Clinical, laboratorial diagnosis and prophylaxis of measles in Brazil

Abstract

ABSTRACT Measles is an acute febrile exanthematic disease of viral etiology, highly contagious, being the cause of morbidity and mortality of children in developing countries, whereas it has become rarer in developed countries due to vaccination. Its differential diagnosis should be made with other childhood viral respiratory diseases such as influenza, rhinovirus and adenovirus, and exanthematic febrile diseases such as rubella, roseola and varicella. In tropical regions, it should be performed with dengue, zika and chikungunya. Its clinical picture presents the following phases: incubation, usually asymptomatic; a prodrome, in which fever, malaise, coryza can occur, besides Koplik’s signs; exanthematic, with presence of maculopapular exanthema after the fever condition that progresses to a craniocaudal evolution, with clinical improvement in uncomplicated cases. Common complications are pneumonia, otitis media, keratitis; the rarest are acute disseminated encephalomyelitis and subacute sclerosing panencephalitis. Nonspecific laboratory alterations are seen in the blood count. The specific laboratory diagnosis is based on the detection of viral ribonucleic acid (RNA) [polymerase chain reaction (PCR) of nasal swab samples, oral mucosa or urine]. Immunoglobulin class M (IgM) can be detected during the exanthematous period by enzyme-linked immunosorbent assay (ELISA), and immunoglobulin class G (IgG) throughout the convalescence period, and the detection of specific IgG by the plaque reduction neutralization test may also be performed. The prophylaxis of the disease is based on vaccination in children from 15 months in order to reach about 85% to 95% of the population, what confers herd immunity. Thus, vaccination is the most effective measure in combating measles, since the treatment consists only of clinical and symptomatic support.