Diagnostic Yield of Laboratory Methods and Value of Viral Genotyping during an Outbreak of Mumps in a Partially Vaccinated Population in British Columbia, Canada.

Mumps remains endemic in North America despite routine use of the measles, mumps, and rubella (MMR) vaccine. In 2016, an outbreak of mumps in British Columbia, Canada, provided an opportunity to determine the diagnostic utility of laboratory testing methods. Specimens from patients with clinical mumps were tested for infection using a commercial enzyme-linked immunosorbent assay (ELISA) for antibody detection and an in-house reverse transcriptase PCR (RT-PCR) targeting viral fusion and small hydrophobic (SH) genes. Viral genotyping was performed by SH gene sequencing. Laboratory data was linked with epidemiologic case data. Of the 139 confirmed cases, 94 (68%) had reported or documented history of MMR vaccination. Specimens were typically collected 1 day (for buccal and IgM tests) or 2 days (for urine tests) after symptom onset. Most confirmed cases (69%) were confirmed by buccal swab RT-PCR. Among cases tested by multiple methods, the percent positivity for buccal swab RT-PCR was 90% (96/107) compared to 43% (30/69) for both IgM ELISA and urine RT-PCR. Mumps IgM detection was higher in confirmed cases with no history of vaccination than in those with history (64% versus 34%, P = 0.02). The outbreak strain was identified as genotype G related to MuVi/Sheffield.GBR/1.05 but with conserved variations in five nucleotides within the SH gene that allowed linkage of geographically distinct cases. In conclusion, RT-PCR of buccal specimens had the highest diagnostic yield during a mumps outbreak in a partially vaccinated population. To optimize mumps diagnostic potential, clinicians should collect specimens depending on when the patient presents for care and their immunization history.

Travellers returning with measles from Thailand to Finland, April 2012: infection control measures.

Countries with no autochthonous measles run the risk of the virus being imported by travellers and transmitted to unprotected citizens. In April 2012, two travellers from Finland and one from Estonia were diagnosed with measles after returning from Phuket, Thailand. They were contagious on their return flights and subsequently exposed several individuals, prompting extensive infection control measures. Two secondary cases were detected: one child who had received one vaccine dose and another who was fully vaccinated.

Safety of measles-mumps-rubella vaccine (MMR) in patients allergic to eggs.

INTRODUCTION: Since the measles and mumps components used in MMR vaccine are grown in cultures of fibroblast from chick embryos, for a long time there have been concerns about the presence of egg protein in the vaccine and the recommendations given to egg allergic patients. We include in this paper our clinical experience vaccinating egg allergic patients with a regular triple viral vaccine, as well as an immunological study of each vaccine available in Spain. The aim of this study was to evaluate the clinical safety of a conventional MMR vaccine in a population of egg allergic patients and to determine the presence of egg allergens in a conventional MMR vaccine and if IgE antibodies from egg allergic can recognize egg allergens in this vaccine. MATERIALS AND METHODS: Children 15 months old with a confirmed diagnosed of egg allergy were included. In all patients, a skin prick test with non diluted MMR vaccine (Priorix, GSK) was made. If negative, each patient received a single dose of measles, mumps, rubella (MMR) vaccine. If positive, a fractionated injection of the vaccine was made following SEICAP recommendations (2004). SDS-PAGE immunoblotting was performed with Priorix vaccine. RESULTS: A cumulative total of 26 patients with egg allergy have safely received MMR vaccine in a single-dose (after a negative SPT in all cases) at our department without any reaction. 5 sera of vaccinated patients and 6 control sera of egg allergic patients (positive oral challenge) were used to immunolabel the membranes. No positive bands corresponding to egg proteins were found in any of the patients. CONCLUSION: Negative results found in SPT support the absence of clinical reaction against the components and Immunological studies point that there is no detectable amount of egg protein in this vaccine to produce an IgE mediated reaction. We can conclude that MMR can be safely administrated in children allergic to egg.

Detection of measles vaccine in the throat of a vaccinated child.

Measles vaccine is widely used, most often in association with mumps and rubella vaccines. We report here the case of a child presenting with fever 8 days after vaccination with a measles-mumps-rubella vaccine. Measles virus was isolated in a throat swab taken 4 days after fever onset. This virus was then further genetically characterised as a vaccine-type virus. Fever occurring subsequent to measles vaccination is related to the replication of the live attenuated vaccine virus. In the case presented here, the vaccine virus was isolated in the throat, showing that subcutaneous injection of an attenuated measles strain can result in respiratory excretion of this virus.

Absence of chicken myelin basic protein residues in commercial formulations of MMR vaccine.

Several preparations of MMR vaccines and their progenitor monovalent vaccine bulks produced by two different manufacturers were examined serologically for the presence of chicken myelin basic protein (MBP) residues. The products were challenged against several commercial preparations of anti-hMBP antisera that reacted positively with the control MBP preparations of human and chicken origins. There was no evidence of the presence of MBP components in MMR vaccines or their progenitor vaccine bulks as shown by the reactivity profiles of the antibody preparations against control and test antigens.