Improved diagnostic and multiplex RT-qPCR for detecting rubella viral RNA

An examination of the nucleic acid sequence alignment of 48 full-length rubella virus genomes revealed that the 5' terminus of the genome is more conserved than the commonly used detection windows for rubella virus RNA located in the E1 protein coding region, suggesting that the 5' terminus could be a target for improving detection of all rubella virus genotypes. Two candidate primer sets were tested and the window between nucleotides (nts) 98 and 251 was found to have the greatest analytical sensitivity for detection of different genotypes. The new method had a limit of detection of four copies of rubella RNA per reaction with high specificity. The average coefficient variation of Ct was 2.2%. Concordance between the new method and currently used method, based on testing 251 clinical specimens collected from a rubella outbreak, was 99.4%. The assay was further improved upon by the incorporation of detection of both rubella virus RNA and mRNA from a cellular reference gene in a multiplex format. The multiplex format did not reduce the sensitivity or the reproducibility of rubella RNA detection and, of 60 specimens tested, the concordance between the single target and multiplex assays was 85.0%. To assess the utility of the multiplex assay for molecular surveillance, 62 rubella IgM positive serum samples from a rubella outbreak were tested, and eleven tested positive using the multiplex method while none were positive using the method targeting E1. These results show that the assay based on the new detection window near the 5' terminus of the genome can improve the detection of rubella virus for the purpose of molecular surveillance and case confirmation, with the added benefit of improved efficiency due to multiplexing.

Association of Persistent Rubella Virus With Idiopathic Skin Granulomas in Clinically Immunocompetent Adults

Importance

Vaccine-derived and wild-type rubella virus (RuV) has been identified within granulomas in patients with inborn errors of immunity, but has not been described in granulomas of healthy adults.

Objective

To determine the association between RuV and atypical granulomatous inflammation in immune-competent adults.

Design, Setting, and Participants

This case series, conducted in US academic dermatology clinics from January 2019 to January 2021, investigated the presence of RuV in skin specimens using RuV immunofluorescent staining of paraffin-embedded tissue sections, real-time reverse-transcription polymerase chain reaction, whole-genome sequencing with phylogenetic analyses, and cell culture by the US Centers for Disease Control and Prevention. Rubella immunoglobulin G, immunoglobulin M enzyme-linked immunoassay, and viral neutralization assays were performed for the sera of immunocompetent individuals with treatment refractory cutaneous granulomas and histopathology demonstrating atypical palisaded and necrotizing granulomas. Clinical immune evaluation was performed.

Main Outcomes and Measures

Identification, genotyping, and culture of vaccine-derived and wild-type RuV within granulomatous dermatitis of otherwise clinically immune competent adults.

Results

Of the 4 total immunocompetent participants, 3 (75%) were women, and the mean (range) age was 61.5 (49.0-73.0) years. The RuV capsid protein was detected by immunohistochemistry in cutaneous granulomas. The presence of RuV RNA was confirmed by real-time reverse-transcription polymerase chain reaction in fresh-frozen skin biopsies and whole-genome sequencing. Phylogenetic analysis of the RuV sequences showed vaccine-derived RuV in 3 cases and wild-type RuV in 1. Live RuV was recovered from the affected skin in 2 participants. Immunology workup results demonstrated no primary immune deficiencies.

Conclusions and Relevance

The case series study results suggest that RuV (vaccine derived and wild type) can persist for years in cutaneous granulomas in clinically immunocompetent adults and is associated with atypical (palisaded and necrotizing type) chronic cutaneous granulomas. These findings represent a potential paradigm shift in the evaluation, workup, and management of atypical granulomatous dermatitis and raises questions regarding the potential transmissibility of persistent live RuV.

