BACKGROUND: The country of Georgia initiated its hepatitis C virus (HCV) elimination program in 2015, at which point a serosurvey showed the adult prevalence of HCV antibody (anti-HCV) and HCV RNA to be 7.7% and 5.4%, respectively. This analysis reports hepatitis C results of a follow-up serosurvey conducted in 2021, and progress towards elimination. METHODS: The serosurvey used a stratified, multistage cluster design with systematic sampling to include adults and children (aged 5-17 years) providing consent (or assent with parental consent). Blood samples were tested for anti-HCV and if positive, HCV RNA. Weighted proportions and 95% confidence intervals (CI) were compared with 2015 age-adjusted estimates. RESULTS: Overall, 7237 adults and 1473 children were surveyed. Among adults, the prevalence of anti-HCV was 6.8% (95% CI, 5.9-7.7). The HCV RNA prevalence was 1.8% (95% CI, 1.3-2.4), representing a 67% reduction since 2015. HCV RNA prevalence decreased among those reporting risk factors of ever injecting drugs (51.1% to 17.8%), and ever receiving a blood transfusion (13.1% to 3.8%; both P < .001). No children tested positive for anti-HCV or HCV RNA. CONCLUSIONS: These results demonstrate substantial progress made in Georgia since 2015. These findings can inform strategies to meet HCV elimination targets.

BackgroundGeorgia has adopted the World Health Organization European Region's and global goals to eliminate viral hepatitis. A nationwide serosurvey among adults in 2015 showed 2.9% prevalence for hepatitis B virus (HBV) surface antigen (HBsAg) and 25.9% for antibodies against HBV core antigen (anti-HBc). HBV infection prevalence among children had previously not been assessed.AimWe aimed to assess HBV infection prevalence among children and update estimates for adults in Georgia.MethodsThis nationwide cross-sectional serosurvey conducted in 2021 among persons aged ≥ 5 years used multi-stage stratified cluster design. Participants aged 5-20 years were eligible for hepatitis B vaccination as infants. Blood samples were tested for anti-HBc and, if positive, for HBsAg. Weighted proportions and 95% confidence intervals (CI) were calculated for both markers.ResultsAmong 5-17 year-olds (n = 1,473), 0.03% (95% CI: 0-0.19) were HBsAg-positive and 0.7% (95% CI: 0.3-1.6) were anti-HBc-positive. Among adults (n = 7,237), 2.7% (95% CI: 2.3-3.4) were HBsAg-positive and 21.7% (95% CI: 20.4-23.2) anti-HBc-positive; HBsAg prevalence was lowest (0.2%; 95% CI: 0.0-1.5) among 18-23-year-olds and highest (8.6%; 95% CI: 6.1-12.1) among 35-39-year-olds.ConclusionsHepatitis B vaccination in Georgia had remarkable impact. In 2021, HBsAg prevalence among children was well below the 0.5% hepatitis B control target of the European Region and met the ≤ 0.1% HBsAg seroprevalence target for elimination of mother-to-child transmission of HBV. Chronic HBV infection remains a problem among adults born before vaccine introduction. Screening, treatment and preventive interventions among adults, and sustained high immunisation coverage among children, can help eliminate hepatitis B in Georgia by 2030.

Mother-to-child transmission (MTCT) of hepatitis B virus (HBV) often results in chronic HBV infection, the leading cause of cirrhosis and liver cancer (1). If not vaccinated, nine in 10 children infected at birth will become chronically infected. Globally, an estimated 6.4 million (range = 4.4-10.8 million) children aged ≤5 years are living with chronic HBV infection (2). In 2016, the World Health Assembly endorsed the goal to eliminate viral hepatitis as a public health threat by 2030, including the elimination of MTCT of HBV (3). Elimination of MTCT of HBV can be validated by demonstrating ≤0.1% prevalence of HBV surface antigen (HBsAg) among children aged ≤5 years, as well as ≥90% coverage with hepatitis B birth dose (HepB-BD) and 3 doses of hepatitis B vaccine (HepB3) (4,5). This report describes global progress toward elimination of MTCT of HBV during 2016-2021. By December 2020, 190 (98%) of 194 World Health Organization (WHO) member states* had introduced universal infant vaccination with hepatitis B vaccine (HepB), and 110 (57%) countries provided HepB-BD to all newborns. During 2016-2020, global HepB3 coverage remained between 82% and 85%, whereas HepB-BD coverage increased from 37% to 43%. In 2020, among the 99 countries reporting both HepB3 and HepB-BD coverage, 41 (41%) achieved ≥90% coverage with both. By December 2021, serosurveys documented ≤0.1% HBsAg prevalence among children in 11 countries. Accelerating HepB-BD introduction, increasing HepB3 coverage, and monitoring programmatic and impact indicators are essential for elimination of MTCT of HBV.

