Epidemic measles in young adults. Clinical, epidemiologic, and serologic studies

High Concentrations of Measles Neutralizing Antibodies and High-Avidity Measles IgG Accurately Identify Measles Reinfection Cases

In the United States, approximately 9% of the measles cases reported from 2012 to 2014 occurred in vaccinated individuals. Laboratory confirmation of measles in vaccinated individuals is challenging since IgM assays can give inconclusive results. Although a positive reverse transcription (RT)-PCR assay result from an appropriately timed specimen can provide confirmation, negative results may not rule out a highly suspicious case. Detection of high-avidity measles IgG in serum samples provides laboratory evidence of a past immunologic response to measles from natural infection or immunization. High concentrations of measles neutralizing antibody have been observed by plaque reduction neutralization (PRN) assays among confirmed measles cases with high-avidity IgG, referred to here as reinfection cases (RICs). In this study, we evaluated the utility of measuring levels of measles neutralizing antibody to distinguish RICs from noncases by receiver operating characteristic curve analysis. Single and paired serum samples with high-avidity measles IgG from suspected measles cases submitted to the CDC for routine surveillance were used for the analysis. The RICs were confirmed by a 4-fold rise in PRN titer or by RT-quantitative PCR (RT-qPCR) assay, while the noncases were negative by both assays. Discrimination accuracy was high with serum samples collected ≥3 days after rash onset (area under the curve, 0.953; 95% confidence interval [CI], 0.854 to 0.993). Measles neutralizing antibody concentrations of ≥40,000 mIU/ml identified RICs with 90% sensitivity (95% CI, 74 to 98%) and 100% specificity (95% CI, 82 to 100%). Therefore, when serological or RT-qPCR results are unavailable or inconclusive, suspected measles cases with high-avidity measles IgG can be confirmed as RICs by measles neutralizing antibody concentrations of ≥40,000 mIU/ml.

Systematic Review of Measles and Rubella Serology Studies

Serological tests provide information about individual immunity from historical infection or immunization. Cross-sectional serological studies provide data about the age- and sex-specific immunity levels for individuals in the studied population, and these data can provide a point of comparison for the results of transmission models. In the context of developing an integrated model for measles and rubella transmission, we reviewed the existing measles and rubella literature to identify the results of national serological studies that provided cross-sectional estimates of population immunity at the time of data collection. We systematically searched PubMed, the Science Citation Index, and references we identified from relevant articles published in English. We extracted serological data for comparison to transmission model outputs. For rubella, serological studies of women of child-bearing age provide information about the potential risks of infants born with congenital rubella syndrome. Serological studies also document the loss of maternal antibodies, which occurs at different rates for the different viruses and according to the nature of the induced immunity (i.e., infection or vaccine). The serological evidence remains limited for some areas, with studies from developed countries representing a disproportionate part of the evidence. The collection and review of serological evidence can help program managers identify immunity gaps in the population, which may help them better understand the characteristics of individuals within their populations who may participate in transmission and manage risks.

The Importance of Nosocomial Transmission of Measles in the Propagation of a Community Outbreak

In late January 1985, a measles outbreak occurred at a community hospital in Columbia county, Florida. The outbreak spread throughout the county and to two neighboring counties (Alachua and Marion), resulting in 79 cases with a 29% hospitalization rate. Hospitals represented the site with the highest frequency of transmission. At the Alachua county hospitals, where strict respiratory isolation measures were taken, no secondary cases occurred among hospitalized patients. Two independent risk factors existed for hospitalization: measles exposure in a hospital setting (P <0.05) and nonvaccination (P <0.00l). Of the total measles cases, 24% were under the age of 16 months and 47% of those aged 16 months or older had a history of appropriate vaccination. Columbia county, which experienced 86% of the cases, had a 5% frequency of unvaccinated students compared to 0.6% frequency at Alachua (P <0.00l) where only 10% of the cases occurred. This outbreak demonstrates the role of uncontrolled nosocomial transmission of measles in the propagation of a community outbreak.

