Global measles control and regional elimination, 1998-1999.
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In 1989, the World Health Assembly adopted the goal of reducing measles morbidity and mortality by 90% and 95%, respectively, by 1995, compared with estimates of the disease burden in the prevaccine era. In 1990, the World Summit for Children adopted a goal of vaccinating 90% of children against measles by 2000. Three regions of the World Health Organization (WHO) have targeted elimination: in 1994, the American Region (AMR) targeted elimination by 2000; in 1997, the Eastern Mediterranean Region (EMR) targeted elimination by 2010; and in 1998, the European Region (EUR) targeted elimination by 2007. This report updates progress since 1997 toward global measles control and regional elimination of measles, and includes vaccination coverage and disease surveillance data received by WHO as of August 14, 1999. Data for 1998 suggest that routine measles vaccination coverage has declined in some regions, the number of countries reporting cases and coverage to WHO has decreased, and measles continues to be an important cause of morbidity and mortality. (+info)
Successful control of epidemic diphtheria in the states of the Former Union of Soviet Socialist Republics: lessons learned.
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Epidemic diphtheria reemerged in the Russian Federation in 1990 and spread to all Newly Independent States (NIS) and Baltic States by the end of 1994. Factors contributing to the epidemic included increased susceptibility of both children and adults, socioeconomic instability, population movement, deteriorating health infrastructure, initial shortages of vaccine, and delays in implementing control measures. In 1995, aggressive control strategies were implemented, and since then, all affected countries have reported decreases of diphtheria; however, continued efforts by national health authorities and international assistance are still needed. The legacy of this epidemic includes a reexamination of the global diphtheria control strategy, new laboratory techniques for diphtheria diagnosis and analysis, and a model for future public health emergencies in the successful collaboration of multiple international partners. The reemergence of diphtheria warns of an immediate threat of other epidemics in the NIS and Baltic States and a longer-term potential for the reemergence of vaccine-preventable diseases elsewhere. Continued investment in improved vaccines, control strategies, training, and laboratory techniques is needed. (+info)
Diphtheria in the Russian Federation in the 1990s.
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A resurgence of diphtheria spread throughout the Russian Federation in the early 1990s; diphtheria had been well controlled, but circulation of toxigenic strains of Corynebacterium diphtheriae had persisted since the implementation of universal childhood vaccination in the late 1950s. More than 115,000 cases and 3,000 deaths were reported from 1990 to 1997, and, in contrast to the situation in the prevaccine era, most of the cases and deaths occurred among adults. Contributing factors included the accumulation of susceptible individuals among both adults and children and probably the introduction of new strains of C. diphtheriae. Vaccine quality, vaccine supply, or access to vaccine providers did not significantly contribute to the epidemic. Mass vaccination of adults and improved childhood immunization controlled the epidemic. High levels of population immunity, especially among children, will be needed to prevent and control similar outbreaks in the future. (+info)
Epidemic diphtheria in Ukraine, 1991-1997.
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In 1991, Ukraine experienced a return of epidemic diphtheria after decades of control that had resulted in <40 sporadic cases reported every year. Increased incidence was first recorded in Kiev, Lviv, and Odessa. By 1993, the epidemic had spread to >50% of the oblasts (provinces) in the country, and by 1995, all regions were affected. In 1995, at the peak of the epidemic, >5,000 cases and >200 deaths were reported. As in Russia, >80% of these cases were diagnosed in persons 16-59 years old. In 1993, the government of Ukraine initiated a program of increased immunization among children and at-risk adults, and by 1995, a mass immunization strategy was adopted in an effort to arrest the epidemic, which was increasing exponentially. In 1996, the number of cases started to decrease, and data from 1998 indicate that the downward trend has continued. It is likely that the diphtheria epidemic in Ukraine started among children, who had been left vulnerable due to inadequate childhood immunizations, and then quickly spread to inadequately protected adults. (+info)
Epidemic diphtheria in Belarus, 1992-1997.