Rubella Virus Infected Macrophages and Neutrophils Define Patterns of Granulomatous Inflammation in Inborn and Acquired Errors of Immunity

Rubella virus (RuV) has recently been found in association with granulomatous inflammation of the skin and several internal organs in patients with inborn errors of immunity (IEI). The cellular tropism and molecular mechanisms of RuV persistence and pathogenesis in select immunocompromised hosts are not clear. We provide clinical, immunological, virological, and histological data on a cohort of 28 patients with a broad spectrum of IEI and RuV-associated granulomas in skin and nine extracutaneous tissues to further delineate this relationship. Combined immunodeficiency was the most frequent diagnosis (67.8%) among patients. Patients with previously undocumented conditions, i.e., humoral immunodeficiencies, a secondary immunodeficiency, and a defect of innate immunity were identified as being susceptible to RuV-associated granulomas. Hematopoietic cell transplantation was the most successful treatment in this case series resulting in granuloma resolution; steroids, and TNF-α and IL-1R inhibitors were moderately effective. In addition to M2 macrophages, neutrophils were identified by immunohistochemical analysis as a novel cell type infected with RuV. Four patterns of RuV-associated granulomatous inflammation were classified based on the structural organization of granulomas and identity and location of cell types harboring RuV antigen. Identification of conditions that increase susceptibility to RuV-associated granulomas combined with structural characterization of the granulomas may lead to a better understanding of the pathogenesis of RuV-associated granulomas and discover new targets for therapeutic interventions.

Granulomatous Dermatitis Associated With Rubella Virus Infection in an Adult With Immunodeficiency

Importance

Immunodeficiency-related, vaccine-derived rubella virus (RuV) as an antigenic trigger of cutaneous and visceral granulomas is a rare, recently described phenomenon in children and young adults treated with immunosuppressant agents.

Objective

To perform a comprehensive clinical, histologic, immunologic, molecular, and genomic evaluation to elucidate the potential cause of an adult patient's atypical cutaneous granulomas.

Design, Setting, and Participants

A prospective evaluation of skin biopsies, nasopharyngeal swabs, and serum samples submitted to the Centers for Disease Control and Prevention was conducted to assess for RuV using real-time reverse-transcriptase polymerase chain reaction (RT-PCR) and viral genomic sequencing. The samples were obtained from a man in his 70s with extensive cutaneous granulomas mimicking both cutaneous sarcoidosis (clinically) and CD8+ granulomatous cutaneous T-cell lymphoma (histopathologically). The study was conducted from September 2019 to February 2021.

Main Outcomes and Measures

Identification and genotyping of a novel immunodeficiency-related RuV-associated granulomatous dermatitis.

Results

Immunohistochemistry for RuV capsid protein and RT-PCR testing for RuV RNA revealed RuV in 4 discrete skin biopsies from different body sites. In addition, RuV RNA was detected in the patient's nasopharyngeal swabs by RT-PCR. The full viral genome was sequenced from the patient's skin biopsy (RVs/Philadelphia.PA.USA/46.19/GR, GenBank Accession #MT249313). The patient was ultimately diagnosed with a novel RuV-associated granulomatous dermatitis.

Conclusions and Relevance

The findings of this study suggest that clinicians and pathologists may consider RuV-associated granulomatous dermatitis during evaluation of a patient because it might have implications for the diagnosis of cutaneous sarcoidosis, with RuV serving as a potential antigenic trigger, and for the diagnosis of granulomatous cutaneous T-cell lymphoma, with histopathologic features that may prompt an evaluation for immunodeficiency and/or RuV.

Descriptive epidemiology of rubella disease and associated virus strains in Uganda

Rubella virus causes a mild disease; however, infection during the first trimester of pregnancy may lead to congenital rubella syndrome (CRS) in over 80% of affected pregnancies. Vaccination is recommended and has been shown to effectively reduce CRS incidence. Uganda plans to introduce routine rubella vaccination in 2019. The World Health Organization recommends assessing the disease burden and obtaining the baseline molecular virological data before vaccine introduction. Sera collected during case-based measles surveillance from January 2005 to July 2018 were tested for rubella immunoglobulin M (IgM) antibodies. Sera from confirmed rubella outbreaks from January 2012 to August 2017 were screened using real-time reverse-transcription polymerase chain reaction (RT-PCR); for positive samples, a region within the E1 glycoprotein coding region was amplified and sequenced. Of the 23 196 suspected measles cases serologically tested in parallel for measles and rubella, 5334 (23%) were rubella IgM-positive of which 2710 (50.8%) cases were females with 2609 (96.3%) below 15 years of age. Rubella IgM-positive cases were distributed throughout the country and the highest number was detected in April, August, and November. Eighteen (18%) of the 100 sera screened were real-time RT-PCR-positive of which eight (44.4%) were successfully sequenced and genotypes 1G and 2B were identified. This study reports on the seroprevalence and molecular epidemiology of rubella. Increased knowledge of former and current rubella viruses circulating in Uganda will enhance efforts to monitor the impact of vaccination as Uganda moves toward control and elimination of rubella and CRS.

