John W. Paisley

Pathogens associated with acute lower respiratory tract infection in young children.

To determine the agents associated with acute lower respiratory infection in young children, we studied 102 hospitalized children less than 5 years old using culture and serology for viruses and Chlamydia trachomatis, fluorescent anti-body testing for pertussis and respiratory syncytial virus, blood cultures and counterimmunoelectrophoresis of nasopharyngeal secretions and urine for pneumococcal and Haemophilus influenzae type b antigens. At least one agent was detected in 87 children and multiple agents were found in 33. Viruses were detected 80 times; respiratory syncytial virus was most common (61 cases) and was detected as often by fluorescent antibody testing as by culture. C. trachomatis was detected in 10 children; all were less than 4 months old and 9 had mixed infections. Bacteria were detected 32 times, were usually pneumococcus (23) or H. influenzae (5) and were detected more often by counterimmunoelectrophoresis than by blood culture. Compared with children yielding only C. trachomatis or viruses, those with bacteria were significantly more likely to have fever, a band count over 2000/mm3 and radiographic consolidation. In this study acute lower respiratory infection was associated commonly with viruses, often with multiple pathogens but not with C. trachomatis after 4 months of age.

Immunogenicity and safety of Haemophilus influenzae type b-tetanus protein conjugate vaccine alone or mixed with diphtheria-tetanus-pertussis vaccine in infants☆☆☆★

Haemophilus capsular polysaccharide-tetanus toxoid conjugate (PRP-T) and diphtheria-tetanus-pertussis (DTP) vaccines were administered in a single syringe (group 1) or separate syringes (group 2) to 284 infants at 2, 4, and 6 months of age. Group 1 infants had a slightly greater incidence of local reactions. Systemic reactions were similar. The geometric mean titers of polyribosylribitol phosphate (PRP) serum antibody concentrations after the third dose of PRP-T vaccine were 4.8 and 4.3 micrograms/ml for groups 1 and 2, respectively. Antibody responses to DTP antigens were also similar. The immunogenicity and safety of the PRP-T and DTP vaccines are equivalent when the vaccines are administered in separate syringes or the same syringe to infants.

Rifampin-resistant meningococcal disease in a contact patient given prophylactic rifampin

In 1943, sulfonamide chemoprophylaxis was shown to be effective in l imiting the spread of epidemic meningococcal disease2 Sulfonamides remained the preferred chemoprophylactic agents until the widespread emergence of sulfonamide-res is tant meningococcal s trains in the 1960s. 2 Studies in mil i tary and civilian populations subsequent ly demons t ra ted tha t both minocycline and r i fampin were 60% to 90% effective in eradicat ing nasal carr iage of Neisseria meningitidi s. Although nei ther agent has been proven effective by controlled clinical trials in prevent ing secondary cases, they are considered effective agents for meningoc0ccal chemoprophylaxis. 2 Because of f requent vest ibular toxici ty associated with prophylact ic minocYcline use, r i fampin is the ,preferred chemoprophylac t ic agent. However, r i fampin prophylaxis has been associated with up to a i2% subsequent frequency of res is tant meningococcal isolates in the nasopharynx? -6 W e now report meningococcal disease caused by a r i fampinresistant organism in a person who had received r i fampin chemoprophylaxis .

Rapid diagnosis of Chlamydia trachomatis pneumonia in infants by direct immunofluorescence microscopy of nasopharyngeal secretions

The recent development of a monoclonal fluorescent antibody test to detect Chlamydia trachomatis by direct microscopy in clinical specimens has allowed rapid diagnosis of chlamydial genitourinary and ocular infections. 1-4 To investigate the ability of the direct FA test to diagnose chlamydial respiratory tract infection rapidly, we compared the FA test with culture in infants with suspected chlamydial pneumonia.