In the IDSA Journals
PVL Not Necessary for Severe MRSA Infection
In the latest study on the clinical role of Panton-Valentine leukocidin (PVL) genes in methicillin-resistant Staphylococcus aureus (MRSA) infections, researchers in Canada studied isolates from 42 patients hospitalized with community-acquired USA400 MRSA. These patients were found to be infected with one of two subclones that were identical except for the presence or absence of PVL genes. Both were capable of causing severe illness. This evidence suggests PVL genes are not required for epidemic community transmission or severe infection. (Zhang et al., J Infect Dis. 2008;197:195–204. Also see editorial commentary by Gorwitz, J Infect Dis. 2008;197:179–182.)
Influenza Death Risk is Genetic
Death from influenza is a heritable risk, according to researchers studying a genealogic database of Utah residents dating back 100 years. Up to third-degree relatives of those who died from influenza were found to have an increased risk of dying from influenza as well. As a control, the researchers looked at relatives of the spouses of those who died from influenza, who would have experienced a similar environment. They found that relatives of spouses did not have as high a risk of death. (Albright et al., J Infect Dis. 2008;197:18–24. Also see editorial commentary by Mubareka and Palese, J Infect Dis. 2008;197:1–3.)
CCR5 Deficiency Increases Human Susceptibility to Severe West Nile Virus and Tickborne Encephalitis Virus Infections
Two studies suggest those individuals with deletions in the CCR5 gene are at higher risk of symptomatic West Nile virus (WNV) infection (Lim et al., J Infect Dis. 2008;197:262-265) and tickborne encephalitis (Kindberg et al., J Infect Dis. 2008;197:266-269) than individuals who do not have these deletions. On the other hand, CCR5 deletions have been shown to reduce the risk of HIV infection. The new HIV entry inhibitor maraviroc works by blocking CCR5. Lim et al. hypothesize that CCR5 inhibitor therapy could increase rates of symptomatic (WNV) infection, though this has not been observed in patients to date. (Also see editorial commentary by Klein, J Infect Dis. 2008;197:183-186.)
Utility of guidelines in preventing TB among foreign-born persons
In 2000, guidelines for targeted testing and treatment of latent tuberculosis (TB) infection in foreign-born persons residing in the United States were issued and were aggressively followed in San Francisco, California, but there was no subsequent decrease in the incidence of TB. A review of cases among foreign-born persons with TB in San Francisco during the period from 2002 to 2003 showed that only 38 percent of these cases were preventable if they adhered to the guidelines. Following the guidelines, though, will likely not significantly reduce the rate of TB among foreign-born persons residing in the United States. (Walter et al., Clin Infect Dis. 2008;46:103-106. Also see editorial commentary by Cain and MacKenzie, Clin Infect Dis. 2008;46:107-109.)
Influenza vaccinations for health care workers
Last year, several committees issued recommendations about the vaccination of health care workers to prevent transmission of influenza within health care facilities and to help prevent absenteeism among the workers. According to a survey of more than 400 members of the Infectious Diseases Society of America’s Emerging Infections Network, the rates of immunization at various institutions were 41 percent to 60 percent and were higher at institutions that required signed declination statements. Other effective elements of a successful vaccination campaign included making the vaccine free of charge, devoting adequate resources to vaccination efforts, and educating targeted groups of health care workers. (Polgreen et al., Clin Infect Dis. 2008;46:14-19.)
Pneumococcal disease in the era of PCV7
This study found that rates of invasive pneumococcal disease among Spanish children increased substantially after the 2002 introduction of 7-valent pneumococcal conjugate vaccine (PCV7), compared with rates during the period before the availability of the vaccine. The increased rates after 2002 were largely caused by non‐PCV7 serotypes. One might conclude that nature deeply resents vacuums. (Muñoz-Amagro et al., Clin Infect Dis. 2008;46:174–182. Also see editorial commentary by Moore and Whitney, Clin Infect Dis. 2008;46:183–185.)
More from the literature…
See the “In This Issue” section of the January 1 and January 15 issues of Clinical Infectious Diseases for summaries of other key articles.
For a review of other recent research in the infectious diseases literature, see “In the Literature,” by Stanley Deresinski, M.D., in each issue of Clinical Infectious Diseases.
- Antibiotic Lock Therapy
- Antibiotic Therapy in the Intensive Care Unit (ICU): A Life Sentence?
- Toxoplasmosis in the United States: A Bear Market
- Methicillin‐Resistant Staphylococcus aureus (MRSA): Quantifying the Problem
- A Primary Immunodeficiency in a Toll-Like Receptor (TLR) Predisposing to Herpes Simplex Virus (HSV) Encephalitis
- The Increased Virulence of West Nile Virus (WNV): Problem Solved?