Seroprevalence of rubella virus antibodies among pregnant women in the Center and South-West regions of Cameroon

Rubella infection in early pregnancy can lead to miscarriages, fetal death, or birth of an infant with congenital rubella syndrome (CRS). In Cameroon, like in many developing countries, rubella surveillance is not well-established. The aim of this study was to determine the prevalence of rubella virus specific antibodies among pregnant Cameroonians. We conducted a cross-sectional study for rubella infection among pregnant women attending antenatal clinics in the Center and South-West regions of Cameroon. Demographic data and blood were collected and tested for rubella specific antibodies (IgG and IgM), and for the IgM positive cases, IgG avidity and real time PCR was done. From December 2015 to July 2017, 522 serum samples were collected and tested from pregnant women. The seroprevalence of rubella specific IgG was 94.4%, presumably due to immunity induced by wild-type rubella virus. The seroprevalence of rubella specific IgM was 5.0%, possibly indicating rubella infection. However, IgG avidity testing of the IgM positive cases detected high avidity IgGs, ranging from 52.37% to 87.70%, indicating past rubella infection. 5.6% (29/522) of the participants had negative results for IgG to rubella virus, indicating susceptibility to rubella infection. None of the participants had received a rubella containing vaccine (RCV), but 51% (266/522) of the pregnant women lived in a house with a child with records of at least one dose of RCV. Rubella virus RNA was not detected in the urine of any IgM positive case. Findings from this study show that rubella infection is significant in Cameroon. Some pregnant women are still susceptible to rubella infection. For a better management of rubella infection in pregnancy in Cameroon, consideration should be taken to investigate for IgG-avidity test in cases with positive rubella IgM result to distinguish between recent from past rubella infection.

Infectious vaccine-derived rubella viruses emerge, persist, and evolve in cutaneous granulomas of children with primary immunodeficiencies

Rubella viruses (RV) have been found in an association with granulomas in children with primary immune deficiencies (PID). Here, we report the recovery and characterization of infectious immunodeficiency-related vaccine-derived rubella viruses (iVDRV) from diagnostic skin biopsies of four patients. Sequence evolution within PID hosts was studied by comparison of the complete genomic sequences of the iVDRVs with the genome of the vaccine virus RA27/3. The degree of divergence of each iVDRV correlated with the duration of persistence indicating continuous intrahost evolution. The evolution rates for synonymous and nonsynonymous substitutions were estimated to be 5.7 x 10-3 subs/site/year and 8.9 x 10-4 subs/site/year, respectively. Mutational spectra and signatures indicated a major role for APOBEC cytidine deaminases and a secondary role for ADAR adenosine deaminases in generating diversity of iVDRVs. The distributions of mutations across the genes and 3D hotspots for amino acid substitutions in the E1 glycoprotein identified regions that may be under positive selective pressure. Quasispecies diversity was higher in granulomas than in recovered infectious iVDRVs. Growth properties of iVDRVs were assessed in WI-38 fibroblast cultures. None of the iVDRV isolates showed complete reversion to wild type phenotype but the replicative and persistence characteristics of iVDRVs were different from those of the RA27/3 vaccine strain, making predictions of iVDRV transmissibility and teratogenicity difficult. However, detection of iVDRV RNA in nasopharyngeal specimen and poor neutralization of some iVDRV strains by sera from vaccinated persons suggests possible public health risks associated with iVDRV carriers. Detection of IgM antibody to RV in sera of two out of three patients may be a marker of virus persistence, potentially useful for identifying patients with iVDRV before development of lesions. Studies of the evolutionary dynamics of iVDRV during persistence will contribute to development of infection control strategies and antiviral therapies.

