Concurrent detection of human herpesvirus type 6 and measles-specific IgMs during acute exanthematic human parvovirus B19 infection

Measles and Rubella Diagnostic and Classification Challenges in Near- and Post-Elimination Countries

Measles and rubella are vaccine-preventable viral diseases and can be prevented by safe, highly effective vaccination with measles- and rubella-containing vaccines. Given the myriad causes of febrile exanthems, laboratory surveillance for both measles and rubella is important to document the incidence of these diseases and to track the progress and maintenance of elimination in near- and post-elimination settings. Diagnostic challenges can hinder effective surveillance and classification challenges can hinder efforts to demonstrate achievement or maintenance of elimination. In this report, we review diagnostic and classification challenges for measles and rubella in near- and post-elimination settings.

Detection of measles vaccine virus and measles-specific immunoglobulin M in children vaccinated against measles-mumps-rubella during measles outbreak

Information regarding the detection perioid of measles vaccine virus (MeVV) RNA in human nasopharyngeal samples and measles-specific antibodies following measles-mumps-rubella (MMR) vaccination is limited. During contact tracing for a measles outbreak at a hospital in Republic of Korea, 4 out of 206 children vaccinated with MMR underwent real-time RT-PCR assay for measles and measles-specific antibodies test. Measles virus RNA was detected in 2 children, all of which was vaccine virus strain RNA (genotype A). In a healthy 27-month-old boy, MeVV RNA was detected 448 days after MMR vaccination. Measles-specific IgM was positive 1097 days following vaccination in a 4-year-old girl. MeVV RNA and measles-specific IgM were detected for a considerable period following primary MMR vaccination. Physicians should exercise caution when interpreting positive RT-PCR results for MeVV or measles-specific IgM from a child with measles-associated symptoms who has been recently vaccinated against measles.

When a viral eruption hides another one: intrafamilial outbreak of parvovirus B19 and measles virus co-infections: case report

Background

Despite high overall population vaccine coverage, identified clusters of persons refraining from vaccination interfere with pursued measles elimination. Clinical diagnosis of measles is often obvious due to its typical rash. Yet, febrile rashes may occur during many viral infections. Misdiagnosis of a specific primary viral infection may have severe consequences, particularly in immunocompromised subjects or pregnant women. To our knowledge, this case presentation is the first description of a measles and parvovirus B19 coinfection outbreak. Analysis of this outbreak underlines rash diagnosis difficulties and potential serology interpretation pitfalls. This case report is helpful for the clinicians in the context of measles re-emergence and proposes several methods to improve the diagnosis approach.

Case presentation

We investigated an outbreak of rash in 6 out of 8 Traveler family members presenting to Rennes University Hospital (West of France). Anti-B19V and measles IgM/IgG antibodies were measured and detection of Parvovirus B19 and measles virus genomes were done on blood and/or respiratory samples. Virological investigations finally documented 6 cases of parvovirus B19 infections, including 4 associated with measles. Interestingly, in the four coinfection cases, the rash was typical of B19V primary infection for the two children but typical of measles for the two adults. Clinical diagnosis of rash may be misleading and thorough virological investigations may be required to avoid misdiagnosis.

Conclusions

This investigation first reports an intra-familial outbreak of MeV/B19V coinfections highlighting the high transmissibility of both viruses and the diagnostic challenges of dual rash-associated infections. This report also underlines the potential deleterious consequences of failure to identify measles cases, especially in a community with low vaccination coverage.

The Detection and Characterization of Herpes Simplex Virus Type 1 in Confirmed Measles Cases

Based on measles surveillance in Shanghai, People's Republic of China, from 2006 to 2015, we found that measles virus isolates from 40 throat swab samples exhibited atypical cytopathic effects in Vero/hSLAM cells, which was found to be a result of coinfection with measles virus (MeV) and human herpes simplex virus type 1 (HSV-1). Serological and molecular approaches were used to confirm and characterize the coinfections in these patients. Among the 40 measles cases, measles-specific IgM was detected in 37 cases, while measles-specific IgG was detected in 27 cases. HSV-1-specific IgM and IgG were detected in 7 and 34 cases, respectively, suggesting that most of the MeV infections were primary, but that HSV-1 infection was due to the reactivation of latent virus in most cases. The titers of HSV-1 IgG in patients with either measles or measles-HSV-1 coinfection were significantly higher than those in the healthy group (P = 0.0026 and P < 0.0001, respectively); however, there was no significant difference in the titers of HSV-1 IgG in the MeV and MeV-HSV-1 coinfection patients (P = 0.105). Nucleic acids from MeV and HSV-1 were detected in 40 and 39 throat swabs, respectively. Twenty five MeV RNA sequences were genotyped, and all represented genotype H1, which is the endemic genotype in China. Sequences from the glycoprotein G gene of HSV-1 were used to classify the isolates into two distinct phylogenetic groups: 34 belonged to group A and 3 belonged to group B.