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In 1990, epidemic diphtheria reemerged in Russia and spread to Belarus in 1992, when 66 cases were reported. Diphtheria cases doubled each year in 1993 and 1994 and peaked in 1995, when 322 cases were reported. Intensified routine immunization of young children and mass vaccination of older children and selected groups of adults were conducted in 1995 and were followed by mass vaccination campaigns targeting all adults in 1996. By the end of 1996, full immunization of >95% of children and coverage of>87% of adults with >/=1 dose resulted in a rapid decline in diphtheria cases. In 1998, only 36 cases of diphtheria were reported. More than 70% of the 965 cases and 26 fatalities reported during 1990-1998 occurred among persons >14 years of age. High levels of immunity among the entire population are needed for rapid control of diphtheria epidemics in the vaccine era. (+info)
Epidemiology and control of diphtheria in the Republic of Moldova, 1946-1996.
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In 1994-1996, the Republic of Moldova was stricken with an epidemic of diphtheria after >30 years of routine diphtheria immunization and the near absence of the disease for nearly 20 years. The intensity of the epidemic gradually grew, reaching a peak in 1994-1995. The epidemiology of diphtheria in Moldova during this period is described along with laboratory findings and control measures. Pharyngeal diphtheria was the predominant clinical form of the disease (97% of cases), and it most often developed in a localized form (70%), with 20% in the toxic form. The clinical diagnosis of diphtheria was bacteriologically confirmed in 91% of cases: Of the cases tested for biotype, 91.3% were gravis, 8.5% were mitis, and 0. 2% were intermedius. Of 494 toxigenic isolates from cases and carriers at the beginning of the epidemic, 47% were nonphagotypeable strains, and 25.7% were phagotype VI strains. Aggressive population-based diphtheria control measures, a mass immunization campaign, rapid case identification, antibiotic prophylaxis and supplemental immunization of close contacts in clusters of infection, and high coverage with routine immunization rapidly controlled the epidemic within Moldova. (+info)
Diphtheria in Lithuania, 1986-1996.
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Diphtheria reappeared in Lithuania in 1986 and rose to epidemic levels by 1992. Between 1991 and 1996, 110 cases of diphtheria were registered, with an incidence of 0.03-1.15/100,000 population. Most cases (84%) and all 17 deaths occurred among persons >/=15 years, most of whom had never been vaccinated. Persons 40-49 years old had the highest average annual age-specific morbidity (1.70/100,000) and mortality (0.53/100,000) rates. Low levels of immunity among individuals 40-49 years old and migration to epidemic areas in Russia and Belarus contributed to the epidemic's occurrence. Between 1991 and 1995, toxigenic Corynebacterium diphtheriae strains were isolated from 84 of all registered patients (76%), and nontoxigenic strains were isolated from 13 (12%). By 1996, two mass vaccination campaigns, which provided one dose of vaccine to individuals 25-30 years old and three doses of vaccine to persons 31-60 years old, helped reduce the number of cases. The first campaign achieved 69% coverage; the second achieved 48% coverage. (+info)
Diphtheria in Latvia, 1986-1996.
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After nearly two decades without a diphtheria case in Latvia, the disease reappeared in 1986. From 1990 to 1996, case counts were highest among adults 40-49 years of age, school-aged children, and adolescents. Nonetheless, the average annualized incidence of disease was highest among infants and preschoolers. In August 1995, mass vaccination efforts began to provide adults 25-60 years of age with at least one dose of vaccine. By the end of the year, a 77% coverage rate was achieved, resulting in a decrease of reported diphtheria cases by 1996. From February to September 1997, special outreach efforts were focused on hard-to-reach populations; as a result, by June 1997, 55% of adults had received three doses of vaccine. While decreases in the incidence of and morbidity from diphtheria have occurred, additional efforts still need to be concentrated on improving vaccination coverage in adults and children <2 years of age and in reducing mortality from diphtheria. (+info)