First report of the genomic characterization of rubella viruses circulating in Cameroon

Rubella is an acute and contagious viral infection whose gravidity resides in infection during pregnancy, which can result in miscarriage, fetal death, stillbirth, or infants with congenital malformations. This study aimed to describe the genome of rubella viruses (RUBVs) circulating in Cameroon. Throat swabs were collected from health districts as part of the measles surveillance program from 2010 to 2016 and sent to the Centre Pasteur of Cameroon. Samples were amplified by genotyping reverse transcription polymerase chain reaction (RT-PCR) in the search of two overlapping fragments of the gene that encodes the E1 envelope glycoprotein of RUBV. PCR products were sequenced and phylogenetic analysis was performed with MEGA 6 software. Overall, 9 of 43 samples (20.93%) were successfully amplified and sequenced but only eight sequences could be exploited for phylogenetic analysis with respect to the required fragment length of 739 nucleotides. Analysis of viral sequences from Cameroon with other epidemiologically relevant sequences from around the world showed that all RUBVs belonged to lineage L1 of genotype 1G. Cameroon sequences clustered with viruses from West Africa including Nigeria, Ivory Coast, and Ghana with a percentage similarity of 95.4% to 99.2%. This study will enable an update on the molecular epidemiology of RUBV in Cameroon and help in monitoring circulating RUBV for a better implementation of elimination strategies.

Rubella Surveillance and Diagnostic Testing among a Low-Prevalence Population, New York City, 2012-2013

The New York City Department of Health and Mental Hygiene (DOHMH) receives clinical and laboratory reports for rubella. Because rubella immunoglobulin M (IgM) assays may produce false-positive results and rubella infections may be asymptomatic, interpretation of positive IgM results can be challenging. Rubella reports received by DOHMH in 2012 to 2013 were reviewed. The rubella IgM testing purpose was determined through case investigation. Results of IgM testing by indirect enzyme-linked immunosorbent assay (ELISA) and capture enzyme immunoassay (EIA) were compared to determine positive predictive value (PPV) and specificity. DOHMH received 199 rubella reports; 2 were true cases. Of all reports, 77.9% were tested for rubella IgM erroneously, 19.6% were tested for diagnostic purposes, 2.0% had unknown test purpose, and 0.5% were not tested. PPV of indirect ELISA was 6% overall, 14% for diagnostic tests, and 0% for tests ordered erroneously. PPV of capture EIA was 29% overall, 50% for diagnostic tests, and 0% for tests ordered erroneously. Overall, specificity was 52% for indirect ELISA and 85% for capture EIA. Limiting rubella IgM testing to patients for whom rubella diagnosis is suspected and using a more specific IgM assay have the potential to reduce false-positive rubella IgM results.

Epidemiological and molecular investigation of a rubella outbreak, Romania, 2011 to 2012

We describe a rubella outbreak that occurred in Romania between September 2011 and December 2012. During this period 24,627 rubella cases, 41.1% (n=10,134) of which female, were notified based on clinical criteria, and a total of 6,182 individuals were found serologically positive for IgM-specific rubella antibody. The median age of notified cases was 18 years (range: <1-65) and the most affected age group 15 to 19 years (n=16,245 cases). Of all notified cases, 24,067 cases (97.7%) reported no history of vaccination. Phylogenetic analysis of 19 sequences (739 nucleotides each), from 10 districts of the country revealed that the outbreak was caused by two distinct rubella virus strains of genotype 2B, which co-circulated with both temporal and geographical overlap. In addition to the 6,182 IgM-positive rubella cases, 28 cases of congenital rubella syndrome (CRS) were identified, including 11 neonatal deaths and one stillbirth. The outbreak underscores the need to encourage higher vaccination uptake in the population, particularly in women of reproductive age, and to strengthen epidemiological and laboratory investigations of suspected rubella cases. Genetic characterisation of wild-type rubella virus is an essential component to enhance surveillance and here we report rubella virus sequences from Romania.

Genetic diversity of currently circulating rubella viruses: a need to define more precise viral groups

Recent studies have shown that the currently circulating rubella viruses are mostly members of two genotypes, 1E and 2B. Also, genetically distinct viruses of genotype 1G have been found in East and West Africa. This study used a Mantel test to objectively include both genetic diversity and geographic location in the definition of lineages, and identified statistically justified lineages (n=13) and sub-lineages (n=9) of viruses within genotypes 1G, 1E and 2B. Genotype 2B viruses were widely distributed, while viruses of genotype 1E as well as 1G and 1J were much more geographically restricted. This analysis showed that more precise groupings for rubella viruses are possible, which should improve the ability to track rubella viruses worldwide. A year-by-year analysis revealed gaps in surveillance that need to be resolved in order to support the surveillance needed for enhanced control and elimination goals for rubella.

