between 1966 and 1986 to 1677 male U.S. Army veterans who were part of a nationwide health study. Hospital of birth medical records were abstracted for these children. Mean birth weights, risks of LBW, LBW occurring with preterm delivery (less than 37 weeks) (LBW/p), and LBW in term infants (LBW/t) were examined in successive singleton siblings according to LBW status of prior siblings. The risk of LBW in infants who had prior siblings with LBW was 9.9%, compared with a risk of 2.8% in infants who had prior siblings without LBW (OR = 3.8, 95% CI 2.0-7.3). The excess recurrence of LBW was specifically due to LBW/p. Infants with prior siblings with LBW/p were at high tisk of LBW/p (OR = 9.2, CI 4.4-19.6) but not of LBW/t (OR = 2.0, CI 0.1-9.1). Using modified logistic regression techniques that incorporate familial risks and the effects of other risk factors, the excess sibling recurrence risk of LBW and LBW/p could not be explained by the tendency for recurrence in siblings of other risk factors for LBW, such as pregnancy complications, maternal illnesses, and birth defects. Although the familial factors involved in LBW may or may not be genetic in nature, such factors need to be investigated in epidemiologic studies of LBW and prematurity.

Recurrence risk of neonatal hyperbilirubinemia in siblings

The recurrence of neonatal hyperbilirubinemia (NHB) in full siblings was studied in 3301 live infants born between 1966 and 1986 to 1669 male US Army veterans who were part of a nationwide health study. The study population included 580 sibships with one infant, 679 with two, and 410 with three or more. Hospital of birth medical records were abstracted on these children. Neonatal hyperbilirubinemia was defined as present if the recorded peak bilirubin level was greater than 205 mumol/L in the absence of hemolytic disease of the newborn. The risk of NHB in newborns who have one or more prior sibs with NHB was 3.1 times higher than that of newborns who have prior sibs without NHB (10.3% vs 3.6%). Simultaneous adjustment for risk factors for NHB, such as feeding patterns, year of birth, maternal obstetric events, and infant health variables, did not explain the excess risk of NHB in sibs. Moreover, the risk of severe NHB (peak bilirubin level, greater than 257 mumol/L) in newborns who have one or more prior sibs with severe NHB was 12.5 times higher than that of newborns who have prior sibs without severe NHB (10.5% vs 0.9%). Separate analyses in sibships where all sibs were breast-fed and in sibships where all sibs were bottle-fed gave similar results. These data clearly suggest the familial nature of NHB. The higher risk of recurrence of NHB in sibs does not seem to be due to known environmental risk factors for NHB.