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Biomedical subjects

V J Dietz

Publications and source records attributed to V J Dietz.

5 recordsLinked to original sources

Potential impact on vaccination coverage levels by administering vaccines simultaneously and reducing dropout rates.

BACKGROUND: Retrospective immunization coverage surveys conducted during 1991 and 1992 demonstrated that coverage levels for the routine childhood vaccines by 24 months of age in selected urban areas of the United States ranged from 10% to 52%, far below the US Public Health Service goal of 90%. Therefore, appropriate programmatic changes must be identified and incorporated. METHODS: We analyzed coverage survey data collected from 21 sites to measure the potential impact on coverage levels of implementing selected changes in vaccination practices. In a multistaged cluster survey design, school health records of kindergarten or first-grade students were randomly selected and dates of vaccination assessed. We evaluated changes in the vaccination practices, such as eliminating missed opportunities for simultaneous administration of vaccines and ensuring that children initiated the vaccination series on time (ie, by 3 months of age). We then calculated potential increases in coverage levels for a best-case scenario. RESULTS: From 77% to 96% of all children in the 21 sites had received at least one vaccination by their first birthday. Children were 2.3 to 17 times more likely to be up to date on their vaccinations by 24 months of age if they were up to date at 3 months of age. Each child had many opportunities for the simultaneous administration of diphtheria and tetanus toxoids and pertussis (DTP) vaccine, oral polio vaccine (OPV), and measles-mumps-rubella (MMR) vaccine that, if used appropriately, could have potentially raised coverage levels by 12% to 22% (median, 17%). The highest coverage levels could have been attained if all children had started the series on time and if advantage had been taken of all opportunities for simultaneous vaccination. Coverage levels for four doses of DTP vaccine, three doses of OPV, and one dose of MMR vaccine would have increased from a baseline of 10% to 52% to levels of 54% to 83%. CONCLUSIONS: Although the majority of children received a vaccination by their first birthday, the coverage level at 24 months of age was low. Tracking systems are needed to ensure that children do not drop out of the system once they have begun the vaccination series. In addition, all children who are late in beginning their vaccination series are at increased risk of not completing the recommended vaccination series on time, and these children need intensive follow-up and recall efforts. Also, providers need to administer all needed vaccines simultaneously.

Child, Preschool

Diagnosis of measles by clinical case definition in dengue-endemic areas: implications for measles surveillance and control.

In many countries, measles surveillance relies heavily on the use of a standard clinical case definition; however, the clinical signs and symptoms of measles are similar to those of dengue. For example, during 1985, in Puerto Rico, 22 (23%) of 94 cases of illnesses with rashes that met the measles clinical case definition were serologically confirmed as measles, but 32 (34%) others were serologically confirmed as dengue. Retrospective analysis at the San Juan Laboratories of the Centers for Disease Control showed also that at least 28% of all laboratory-confirmed cases of dengue in Puerto Rico in 1985 met the measles clinical case definition. If the true measles vaccine efficacy (VE) is assumed to be 90%, the occurrence of laboratory-confirmed dengue cases that meet the measles clinical case definition results in a reduction of the apparent measles VE to only 64% (a 29% relative reduction from the true VE). The results of the study demonstrate the importance of a laboratory-based surveillance system in measles control or elimination efforts in dengue-endemic areas.

Adolescent

Smoking-attributable mortality, years of potential life lost, and direct health care costs for Puerto Rico, 1983.

The authors report the impact of smoking upon health in Puerto Rico for the year 1983. Using a microcomputer spread-sheet program that calculates smoking-attributable disease impact, they estimated that 2,468 deaths were attributable to smoking. This represented 11.5% of all deaths on the island in 1983 and resulted in approximately 19,445 years of potential life lost (YPLL). It appears that cigarette smoking caused US+55.9 million in direct health care expenditures for Puerto Rico in 1983, an amount equal to 10% of the island's yearly expenditures on health. Calculations such as these demonstrate the enormous disease impact of smoking and may assist policy-makers in planning prevention and intervention activities, both in Puerto Rico and elsewhere in Latin America.

Adolescent

Epidemic dengue 1 in Brazil, 1986: evaluation of a clinically based dengue surveillance system.

In the last 15 years, dengue fever has emerged as a major health problem in tropical America. Prevention and control of epidemic disease are enhanced by the rapid identification of new or increased dengue activity. Most surveillance systems, however, identify cases by clinical case reports and, therefore, lack the sensitivity needed for early detection. During the 1986 dengue 1 epidemic in Rio de Janeiro, Brazil, the authors evaluated the usefulness of a clinical case definition by comparing it with laboratory-confirmed infection status of residents in two cities. The case definition had a sensitivity of 64% and a false-positive rate of 57%. Thus, for every 100 laboratory-confirmed dengue infections, 230 cases were reported. Both infected and noninfected residents who used medical services and who lived in the city with the highest transmission were more likely to meet the case definition. Thus, factors unrelated to actual infection influenced the sensitivity. With the use of stepwise logistic regression, the authors analyzed combinations of patient symptoms and produced nine new hypothetical case definitions. However, none of the new definitions had a false-positive rate lower than 38%. This study emphasizes the need for laboratory-based dengue surveillance systems.

Adolescent