New Hypervirulent Strain Causing C. Difficile Infection 

Since 2005, an increase in the prevalence of Clostridium difficile infection due to PCR ribotype 078 has been noticed in The Netherlands. From February 2005 through February 2008, the proportion of infections due to type 078 strains increased from 3 percent to 13 percent, whereas the proportion of infections due to the hypervirulent type 027 strain decreased from 27 percent to 1 percent. Researchers found that patients with C. difficile infection due to type 078 were younger than those with infection due to type 027, with a higher proportion of community-associated disease and equal proportions of severe diarrhea and mortality. (Goorhuis et al., Clin Infect Dis. 2008;47:1162-1170.)

Rifampicin-miconazole-impregnated Catheters Reduce Catheter-related Bacteremia  

Previous studies have found a higher incidence of central venous catheter-related bacteremia (CVC-RB) in femoral and central jugular access than in other venous sites. To evaluate a preventive device, patients were catheterized with either rifampicin-miconazole-impregnated catheters or standard catheters in femoral and central jugular venous accesses. Rifampicin-miconazole-impregnated catheters were found to result in a 77 percent reduction in CVC-RB for both of the sites. (Lorente et al., Clin Infect Dis. 2008;47:1171-1175.)

Emergence of W/Beijing strains of Tuberculosis  

W/Beijing strains of Mycobacterium tuberculosis are more virulent and more resistant to conventional drugs than are other strains. To determine the extent to which such strains are emerging in southern Africa, the authors used molecular testing to genotype strains obtained from patients admitted to pediatric hospitals in Cape Town, South Africa, over a period of four years, as well as strains present in archived tissue samples. W/Beijing strains were absent during 1930–1965, rare during 1966–1995, and increasingly common during 1996–2005. The proportion of W/Beijing strains among children increased from 13 percent in 2000 to 33 percent in 2003. (Cowley et al., Clin Infect Dis. 2008;47:1252-1259.)

Factors Affecting HCV Clearance, Genotype in HIV Co-infected Patients

Fewer than one quarter of HIV-positive patients with evidence of hepatitis C virus (HCV) infection spontaneously cleared HCV in the EuroSIDA cohort of nearly 2,000 patients. Spontaneous clearance was less likely in injection drug users than in men who have sex with men (20 percent vs. 39 percent), whereas clearance was more likely in those who tested positive for hepatitis B virus than those who did not (43 percent vs. 21 percent). Of those with chronic infection, more than half were infected with HCV genotype 1, which was associated with higher serum levels of HCV RNA. (Soriano et al., J Infect Dis. 2008;198:1337-1344.) According to an accompanying editorial, the study suggests most members of the EuroSIDA cohort are poor candidates for anti-HCV therapy, and early antiretroviral therapy may be the best option for these patients, in an attempt to avoid end-stage liver disease. (Bruno and Sacchi, J Infect Dis. 2008;198:1262-1264.)

More Sensitive WNV Screening Needed for Blood Supply?

Blood collection centers currently use the most sensitive WNV RNA detection method only during outbreaks or WNV season. Transfused blood contaminated with very low levels of West Nile virus (WNV) has only rarely caused disease, leading to speculation that the presence of WNV antibodies in these samples provides protection. This study found that viremic samples containing antibodies were capable of infecting cells in culture, although less so than those without antibodies. (Rios et al., J Infect Dis. 2008;198:1300-1308.) An accompanying editorial says the results raise the question of whether blood should routinely be screened using the most sensitive method to detect WNV RNA. However, the author says that the benefits may not outweigh the costs. (Katz et al., J Infect Dis. 2008;198:1258-1261.)

More from the literature: the IDSA Journal Club

The IDSA Journal Club helps you stay up to date on the infectious diseases literature. Each month, the Journal Club features brief summaries of key infectious diseases studies in the previous month’s major journals.

In addition, the “In This Issue” section of each issue of Clinical Infectious Diseases (CID) highlights several important studies from that journal. (Click for December 1 or December 15.) For a review of other recent research in the infectious diseases literature, see “In the Literature,” by Stanley Deresinski, MD, in each issue of CID:

December 1:

• Neurosyphilis and HIV Infection
• Amoeba, Mamavirus, Sputnik, and Ever-Smaller Fleas: Virophage Make Their Debut
• Abacavir (and Didanosine) and Acute Myocardial Infarction

December 15:

• Adjunctive Rifampin for Staphylococcal Endocarditis
• Vancomycin “Just Can't Get No Respect”
• Vancomycin, metronidazole, Clostridium difficile, and Vancomycin-Resistant Enterococci (VRE)

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