Atar Baer

Maternal, delivery, and perinatal characteristics associated with cryptorchidism: a population-based case-control study among births in Washington State.

Background. The etiology of cryptorchidism is largely unknown. To identify maternal, perinatal, and delivery characteristics associated with cryptorchidism at birth, we conducted a population-based case-control study using Washington State birth certificates linked to birth hospitalization records. Methods. We identified 2,395 cases of cryptorchidism among male infants born in Washington State during 1986–1996, and, for comparison, we randomly selected four controls per case (N = 9,580), frequency-matched by year of birth. Results. Infant characteristics associated with cryptorchidism included low birth weight (OR = 1.5; 95% CI = 1.3–1.8), small size for gestational age (OR = 1.9; 95% CI = 1.6–2.2), and breech presentation (OR = 1.7; 95% CI = 1.4–2.1). In addition to cryptorchidism, cases were more likely to have another type of congenital malformation (OR = 3.7; 95% CI = 3.2–4.2), particularly digestive (OR = 6.8; 95% CI = 3.7–12.7) or genitourinary (OR = 4.1; 95% CI = 3.0–5.6). Maternal and pregnancy characteristics associated with cryptorchidism included nulliparity (OR = 1.2; 95% CI = 1.1–1.3), maternal smoking during pregnancy (OR = 1.2; 95% CI = 1.1–1.4), and the following pregnancy complications: oligohydramnios (OR = 1.8; 95% CI = 1.3–2.6), placental abnormality (OR = 1.3; 95% CI = 1.0–1.8), and pregnancy-induced hypertension (OR = 1.6; 95% CI = 1.4–1.9). Odds ratios were similar when the analysis was restricted to term infants. Conclusions. These findings suggest that factors affecting fetal growth and development may increase the risk of cryptorchidism.

Spring 2009 H1N1 influenza outbreak in King County, Washington.

BACKGROUND In April 2009, King County, Washington, experienced a sustained outbreak of 2009 H1N1 influenza A. This report describes the epidemiology of that outbreak in King County, home to a diverse population of 1.9 million people. METHODS The 2 primary sources of data are case investigations of reported laboratory-confirmed 2009 H1N1 influenza A and a population-based syndromic surveillance system that captures data from emergency departments (EDs). A syndromic category for influenza-like illness was defined based on chief complaint and diagnosis. RESULTS ED visits for influenza-like illness peaked quickly in the first week of the outbreak and remained high for approximately 6 weeks, with school-age children accounting for the greater number of ED visits, followed by young adults. Children ages 0 to 4 years had the highest rate of hospitalization. Among reported cases, blacks, Asians, and Hispanics were more likely to be hospitalized. Predisposing factors associated with admission were immune compromise, chronic lung disease, chronic heart disease, pregnancy, diabetes, and asthma. Of people receiving antiviral treatment, 34% started their medication more than 2 calendar days after the onset of illness. Mean days between illness onset and antiviral treatment were greater for blacks, Hispanics, and foreign language speakers. CONCLUSIONS The spring 2009 influenza A H1N1 outbreak disproportionately affected children, young adults, and racial and ethnic minorities. Opportunities exist to improve the timeliness of antiviral treatment. Potential barriers to care for racial and ethnic minorities should be proactively addressed to ensure prompt evaluation and treatment.

Accuracy and cost-effectiveness of cervical cancer screening by high-risk human papillomavirus DNA testing of self-collected vaginal samples.

