Infection Control Crucial to Stop XDR TB Spread

Infection control strategies are urgently needed to stop the spread of multidrug-resistant (MDR) and extensively drug-resistant (XDR) tuberculosis (TB), according to a study from South Africa. Examining 17 patients who developed MDR or XDR TB after being hospitalized for less-resistant TB, the authors found all of them were cases of re-infection rather than acquired resistance. The study suggests efforts to emphasize adherence to therapy will not be enough to control the epidemic. (Andrews et al., J Infect Dis. 2008;198:1582-89.) An editorial commentary says the study shows that susceptibility testing and optimized therapy also are essential. (Horsburgh, J Infect Dis. 2008;198:1577-78.)

Hepatitis E Linked to Meat

This study suggests hepatitis E is a food-borne viral disease. Most cases identified from Germany’s routine-surveillance system between May 2006 and August 2007 were not linked to travel. Consumption of offal or wild boar meat were risk factors. (Wichmann et al., J Infect Dis. 2008;198:1732-41. Editorial commentary by Kuniholm and Nelson, J Infect Dis. 2008;198:1727–28.)

Hepatitis A Immunization Lasts 10+ Years

Nearly all children and adults who received 3 doses of hepatitis A vaccine in this study had protective levels of antibodies up to 10 years after receiving the last dose. Judging by the rate of decline, antibody protection was estimated to last 21-27 years. (Hammitt et al., J Infect Dis. 2008;198:1776-82.)

Severity Scores for Patients with Pneumonia

Because of concerns regarding the accuracy of severity scores for young adults with pneumonia, the authors observed patients who were admitted to a UK hospital. In a group of 335 patients under 50 years of age, 45 percent of those who required mechanical ventilation and/or inotropic support were inappropriately classified as being at low to intermediate risk. The authors argue that, because of the high rate of misclassification, such scores should only be used in conjunction with a formal clinical assessment. (Chalmers et al., Clin Infect Dis. 2008;47:1571-74.)

Optimal Time to Begin Antiretroviral Therapy

The optimal time to start antiretroviral therapy (ART) for HIV-infected individuals remains uncertain. The original thinking in the mid- to late 1990s was to initiate ART as early as possible, to aggressively attack the virus. However, the realization that inconvenience and drug-related toxicity often resulted in the failure of therapy and the development of drug resistance prompted a movement toward delaying treatment. Current ART is effective, convenient, and well tolerated, and data from cohort studies and clinical trials suggest that the initiation of ART in patients with CD4+ cell counts under 350 cells/μL is beneficial. (Wilkin et al., Clin Infect Dis. 2008;47:1580-86.)

Internet Searches Predict Influenza Patterns

With use of search queries from Yahoo, the authors examined the relationship between Internet searches for influenza and actual influenza occurrence. The frequency of searches predicted an increase in the number of positive influenza culture results one to three weeks in advance, as well as an increase in mortality attributable to pneumonia and influenza up to five weeks in advance. (Polgreen et al., Clin Infect Dis. 2008;47:1443-48.)

Figure: Comparison of searches for influenza and positive culture results, by week.

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 January 1 or January 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:

January 1

• Pulmonary Tuberculosis in Extrapulmonary Tuberculosis
• Oseltamivir Resistance
• Chikungunya and the CNS

January 15

• Trimethoprim-Sulfamethoxazole (TMP‐SMZ) Prophylaxis in Africa and Microbial Resistance
• Melioidosis: Another “Great Mimic”
• Natural History of Lymphadenitis due to Nontuberculous Mycobacteria