BACKGROUND: Checking vaccination status at school is widely recommended as a strategy to strengthen routine childhood vaccination coverage. Documentation of approaches, challenges, strengths, and impact of this strategy in a variety of contexts is key to enhancing adoption and implementation. However, there is limited information about the prevalence of policies and the implementation of checking vaccination status at school globally. METHODS: A one-time supplementary survey was circulated with the annual World Health Organization (WHO) and United Nations International Children's Emergency Fund (UNICEF) Joint Reporting Form in 2019 to all WHO member states and non-member state reporting entities. Additional publicly available country-level data, including primary school enrollment, home-based record (HBR) ownership, and World Bank income classification were linked to the supplementary survey responses, which were descriptively analyzed. RESULTS: We received survey responses from 130 of the 194 (67%) WHO member states and 15 non-member state reporting entities. Almost half (46%) of the respondents reported having a law requiring proof of vaccination to enter at least one level of education, and 60% of the respondents reported having a law that requires checking vaccination status at school in 2018. Three-quarters of the respondents (77%) reported the practice of routinely checking vaccination status at school. Both laws and the practice of checking were more common in the WHO Region of the Americas and the WHO European Region, and in high- and upper-middle-income countries. Individual HBR was the document most frequently checked. Catch-up vaccination occurred most frequently at health centers. Evaluation of checking vaccination status at school to determine what has worked and its effect was infrequently reported. CONCLUSION: Despite widespread implementation of checking vaccination status at school in 2018, documentation of the experiences in planning and implementing this strategy, and its effects remains sparse, particularly in low- and middle-income countries.

BACKGROUND: The drastic decline of Ukraine's immunization coverage since 2009 led to concerns about potential resurgence diphtheria and tetanus, along with other vaccine-preventable diseases. METHODS: To assess population immunity against diphtheria and tetanus, we tested specimens from the serosurvey conducted in 2017 among children born in 2006-2015, the birth cohorts targeted by the nationwide outbreak response immunization following a circulating vaccine-derived poliovirus type 1 outbreak in Zakarpattya province in 2015. We surveyed four regions of Ukraine, using cluster sampling in Zakarpattya, Sumy, and Odessa provinces and simple random sampling in Kyiv City. We tested serum specimens for IgG antibodies against diphtheria and tetanus, using microbead assays (MBA). We estimated seroprevalence and calculated 95% confidence intervals. We also obtained information on the immunization status of surveyed children. RESULTS: Seroprevalence of 0.1IU/mL diphtheria antibodies was <80% in all survey sites (50.0%-79.2%). Seroprevalence of 0.1IU/mL tetanus antibodies was 80% in Sumy, Kyiv City, and Odessa (80.2%-89.1%) and 61.6% in Zakarpattya. Across the sites, the proportion of children vaccinated age-appropriately with diphtheria-tetanus-containing vaccines (DTCV) was 28.5%-57.4% among children born in 2006-2010 and 34.1%-54.3% among children born in 2011-2015. The proportion of recipients of<3 DTCV doses increased from 7.1%-16.7% among children born in 2006-2010 to 19.8%-38.6% among children born in 2011-2015, as did the proportion of recipients of zero DTCV doses (2.6%-8.8% versus 8.0%-14.0%, respectively). CONCLUSIONS: Protection against diphtheria among children born in 2006-2015 was suboptimal (<80%), particularly in Zakarpattya. Protection against tetanus was adequate (80%) except in Zakarpattya. Diphtheria-tetanus immunization status was suboptimal across all sites. Catch-up vaccination of unvaccinated/under-vaccinated children and other efforts to increase immunization coverage would close these immunity gaps and prevent the resurgence of diphtheria and tetanus in Ukraine, particularly in Zakarpattya.

In 2019, an estimated 14 million persons in the World Health Organization (WHO) European Region* (EUR) were chronically infected with hepatitis B virus (HBV), and approximately 43,000 of these persons died from complications of chronic HBV infection (1). In 2016, the WHO Regional Office for Europe set hepatitis B control program targets for 2020, including 1) ≥90% coverage with 3 doses of hepatitis B vaccine (HepB3), 2) ≥90% coverage with interventions to prevent mother-to-child transmission (MTCT) of HBV,(†) and 3) ≤0.5% prevalence of HBV surface antigen (HBsAg)(§) in age groups eligible for vaccination with hepatitis B vaccine (HepB) (2-4). This report describes the progress made toward hepatitis B control in EUR during 2016-2019. By December 2019, 50 (94%) of 53 countries in EUR provided routine vaccination with HepB to all infants or children aged 1-12 years (universal HepB), including 23 (43%) countries that offered hepatitis B birth dose (HepB-BD) to all newborns. In addition, 35 (73%) of the 48 countries with universal infant HepB vaccination reached ≥90% HepB3 coverage annually during 2017-2019, and 19 (83%) of the 23 countries with universal birth dose administration achieved ≥90% timely HepB-BD coverage(¶) annually during that period. Antenatal hepatitis B screening coverage was ≥90% in 17 (57%) of 30 countries that selectively provided HepB-BD to infants born to mothers with positive HBsAg test results. In January 2020, Italy and the Netherlands became the first counties in EUR to be validated to have achieved the regional hepatitis B control targets. Countries can accelerate progress toward hepatitis B control by improving coverage with HepB and interventions to prevent MTCT and documenting achievement of the HBsAg seroprevalence target through representative serosurveys or, in low-endemicity countries, antenatal screening.