Genotypes of rubella virus and the epidemiology of rubella infections in the Democratic Republic of the Congo, 2004-2013

Rubella is a viral infection that may cause fetal death or congenital defects, known as congenital rubella syndrome (CRS), during early pregnancy. The World Health Organization (WHO) recommends that countries assess the burden of rubella and CRS, including the determination of genotypes of circulating viruses. The goal of this study was to identify the genotypes of rubella viruses in the Democratic Republic of the Congo (DRC). Serum or throat swab samples were collected through the measles surveillance system. Sera that tested negative for measles IgM antibody were tested for rubella IgM antibody. Serum collected within 4 days of rash onset and throat swabs were screened by real-time RT-PCR for rubella virus RNA. For positive samples, an amplicon of the E1 glycoprotein gene was amplified by RT-PCR and sequenced. 11733 sera were tested for rubella IgM and 2816 (24%) were positive; 145 (5%) were tested for the presence of rubella RNA by real-time RT-PCR and 10 (7%) were positive. Seventeen throat swabs were analyzed by RT-PCR and three were positive. Sequences were obtained from eight of the positive samples. Phylogenetic analysis showed that the DRC rubella viruses belonged to genotypes 1B, 1E, 1G, and 2B. This report provides the first information on the genotypes of rubella virus circulating in the DRC. These data contribute to a better understanding of rubella burden and the dynamics of rubella virus circulation in Africa. Efforts to establish rubella surveillance in the DRC are needed to support rubella elimination in Africa. J. Med. Virol. 88:1677-1684, 2016. © 2016 Wiley Periodicals, Inc.

Genomic analysis of the Chinese genotype 1F rubella virus that disappeared after 2002 in China

Genotype 1F was likely localized geographically to China as it has not been reported elsewhere. In this study, whole genome sequences of two rubella 1F virus isolates were completed. Both viruses contained 9,761 nt with a single nucleotide deletion in the intergenic region, compared to the NCBI rubella reference sequence (NC 001545). No evidence of recombination was found between 1F and other rubella viruses. The genetic distance between 1F viruses and 10 other rubella virus genotypes (1a, 1B, 1C, 1D, 1E, 1G, 1J 2A, 2B, and 2C) ranged from 3.9% to 8.6% by pairwise comparison. A region known to be hypervariable in other rubella genotypes was also the most variable region in the 1F genomes. Comparisons to all available rubella virus sequences from GenBank identified 22 nucleotide variations exclusively in 1F viruses. Among these unique variations, C9306U is located within the recommended molecular window for rubella virus genotyping assignment, could be useful to confirm 1F viruses. Using the Bayesian Markov Chain Monte Carlo (MCMC) method, the time of the most recent common ancestor for the genotype 1F was estimated between 1976 and 1995. Recent rubella molecular surveillance suggests that this indigenous strain may have circulated for less than three decades, as it has not been detected since 2002.

Phylogenetic analysis of rubella viruses identified in Uganda, 2003-2012

Molecular data on rubella viruses are limited in Uganda despite the importance of congenital rubella syndrome (CRS). Routine rubella vaccination, while not administered currently in Uganda, is expected to begin by 2015. The World Health Organization recommends that countries without rubella vaccination programs assess the burden of rubella and CRS before starting a routine vaccination program. Uganda is already involved in integrated case-based surveillance, including laboratory testing to confirm measles and rubella, but molecular epidemiologic aspects of rubella circulation have so far not been documented in Uganda. Twenty throat swab or oral fluid samples collected from 12 districts during routine rash and fever surveillance between 2003 and 2012 were identified as rubella virus RNA positive and PCR products encompassing the region used for genotyping were sequenced. Phylogenetic analysis of the 20 sequences identified 19 genotype 1G viruses and 1 genotype 1E virus. Genotype-specific trees showed that the Uganda viruses belonged to specific clusters for both genotypes 1G and 1E and grouped with similar sequences from neighboring countries. Genotype 1G was predominant in Uganda. More epidemiological and molecular epidemiological data are required to determine if genotype 1E is also endemic in Uganda. The information obtained in this study will assist the immunization program in monitoring changes in circulating genotypes.