Clinical and epidemiological findings during a measles outbreak occurring in a population with a high vaccination coverage

From March 1991 to April 1992, 250 measles suspected cases were studied in the Municipality of Niterói, State of Rio de Janeiro. The median age found was 11 years and 76.0% of the cases were in school age children. Exposure histories were present in 149 patients and schools were the most frequent sites of transmission (45.0%). Vaccination status was known for 127 studied cases and 76.4% of them had received measles vaccine before their first birthday. One or more complications were reported for 68 cases and in 8.9% of the studied cases hospitalization was required. Frequency of complications varied according to each age group studied and were more commonly encountered among children < 1 year of age (55.6%). The history of previous vaccination did not diminish the number of complications of the cases studied. The results of this work show changes in age distribution of measles leading to sizeable outbreaks among teenagers and young adults.

The risk of measles, mumps, and varicella among young adults: a serosurvey of US Navy and Marine Corps recruits

OBJECTIVES

To assess the risk of epidemic transmission and to guide immunization policy, the seroprevalence of antibody to measles, mumps, and varicella was determined in a group of young adults.

METHODS

A cross-sectional study of 1533 US Navy and Marine Corps recruits was conducted in June 1989. Antibody status was determined with commercially available enzyme-linked immunosorbent assays.

RESULTS

Direct sex and race adjustment to the 15- to 29-year-old US population resulted in seronegativity rates of 17.8% for measles, 12.3% for mumps, and 6.7% for varicella. Measles and mumps seronegativity rates were higher among Whites whereas varicella seronegativity was higher among non-Whites. Recruits enlisting from outside the 50 US states, especially those from island territories, were more likely to lack varicella antibody. The sensitivity of a positive history of vaccination or disease in predicting antibody status was less than 90% for all diseases.

CONCLUSIONS

These results suggest a continued potential for epidemics, especially of measles, and the need for mandatory immunization policies. Immigrants to the United States, especially those from island territories, may be a high-risk group that could benefit from varicella vaccination.

Immunoglobulin M antibody response to measles virus following primary and secondary vaccination and natural virus infection

The use of IgM antibody detection for the classification of the primary and secondary measles antibody response in persons following primary and secondary vaccination and natural measles virus infection was examined. Of 32 nonimmune children receiving primary measles vaccination, 31 (97%) developed IgM antibodies, consistent with a primary antibody response. Of 21 previously vaccinated children with low levels of preexisting IgG antibodies who responded to revaccination, none developed detectable IgM antibodies, whereas 33 of 35 (94%) with no detectable preexisting IgG antibodies developed an IgM response. Of a sample of 57 measles cases with a prior history of vaccination, 55 (96%) had detectable IgM antibodies. Of these, 30 (55%) were classified as having a primary antibody response and 25 (45%) a secondary antibody response based on differences in their ratios of IgM to IgG antibodies. Differences in the severity of clinical symptoms between these 2 groups were consistent with this classification scheme. These findings suggest that 1) an IgM response follows primary measles vaccination in the immunologically naive, 2) an IgM response is absent on revaccination of those previously immunized, and 3) an IgM response may follow clinical measles virus infection independent of prior immunization status.

Seroimmunity to measles and mumps among medical students and nurses in a teaching hospital in Lebanon

Two hundred thirty-three newly enrolled medical and nursing students at the American University of Beirut, Lebanon, were tested for antibodies to measles and mumps. Antibodies to measles were detected in 95% of the sample, and antibodies to mumps in 84% of the sample. Susceptible individuals were appropriately immunized.

A survey of hospital infection control policies and employee measles cases during Los Angeles County's measles epidemic, 1987 to 1989

BACKGROUND

Between December 1987 and December 1989, 74 adults employed in Los Angeles County acute care hospitals were found to have measles. To investigate measles infection control policies in Los Angeles County and to gain information on employee measles cases, two surveys were performed.