We validated a multiplex bead assay for diphtheria toxoid IgG antibodies against the Vero cell toxin neutralization test using 1300 specimens (correlation = 0.88). At the ≥0.01 IU/mL cutoff for minimal seroprotection, sensitivity was 95% and specificity was 83%. Agreement for three categories (<0.01, 0.01-<0.1, ≥0.1 IU/mL) was 81% (kappa = 0.71).

BACKGROUND: Before hepatitis B vaccine (HepB) introduction, level of endemicity of hepatitis B virus (HBV) in Ukraine was estimated as intermediate but the prevalence of HBV infection markers has not been measured in population-based serosurveys. Coverage with 3 doses of HepB, introduced in 2002, was 92%-98% during 2004-2007 but declined to 21%-48% during 2010-2016. To obtain data on HBV prevalence among children born after HepB introduction, we tested specimens from a serosurvey conducted in Ukraine in 2017, following circulating vaccine-derived poliovirus outbreak in 2015, among birth cohorts eligible for polio immunization response. METHODS: The serosurvey was conducted in Zakarpattya, Sumy, and Odessa provinces, and Kyiv City, targeting 2006-2015 birth cohorts. One-stage cluster sampling in the provinces and stratified simple random sampling in Kyiv were used for participant selection. All participants were tested for antibodies against HBV core antigen (anti-HBc). Anti-HBc-positive children were tested for HBV surface antigen (HBsAg). We also obtained information on HepB vaccination status for all children. RESULTS: Of 4,596 children tested, 81 (1.8%) were anti-HBc-positive and eight (0.2%) were HBsAg-positive. HBsAg prevalence was 0.7% (95% confidence interval, 0.3%-1.4%) in Zakarpattya, 0.1% (0.0%-0.4%) in Sumy, 0% (0.0%-03%) in Odessa, and 0.1% (0.0%-0.8%) in Kyiv. Across survey sites, the proportion of recipients of ≥ 3 HepB doses was 53%-80% in the 2006-2009 cohort and 28%-59% in the 2010-2015 cohort. CONCLUSION: HBV prevalence among children in surveyed regions of Ukraine in 2017 was low, including in Zakarpattya-the only site above the 0.5% European Regional target for HBsAg seroprevalence. However, HepB vaccination was suboptimal, particularly among children born after 2009, resulting in large numbers of unvaccinated or incompletely vaccinated children at risk of future HBV infection. HepB coverage should be increased to further reduce HBV transmission among children in Ukraine and achieve regional and global hepatitis B control/elimination targets.

Controlling measles outbreaks in the country of Georgia and throughout Europe is crucial for achieving the measles elimination goal for the World Health Organization's European Region. However, large-scale measles outbreaks occurred in Georgia during 2013-2015 and 2017-2018. The epidemiology of these outbreaks indicates widespread circulation and genetic diversity of measles viruses and reveals persistent gaps in population immunity across a wide age range that have not been sufficiently addressed thus far. Historic problems and recent challenges with the immunization program contributed to outbreaks. Addressing population susceptibility across all age groups is needed urgently. However, conducting large-scale mass immunization campaigns under the current health system is not feasible, so more selective response strategies are being implemented. Lessons from the measles outbreaks in Georgia could be useful for other countries that have immunization programs facing challenges related to health-system transitions and the presence of age cohorts with historically low immunization coverage.

A large-scale measles outbreak (11 495 reported cases, 60% aged >/=15 years) occurred in Georgia during 2013-2015. A nationwide, multistage, stratified cluster serosurvey for hepatitis B and C among persons aged >/=18 years conducted in Georgia in late 2015 provided an opportunity to assess measles and rubella (MR) susceptibility after the outbreak. Residual specimens from 3125 participants aged 18-50 years were tested for Immunoglobulin G antibodies against MR using ELISA. Nationwide, 6.3% (95% CI 4.9%-7.6%) of the surveyed population were seronegative for measles and 8.6% (95% CI 7.1%-10.1%) were seronegative for rubella. Measles susceptibility was highest among 18-24 year-olds (10.1%) and declined with age to 1.2% among 45-50 year-olds (P < 0.01). Susceptibility to rubella was highest among 25-29 year-olds (15.3%), followed by 18-24 year-olds (11.6%) and 30-34 year-olds (10.2%), and declined to <5% among persons aged >/=35 years (P < 0.001). The susceptibility profiles in the present serosurvey were consistent with the epidemiology of recent MR cases and the history of the immunization programme. Measles susceptibility levels >10% among 18-24 year-olds in Georgia revealed continued risk for outbreaks among young adults. High susceptibility to rubella among 18-34 year-olds indicates a continuing risk for congenital rubella cases.