Analysis of whole genome sequences of 16 strains of rubella virus from the United States, 1961-2009

Rubella virus is the causative agent of rubella, a mild rash illness, and a potent teratogenic agent when contracted by a pregnant woman. Global rubella control programs target the reduction and elimination of congenital rubella syndrome. Phylogenetic analysis of partial sequences of rubella viruses has contributed to virus surveillance efforts and played an important role in demonstrating that indigenous rubella viruses have been eliminated in the United States. Sixteen wild-type rubella viruses were chosen for whole genome sequencing. All 16 viruses were collected in the United States from 1961 to 2009 and are from 8 of the 13 known rubella genotypes. Phylogenetic analysis of 30 whole genome sequences produced a maximum likelihood tree giving high bootstrap values for all genotypes except provisional genotype 1a. Comparison of the 16 new complete sequences and 14 previously sequenced wild-type viruses found regions with clusters of variable amino acids. The 5' 250 nucleotides of the genome are more conserved than any other part of the genome. Genotype specific deletions in the untranslated region between the non-structural and structural open reading frames were observed for genotypes 2B and genotype 1G. No evidence was seen for recombination events among the 30 viruses. The analysis presented here is consistent with previous reports on the genetic characterization of rubella virus genomes. Conserved and variable regions were identified and additional evidence for genotype specific nucleotide deletions in the intergenic region was found. Phylogenetic analysis confirmed genotype groupings originally based on structural protein coding region sequences, which provides support for the WHO nomenclature for genetic characterization of wild-type rubella viruses.

Rubella contact tracing associated with air travel

This report reviews U.S. guidelines for the identification of persons exposed to rubella during air travel. In response to an individual with rubella who traveled on multiple flights, CDC conducted an airline contact investigation that was expanded beyond customary protocol to assess if current operating procedures are adequate. Of 250 potentially exposed airline passengers, 215 (86%) were contacted and none developed a rubella-like rash, arguing against the need to notify passengers beyond the standard protocol in most cases.

Evidence used to support the achievement and maintenance of elimination of rubella and congenital rubella syndrome in the United States

On 29 October 2004, an expert panel was convened to review the status of elimination of rubella and congenital rubella syndrome (CRS) in the United States. Primarily based on 5 types of information presented--epidemiology of reported cases, molecular epidemiology, seroprevalence, vaccine coverage, and adequacy of surveillance--the panel unanimously agreed that rubella virus is no longer endemic in the United States. Since 2004, new data continue to support the conclusion that elimination has been achieved and maintained. In documenting elimination in the United States, each of the 5 types of data provided evidence for elimination and collectively provided much stronger evidence than any one type could individually. As countries document the elimination of rubella and CRS, many sources and types of data will likely be necessary. Rigorous data evaluation must be conducted to look for inconsistencies among the available data. To maintain elimination, countries should maintain high vaccine coverage, adequate surveillance, and rapid response to outbreaks.

Dried blood spots versus sera for detection of rubella virus-specific immunoglobulin M (IgM) and IgG in samples collected during a rubella outbreak in Peru

Most persons with rubella virus-specific immunoglobulin M (IgM)- or IgG-positive sera tested positive (98% [n = 178] and 99% [n = 221], respectively) using paired filter paper dried blood spot (DBS) samples, provided that DBS indeterminate results were called positive. For persons with IgM- or IgG-negative sera, 97% and 98%, respectively, were negative using DBS.

Genetic analysis of rubella viruses found in the United States between 1966 and 2004: evidence that indigenous rubella viruses have been eliminated

Wild-type rubella viruses are genetically classified into 2 clades and 10 intraclade genotypes, of which 3 are provisional. The genotypes of 118 viruses from the United States were determined by sequencing part of the E1 coding region of these viruses and comparing the resulting sequences with reference sequences for each genotype, using the Bayesian inference program MRBAYES. Three genotypes of rubella viruses were found in the United States too infrequently to be considered for indigenous transmission. A fourth genotype was found frequently until 1981, and a fifth genotype was found frequently until 1988, but neither was obtained from nonimported cases after 1988. A sixth genotype was found frequently during 1996-2000, likely because of multiple importations from neighboring countries. The results of the present genetic analysis of rubella viruses found in the United States are consistent with elimination of indigenous viruses by 2001, the year when rubella was considered to be eliminated on the basis of epidemiological evidence.

