Updates

By Carol A. Kemper, MD, FACP, Clinical Associate Professor of Medicine, Stanford University, Division of Infectious Diseases; Santa Clara Valley Medical Center, Section Editor, Updates; Section Editor, HIV, is Associate Editor for Infectious Disease Alert.

Pat the Bunny (Don't Kiss It)

Source: Kawashima S, et al. J neurol. 2010;257:654-664.

The authors describe a previously healthy 44-year-old woman who presented with bacterial meningitis. On presentation, she was alert but complained of high fever and meningismus. She had no other neurologic symptoms. Lumbar puncture showed 2,880 white blood cells per microliter, an elevated protein of 156 mg/dL, and a reduced glucose of 51 mg/dL. A Gram stain revealed gram-negative rods; she was treated with empiric vancomycin and meropenem. Blood and cerebrospinal fluid cultures grew Pasteurella multocida.

Further questioning revealed she not only kissed her dog's face — she fed it mouth-to-mouth. She described no scratches or bites and no other animal contact.

P. multocida is a gram-negative coccobacillus that is commonly present in the nasopharynx and gastrointestinal tract in animals, and a normal part of the oral mouth flora of dogs and cats (up to 75%). It is generally susceptible to penicillins, although cases of penicillin resistance have been described. Cellulitis and bacteremia may occur from infection with P. multocida, generally as the result of bites or scratches, but meningitis is rare. The presentation is similar to other common bacterial meningitides, and about 17%-22% have neurologic symptoms. The authors found three other cases in the literature of P. multocida meningitis as a result of mouth kissing of a pet cat, dog, or bunny. The authors cautioned that P. multocida should be considered in animal lovers, and people should refrain from close oral contact with their pets. I wonder, I mean really, how many women don't kiss their cats?

Airborne C. difficile?

Sources: Best EL, et al. The potential for airborne dispersal of Clostridium difficile from symptomatic patients. Clin Infect Dis. 2010; 50:1450-1457; Donskey CJ. Preventing transmission of Clostridium difficile: Is the answer blowing in the wind? Clin Infect Dis. 2010; 50:1458-1461.

Not only is C. difficile in the hospital tough to eradicate despite enhanced infection-control measures and extensive cleaning and bleaching of rooms, but it often seems to come from nowhere. To test the theory that airborne transmission of C. difficile spores may occur, the authors sampled the air space around patients with symptomatic CDI. The first phase of the project sampled the air space of 50 patients being treated for confirmed CDI for one hour intermittently over several days (total 50 hours). Six (12%) of the samples were positive. A trend was observed toward more positive samples in patients with more active diarrheal symptoms than those without.

The period of air sampling was subsequently extended to 10 hours over two days (total 130 hours) in 10 patients with suspected CDI, pending laboratory confirmation, and those with symptomatic confirmed CDI. Environmental samples were also collected for comparison of isolates by DNA fingerprinting. Of those with suspected infection, three were confirmed by the laboratory based on cytotoxic studies; the other seven patients were considered "controls." Of the three CDI-positive patients, one had positive air samples on three different days (associated with various activities such as changing the bed, closing the curtain, and room cleaning). Two control subjects (diarrheal) with negative air samples for C. difficile had positive environmental samples (from the commode, sink, floor, bed, and bedside table), suggesting they may have been colonized with the organism.

When the duration of the air space sampling of 10 symptomatic patients with confirmed CDI was extended to 10 hours over several days, seven (70%) had positive air samples, four of whom had multiple positive samples intermittently over several days. Positive samples generally occurred during periods of activity around the patient, such as serving drinks or lunch, visiting hours, ward rounds, or bed changes.

Ten percent of environmental isolates from these patients were also positive, similar to the results of another recent study for symptomatic patients receiving treatment. In all, six of the 10 patients with confirmed CDI had positive air space and environmental samples. DNA fingerprinting confirmed the organisms from the airspace and those from the environmental were similar for an individual patient in three cases, suggesting an epidemiological link.

Current hospital infection-control measures (e.g., contact precautions) for C. difficile would not protect against airborne transmission of the organism. This study demonstrated that airborne transmission not only occurs, but occurs with surprising frequency (in up to 70% of symptomatic patients with C difficile infection [CDI]). This likely contributes to environmental colonization, especially during periods of activity in the room, such as bed changes. Dispersal of spores via the air may explain the frequent colonization/exposure of health-care workers, despite good handwashing and contact precautions, or the frequent gastrointestinal colonization of long-term care facility residents. Furthermore, C. difficile was found in the airspace of 30% of patients with diarrhea without laboratory-confirmed CDI, suggesting that even those patients with gastrointestinal colonization with diarrhea for other reasons (e.g., antibiotic-associated diarrhea) may contribute to environmental contamination.