OBJECTIVE: To describe cases and estimate subacute sclerosing panencephalitis (SSPE) risk following large-sale measles outbreaks in Georgia. SSPE, a rare, fatal late complication of measles, is often overlooked in assessments focused on the acute illness. Georgia had 8,377 and 11,495 reported measles cases during the 2004-2005 and 2013-2015 outbreaks, respectively, but SSPE burden has not been assessed. METHODS: SSPE cases diagnosed during 2008-2017 were identified from hospitalization registries in major neurologic departments likely to admit SSPE patients. Information on reported measles cases and deaths was obtained from the national measles surveillance system and published reports. The risk of SSPE (number of measles cases per one SSPE case) was calculated for cases associated with the 2004-2005 outbreak. Crude estimates were adjusted to account for potential underreporting of measles, using 50%, 25% and 10% estimates of completeness of reporting. RESULTS: Sixteen SSPE cases diagnosed during 2008-2017 were identified. Eleven (92%) of 12 SSPE cases with known history of measles had infection at <2 years and one (8%) at 3 years of age. Crude estimate of SSPE risk for the 2004-2005 outbreak was 1:1,396. Adjusted estimates were 1:2,792, 1:1:5,584, and 1:13,960, assuming 50%, 25% and 10% completeness of reporting measles cases, respectively. CONCLUSIONS: The review demonstrated substantial risk of SSPE in Georgia, supporting recent data suggesting that risk of SSPE following measles infection is higher than previously thought. To prevent SSPE in Georgia, very high timely immunization coverage for measles should be achieved among children and immunity gap among adults should be closed.

We estimated the economic impact of concurrent measles and rubella outbreaks in Romania during 2011-2012. We collected costs from surveys of 428 case-patients and caretakers, government records, and health staff interviews. We then estimated financial and opportunity costs. During the study period, 12,427 measles cases and 24,627 rubella cases were recorded; 27 infants had congenital rubella syndrome (CRS). The cost of the outbreaks was US $9.9 million. Cost per case was US $439 for measles, US $132 for rubella, and US $44,051 for CRS. Up to 36% of households needed to borrow money to pay for illness treatment. Approximately 17% of patients continued to work while ill to pay their treatment expenses. Our key study findings were that households incurred a high economic burden compared with their incomes, the health sector bore most costs, and CRS costs were substantial and relevant to include in rubella outbreak cost studies.

BACKGROUND: The European Region, certified polio-free in 2002, remains at risk of wild poliovirus reintroduction and emergence of circulating vaccine-derived polioviruses (cVDPV) until global polio eradication is achieved, as demonstrated by the cVDPV1 outbreak in Ukraine in 2015. METHODS: We reviewed epidemiologic, clinical and virology data on cVDPV cases, surveillance and immunization coverage data, and reports of outbreak-related surveys, country missions, and expert group meetings. RESULTS: In Ukraine, 3-dose polio vaccine coverage declined from 91% in 2008 to 15% by mid-2015. In summer, 2015, two unrelated children from Zakarpattya province were paralyzed by a highly divergent cVDPV1. The isolates were 20 and 26 nucleotide divergent from prototype Sabin strain (with 18 identical mutations) consistent with their common origin and approximately 2-year evolution. Outbreak response recommendations developed with international partner support included conducting three nationwide supplementary immunization activities (SIAs) with tOPV, strengthening surveillance and implementing communication interventions. SIAs were conducted during October 2015-February 2016 (officially reported coverage, round 1-64.4%, round 2-71.7%, and round 3-80.7%). Substantial challenges to outbreak response included lack of high-level support, resistance to OPV use, low perceived risk of polio, widespread vaccine hesitancy, anti-vaccine media environment, economic crisis and military conflict. Communication activities improved caregiver awareness of polio and confidence in vaccination. Surveillance was enhanced but did not consistently meet applicable performance standards. Post-outbreak assessments concluded that cVDPV1 transmission in Ukraine has likely stopped following the response, but significant gaps in population immunity and surveillance remained. CONCLUSIONS: Chronic under-vaccination in Ukraine resulted in the accumulation of children susceptible to polioviruses and created favorable conditions for VDPV1 emergence and circulation, leading to the outbreak. Until programmatic gaps in immunization and surveillance are addressed, Ukraine will remain at high-risk for VDPV emergence and circulation, as well as at risk for other vaccine-preventable diseases.