METHODS

A survey of all infection control practitioners (N = 102) of acute care hospitals was conducted in July 1989. Reported employee measles cases were surveyed after initial case reports were reviewed.

RESULTS

The survey of acute care hospitals revealed that only 17% had mandatory measles infection control policies requiring written proof of past measles vaccination, disease, or seropositivity. Only 4% of hospitals had policies affecting students or volunteers. A second survey of hospital employees with confirmed measles revealed that 46% (34/74) were working in hospitals without measles infection control policies, 43% (32/74) were born before 1957, and 31% (21/67) were working in jobs not traditionally considered to provide a high risk of measles exposure. One third of the sick employees were hospitalized. The standard of either birth date before 1957 or oral history of measles illness or vaccination would have classified 93% (39/42) of the employees with measles as immune.

CONCLUSIONS

Effective infection control policies against measles and rubella should be adopted and enforced. Those policies should only allow written documentation as proof of measles immunity and should address all employees, regardless of age or job description.

Measles immunity among community hospital employees

OBJECTIVE

To define measles immunity rates among employees at 2 hospitals during a community outbreak in 1990.

DESIGN

Cohort survey using enzyme-linked immunosorbent assay (ELISA) and questionnaire.

SETTING

Two community hospitals.

PARTICIPANTS

Seventy-six percent of 2,060 employees.

RESULTS

Seven percent (115/1566) of participants lacked ELISA-defined measles immunity. Among employees whose ages were known, 14% (64/467) of those born after 1956 and 5% (50/1086) of those born before 1957 lacked serologic evidence of immunity. Fifty-eight percent of the susceptible persons had substantial patient contact. With ELISA results as the reference for immunity, the predictive value of an undocumented positive history of measles disease or vaccination was 95%; the predictive value of a negative history of both was 52%. Measles developed in 7 employees.

CONCLUSIONS

A substantial number of hospital employees lacked ELISA-defined measles immunity, including many who had patient contact or who had been born before 1957. Undocumented disease and vaccination histories were not adequate predictors of serologic status. This study supports the recommendations and suggestions of the Immunization Practices Advisory Committee that hospitals should require documented evidence of measles immunity from employees who have patient contact.

Adverse events following measles-mumps-rubella and measles vaccinations in college students

We studied adverse events reported by 401 measles, mumps and rubella (MMR) vaccinees and 391 unvaccinated controls at one college, and 133 measles (M) vaccinees and 352 unvaccinated controls at an adjacent college during a measles outbreak in Massachusetts in 1985. Rates of symptoms and signs experienced by MMR vaccinees, M vaccinees, and controls were essentially similar. No serious adverse events were detected.

Measles. Forgotten but not gone

Vaccination has greatly reduced the incidence of measles in the United States. Yet, because of the highly infectious nature and potentially fatal complications of the disease, primary care physicians need to remain alert to possible cases and to react aggressively during an outbreak. Dr Holtan discusses why measles persists, who is at risk, and how immunity is achieved.

The importance of nosocomial transmission of measles in the propagation of a community outbreak

In late January 1985, a measles outbreak occurred at a community hospital in Columbia county, Florida. The outbreak spread throughout the county and to two neighboring counties (Alachua and Marion), resulting in 79 cases with a 29% hospitalization rate. Hospitals represented the site with the highest frequency of transmission. At the Alachua county hospitals, where strict respiratory isolation measures were taken, no secondary cases occurred among hospitalized patients. Two independent risk factors existed for hospitalization: measles exposure in a hospital setting (P less than 0.05) and nonvaccination (P less than 0.001). Of the total measles cases, 24% were under the age of 16 months and 47% of those aged 16 months or older had a history of appropriate vaccination. Columbia county, which experienced 86% of the cases, had a 5% frequency of unvaccinated students compared to 0.6% frequency at Alachua (P less than 0.001) where only 10% of the cases occurred. This outbreak demonstrates the role of uncontrolled nosocomial transmission of measles in the propagation of a community outbreak.

