A nonneutropenic patient with treated low-grade non-Hodgkin's (
Follicular) lymphoma and secondary
hypogammaglobulinemia recovered from
pneumococcal pneumonia and
septicemia (serotype 7F; ST191) subsequent to
influenza A H1N1 (2009). Both
infections were potentially
vaccine preventable. The patient then developed
pneumococcal meningitis due to a serotype 35F pneumococcus with a unique Multilocus Sequence Type (ST7004) which was not
vaccine preventable. Patient management was influenced by host predisposition to
pneumococcal infection,
antibiotic intolerance, and poor response to
polysaccharide pneumococcal vaccine. Indirect immunofluorescence with anti-human
immunoglobulin confirmed a poor or intermediate response to
Pneumovax II. Prophylactic
erythromycin was initiated, and
immunoglobulin transfusions were also commenced as a preventive strategy. ST7004 is a single locus variant of ST1635 which has been associated with the serotype 35F
capsule in England. The spi gene in ST7004, which differentiates it from ST1635, is the same as the spi gene present in ST191 which could have arisen from the first disease episode suggesting that horizontal gene transfer may have occurred between different populations of pneumococci present within the patient in an attempt to evade vaccination selection pressure.