BACKGROUND: Tajikistan, considered highly endemic area for hepatitis B virus (HBV) in a pre-vaccine era, introduced hepatitis B vaccine in 2002 and reported ≥80% coverage with three doses of hepatitis B vaccine (HepB3) since 2004. However, the impact of vaccine introduction has not been assessed. METHODS: We tested residual serum specimens from a 2010 national serosurvey for vaccine-preventable diseases in Tajikistan and assessed the prevalence of HBV infection across groups defined based on the birth cohorts' routine infant hepatitis B vaccination program implementation and HepB3 coverage achieved (≥80% versus <80%). Serosurvey participants were selected through stratified multi-stage cluster sampling among residents of all regions of Tajikistan aged 1-24 years. All specimens were tested for antibodies against HBV core antigen (anti-HBc) and those found positive were tested for HBV surface antigen (HBsAg). Seroprevalence and 95% confidence intervals were calculated and compared across subgroups using Satterthwaite-adjusted chi-square tests, accounting for the survey design and sampling weights. RESULTS: A total of 2188 samples were tested. Prevalence of HBV infection markers was lowest among cohorts with ≥80% HepB3 coverage (ages, 1-6 years), 2.1% (95% confidence interval, 1.1-4.3%) for anti-HBc, 0.4% (0.1-1.3%) for HBsAg, followed by 7.2% (4.1-12.4%) for anti-HBc and 2.1% (0.7-6.1%) for HBsAg among cohorts with <80% HepB3 coverage (ages, 7-8 years), by 12.0% (8.7-16.3%) for anti-HBc and 3.5% (2.2-5.6%) for HBsAg among children's cohorts not targeted for vaccination (ages, 9-14 years), and 28.9% (24.5-33.8%) for anti-HBc and 6.8% (4.5-10.1%) for HBsAg among unvaccinated adult cohorts (ages, 15-24 years). Differences across groups were significant (p<0.001, chi-square) for both markers. CONCLUSIONS: The present study demonstrates substantial impact of hepatitis B vaccine introduction on reducing HBV infections in Tajikistan. To achieve further progress in hepatitis B control, Tajikistan should maintain high routine coverage with hepatitis B vaccine, including birth dose.

BACKGROUND: Poliovirus importations and related outbreaks continue to occur in polio-free countries, including those in the World Health Organization (WHO) European Region. National preparedness plans for responding to poliovirus introduction are insufficient in many countries of the European Region. We describe a series of polio outbreak simulation exercises that were implemented to formally test polio outbreak preparedness plans in the European Region. METHODS: We designed and implemented the exercises, reviewed the results, made recommendations, and assessed the role of outbreak simulation exercises in maintaining regional polio-free status. In addition, we performed a comprehensive review of the national plans of all WHO Member States in the European Region. RESULTS: Three exercises, delivered during 2011-2013 (for the Balkans, United Kingdom, and the Caucasus and Ukraine), revealed that participating countries were generally prepared for poliovirus introduction, but the level of preparedness needed improvement. The areas in particular need of strengthening were national preparedness plans, initial response, plans for securing vaccine supply, and communications. CONCLUSIONS: Polio outbreak simulation exercises can be valuable tools to help maintain polio-free status and should be extended to other high-risk countries and subnational areas in the European Region and elsewhere.

BACKGROUND: The European region, certified as polio free in 2002, had recent wild poliovirus (WPV) introductions, resulting in a major outbreak in Central Asian countries and Russia in 2010 and in current widespread WPV type 1 circulation in Israel, which endangered the polio-free status of the region. METHODS: We assessed the data on the major determinants of poliovirus transmission risk (population immunity, surveillance, and outbreak preparedness) and reviewed current threats and measures implemented in response to recent WPV introductions. RESULTS: Despite high regional vaccination coverage and functioning surveillance, several countries in the region are at high or intermediate risk of poliovirus transmission. Coverage remains suboptimal in some countries, subnational geographic areas, and population groups, and surveillance (acute flaccid paralysis, enterovirus, and environmental) needs further strengthening. Supplementary immunization activities, which were instrumental in the rapid interruption of WPV1 circulation in 2010, should be implemented in high-risk countries to close population immunity gaps. National polio outbreak preparedness plans need strengthening. Immunization efforts to interrupt WPV transmission in Israel should continue. CONCLUSIONS: The European region has successfully maintained its polio-free status since 2002, but numerous challenges remain. Staying polio free will require continued coordinated efforts, political commitment and financial support from all countries.

As polio eradication inches closer, the absence of poliovirus circulation in most of the world and imperfect vaccination coverage are resulting in immunity gaps and polio outbreaks affecting adults. Furthermore, imperfect, waning intestinal immunity among older children and adults permits reinfection and poliovirus shedding, prompting calls to extend the age range of vaccination campaigns even in the absence of cases in these age groups. The success of such a strategy depends on the contribution to poliovirus transmission by older ages, which has not previously been estimated. We fit a mathematical model of poliovirus transmission to time series data from two large outbreaks that affected adults (Tajikistan 2010, Republic of Congo 2010) using maximum-likelihood estimation based on iterated particle-filtering methods. In Tajikistan, the contribution of unvaccinated older children and adults to transmission was minimal despite a significant number of cases in these age groups [reproduction number, R = 0.46 (95% confidence interval, 0.42-0.52) for >5-y-olds compared to 2.18 (2.06-2.45) for 0- to 5-y-olds]. In contrast, in the Republic of Congo, the contribution of older children and adults was significant [R = 1.85 (1.83-4.00)], perhaps reflecting sanitary and socioeconomic variables favoring efficient virus transmission. In neither setting was there evidence for a significant role of imperfect intestinal immunity in the transmission of poliovirus. Bringing the immunization response to the Tajikistan outbreak forward by 2 wk would have prevented an additional 130 cases (21%), highlighting the importance of early outbreak detection and response.

