RESUMEN

Since Kenya first reported Rift Valley fever (RVF)-like disease in livestock in 1912, the country has reported the most frequent epizootics of RVF disease. To determine the pattern of disease spread across the country after its introduction in 1912, and to identify regions vulnerable to the periodic epizootics, annual livestock disease records at the Department of Veterinary Services from 1910 to 2007 were analysed in order to document the number and location of RVF-infected livestock herds. A total of 38/69 (55%) administrative districts in the country had reported RVF epizootics by the end of 2007. During the 1912-1950 period, the disease was confined to a district in Rift Valley province that is prone to flooding and where livestock were raised in proximity with wildlife. Between 1951 and 2007, 11 national RVF epizootics were recorded with an average inter-epizootic period of 3·6 years (range 1-7 years); in addition, all epizootics occurred in years when the average annual rainfall increased by more than 50% in the affected districts. Whereas the first two national epizootics in 1951 and 1955 were confined to eight districts in the Rift Valley province, there was a sustained epizootic between 1961 and 1964 that spread the virus to over 30% of the districts across six out of eight provinces. The Western and Nyanza provinces, located on the southwestern region of the country, had never reported RVF infections by 2007. The probability of a district being involved in a national epizootic was fivefold higher (62%) in districts that had previously reported disease compared to districts that had no prior disease activity (11%). These findings suggests that once introduced into certain permissive ecologies, the RVF virus becomes enzootic, making the region vulnerable to periodic epizootics that were probably precipitated by amplification of resident virus associated with heavy rainfall and flooding.

Asunto(s)

Asunto(s)

Asunto(s)

RESUMEN

BACKGROUND: Childhood vaccinations have a major impact on the reduction and elimination of many causes of morbidity and mortality among children. Monitoring of annual vaccination coverage levels over time is necessary to characterize undervaccination. Here, coverage estimates for 1996 (1997 for varicella) were compared with those of 1999. METHODS: Immunization coverage among children aged 19 to 35 months in 1996 (1997 for varicella) and 1999 for a variety of vaccines and vaccine series were compared using Wald chi-square tests and data from the National Immunization Survey. RESULTS: Record high immunization coverage among children aged 19 to 35 months in the United States has increased by a statistically significant amount between 1996 and 1999 for diphtheria, tetanus, and pertussis; measles, mumps, and rubella; Haemophilus influenzae type b; hepatitis B; and standard series made up of these individual vaccines. Coverage with the vaccine for varicella dramatically increased between 1997 and 1999. However, between 1996 and 1999, coverage with three or more doses of polio vaccine decreased by a small but statistically significant amount. CONCLUSION: Despite the drop for polio vaccine, coverage remains high. Continued monitoring is required to determine if the drop in polio coverage is a cause for concern.

Asunto(s)

RESUMEN

BACKGROUND: This study characterizes the healthcare visits at which children receive vaccinations, including the number of these visits and the number of vaccinations that are administered. METHODS: The 1999 National Immunization Survey (NIS) is a nationally representative sample of children aged 19 to 35 months, verified by provider records, that is conducted to obtain estimates of vaccination coverage rates. We describe the number of healthcare visits in which one or more vaccinations were given, the number of vaccinations given at these visits, and the number of visits and vaccinations needed for an underimmunized child to complete the recommended vaccination series. RESULTS: Of the children who did not receive all doses of the recommended vaccinations (4:3:1:3:3 vaccination series), three fourths had four or more immunization visits. Vaccination coverage increased as the number of visits increased, and children who had completed the series were more likely to receive multiple vaccinations than those who had not. Most children (70.7%) received a maximum of four vaccinations in any immunization visit. The majority of children (73.5%) who had not completed the 4:3:1:3:3 vaccination series needed only a single visit to complete the series. The majority (61.7%) of children who needed only one visit also needed only one additional vaccination. CONCLUSIONS: While estimated national coverage for all recommended vaccinations is considerably below the Healthy People 2000 and Healthy People 2010 goal of 90%, achieving this goal is in essence just one visit away. If all children who needed one more visit were to receive that final visit, the national coverage among children 19 to 35 months for all recommended vaccinations would be 93%.

Asunto(s)

RESUMEN

BACKGROUND: Poverty and factors associated with poverty are strong and persistent barriers to childhood immunization. Substantive differences in coverage with basic vaccinations have been consistently observed over time between children living in poverty and those who are not. METHODS: The National Immunization Survey (NIS) uses a random-digit-dialing sample of telephone numbers in each state and in 28 urban areas. The NIS provides vaccination coverage information representative of all U.S. children aged 19 to 35 months. We categorized children in the NIS using Bureau of Census categories of poverty as follows: "above poverty" for household income > or = 125% of the federal poverty threshold for the household's size and composition; "near poverty," 100% to <125% of the poverty threshold; "intermediate poverty," 50% to <100% of the poverty threshold; and "severe poverty," <50% of the poverty threshold. We described coverage with basic vaccinations from 1996 through 1999 by poverty category and compare coverage between children in poverty and above poverty. RESULTS: From 1996 to 1999, estimated vaccination coverage with the basic vaccine series was consistently higher among children living above the poverty level than all other children. The difference in estimated vaccination coverage between children living in severe poverty and those living above poverty was 13.6 percentage points in 1996, and 10.0 percentage points in 1999. Vaccination coverage with the series 4:3:1:3 among children living in near poverty was similar to that of children living in poverty (74.7% vs 73.3%, p=0.52). Estimated vaccination coverage increased significantly (p<0.05) between 1996 and 1999 for most antigens among children living above poverty and among those living in intermediate and severe poverty. Vaccination coverage among children living in poverty increased significantly (p<0.05) between 1996 and 1999 in 1 of the 28 urban areas in the NIS. CONCLUSIONS: Low vaccination coverage among children living in and near poverty is a persistent problem in the United States. Additional efforts are needed to improve coverage.

