The clinical and public health value of non-culture methods in the investigation of a cluster of unexplained pneumonia cases

Abstract

During 2003, a cluster of initially unexplained pneumonia cases (two fatal) occurred in patients aged <50 years in a British city. Routine culture tests were inconclusive, however, pneumococcal infection was suspected and the putative outbreak was investigated using non-culture methods. Clinical samples from ten patients were tested by pneumococcal polymerase chain reaction (PCR) and multi-locus sequence typing (MLST), or Binax NOW pneumococcal urine antigen test and serotype-specific enzyme-linked immunosorbent assay (ELISA). Lung samples from the deceased patients were PCR positive and yielded different MLST types. Two patients in one family group were serotype 1 pneumococcal antigen positive. Two further patients were serotype 1 antigen positive, and one serotype 4 positive. Two antigen-positive cases were also serum PCR positive. Non-culture methods confirmed the disease aetiology in six cases. Serotype and MLST results showed no single outbreak, but a family cluster of cases in a high background of pneumococcal pneumonia, providing important epidemiological data that would not otherwise have been available.

Outbreaks of serious pneumococcal disease in closed settings in the post-antibiotic era: A systematic review

“…In a paper by Sheppard et al investigating a cluster of initially unexplained pneumonia cases, they describe the identification of a family cluster of cases using exclusively non-culture methods. 59 Although we aimed to identify all published papers describing outbreaks of serious pneumococcal infection, it is possible that there were reports that we did not identify. Also, it is likely that there is significant publication bias as indicated by the small number of countries from which the reports emanate.…”