BACKGROUND: Tajikistan had a major diphtheria outbreak ( approximately 10,000 cases) in the 1990s, which was controlled after nationwide immunization campaigns with diphtheria-tetanus toxoid in 1995 and 1996. Since 2000, only 52 diphtheria cases have been reported. However, in coverage surveys conducted in 2000 and 2005, diphtheria-tetanus-pertussis vaccine coverage was lower than administratively reported estimates raising concerns about potential immunity gaps. To further assess population immunity to diphtheria in Tajikistan, diphtheria antibody testing was included in a large-scale nationwide serosurvey for vaccine-preventable diseases conducted in connection with a poliomyelitis outbreak in 2010. In addition, the serosurvey provided an opportunity to assess population immunity to tetanus. METHODS: Residents of all regions of Tajikistan aged 1-24 years were included in the serosurvey implemented during September-October 2010. Participants were selected through stratified cluster sampling. Specimens were tested for diphtheria antibodies using a Vero cell neutralization assay and for tetanus antibodies using an anti-tetanus IgG ELISA. Antibody concentrations ≥0.1IU/mL were considered seropositive. RESULTS: Overall, 51.4% (95% CI, 47.1%-55.6%) of participants were seropositive for diphtheria and 78.9% (95% CI, 74.7%-82.5%) were seropositive for tetanus. The lowest percentages of seropositivity for both diseases were observed among persons aged 10-19 years: diphtheria seropositivity was 37.1% (95% CI, 31.0%-43.7%) among 10-14 year-olds, and 35.3% (95% CI, 29.9%-41.1%) among 15-19 year-olds; tetanus seropositivity in respective age groups was 65.3% (95% CI, 58.4%-71.6%) and 70.1% (95% CI, 64.5%-75.2%). CONCLUSIONS: Population immunity for diphtheria in Tajikistan is low, particularly among 10-19 year-olds. Population immunity to tetanus is generally higher than for diphtheria, but is suboptimal among 10-19 year-olds. These findings highlight the need to improve routine immunization service delivery, and support a one-time supplementary immunization campaign with diphtheria-tetanus toxoid among birth cohorts aged 1-19 years in 2010 (3-21 years in 2012) to close immunity gaps and prevent diphtheria outbreaks.

BACKGROUND: A serosurvey to evaluate population immunity to polioviruses (PVs) in the context of the importation-related wild PV1 outbreak in Tajikistan in 2010 (461 confirmed cases among children and young adults) was conducted. METHODS: Serum specimens from a nationwide sample of 1-24 year-old persons selected through stratified cluster sampling (n=2447) were tested for neutralizing antibodies to all three PV types. Samples with titers<1:8 were considered seronegative. The serosurvey was conducted during the interval after mOPV1 supplementary immunization activities (SIAs) and before tOPV SIAs (targeting ages≤15 years) implemented to control the outbreak. In the absence of pre-outbreak specimens, results for PV3 were used as a proxy for pre-outbreak PV1 immunity patterns. RESULTS: Overall, PV1 seroprevalence was 98.9%, PV2 seroprevalence was 98.8%, and PV3 seroprevalence was 86.9%. PV1 and PV2 seroprevalence exceeded 95% in all age groups and regions. PV3 seroprevalence was <90% in all age groups and regions, except 15-19 year-olds (91.7%) and Dushanbe (90.0%). PV3 seroprevalence was lowest among 1-4 (82.7%) and 5-9 (84.4%) year-olds, particularly among 1-4 year-olds in Kurgan-Tube (76.3%) and RRS (80.0%) regions. Birth cohorts immunized only through routine services (ages, 1-7 years) had lower PV3 seroprevalence than birth cohorts targeted by the SIAs during 1995-2002 (8-19 years): 82.5% versus 89.3%, p<0.001. CONCLUSIONS: Suboptimal (<90%) PV3 seroprevalence across wide age range suggests the outbreak resulted from accumulation of susceptibles due to suboptimal coverage over a long time period, particularly in the birth cohorts immunized only through routine services and in areas where the outbreak began (Kurgan-Tube and RRS). High PV1 seroprevalence indicates that mOPV1 SIAs with expanded target age (≤15 years) succeeded in closing the immunity gap and ongoing WPV1 transmission is unlikely. To accelerate outbreak control in areas which have been polio-free for long time, expanding SIA target age should be considered.