Asunto(s)

RESUMEN

BACKGROUND: Vaccination-promoting strategies in the Supplemental Nutrition Program for Women, Infants, and Children (WIC) have been shown to produce dramatic improvements in coverage and other health outcomes. OBJECTIVES: To determine national and state-specific population-based vaccine coverage rates among preschool children who participate in the WIC program, and to describe the strategies for promoting vaccination in WIC. DESIGN/METHODS: Demographic data, WIC participation, and vaccination histories for children aged 24 to 35 months in 1999 were collected from parents through the National Immunization Survey. The healthcare providers for the children in the survey were contacted to verify and complete vaccination information. We defined children as up-to-date (UTD) if they had received four doses of diphtheria and tetanus toxoids and pertussis vaccine (DPT), three doses of poliovirus vaccine, one dose of measles-mumps-rubella vaccine (MMR), and three doses of Haemophilus influenzae type b vaccine (Hib) by 24 months. Description of state-level vaccination-promoting activities in WIC was collected through an annual survey completed by the state WIC and immunization program directors. RESULTS: Complete data were collected on 15,766 children, of whom 7783 (49%) participated in WIC sometime in their lives. Nationally, children who had ever participated in WIC were less well-immunized at 24 months compared to children who had not: 72.9% UTD (95% CI, 71.3-74.5) versus 80.8% UTD (95% CI, 79.5-82.1), respectively. In 42 states, 24-month coverage among WIC participants was less than among non-WIC participants, including 13 states where the difference was > or = 10%. Vaccination activities linked with WIC were reported from 76% of 8287 WIC sites nationwide. States conducting more-frequent interventions and reaching a higher proportion of WIC participants had 40% higher vaccination coverage levels for the WIC participants in that state (p<0.05). CONCLUSIONS: Children served by WIC remain less well-immunized than the nation's more-affluent children who do not participate in WIC. Thus, WIC remains a good place to target these children. This study provides evidence that fully implemented WIC linkage works to improve vaccination rates. Strategies that have been shown to improve the vaccination coverage levels of WIC participants should be expanded and adequately funded to protect these children.

Asunto(s)

RESUMEN

BACKGROUND: Assessment of vaccination coverage is an important component of the U.S. vaccination program and is primarily measured by the National Immunization Survey (NIS). METHODS: The 1999 NIS is a nationally representative sample of children aged 19 to 35 months, verified by provider records, that is conducted to obtain estimates of vaccination coverage rates. Coverage estimates are calculated for the nation, states, and selected urban areas for recommended vaccines and selected vaccine series. RESULTS: Coverage estimates are presented by a variety of demographic and healthcare-related factors: overall, by poverty status, race/ethnicity, selected milestone ages, participation in WIC, level of urbanicity, provider participation in VFC, and by provider facility type. In 1999, national coverage estimates were high for most vaccines and among most demographic groups. State and urban-area level estimates varied.

Asunto(s)

RESUMEN

OBJECTIVE: To examine trends in alcohol use among pregnant women in the United States and to characterize pregnant women who use alcohol, with an emphasis on frequent use (at least five drinks per occasion or at least seven drinks per week). METHODS: We used the Behavioral Risk Factor Surveillance System data from 1988 through 1995 to obtain the percentage of pregnant women who used alcohol. We used multiple logistic models to identify subgroups of pregnant women who are at increased risk for alcohol use. RESULTS: Overall, 14.6% (869 of 5983) of pregnant women consumed alcohol and 2.1% (133 of 5983) consumed alcohol frequently. Among pregnant women, alcohol use decreased from 22.5% (95% confidence interval [CI] 20.8, 23.9) in 1988 to 9.5% (95% CI 7.9, 11.8) in 1992 and then increased to 15.3% (95% CI 13.1, 17.2) by 1995. Among pregnant women, frequent alcohol use decreased from 3.9% (95% CI 2.4, 5.2) in 1988 to 0.9% (95% CI 0.4, 1.6) in 1991 and then increased to 3.5% (95% CI 2.0, 5.1) by 1995. Pregnant women who were at high risk for alcohol use were college educated, unmarried, employed, or students, had annual household incomes of more than $50,000, or were smokers. Pregnant women who were at high risk for frequent alcohol use were more likely to be unmarried, or smokers. CONCLUSION: The increasing prevalence of alcohol use among pregnant women calls for increased ascertainment of alcohol use among preconceptional and pregnant women. Brief interventions by clinicians, increased referral to alcohol treatment programs, and increased use of contraception by women of reproductive age who are problem drinkers should be considered as means of preventing alcohol-exposed pregnancies.

Asunto(s)