Objective. Estimate the accuracy and cost-effectiveness of cervical cancer screening strategies based on high-risk human papillomavirus (HPV) DNA testing of self-collected vaginal samples. Materials and Methods. A subset of 1,665 women (age range, 18-50 y) participating in a cervical cancer screening study were screened by liquid-based cytology and by high-risk HPV DNA testing of both self-collected vaginal swab samples and clinician-collected cervical samples. Women with positive/abnormal screening test results and a subset of women with negative screening test results were triaged to colposcopy. On the basis of individual and combined test results, 5 screening strategies were defined. Estimates of sensitivity and specificity for cervical intraepithelial neoplasia grade 2 or worse were calculated, and a Markov model was used to estimate the incremental cost-effectiveness ratios for each strategy. Results. Compared with cytology-based screening, high-risk HPV DNA testing of self-collected vaginal samples was more sensitive (68%, 95% CI = 58%-78% vs 85%, 95% CI = 76%-94%) but less specific (89%, 95% CI = 86%-91% vs 73%, 95% CI = 67%-79%). A strategy of high-risk HPV DNA testing of self-collected vaginal samples followed by cytology triage of HPV-positive women was comparably sensitive (75%, 95% CI = 64%-86%) and specific (88%, 95% CI = 85%-92%) to cytology-based screening. In-home self-collection for high-risk HPV DNA detection followed by in-clinic cytology triage had a slightly lower lifetime cost and a slightly higher quality-adjusted life year (QALY) expectancy than did cytology-based screening (incremental cost-effectiveness ratio of triennial screening compared with no screening was

Association between school closure and subsequent absenteeism during a seasonal influenza epidemic.

9,871/QALY and

Liquid-based Papanicolaou smears without a transformation zone component: should clinicians worry?

12,878/QALY, respectively). Conclusions. Triennial screening by high-risk HPV DNA testing of in-home, self-collected vaginal samples followed by in-clinic cytology triage was cost-effective.

Usefulness of syndromic data sources for investigating morbidity resulting from a severe weather event

Background: Mathematical models suggest that social distancing measures, such as school closures, may mitigate community transmission during an influenza pandemic. Because closures are disruptive to schools and families, they are rarely employed during seasonal influenza outbreaks. A rare circumstance enabled us to examine the association between school closure and absenteeism during a seasonal influenza outbreak when half of King County, Washington public schools closed for a winter recess 19–23 February 2007, while half remained open for all or part of the week. Methods: Using absenteeism as a proxy for influenza activity, we tested the hypothesis that schools on break would experience lower rates of post-break absenteeism than schools remaining open. We conducted daily retrospective and prospective surveillance from 5 February–9 March 2007 in schools on break (n = 256) and in session (n = 205). We use generalized estimating equations with Poisson distribution to evaluate whether mean absenteeism after the break differed between schools on break and those in session, adjusting for baseline absenteeism and repeated measurements by schools over time. Results: Results indicate no difference in post-break absenteeism in schools on break compared with schools that remained in session (relative risk = 1.07 [95% confidence interval = 0.96–1.20]). This result held in elementary schools (1.00 [0.91–1.10]), where absenteeism patterns are thought to be most representative of community influenza activity. Conclusion: We did not find that school closure during a seasonal influenza outbreak reduced subsequent absenteeism. However, limitations in this “natural experiment” hampered our ability to detect a benefit if one truly was present.

Infant pertussis epidemiology and implications for tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccination: King County, Washington, 2002 through 2007.

OBJECTIVE To evaluate whether ThinPrep smears without versus those with a transformation zone component were more likely to have falsely negative cytology findings. METHODS Women aged 18–50 (N = 4389) attended one of three Planned Parenthood clinics between 1997 and 2001 for screening by ThinPrep Papanicolaou and polymerase chain reaction‐based human papillomavirus (HPV) DNA testing. Women with 1) any cytologic abnormality, 2) high‐risk HPV types, and 3) a random sample with normal Papanicolaou and negative HPV tests were offered repeat cytology, colposcopy, and biopsy. Cytology and biopsy diagnoses at the colposcopy visit were reviewed according to the presence (n = 3689) or absence (n = 700) of a transformation zone component at screening. RESULTS Among women with normal cytology at screening, histologic detection of at least cervical intraepithelial neoplasia grade 2 (odds ratio 1.3, 95% confidence interval 0.5, 3.3) at colposcopy did not differ significantly between transformation zone‐positive and zone‐negative smears. Histologically confirmed cervical intraepithelial neoplasia grade 1 was detected more often among smears lacking a transformation zone component (odds ratio 2.0, confidence interval 1.0, 3.8). Transformation zone‐negative smears were more common among older women, current oral contraceptive users, those past the 14th day of their last menstrual period, and those negative for high‐risk HPV types. CONCLUSION Absence of a transformation zone component in a screening ThinPrep Papanicolaou test was not associated with missed high‐grade lesions. Based upon our data, we do not recommend repeat screening of reproductive‐aged women with negative liquid‐based tests and no cytologic evidence of a transformation zone component.

