Measles and rubella seroprevalence among adults in Georgia in 2015: helping guide the elimination efforts

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.

High risk of subacute sclerosing panencephalitis following measles outbreaks in Georgia

OBJECTIVE

To describe cases and estimate subacute sclerosing panencephalitis (SSPE) risk following large-sale measles outbreaks in Georgia. A rare, fatal late complication of measles, SSPE is often overlooked in assessments focused on the acute illness. Georgia had 8377 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 neurological 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 under-reporting 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 a 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 1:1396. Adjusted estimates were 1:2792, 1:1:5584 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.

Impact of unfounded vaccine safety concerns on the nationwide measles-rubella immunization campaign, Georgia, 2008

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 ∼ 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.

Trends in encephalitis-associated deaths in the United States

The United States national mortality statistics and HIV/AIDS surveillance data were analysed to determine trends in encephalitis-associated deaths and to assess the impact of HIV infection on those deaths during 1979-1998, a period when ICD-9 codes were used for coding deaths in the United States. A total of 25125 encephalitis deaths were reported; 4779 of them (19%) had concurrent HIV infection. Overall encephalitis death rates remained stable, but they increased for groups where HIV infection was common and declined or remained unchanged for others. For persons without HIV infection, the rates declined in all demographic groups. Encephalitis deaths in HIV-infected persons followed general trends for HIV deaths in the United States. The rates in the HIV-infected population were several hundred- to thousand-fold higher than in the HIV-uninfected population. HIV infection was largely responsible for the lack of overall decline in the considerable mortality associated with encephalitis in the United States during 1979-1998.

Pertussis outbreak in an elementary school with high vaccination coverage

BACKGROUND

An outbreak of pertussis in a US elementary school with high vaccination coverage was investigated to evaluate vaccine effectiveness and to identify potential contributing factors.

METHODS

Survey and cohort study of all 215 students of an elementary school (including 36 case patients) and 16 secondary cases among contacts.

RESULTS

Fifty-two pertussis cases were identified (attack rate among students, 17%). Receipt of <3 doses of pertussis-containing-vaccine compared with receipt of complete vaccination series was a significant risk factor for pertussis [relative risk, 5.1; 95% confidence interval (CI), 3 to 8.6]. The effectiveness of the complete vaccination series was 80% (95% CI 66 to 88). No evidence of waning immunity among students was found. The following contributing factors for the outbreak were identified: multiple introductions of pertussis from the community; delays in identification and treatment of early cases; and high contact rates among students. Antimicrobial treatment initiated >14 days after cough onset was associated with increased risk of further transmission of pertussis (relative risk, 10.1; 95% CI 1.5 to 70.3) compared with treatment within 14 days of onset.

CONCLUSIONS

This investigation demonstrated the potential for pertussis outbreaks to occur in well-vaccinated elementary school populations. Aggressive efforts to identify cases and contacts and timely antimicrobial treatment can limit spread of pertussis in similar settings. High vaccination coverage should be maintained, because vaccination significantly reduces the risk of the disease throughout the elementary school years, and to ensure timely diagnosis and treatment health care providers should maintain a high index of suspicion for pertussis among elementary school age children.

Evaluation of a single dose of diphtheria toxoid among adults in the Republic of Georgia, 1995: immunogenicity and adverse reactions

To determine the immunogenicity and safety of a single dose of diphtheria toxoid among adults, blood samples for detecting serum antitoxin levels were obtained from 18- to 59-year-old subjects (n=248) before and 30 days after immunization with Td (tetanus-diphtheria toxoids; manufactured by Serum Institute of India). By day 30, the seroprevalence of antitoxin levels >/=0.1 IU/mL increased from 22.6% to 81.5%; median antitoxin levels increased from 0.01 to 4.0 IU/mL. These parameters were lowest among subjects who were 40-59 years old, especially among those 40-49 years old. Adverse reactions (local redness, swelling, induration, fever>39 degrees C) were reported by 5.3% of participants. Our findings suggest that, in general, one dose of the Indian-produced Td vaccine is efficacious and safe in inducing an adequate immune response against diphtheria in adults; however, in Georgia, persons 40-59 years old, especially those 40-49 years old, will require additional doses of toxoid to achieve protective levels of antitoxin.

Diphtheria epidemic in the Republic of Georgia, 1993-1997

Epidemic diphtheria reemerged in the republic of Georgia in 1993. From 1993 to 1997, 1405 cases were reported (28 in 1993, 312 in 1994, 429 in 1995, 348 in 1996, and 288 in 1997), with a cumulative incidence of 25.8/100,000 and a case fatality ratio of 9.5%. During 1993-1997, 53% of the diphtheria cases occurred among persons >/=15 years of age. Unvaccinated patients were more likely to have toxic forms (relative risk=2.24; 95% confidence interval=1.69-2.96) or to die of diphtheria (relative risk=2.24; 95% confidence interval=1. 36-3.68) than those who had received at least one dose of diphtheria toxoid. Improvement in routine childhood vaccination coverage and implementation of mass adult vaccination campaigns have been critical to bringing the epidemic under control. By mid-1998, the overall diphtheria situation in Georgia appeared to have been controlled. Only 53 cases were reported from January to June 1998, representing a 64% decrease from the 148 cases during the corresponding period in 1997.