The epidemiological profile of rubella and congenital rubella syndrome in the United States, 1998-2004: the evidence for absence of endemic transmission

In 1969, the United States established its national rubella vaccination program. With the success of the program, 32 years later, reports of rubella reached record low numbers. To assess the achievement of elimination of rubella and congenital rubella syndrome (CRS) in the United States, 7 epidemiological criteria were used. Rubella cases reported to the National Notifiable Diseases Surveillance System from 1998 through 2004 and CRS cases reported to the National Congenital Rubella Syndrome Registry from 1998 through 2004 were analyzed. During 1998-2000, the median number of reported rubella cases was 272, whereas, during 2001-2004, the median number reported was 13. The incidence of rubella decreased significantly, from 0.1/100,000 population in 1998 to 0.005/100,000 population in 2004. Since 2001, 5 infants with CRS have been reported--3 were born in 2001, 1 was born in 2003, and 1 was born in 2004. The epidemiological evidence strongly supports the claim that rubella is no longer endemic in the United States. To prevent future rubella outbreaks and CRS cases, current strategies must be maintained.

The changing epidemiology of rubella in the 1990s: on the verge of elimination and new challenges for control and prevention

CONTEXT

In 1989, the United States established a goal to eliminate indigenous rubella and congenital rubella syndrome (CRS) by 2000. Reported rubella cases are at record low levels; however, cases and outbreaks have occurred, primarily among unvaccinated foreign-born adults.

OBJECTIVE

To evaluate the current epidemiology of rubella and CRS and assess progress toward elimination.

DESIGN, SETTING, AND SUBJECTS

Analysis of rubella cases reported to the National Notifiable Diseases Surveillance System from 1990 through 1999 and CRS cases reported to the National Congenital Rubella Syndrome Registry from 1990 through 1999. Since 1996, US and international viral isolates have been sequenced.

MAIN OUTCOME MEASURES

Incidence and characteristics of rubella and CRS cases; molecular typing of virus isolates.

RESULTS

Annually from 1990 through 1999, the median number of reported rubella cases was 232 (range, 128-1412), and between 1992 and 1999, fewer than 300 rubella cases were reported annually, except in 1998. During the 1990s, the incidence of rubella in children younger than 15 years decreased (0.63 vs 0.06 per 100 000 in 1990 vs 1999), whereas the incidence in adults aged 15 to 44 years increased (0.13 vs 0.24 per 100 000). In 1992, incidence among Hispanics was 0.06 per 100 000 and increased to a high in 1998 of 0.97 per 100 000. From 1997 through 1999, 20 (83%) of 24 CRS infants were born to Hispanic mothers, and 21 (91%) of 23 CRS infants were born to foreign-born mothers. Molecular typing identified 3 statistically distinct genotypic groups. In group 1, the close relatedness of viruses suggests that a single imported source seeded an outbreak that did not spread beyond the Northeast. Similarly, within groups 2 and 3, relatedness of viruses obtained from clusters of cases suggests that single imported sources seeded each one. Diversity of viruses found in 1 state is consistent with the conclusion that several viruses were imported. Moreover, the similarity of viruses found across the country, combined with a lack of epidemiologic evidence of endemic transmission, support the conclusion that some viruses that are common abroad, particularly in Latin America and the Caribbean, were introduced into the United States on several separate occasions.

CONCLUSIONS

The epidemiology of rubella and CRS has changed significantly in the last decade. These changes and molecular typing suggest that the United States is on the verge of elimination of the disease. To prevent future rubella outbreaks and CRS, current strategies must be enhanced and new strategies developed.

Gene therapy of cancer

OBJECTIVE

To provide a review of the basic concepts and terminology of human genetics, the clinical application and risks of gene therapy, and ethical and societal issues.

DATA SOURCES

Review articles, research studies, and book chapters related to genetics and human gene therapy.

CONCLUSIONS

The genetic changes that play a role in the development of cancer have begun to be elucidated, and these discoveries have led to strategies to destroy cancers by correcting genetic defects or manipulating genes to induce tumoricidal activities. Gene therapy is a novel investigational intervention that is constantly evolving.

IMPLICATIONS FOR NURSING PRACTICE

Oncology nurses will need an increased understanding of cellular biology, genetics, and genetics engineering. Major considerations for nursing practice include patient and family education, informed consent, side effects, and ethical and societal issues.