Rubeola and Rubella

Rubeola and Rubella

Fever and rash in children are caused by many types of viral illnesses. They may have  typical or atypical manifestation. Diagnosis is usually based on thorough history and physical examination and often has limited diagnostic work-up.

A common illness in children  that presents with fever and rash is Measles, also known as Rubeola. Measles present with prodromal fever, cough, coryza, conjunctivitis, and a pathognomonic enanthem (i e, Koplik spots), followed by an erythematous maculopapular rash on the third to seventh day¹. The disease is more severe in infants and adults. A generalized immunosuppression that follows acute measles frequently predisposes young patients to bacterial otitis media, bronchopneumonia, laryngotracheobronchitis (ie, croup), and diarrhea. Twenty percent (20%) of infected people have complication that include seizures, deafness and encephalitis. According to World Health Organization (WHO), measles killed 164,000 people in 2008 with approximately 450 deaths every day and 18 deaths every hour ². Treatment of measles mainly involves supportive measures, such as fluids and antipyretics. Measles vaccine is important, especially to infants and susceptible household contacts ³. Measles is unlikely in people who are fully immunized or who have previously contracted the infection. Vaccination with one dose of the combined measles, mumps, and rubella (MMR) vaccine confers about 90% immunity. In the UK, seroprevalence studies indicate that less than 1% of people born before 1970, and less than 10% of people born between 1970 and 1980, is antibody-negative to measles. This suggests that the people most likely to present with measles are younger people who have not received the MMR vaccine and who have not been previously exposed to the virus (which is likely, as measles has become much less prevalent since the introduction of the MMR vaccine) ^5,6,7.

Another childhood condition that presents with fever and rash is Rubella. Rubella is an airborne disease transmitted by an infected individual. It is moderately contagious, mostly when the rash is erupting, but is communicable from 1 week before, to 5-7 days or more after the onset of the rash. Rubella mostly affects children, adolescents and young adults. Clinical diagnosis is difficult because symptoms and rashes are similar to other viral infections. Approximately 50% of rubella infections are subclinical and may not be detected except through laboratory confirmation. Congenital rubella syndrome (CRS) is the most serious consequence of rubella. It arises from fetal rubella infection during the first trimester of pregnancy and can cause abortion, miscarriage, stillbirth or multiple defects. Deafness is the most common and often the sole manifestation of CRS. Rubella is worldwide, it is estimated that more than 100 000 infants are born with CRS each year. Most of these cases occur in developing countries that have not yet introduced rubella vaccine ⁴ . Treatment is supportive, but of importance is the care of exposed persons, especially a pregnant woman. The existing, internationally-licensed rubella vaccines, single or in combination with vaccines against mumps and/or measles have proved to be highly efficacious in the prevention of rubella infection and CRS in different parts of the world. WHO recommends the use of rubella vaccine in all countries with well-functioning childhood immunization programmes with sustained routine coverage of >80%, where reduction or elimination of CRS is considered a public health priority, and where resources may be mobilized to assure implementation of an appropriate strategy ⁴.

Rubeola and Rubella are solely based on clinical signs and symptoms. But because these two conditions may mimic many other causes of fever and rash, a laboratory confirmation is still needed to provide evidence of infection. Measles specific IgM antibody titer is one of the laboratory tests for confirming suspected cases. Both IgM and IgG antibodies are produced during the primary immune response and can be detected in the serum within a few days of rash onset. Using sensitive ELISA IgM assays, 90% of measles cases are IgM positive at 3 days post rash onset. IgM antibody levels peak after about 7-10 days and then decline rapidly, being rarely detectable after 6-8 weeks.  Measles IgM is detectable for at least 1 month after rash onset in unimmunized people but might be absent or present only transiently in people immunized with 2 vaccine doses. People with febrile rash illness that are seronegative for measles IgM are usually tested for rubella  ^4,5,6.

The introduction of measles vaccine into routine immunization programmes results in a marked reduction in incidence of the disease and its associated morbidity and mortality. An effective surveillance system is required to ensure the adequate control and the eventual elimination of a vaccine-preventable disease⁷.  The DOH has been presently undertaking surveillance for measles suspects in 1992.  At BGH-MC, all pediatric patients who presented with fever and rash from the period of January 2010 to January 2011 were referred to the City and Regional Epidemiology and Surveillance Units (CESU and RESU). Patient’s data are obtained and blood sample sent for laboratory confirmation. After blood analysis, the result will be released to CESU and RESU. In this study, all pediatric patients who presented with fever and rash who were laboratory confirmed to have measles/rubella are the subjects.  Profiles of these pediatric patients with laboratory confirmed tests will also be reviewed and their respective vaccination status will be noted. The Department of Pediatrics BGHMC was observed to have increased cases of fever and rash in the period of January 2010 to December 2011. This number of cases noted to be unusually high since it was presumed that children below 18 years old received adequate doses of Measles/MMR vaccination as part of the Expanded Immunization program.