RESUMO
Campylobacter jejuni is an unusual cause of travelers' diarrhea acquired in Mexico, but previous studies have relied only on stool culture for diagnosis. We conducted a cohort study to determine if antibody seroconversion to C jejuni would better reflect the occurrence of infection acquired in Mexico. Serum IgG, IgA, and IgM antibodies to Campylobacter seroconverted in only 2 of 353 participants (0.6%). These data further support that C jejuni infection is an unusual cause of travelers' diarrhea in US visitors to Mexico.
Assuntos
Anticorpos Antibacterianos/análise , Infecções por Campylobacter/imunologia , Campylobacter jejuni/fisiologia , Diarreia/microbiologia , Imunoglobulinas/análise , Viagem , Adolescente , Adulto , Infecções por Campylobacter/diagnóstico , Infecções por Campylobacter/epidemiologia , Campylobacter jejuni/isolamento & purificação , Criança , Estudos de Coortes , Diarreia/diagnóstico , Diarreia/epidemiologia , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Imunoglobulina A/análise , Imunoglobulina G/análise , Imunoglobulina M/análise , Masculino , México , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Fatores de Risco , Estados Unidos , Adulto JovemRESUMO
BACKGROUND AND AIMS: Enterotoxigenic Escherichia coli (ETEC) is the most common bacterial pathogen isolated from travelers suffering of diarrhea. Exposure to heat-labile toxin (LT) produces a high rate of seroconversion. However, the role of LT-producing ETEC (LT-ETEC) as a cause of diarrhea is controversial. We conducted a cohort study in US students traveling to Mexico to assess the ETEC-LT seroconversion rate after natural exposure. METHODS: Participants provided a serum sample on arrival and departure and a stool sample when ill. ETEC-LT immunoglobulin G antibodies were measured by enzyme-linked immunosorbent assay, and LT-ETEC were detected by means of polymerase chain reaction done on fecal DNA. RESULTS: A total of 422 participants with a mean age of 34.5 years were followed a mean of 19.9 days; 304 were females (72.0%), and 319 (75.6%) traveled during the summer months. In total, 177 individuals (41.9%) developed travelers' diarrhea and 33.9% had LT-ETEC identified in their stools. Among individuals having an LT-ETEC strain, 74% seroconverted compared to 11% of those not having diarrhea (p < 0.0001). When analyzed with a logistic regression model, the odds of seroconversion were significantly reduced in participants not having LT-ETEC in their stool (odds ratio = 0.1, p < 0.0001) after adjusting for season, length of stay, age, gender, race, and ethnicity. CONCLUSION: In US young adults traveling to Mexico, ETEC-LT seroconversion reliably identifies individuals naturally exposed to ETEC and correlates with symptomatic illness, length and season of travel.