The family Picornaviridae is a large and diverse group of viruses that infect humans and animals. Picornaviruses are among the most common infections of humans and cause a wide spectrum of acute human disease. This study began as an investigation of acute flaccid paralysis (AFP) in a small area of eastern Bolivia, where surveillance had identified a persistently high AFP rate in children. Stools were collected and diagnostic studies ruled out poliovirus. We tested stool specimens from 51 AFP cases and 34 healthy household or community contacts collected during 2002-2003 using real-time and semi-nested RT-PCR assays for enterovirus, parechovirus, cardiovirus, kobuvirus, salivirus, and cosavirus. Anecdotal reports suggested a temporal association with neurologic disease in domestic pigs, so six porcine stools were also collected and tested with the same set of assays, with the addition of an assay for porcine teschovirus. A total of 126 picornaviruses were detected in 73 of 85 human individuals, consisting of 53 different picornavirus types encompassing five genera (all except Kobuvirus). All six porcine stools contained porcine and/or human picornaviruses. No single virus, or combination of viruses, specifically correlated with AFP; however, the study revealed a surprising complexity of enteric picornaviruses in a single community.

While global polio eradication requires tremendous efforts in countries where wild polioviruses (WPVs) circulate, numerous outbreaks have occurred following WPV importation into previously polio-free countries. Countries that have interrupted endemic WPV transmission should continue to conduct routine risk assessments and implement mitigation activities to maintain their polio-free status as long as wild poliovirus circulates anywhere in the world. This article reviews the methods used by World Health Organization (WHO) regional offices to qualitatively assess risk of WPV outbreaks following an importation. We describe the strengths and weaknesses of various risk assessment approaches, and opportunities to harmonize approaches. These qualitative assessments broadly categorize risk as high, medium, or low using available national information related to susceptibility, the ability to rapidly detect WPV, and other population or program factors that influence transmission, which the regions characterize using polio vaccination coverage, surveillance data, and other indicators (e.g., sanitation), respectively. Data quality and adequacy represent a challenge in all regions. WHO regions differ with respect to the methods, processes, cut-off values, and weighting used, which limits comparisons of risk assessment results among regions. Ongoing evaluation of indicators within regions and further harmonization of methods between regions are needed to effectively plan risk mitigation activities in a setting of finite resources for funding and continued WPV circulation.

BACKGROUND: The World Health Organization European Region has a goal for rubella elimination and congenital rubella syndrome (CRS) prevention. Although all Member States recommend a rubella-containing vaccine in their national immunization programs, rubella and CRS continue to occur, and surveillance quality varies throughout the region. METHODS: To describe the status of regional rubella and CRS surveillance and assess progress toward elimination, we reviewed surveillance practices by surveying all 53 Member States and analyzed rubella and CRS surveillance data during 2005-2009. RESULTS: Overall, 41 (91%) of 45 responding Member States have nationwide rubella surveillance, and 39 (87%) have nationwide CRS surveillance. During 2005-2009, rubella cases reported in the region decreased by 94% from 206,359 cases to 11,623 cases. The greatest decrease (99%) was observed in newly independent states of the former Soviet Union. In the rest of the region, high rubella incidence was observed in Poland, Romania, Italy, and San Marino during 2005-2008 and in Poland, Bosnia and Herzegovina, and Austria in 2009. A total of 68 CRS cases were reported during 2005-2009. CONCLUSIONS: As the foundation to achieving and verifying rubella elimination, high-quality rubella and CRS surveillance needs to be implemented and sustained in all Member States.

BACKGROUND: Supplementary immunization activities (SIAs) using measles-containing vaccine (MCV) have had a substantial impact on reducing mortality associated with measles worldwide. METHODS: To assess impact of SIAs on measles incidence in the World Health Organization European Region and their role at the final stages of measles elimination efforts in Europe, we reviewed information on SIAs, measles surveillance, and routine vaccination coverage during 2000-2009. RESULTS: During 2000-2009, >57 million persons received MCV through SIAs in 16 countries. The Region primarily focused on catch-up campaigns with wider target age groups than in other regions and subsequently relied on routine vaccination rather than periodic follow-up SIAs for the second MCV dose. In addition, the concept of SIAs has been expanded from short-term (<30 days) mass campaigns implemented in other regions to incorporate vaccination efforts over longer periods and outbreak response vaccination. In 2009, 14 of 16 countries that conducted SIAs reported no measles cases or <1 case per 1,000,000 population, reflecting the post-SIA decrease in incidence. CONCLUSIONS: SIAs have made a substantial contribution to the success of measles elimination efforts and will likely remain an important strategy for interrupting measles virus transmission in the European Region, although specific approaches will vary by country.