An outbreak of measles among young adults. Clinical and laboratory features in 461 patients

We report the clinical and laboratory characteristics of measles infection in an unselected group of 461 young adults. Otitis media was diagnosed in 9.8%, sinusitis in 4.1%, pneumonia in 3.7%, and keratitis in 3.3% of the patients. Minor T-wave changes on electrocardiogram were observed in only 0.7% and jaundice in 0.4%. Elevated liver enzymes were found in 51% of the patients. Creatine kinase (CK) MM fraction was high in 44%. Traces of myoglobin were found in the urine of 14% of those with a high CK, and of the 13 patients with the higher CKs, 12 had an abnormal serum aldolase. We emphasize several points of interest in this large and unselected group of young adults. There was 1) possible evidence of rhabdomyolisis in some of our patients; 2) a lower rate of electrocardiogram abnormalities than previously reported; 3) no evident correlation between initial laboratory values and subsequent complications; and 4) lack of a clinical or laboratory difference between patients who had been vaccinated with an attenuated virus during childhood and those who had not.

Measles (rubeola) infection in a hospital setting

Although acquisition of measles infection in medical facilities is well documented, hospital outbreaks have been rare. During a recent community measles epidemic, one patient and four employees of the Mary Hitchcock Memorial Hospital developed the disease. Two of the employees were born before 1956, the year recommended by the Centers for Disease Control as an appropriate cutoff year for routine measles vaccination. Screening of 456 hospital employees for measles immunity demonstrated a 5% incidence of susceptibility in 135 individuals born between 1950 and 1956. This experience demonstrates the significant potential for the spread of a community measles outbreak into the hospital setting. Because of the high transmissibility of this disease and its potentially serious consequences in hospitalized patients, we suggest that all hospital employees born after 1950 who have significant patient contact should have documented immunity against measles.

Prevalence of measles antibodies in hospital personnel

A community outbreak of measles prompted a serologic survey of personnel in a hospital serving that community. Two hundred sixty-six personnel, primarily physicians (129) and nurses (100), voluntarily participated. Serum specimens were initially tested by the immunofluorescent antibody and enzyme-linked immunosorbent assay (EIA) methods. Specimens with negative results by either test were further examined using the hemagglutination inhibition and plaque neutralization (PN) methods. If EIA and PN results were negative, an individual was considered susceptible. Only one of the 98 participants born during or after 1957 and none of the 168 participants born before 1957 were serosusceptible. The low rate of serosusceptibility, in contrast to previous studies of young adults, appears attributable to the sensitivity of the testing methods used. Based on our experience, institutions considering a measles serologic testing and immunization program should expect to identify very few serosusceptible personnel, even among those born during or after 1957.

Imported measles outbreak in a university

In 1981, a measles outbreak in an Arkansas university involved 16 students and four persons who were contacts of these students. The first two cases were in students who recently returned from Honduras. Of the 16 students with measles, 12 had significant gastrointestinal symptoms; five had elevated liver transaminase, and eight were hospitalized. Only two of the students were considered adequately immunized. A voluntary immunization clinic held on the university campus resulted in 67 per cent of 3,076 students being vaccinated.

Distribuição etária do sarampo e vacinação: considerações sobre alguns dados do município do Rio de Janeiro

São apresentados alguns dados sobre a distribuição etária dos casos notificados de sarampo no Município do Rio de Janeiro entre 1964 e 1982, observando-se a modificação ocorrida nesta distribuição entre o período pré-vacinação e o período pós-vacinação. Estes dados são comparados com dados de alguns outros países e é feita uma breve discussão sobre a influência da vacinação na epidemiologia do sarampo.

Viral exanthems

In this monograph I have tried to present several aspects of viral exanthematous diseases that allow for diagnosis. With a systematic approach to the diagnosis, the physician frequently can make a specific diagnosis and nearly always can assign illness to the correct category. Accurate diagnosis is useful because it prevents unnecessary therapy and apprehension in some patients, allows definitive therapy in others, and, most important, it is fun and scientifically rewarding for the physician.