Diphtheria in the Republic of Georgia: use of molecular typing techniques for characterization of Corynebacterium diphtheriae strains

Sixty-six Corynebacterium diphtheriae strains (62 of the gravis biotype and 4 of the mitis biotype) isolated during the Georgian diphtheria epidemic of 1993 to 1998 and 13 non-Georgian C. diphtheriae strains (10 Russian and 3 reference isolates) were characterized by (i) biotyping, (ii) toxigenicity testing with the Elek assay and PCR, (iii) the randomly amplified polymorphic DNA (RAPD) technique, and (iv) pulsed-field gel electrophoresis (PFGE). Fifteen selected strains were ribotyped. Six RAPD types and 15 PFGE patterns were identified among all strains examined, and 12 ribotypes were found among the 15 strains that were ribotyped. The Georgian epidemic apparently was caused by one major clonal group of C. diphtheriae (PFGE type A, ribotype R1), which was identical to the predominant epidemic strain(s) isolated during the concurrent diphtheria epidemic in Russia. A dendrogram based on the PFGE patterns revealed profound differences between the minor (nonpredominant) epidemic strains found in Georgia and Russia. The methodologies for RAPD typing, ribotyping, and PFGE typing of C. diphtheriae strains were improved to enable rapid and convenient molecular typing of the strains. The RAPD technique was adequate for biotype differentiation; however, PFGE and ribotyping were better (and equal to each other) at discriminating between epidemiologically related and unrelated isolates.

Prevalence of childhood asthma, rhinitis and eczema in Scandinavia and Eastern Europe

There is evidence that the prevalence of allergies and asthma differs between populations in western and eastern Europe. This study investigated the prevalence of wheezing, rhinitis and eczema among schoolchildren in urban and rural areas of Scandinavia and the formerly socialist countries of Eastern Europe. A total of 79,000 children from two age groups (13-14 yrs and 6-7 yrs) in 18 study centres responded to a questionnaire within the International Study of Asthma and Allergy in Children (ISAAC). The 12 month period prevalence of symptoms of asthma, allergic rhinoconjunctivitis and atopic eczema was calculated. The prevalence of wheezing among the 13-14 yr old children was 11.2-19.7% in Finland and Sweden, 7.6-8.5% in Estonia, Latvia and Poland and 2.6-5.9% in Albania, Romania, Russia, Georgia and Uzbekistan (except Samarkand). The prevalence of itching eyes and flexural dermatitis varied in a similar manner between the three regions. The regional differences were less pronounced among the 6-7 yr old children in the seven participating centres. The highest prevalence of rhinitis was recorded in April-July in Scandinavia and during the winter months in the other countries. The prevalence of atopy-related disorders was higher in Scandinavia than in Estonia, Latvia and Poland, which in turn had a higher prevalence than five other countries of eastern Europe with a culture less similar to western Europe. This supports the hypothesis that "Western life style" is associated with a high prevalence of childhood allergy.

Tetanus surveillance--United States, 1995-1997

PROBLEM/CONDITIONS: Despite widespread availability of a safe and effective vaccine against tetanus, 124 cases of the disease were reported during 1995-1997. Only 13% of patients reported having received a primary series of tetanus toxoid (TT) before disease onset. Of patients with known illness outcome, the case-fatality ratio was 11%.

REPORTING PERIOD COVERED

1995-1997.

DESCRIPTION OF SYSTEM

Physician-diagnosed cases of tetanus are reported by state and local health departments to CDC's National Notifiable Diseases Surveillance System. In addition, since 1965, supplemental clinical and epidemiologic information for cases has been provided to CDC's National Immunization Program.

RESULTS

From 1995 through 1997, a total of 124 cases of tetanus were reported from 33 states and the District of Columbia, accounting for an average annual incidence of 0.15 cases per 1,000,000 population. Sixty percent of patients were aged 20-59 years; 35% were aged > or =60 years; and 5% were aged <20 years, including one case of neonatal tetanus. For adults aged > or =60 years, the increased risk for tetanus was nearly sevenfold that for persons aged 5-19 years and twofold that for persons aged 20-59 years. The case-fatality ratio varied from 2.3% for persons aged 20-39 years to 16% for persons aged 40-59 years and to 18% for persons aged > or =60 years. Only 13% of patients reported having received a primary series of TT before disease onset. Previous vaccination status was directly related to severity of disease, with the case-fatality ratio ranging from 6% for patients who had received one to two doses to 15% for patients who were unvaccinated. No deaths occurred among the 16 patients who previously had received three or more doses. Tetanus occurred following an acute injury in 77% of patients, but only 41% sought medical care for their injury. All patients who sought care were eligible for TT as part of wound prophylaxis, but only 39% received it. Tetanus in injecting-drug users (IDUs) with no known acute injury comprised 11% of all cases, compared with 3.6% during 1991-1994. None of the IDU-associated tetanus cases occurred among persons who were known to have been vaccinated. Sixty-nine percent of IDU-associated tetanus cases were reported from California, and 77% of these cases occurred in heroin users.

INTERPRETATION

Tetanus remains a severe disease that primarily affects unvaccinated or inadequately vaccinated persons. Adults aged > or =60 years continue to be at highest risk for tetanus and for severe disease. However, the overall incidence of tetanus has decreased slightly since the late 1980s and early 1990s, from 0.20 to 0.15, a result primarily of a decreased incidence among persons aged > or =60 and <20 years.

ACTIONS TAKEN

Tetanus is preventable through both routine vaccination and appropriate wound management. In addition to decennial booster doses of diphtheria and tetanus toxoids during adult life, the Advisory Committee on Immunization Practices (ACIP) recommends vaccination visits for adolescents at age 11-12 years and for adults at age 50 years to enable health-care providers to review vaccination histories and administer any needed vaccine. Every contact with the health-care system, particularly among older adults and IDUs, should be used to review and update vaccination status as needed.