An automated system for public health surveillance of school absenteeism.

OBJECTIVE We evaluated emergency department (ED) data, emergency medical services (EMS) data, and public utilities data for describing an outbreak of carbon monoxide (CO) poisoning following a windstorm. METHODS Syndromic ED data were matched against previously collected chart abstraction data. We ran detection algorithms on selected time series derived from all 3 data sources to identify health events associated with the CO poisoning outbreak. We used spatial and spatiotemporal scan statistics to identify geographic areas that were most heavily affected by the CO poisoning event. RESULTS Of the 241 CO cases confirmed by chart review, 190 (78.8%) were identified in the syndromic surveillance data as exact matches. Records from the ED and EMS data detected an increase in CO-consistent syndromes after the storm. The ED data identified significant clusters of CO-consistent syndromes, including zip codes that had widespread power outages. Weak temporal gastrointestinal (GI) signals, possibly resulting from ingestion of food spoiled by lack of refrigeration, were detected in the ED data but not in the EMS data. Spatial clustering of GI-based groupings in the ED data was not detected. CONCLUSIONS Data from this evaluation support the value of ED data for surveillance after natural disasters. Enhanced EMS data may be useful for monitoring a CO poisoning event, if these data are available to the health department promptly.

Evaluation of electronic ambulatory care data for influenza-like illness surveillance, Washington State.

OBJECTIVES To describe the epidemiology of infant pertussis in King County, Washington, and to better understand the implications for tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccination among older children, adolescents, and adults. DESIGN Retrospective analysis of reported pertussis cases among infants younger than 1 year, January 1, 2002, through December 31, 2007. SETTING King County, Washington. PARTICIPANTS Reported pertussis cases among infants younger than 1 year between 2002 and 2007. MAIN OUTCOME MEASURES Bordetella pertussis from a household member or close contact was the primary exposure. The main outcome measures were age and vaccination status, incidence by race/ethnicity, suspected exposure, and Tdap eligibility of household members and close contacts. RESULTS Among 176 confirmed cases of infants with pertussis, the median age was 3 months (age range, 0-11 months); 80.1% were younger than 6 months. Seventy-seven percent were age-appropriately vaccinated. Between 2002 and 2007, the overall mean annual incidence was 136 cases per 100,000 infant population. Compared with a mean annual incidence of 73 cases per 100,000 infant population among whites, the incidence was 246 cases per 100,000 infant population among blacks (rate ratio [RR], 3.37; 95% confidence interval [CI], 2.59-4.44) and 194 cases per 100,000 infant population among Hispanics (RR, 2.66; 95% CI, 2.02-3.53). Households were the suspected exposure location for 70.0% of cases. Case households had a median of 3 (range, 1-15) Tdap-eligible persons. CONCLUSIONS The burden of infant pertussis in King County, Washington, was high between 2002 and 2007, especially among racial/ethnic minorities. Tdap vaccination of eligible household members and close contacts should be promoted as an additional means of protecting infants from pertussis.

Using a Syndromic Surveillance System to Evaluate the Impact of a Change in Alcohol Law

Public Health-Seattle & King County established an automated system for monitoring school absenteeism data from 18 of 19 public school districts in King County, Washington. The system receives a daily aggregate count of the number of students enrolled and absent, stratified by school district, school name, and grade. A name and unique identifier are provided for each school and district, as well as the level (eg, elementary, middle, high, alternative, other) and zip code of each school. Files are transmitted to the health department daily and include data from the previous school day. Public Health-Seattle & King County developed a series of visualizations that summarize the data by day, week, and month for each level of stratification. The automated system for collecting and monitoring school absenteeism data was more acceptable, simple, timely, complete, and useful relative to traditional manual data collection methods.