Congenital and neonatal measles during an epidemic in São Paulo, Brazil in 1997.

During a measles outbreak, 2 mothers with measles gave birth at University Hospital in São Paulo City, Brazil. Blood, saliva and urine were collected from the mothers and newborns. Measles virus genome and IgM antibodies against measles were detected. In 1 infant, measles virus genome persisted in peripheral blood mononuclear cells for 157 days after birth.

Evaluation of the measles clinical case definition.

An accurate system of identifying and classifying suspected measles cases is critical for the measles surveillance system in the United States. To examine the performance of the clinical case definition in predicting laboratory confirmation of suspected cases of measles, we reviewed 4 studies conducted between 1981 and 1994. A clinical case definition was examined that included a generalized maculopapular rash, fever (>or=38.3 degrees C, if measured), and either a cough, coryza, or conjunctivitis. Serological confirmation of measles was done either by hemagglutination inhibition assay, complement fixation assay, or enzyme immunoassays. The positive predictive value of the clinical case definition decreased from 74% to 1% as incidence decreased from 171 cases/100000 population to 1.3 cases/100000 population. Sensitivity was high, and for the larger studies with the most precise estimates, sensitivity was 76%-88%. The low positive predictive value of the clinical case definition in settings of low incidence demonstrates that serological confirmation is essential to ensure an accurate diagnosis of measles when measles is rare.

Immunologic studies of specific mucosal and systemic immune responses in Mexican school children after booster aerosol or subcutaneous immunization with measles vaccine.

The purpose of the present study was to compare serum and mucosal immune responses following either aerosol (Aer) or subcutaneous (SQ) measles immunization of Mexican school children. A cohort of 49 children from 6 to 7 years of age received either Aer ( n = 22) or SQ ( n = 27) Edmonston-Zagreb (EZ) measles vaccine. Serum and nasal secretions were collected prior to (Pre), 1 and 3 months (mos) intervals and analyzed for immunoglobulin (Ig) concentrations and measles specific Ig isotype-associated antibody by enzyme immunoassay (EIA). Serum and nasal IgG and IgA antibody responses were stimulated following immunization with live, attenuated EZ measles vaccine administered either by SQ or Aer routes but these responses were significantly greater by the Aer compared to the SQ route. These studies also suggest that the level of antibody in these secretions may serve as an important marker of immunity to measles and lend further support for aerosol immunization as an effective alternative vaccine delivery strategy for measles eradication.

Genetic homogeneity of measles viruses associated with a measles outbreak, São Paulo, Brazil, 1997.

During a resurgence of measles in São Paulo, Brazil, in 1997, >40,000 cases (peak incidence rate of 246/100,000 inhabitants) and 42 measles-related deaths were reported. Reverse transcriptase-polymerase chain reaction and nucleotide sequencing were used to analyze specimens from patients who had typical clinical measles infection during this outbreak and from six patients who had had measles in 1995 and 1996. Although wild-type measles viruses (genotypes D5 and D6) were present in São Paulo before this resurgence, we detected only D6 viruses. The genotype D6 viruses isolated during this outbreak had identical sequences to genotype D6 viruses isolated in other parts of Brazil and South America in 1997 and 1998, suggesting that a single chain of transmission was responsible. We also identified genotype A viruses in two vaccine-associated cases from 1995 and 1996. Our findings extend the knowledge of the circulation patterns of measles virus in South America, contributing to measles control efforts in the Americas.