A fourteen-year study to identify measles antigen in urine specimens by fluorescent-antibody methods

Between 1965 and 1979 inclusive, 426 morning urine specimens from 410 patients admitted to hospital with the provisional diagnosis of measles were tested for measles antigen by fluorescent-antibody methods. One hundred and forty-two specimens (33.3 per cent) were positive. Of 74 patients who were clinically assessed not to have measles, 6/77 specimens (7.8 per cent) gave false positive results, and 71/77 (92.2 per cent) gave true negative results. Three hundred and forty-nine urine specimens were tested from 336 patients clinically judged to have had measles and 136 of these specimens (39 per cent) were positive. The positive rate was highest in a small number of specimens taken before the rash and next highest at the onset of the rash. The positive rate then fell; it rose again near the end of the first week, but the further increased positive rate after that time was associated with very small numbers of specimens. Of 12 child contacts of measles, 5/12 (41.67 per cent) had positive urine specimens and one of them developed measles two days after sampling. None of the seven patients with negative urine specimens developed measles. Measles antigen was detected in urine sediment by fluorescent-antibody tests in 39 per cent of the patients with measles studied.

Serological survey: immunity to vaccine preventable diseases among detainees at a Juvenile Hall facility

Sera from 378 juveniles interned in a juvenile hall facility between February and March, 1978, were tested for antibody to polio viruses types 1, 2, and 3; diphtheria; tetanus; measles; and rubella. Only 57% of juveniles ages 11-18 years had neutralizing antibody greater than or equal to 1:8 to all three types of polio viruses. Juveniles most often lacked antibody to polio type 3. Over 92% of juveniles tested had a protective level of antitoxin (greater than or equal to .01 U/ml) to diphtheria and tetanus. Hemagglutination inhibition (HAI) antibody tests performed for measles and rubella revealed 87.5% and 81% with titers greater than or equal to 1:8 respectively. No major differences in immune status were found between those with a previously documented vaccination history and those without. Based on these data a uniform immunization policy was adopted for Los Angeles County's Juvenile Hall facilities.

Measles pneumonia in young adults. An analysis of 106 cases

Measles occurred in 3,220 Air Force recruits between January 1976 and July 1979 and was complicated by pneumonia in 106 cases (3.3 percent). Although no deaths occurred, the illness was characterized as clinically severe with high fever and prolonged hospitalization (mean, 14.5 days). Bacterial superinfection as documented by transtracheal aspiration occurred in 35 cases (30.3 percent) and was caused by Hemophilus influenzae (18), Hemophilus parainfluenzae (two), Neisseria meningitidis (nine), Streptococcus pneumoniae (three), Streptococcus pyogenes (two) and Moraxella kingae (one). Clinical evidence of bronchospasm was present in 18 patients (17 percent) and required bronchodilators in six. Other complications included liver function abnormalities (31 percent), otitis media (29 percent) and sinusitis (25 percent). Measles pneumonia in adolescents is clinically severe with a generally benign outcome.

Nosocomial viral infections: III. Guidelines for prevention and control of exanthematous viruses, gastroenteritis viruses, picornaviruses, and uncommonly seen viruses

This communication is the third in a four-part series on nosocomial viral infections from the Strong Memorial Hospital. This third article discusses guidelines for prevention and control of exanthematous viruses, gastroenteritis, viruses, adenoviruses and the picornaviruses other than rhinoviruses. Several uncommonly seen viruses, such as the virus of Creutzfeldt-Jakob disease and Marburg, Ebola, and Lassa fever viruses, also are reviewed briefly.

The 'new' epidemiology of measles and rubella

Both diseases have been effectively controlled in the pediatric population that, in the prevaccine era, harbored them. However, with the shift in prevalence to adolescents and young adults, it is possible the diseases may be "time bombs."