Diane M Simpson

Autism and thimerosal-containing vaccines

BACKGROUND In 1999, concerns were raised that vaccines containing the preservative Thimerosal might increase the risk of autism and/or other neurodevelopmental disorders. METHODS Between the mid-1980s through the late-1990s, we compared the prevalence/incidence of autism in California, Sweden, and Denmark with average exposures to Thimerosal-containing vaccines. Graphic ecologic analyses were used to examine population-based data from the United States (national immunization coverage surveys and counts of children diagnosed with autism-like disorders seeking special education services in California); Sweden (national inpatient data on autism cases, national vaccination coverage levels, and information on use of all vaccines and vaccine-specific amounts of Thimerosal); and Denmark (national registry of inpatient/outpatient-diagnosed autism cases, national vaccination coverage levels, and information on use of all vaccines and vaccine-specific amounts of Thimerosal). RESULTS In all three countries, the incidence and prevalence of autism-like disorders began to rise in the 1985-1989 period, and the rate of increase accelerated in the early 1990s. However, in contrast to the situation in the United States, where the average Thimerosal dose from vaccines increased throughout the 1990s, Thimerosal exposures from vaccines in both Sweden and Denmark-already low throughout the 1970s and 1980s-began to decrease in the late 1980s and were eliminated in the early 1990s. CONCLUSIONS The body of existing data, including the ecologic data presented herein, is not consistent with the hypothesis that increased exposure to Thimerosal-containing vaccines is responsible for the apparent increase in the rates of autism in young children being observed worldwide.

Ebola (Subtype Reston) Virus among Quarantined Nonhuman Primates Recently Imported from the Philippines to the United States

In April 1996, laboratory testing of imported nonhuman primates (as mandated by quarantine regulations) identified 2 cynomolgus macaques (Macaca fascicularis) infected with Ebola (subtype Reston) virus in a US-registered quarantine facility. The animals were part of a shipment of 100 nonhuman primates recently imported from the Philippines. Two additional infected animals, who were thought to be in the incubation phase, were identified among the remaining 48 animals in the affected quarantine room. The other 50 macaques, who had been held in a separate isolation room, remained asymptomatic, and none of these animals seroconverted during an extended quarantine period. Due to the rigorous routine safety precautions, the facility personnel had no unprotected exposures and remained asymptomatic, and no one seroconverted. The mandatory quarantine and laboratory testing requirements, put in place after the original Reston outbreak in 1989-1990, were effective for detecting and containing Ebola virus infection in newly imported nonhuman primates and minimizing potential human transmission.

Forty years and four surveys: How does our measuring measure up?

OBJECTIVE This article reviews four surveys methodologies that have been used over the past 40 years to assess immunization rates in young children in the United States. These methods include three national surveys: (1) United States Immunization Survey (1959-1985), which was first a household and then a telephone survey; (2) National Health Interview Survey (1991-present), which interviews people in their homes; and (3) National Immunization Survey (1994-present), a random-digit-dialing telephone survey. In addition, a series of retrospective school record surveys that used standard sampling and assessment methodologies were conducted nationally during 4 school years September 1990-May 1991. METHODS Federal publications, National Immunization Conference proceedings, and Centers for Disease Control and Prevention (CDC) internal reports regarding national immunization surveys were reviewed. The methodology used in each survey is presented, and selected examples of previously tabulated results are presented. CONCLUSIONS The assessment of immunization coverage in American preschool children requires ongoing commitment and survey expertise. Over the past 40 years the CDCs efforts to determine vaccination coverage in young children has evolved from the comparatively simple United States Immunization Survey to the current National Immunization Survey that utilizes sophisticated statistical and survey techniques to obtain the most-accurate results yet available.

Polio Eradication Initiative in Afghanistan, 1997–2013

BACKGROUND This article reviews the epidemiology of polio, acute flaccid paralysis (AFP) surveillance, and the implementation of supplemental immunization activities (SIAs) in Afghanistan from 1997 thru 2013. METHODS Published reports and unpublished national data on polio cases, AFP surveillance, and SIAs were analyzed. Recommendations from independent advisory groups and Afghan government informed the conclusions. RESULTS From 1997 thru 2013, the annual number of confirmed polio cases fluctuated from a low of 4 in 2004 to a high of 80 in 2011. Wild poliovirus types 2 and 3 were last reported in 1997 and 2010, respectively. Circulating vaccine-derived poliovirus type 2 emerged in 2009. AFP surveillance quality in children aged <15 years improved over time, achieving rates>8 per 100,000 population. Since 2001, at least 6 SIAs have been conducted annually. CONCLUSIONS Afghanistan has made progress moving closer to eliminating polio. The program struggles to reach all children because of management and accountability problems in the field, inaccessible populations, and inadequate social mobilization. Consequently, too many children are missed during SIAs. Afghanistan adopted a national emergency action plan in 2012 to address these issues, but national elimination will require consistent and complete implementation of proven strategies.

Texas physician immunization practices.

INTRODUCTION Immunization levels among young children could be improved if physicians administered immunizations at both well and urgent visits, provided simultaneous vaccinations, and knew the guidelines on valid contraindications, part of the Standards for Pediatric Immunization Practices (Standards). We report on a survey measuring the immunization knowledge and practice of Texas pediatricians, family practitioners, and general practitioners. METHODS A survey was mailed to a random sample of physicians. Questionnaire items covered 8 of the 18 Standards. RESULTS The response rate was 62% (608 of 976 eligible physicians). The mean summary adherence-to-Standards score was 4.1 for pediatricians, 3.6 for family practitioners, and 3.0 for general practitioners. Specialty and practice location were significant predictors of the summary score, whereas gender, managed-care participation, and graduation year were not. DISCUSSION Our study results suggest that in Texas, pediatricians and rural physicians most often adhere to the Standards. Improving the reimbursement level of administrative costs for immunization delivery, educating physicians on the Standards, and encouraging the use of patient immunization tracking systems are actions that could potentially improve immunization rates.