Comparison of Binax NOW urine antigen test and pneumococcal DNA assay using qPCR before and after nasopharyngeal swabbing in healthy Malawian children.

Diagnosis of invasive pneumococcal disease is challenging. We compared Binax NOW pneumococcal urinary antigen test with blood pneumococcal PCR in healthy Malawian children with and without pneumococcal carriage, and we found a high false-positive rate with Binax NOW. Blood pneumococcal PCR positivity was 66/88 (75%) compared to 5/27 (18%) when nasopharyngeal swabbing was performed first compared to after blood sampling for pneumococcal blood PCR. We speculate that nasopharyngeal swabbing may be causing a breach of mucosal integrity, leading to invasion into the bloodstream. These findings need to be confirmed with autolysin-based PCR assays.

The outcome of non-typhoidal salmonella meningitis in Malawian children, 1997-2006.

INTRODUCTION: The clinical course and outcome of non-typhoidal salmonella (NTS) meningitis in Malawian children over a 10-year period (1997-2006) is described. METHODS: Demographic, clinical and laboratory data were collected for all children over 2 months of age admitted with salmonella meningitis to Queen Elizabeth Central Hospital from 1997 to 2006. In the 1st year, salmonellae were susceptible to chloramphenicol, and children received 2 weeks of chloramphenicol treatment. When NTS resistance to chloramphenicol started to appear in 1998, treatment was changed to ceftriaxone. From 2002, the duration of antibiotic therapy was extended to 4-weeks which included 2 weeks of intravenous ceftriaxone and a further 2 weeks of oral ciprofloxacin. RESULTS: The in-hospital case fatality rate (CFR) was 52.3% (48.2% until 2002 and 53.9% after prolonged antibiotic therapy was introduced). Of the survivors, one in 12 (8.3%) became completely well (sequelae-free) in the period 1997-2001 while 18 of 31 survivors (58.1%) made a complete recovery during 2002-2006 (p<0.01). After the 4-week course of antimicrobial therapy was introduced, the number of relapses or recurrences fell from nine in 15 (60%) survivors treated with chloramphenicol or ceftriaxone to three in 35 (8.7%) survivors who received 4 weeks of antibiotics (p<0.0001). CONCLUSION: In Malawi, salmonella meningitis has a CFR of approximately 50%, which has remained constant over many years. Residual morbidity, however, has decreased over 10 years, despite rising numbers of multi-drug-resistant cases of NTS. This improvement might be owing to better treatment and management and/or reduced pathogenicity of the multi-drug-resistant bacteria.