Viral Infections In Children Receiving Anticancer Chemotherapy

OBJECTIVE: To determine the presence of bacterial and viral infectious agents in children with fever during anticancer chemotherapy. DESIGN: Analysis of data obtained during a prospective cohort study. SETTING: The pediatric oncology unit of Tygerberg Children's Hospital; Cape Town. SUBJECTS: All patients up to the age of 15 years who deve- loped fever secondary to anticancer chemotherapy from February 9th 2000 to April 9th 2001. OUTCOME MEASURES: Viruses were isolated or antigens detected on venous blood samples; nasopharyngeal aspirates; throat swabs; urine and feces where possible. Blood for aerobic and anaerobic culture was obtained from an indwelling intravenous catheter and/or a peripheral vein. RESULTS: Thirty-four children were analyzed for a total of 102 febrile episodes. The absolute neutrophil count on admission was below 0.5*109/L in 57 (56) episodes and thus considered neutropenic. Thirty-five viral isolates were identified in 31 (30) febrile episodes: HSV-1 (n=14); HSV-2 (n=2); CMV (n=10); rotavirus (n=5); adenovirus (n=2); Para influenza type 3 (n=1) and hepatitis B (n=1). The blood culture was positive in 24 (24) febrile episodes. Within these; a combined viral and bacterial infection was demonstrated in 6 (6) episodes. Infections were more frequent in neutropenic compared to non-neutropenic episodes; however; this was not significant. CONCLUSIONS: Viral infections clearly are an important cause of fever in children receiving anticancer therapy and may occur together with a bacterial infection. Diagnostic tests for viral infections should be used more frequently and could be of considerable value in evaluating fever and establishing appropriate treatment in these patients

Potassium-Uptake Systems of Mycobacterium tuberculosis: Genomic and Protein Organization and Potential Roles in Microbial Pathogenesis and Chemotherapy

Mycobacterium tuberculosis (MTB) is a formidable microbial pathogen which uses multiple mechanisms to subvert host immune defences. These include the effective; protective barrier presented by the outer waxy coat; intracellular concealment from host defences; and the ability to enter a prolonged; dormant phase in the infected host. Priority strategies to combat the scourge of TB include the identification of novel and selective targets on/in MTB which are amenable to pharmacological or immune-mediated control. Because they are structurally different from their counterparts in eukaryotic cells and are likely to be essential for survival and growth; the major K+ transporters of MTB represent alternative and novel targets for drug and vaccine design. These K+-uptake systems of MTB are the primary focus of this review; with particular emphasis on their genomic and protein structures; properties and functions; and potential roles in intracellular survival