Measles, Mumps and Rubella & Vaccine for Viral Infections

• Measles, Mumps, and Rubella are important vaccine-preventable viral infections
• Measles is highly contagious with an R0 of 12-18, and it has a high inoculum and low infecting dose, making infection possible with brief exposure, especially in crowded and poorly ventilated environments
• Complications of measles include death, diarrhea, otitis media, pneumonia, and neurological complications like Measles Inclusion Body Encephalitis (MIBE), Acute Disseminated Encephalomyelitis (ADEM), and Subacute Sclerosing Panencephalitis (SSPE)
• Laboratory diagnosis of measles involves NAAT for measles RNA, serology testing for IgM on buccal swab, or a four-fold rise in IgG titre on serum samples from acute and convalescent phases of illness
• Transmission-based precautions for measles include airborne precautions in addition to standard precautions, requiring the use of FFP2/N95 respirator masks and isolation in an airborne infection isolation room
• Rubella typically starts its rash on the face and moves down the body, with a prodrome of low-grade fever, malaise, and anorexia
• Rubella transmission occurs through droplet spread, with a peak season in late Winter/Spring in temperate regions
• Rubella's pathogenesis involves a prodrome of low-grade fever, malaise, anorexia, followed by a generalised maculopapular rash that starts on the face and moves down, with associated arthritis/arthralgia and lymphadenopathy in the head and neck
• The rash in rubella can be difficult to see on darker skin tones but may feel rough or bumpy, as it is maculopapular
• Congenital Rubella Syndrome (CRS) is due to infection in a non-immune mother and may lead to foetal death or premature delivery, with potential severe damage to the fetus depending on the gestational age
• To confirm a rubella diagnosis, laboratory tests include NAAT for Rubella RNA in oral fluid, urine, blood, and respiratory secretions, as well as serology testing for IgM on buccal swab or a fourfold rise in IgG titre on serum samples from acute and convalescent phases of illness
• Mumps presents with fever, flu-like prodrome, earache, and sudden onset of unilateral or bilateral parotid swelling (parotitis), with complications such as aseptic meningitis being common
• To confirm a mumps diagnosis, laboratory tests include NAAT for mumps RNA in oral fluid, buccal swabs, urine, CSF, as well as serology testing for IgM on buccal swab or a fourfold rise in IgG titre on serum samples from acute and convalescent phases of illness
• In addition to standard precautions, droplet precautions should be used for mumps transmission-based precautions
• Prevention strategies for mumps include childhood vaccination, catch-up booster vaccinations for adolescents and young adults, and hospital precautions involving droplet precautions
• A non-immune pregnant woman can receive the MMR vaccine
• Measles, mumps, and rubella are vaccine-preventable infections associated with significant morbidity and mortality worldwide, with measles being a potentially severe multisystem illness, while mumps and rubella are generally mild URTI-like illnesses with some characteristic features