Molecular Epidemiology of Haemophilus influenzae within Families in Santiago, Chile

• Published in: The Journal of infectious diseases 1991-12, Vol.164 (6), p.1149-1153
• Main Authors: Lagos, Rosanna, Avendano, A., Horwitz, I., Musser, James M., Hoiseth, Susan K., Maneval, David R., Jones, M. Jeanette, Levine, Myron M., Dattas, J. P., Prenzel, I., Enriquez, N., Topelberg, S., Olivari, F., Morris, J. Glenn
• Format: Article
• Language: English
• Subjects: Bacterial diseases; Bacterial diseases of the respiratory system; Bacterial Outer Membrane Proteins - analysis; Biological and medical sciences; Cellulitis - epidemiology; Cellulitis - microbiology; Child, Preschool; Children; Chile - epidemiology; Communities; DNA, Bacterial - analysis; Electrophoresis; Electrophoresis, Starch Gel; Enzymes; Epidemiology; Face; Family Health; Haemophilus Infections - epidemiology; Haemophilus Infections - microbiology; Haemophilus Infections - transmission; Haemophilus influenzae; Haemophilus influenzae - classification; Haemophilus influenzae - genetics; Haemophilus influenzae - isolation & purification; Haemophilus influenzae type b; Human bacterial diseases; Humans; Infant; Infectious diseases; Medical sciences; Membrane proteins; Meningitis, Haemophilus - epidemiology; Meningitis, Haemophilus - microbiology; Meningitis, Haemophilus - transmission; Microbial colonization; Neighborhoods; Nucleic Acid Hybridization; Pharynx - microbiology; Pneumonia - epidemiology; Pneumonia - microbiology; Prospective Studies
• ISSN: 0022-1899; 1537-6613
• DOI: 10.1093/infdis/164.6.1149

Thirty-six consecutive patients with invasive Haemophilus influenzae type b (Rib) infections at Roberto del Rio Children's Hospital, Santiago, Chile, were enrolled in a prospective study. Throat cultures were obtained from household contacts of each index case, adjacent neighbors, and matched community control households. Colonization rates for H. influenzae were comparable among groups; however, among household contacts 18% of colonizing isolates were Rib, compared with 2% and 3% among neighbor and community controls. When selected isolates were evaluated further by outer membrane protein (OMP) profiles and multilocus enzyme electrophoresis, only one of the four Hib isolates from household members matched the corresponding index case isolate. One serologically non typeable isolate from a household contact had an OMP profile and electrophoretic type identical to that of the corresponding Rib index case isolate; hybridization studies with a 9-kb capsular gene probe showed a profile consistent with a capsule-deficient mutant. Rib strains were isolated more frequently from household contacts than from control persons living in Santiago, but colonizing Rib strains were often unrelated to the index case strain.