Immunoglobulin M for Acute Infection: True or False?

Immunoglobulin M (IgM) tests have clear clinical utility but also suffer disproportionately from false-positive results, which in turn can lead to misdiagnoses, inappropriate therapy, and premature closure of a diagnostic workup. Despite numerous reports in the literature, many clinicians and laboratorians remain unaware of this issue. In this brief review, a series of virology case examples is presented. However, a false-positive IgM can occur with any pathogen. Thus, when an accurate diagnosis is essential for therapy, prognosis, infection control, or public health, when the patient is sick enough to be hospitalized, or when the clinical or epidemiologic findings do not fit, IgM detection should not be accepted as a stand-alone test. Rather, whenever possible, the diagnosis should be confirmed by other means, including testing of serial samples and the application of additional test methods.

Performance of the Epstein-Barr virus and herpes simplex virus immunoglobulin m assays on the liaison platform with sera from patients displaying acute parvovirus B19 infection

Acute parvovirus B19 infection has been reported to cause false-positive results frequently in the Epstein-Barr (EBV) and herpes simplex virus (HSV) immunoglobulin M (IgM) assays from DiaSorin performed on the Liaison platform. We tested 65 sera from patients with a presumptive or conclusive diagnosis of acute parvovirus B19 infection in both assays and obtained no false-positive results in the EBV IgM test and 10.4% nonspecific reactivities in the HSV IgM assay. Our data support the specificity of both assays in this clinical setting.

Evaluation of an immunofiltration assay that detects immunoglobulin M antibodies against the ZEBRA protein for the diagnosis of Epstein-Barr virus infectious mononucleosis in immunocompetent patients

The performance of an immunofiltration assay (IMFA) that detects immunoglobulin M (IgM) antibodies to the Epstein-Barr virus (EBV) ZEBRA (BamHI Z EBV replication activator) protein was evaluated for the diagnosis of EBV infectious mononucleosis (IM) in immunocompetent patients. The test panel consisted of 47 sera displaying an EBV-specific antibody profile compatible with an acute primary EBV infection from patients with clinical and biological features of EBV IM, 20 sera from healthy individuals either with a past EBV infection or who were EBV seronegative, 20 sera displaying an equivocal EBV antibody pattern (viral capsid antigen IgG positive [VCA IgG+], VCA IgM+, and EBV nuclear antigen-1 IgG+), and 15 sera obtained from patients with a mononucleosis-like syndrome owing to cytomegalovirus, human herpesvirus 6, or parvovirus B19. Overall, the sensitivity and the specificity of the assay were found to be 92.5%, and 97.3%, respectively. The sensitivity of the assay for the diagnosis of heterophile antibody-negative EBV IM was 86.2%. The IMFA is rapid, easy to perform, and, thus, suitable for point-of-care testing, and it may be used as a first-line test for the diagnosis of acute EBV IM in immunocompetent patients.

Acute parvovirus B19 infection frequently causes false-positive results in Epstein-Barr virus- and herpes simplex virus-specific immunoglobulin M determinations done on the Liaison platform

During an outbreak of parvovirus B19 we collected serum samples from 68 nonpregnant patients in the region of Antwerp (Belgium). Fifty-seven (84%) of the parvovirus B19 immunoglobulin M (IgM)-positive sera had a positive result for Epstein-Barr virus (EBV) IgM by Liaison testing, 61 (90%) had a positive result for herpes simplex virus (HSV) IgM, 20 (29%) samples were positive for cytomegalovirus IgM, and 15 (22%) had a positive result for Borrelia burgdorferi sensu lato IgM. As assay interference was suspected, sera were further investigated by using additional infectious-disease serology tests and by performing various interference elimination procedures. We could show that the EBV IgM and HSV IgM results were false positives due to aspecific IgM reactions with the solid phase. All samples were also analyzed by a modified Liaison EBV IgM assay, based on the addition of polyvinylpyrrolidone and polyvinyl alcohol to the dilution buffer, which partially eliminated this type of assay interference. Although the Liaison is a very convenient, automated immunoassay platform, this study demonstrates the potential for improvement of mainly the EBV IgM and HSV IgM tests.