Enterovirus (EV) surveillance data are useful for establishing temporal and geographic patterns of circulation and for virus characterization to determine phylogenetic relationships between strains. Almost no information is available on circulating enteroviruses (EV) in Georgia and the surrounding region. To describe EV circulation in Georgia, determine relationships with previously characterized strains, and assess the role of environmental and clinical EV surveillance, we analyzed a total of 112 non-polio EV isolates identified during 2002-2005 from sewage and human stool samples. Viruses were isolated in cell culture using standard methods and typed by partial sequencing of VP1 gene. A total of 20 different non-polio EV serotypes were identified over the four-year period. Most commonly detected EV included echovirus (E) 6 (21 isolates), E20, E3, and E7 (11 isolates each), E11, coxsackievirus (CV) B4, and CVB5 (7 isolates each), and E13, E19, and E30 (6 isolates each). Phylogenetic analysis showed that many serotypes were represented by more than one genetic lineage. The present study showed a very high degree of EV diversity in Georgia and demonstrated the added value of environmental EV surveillance, particularly in settings with limited clinical surveillance. Several serotypes would not have been detected without having both clinical and environmental surveillance in place. Several serotypes detected in Georgia were among those rarely reported in the United States and Europe (e.g. E3, E20, and E19). Since the emergence of new genetic lineages of EV in a particular area is often associated with large scale outbreaks, continued monitoring of EV strains by both environmental and clinical surveillance and genetic characterization should be encouraged.

Vaccine safety fears following media reports of adverse events led to low (50.3%) coverage in a supplementary measles-rubella immunization campaign in Georgia in 2008. Review of adverse events associated with the campaign identified 432 reports (<0.1% of approximately 493,000 vaccinees) including 338 (78.2%) cases of syncope. There were no deaths. Causality assessment was performed for 79 cases perceived by providers as severe and with clinical details available. Conditions likely caused by the vaccine were identified in 13 (16.5%) cases (allergic and local reactions, thrombocytopenia). Thirty-seven (46.8%) cases had symptoms consistent with syncope or anxiety attack; 36 (97.3%) of them were initially misdiagnosed as anaphylactic shock/allergies/"postvaccinal reactions". Twenty-nine (36.7%) cases had coincidental illnesses. Safety fears were unfounded and exaggerated by media reports and providers' difficulties in recognizing syncope/anxiety attacks. Risk communication strategies to address perceived vaccine safety concerns are urgently needed to ensure that the goal of measles and rubella elimination in the European Region of the World Health Organization is met.

BACKGROUND: Japanese encephalitis virus (JEV) is endemic in Thailand and prevention strategies include vaccination, vector control, and health education. METHODS: Between July 2003 and August 2005, we conducted hospital-based surveillance for encephalitis at seven hospitals in Bangkok and Hat Yai. Serum and cerebrospinal (CSF) specimens were tested for evidence of recent JEV infection by immunoglobulin M (IgM) enzyme-linked immunosorbent assay (ELISA) and a plaque reduction neutralization test (PRNT). RESULTS: Of the 147 patients enrolled and tested, 24 (16%) had evidence of acute flavivirus infection: 22 (15%) with JEV and two (1%) with dengue virus. Of the 22 Japanese encephalitis (JE) cases, 10 (46%) were aged ≤15 years. The median length of hospital stay was 13 days; one 13-year-old child died. Ten percent of encephalitis patients enrolled in Bangkok hospitals were found to have JEV infection compared to 28% of patients enrolled in hospitals in southern Thailand (p<0.01). Four (40%) of the 10 children with JE were reported as being vaccinated. CONCLUSIONS: JEV remains an important cause of encephalitis among hospitalized patients in Thailand. The high proportion of JE among encephalitis cases is concerning and additional public health prevention efforts or expanded vaccination may be needed.

In the summer and fall of 2007, we observed a unique cluster of cases of severe coxsackievirus B1 (CVB1) infection among Chicago area neonates. Eight neonates had closely related strains of CVB1 that were typed at the Centers of Disease Control and Prevention; 2 other neonates had CVB infections, 1 of which was further identified as serotype CVB1. All had severe myocarditis; 1 neonate underwent heart transplantation, and 1 died of severe left ventricular dysfunction.

BACKGROUND: Enterovirus infections are very common and typically cause mild illness, although neonates are at higher risk for severe illness. In 2007, the Centers for Disease Control and Prevention (CDC) received multiple reports of severe neonatal illness and death associated with coxsackievirus B1 (CVB1), a less common enterovirus serotype not previously associated with death in surveillance reports to the CDC. METHODS: This report includes clinical, epidemiologic, and virologic data from cases of severe neonatal illness associated with CVB1 reported during the period from 2007 through 2008 to the National Enterovirus Surveillance System (NESS), a voluntary, passive surveillance system. Also included are data on additional cases reported to the CDC outside of the NESS. Virus isolates or original specimens obtained from patients from 25 states were referred to the CDC picornavirus laboratory for molecular typing or characterization. RESULTS: During 2007-2008, the NESS received 1079 reports of enterovirus infection. CVB1 accounted for 176 (23%) of 775 reported cases with known serotype, making it the most commonly reported serotype for the first time ever in the NESS. Six neonatal deaths due to CVB1 infection were also reported to the CDC during that time. Phylogenetic analysis of the 2007 and 2008 CVB1 strains indicated that the increase in cases resulted from widespread circulation of a single genetic lineage that had been present in the United States since at least 2001. CONCLUSIONS: Healthcare providers and public health departments should be vigilant to the possibility of continuing CVB1-associated neonatal illness, and testing and continued reporting of enterovirus infections should be encouraged.