Hospitals must consider these findings as they strive to beef up infection-control and environmental measures to combat the increasing presence of CDI in hospitals. Whether a HEPA filter or air exchanger would be beneficial in reducing environmental contamination was not addressed by this study. The accompanying editorial suggests that restricting patients with recognized CDI to a private room, daily room cleaning, and continuing contact precautions throughout the hospital stay may all be necessary but not sufficient to prevent environmental spread.

Travel Recommendations for the World Cup

Source: Blumberg LH, et al. The 2010 FIFA World Cup: Communicable disease risks and advice for visitors to South Africa. J Travel Med. 2010;17:150-152.

It is anticipated that more than 350,000 people will attend the World Cup games in South Africa, in June and July this year. Given the crowd conditions and mass gathering of people from all over the globe, there is a greater potential for outbreaks of communicable diseases, especially respiratory infections. The following is a list of precautionary measures recommended for 2010 World Cup travelers:

  • Influenza vaccine is recommended for all travelers and team participants. During the 2009 South African influenza season, Influenza A H1N1 replaced the previous H3N2 strain. The risk of influenza transmission during the World Cup may be high.
  • The Gauteng Province has been experiencing a measles outbreak since 2009, which has affected neighboring regions. In anticipation of an influx of large numbers of people, a mass measles campaign was planned for the country in April 2010. Pre-travel measles immunization is recommended for any non-immune persons.
  • Consideration should be given to pre-exposure vaccination for meningococcal infection. Although the risk is considered low, a modest seasonal increase in meningococcal infections occurs in South African between May and October, and the crowd conditions may increase the risk for exposure. The dominant serotype in South Africa is W135.
  • No case of wild-type polio has been reported in South Africa since 1989. However, polio boosters are recommended for persons traveling to South African from polio-endemic countries such as Nigeria, Pakistan, Afghanistan, and India, or for persons less than 15 years of age traveling from countries where polio has occurred.
  • Since the stadia for the World Cup are outside malaria risk areas, the risk for malaria should be low and malaria chemoprophylaxis is not necessary for World Cup participants or observers; however, chemoprophylaxis is recommended for visitors who travel to Kruger National Park or other neighboring countries, such as Zambia, Mozambique, or Zimbabwe, along with the usual clothing and mosquito repellent precautions.
  • While chemoprophylaxis is not necessary, South Africa is considered endemic for rabies, generally from contact with dogs. Persons with dog bites, or contact with other animals suspicious for rabies, should take appropriate steps.
  • Finally, travelers to South Africa should be counseled regarding appropriate STD precautions. Travel sex is often a big part of travel for these kinds of events, and an increased demand for sexual services was seen at the 2000 Sydney Olympic Games. Approximately 29% of South African woman ages 15 to 49 years old are HIV+. Safe sex and use of condoms is essential.

HIV+ Patients Living Longer

Source: Van Sighem A, et al. Life expectancy of recently diagnosed asymptomatic HIV-infected patients approaches that of uninfected individuals. AIDS. 2010, May 12. (epub ahead of print).

Based on data derived from the ATHENA national observational HIV cohort in the Netherlands, these authors compared the life expectancy of 4,612 HIV+ individuals with age- and gender-matched uninfected controls. The patients presented for care between 1998 and 2007, and remained antiretroviral treatment-naïve for at least 24 weeks after diagnosis. Of these, 4,174 (90.5%) did not experience a CDC-B or –C event during those 24 weeks after diagnosis. For these individuals, a multivariate hazards model demonstrated that the median number of years lived from age 25 was 52.7 for HIV+ men and 57.8 years for HIV+ women. In other words, newly diagnosed HIV+ persons who did not experience a CDC-B or –C event within the first 24 weeks of presentation are expected to live nearly as long as their uninfected age-matched controls. For persons presenting at the age of 25, the number of life-years lost in the model was 0.4, and for persons diagnosed at age 55, about 1.4. The life-years lost for persons who experience a CDC-B event within 24 weeks of presentation were estimated to be 1.8 to 8 years.