Measles Antibodies, IgG

The measles virus belongs to the Paramyxoviridae family, which also includes parainfluenza virus serotypes 1-4, mumps, respiratory syncytial virus (RSV), and metapneumovirus. Measles is highly contagious, primarily transmitted through direct contact with aerosolized droplets or respiratory secretions from infected individuals.

Measles has an incubation period of about 8 to 12 days, followed by a prodromal phase characterized by high fever, cough, coryza, conjunctivitis, and malaise. Koplik spots, which can last for 12 to 72 hours, may appear on the buccal mucosa.

After this initial phase, a maculopapular, erythematous rash develops, starting behind the ears and on the forehead, eventually spreading centrifugally to involve the trunk and extremities.

Immunocompromised individuals, pregnant women, and those with nutritional deficiencies are at higher risk of severe complications, including pneumonia and central nervous system involvement, following measles infection.

Since the introduction of the national measles vaccination program in 1963, measles incidence in the United States has dropped to fewer than 0.5 cases per 1,000,000 population, making it non-endemic. However, sporadic outbreaks still occur due to exposure of nonimmune individuals or waning immunity among travelers. The 2011 measles outbreak in Western Europe underscores the virus's persistence globally, emphasizing the importance of vaccination programs.

Measles diagnosis often relies on clinical presentation, but screening for IgG-class antibodies to the measles virus can help identify nonimmune individuals.