Infectious Diseases Clinical Capsules
Avian Flu
Two cases of Avian influenza in a family in Thailand appear to have resulted from person-to-person transmission of the disease. In most of the previous human cases, the individuals had well-documented contact with sick or dying poultry, Kumnuan Ungchusak, M.D., of the Thai Ministry of Public Health, Nonthaburi, Thailand, and colleagues reported.
The index patient became ill following exposure to dying household chickens, and her mother, who came from a distant city to care for her, developed pneumonia and died after providing 16-18 hours of unprotected nursing care. She had no known exposure to poultry. An aunt who helped care for the index patient also developed fever and then pneumonia in the days following the care (N. Engl. J. Med. 2005;352:333-40).
Autopsy tissue from the mother and nasopharyngeal and throat swabs from the aunt were positive for influenza A. Viral gene sequencing showed no change in key features of the virus; the sequences clustered closely with others from recent avian isolates in Thailand, they noted.
Bacterial Meningitis
Ciprofloxacin and ceftriaxone are better than rifampin for prevention of bacterial meningitis in patients at risk of developing the infection, a recent Cochrane Review suggests.
These drugs appear to be as effective as rifampin—the treatment that tends to be used for eradicating Neisseria meningitidis associated with bacterial meningitis—but they are associated with less risk of development of antibiotic resistance, said Abigail Fraser, M.D., of Rabin Medical Centre, Petah-Tikan, Israel, and her colleagues.
Furthermore, ciprofloxacin and ceftriaxone are each given in a single dose, whereas rifampin is given twice daily for 2 days. For this reason, selecting ciprofloxacin or ceftriaxone could improve compliance, the reviewers concluded (Cochrane Database Syst, Rev. 2005 [1]:CD004785.pub2. DOI:10.1002/14651858.CD004785.pub2).
Preventing IPD
A recent outbreak of invasive pneumococcal disease in Alaska led to an investigation that has underscored the preventability of the disease and the importance of vaccination.
Between January 2003 and March 2004, 14 cases of invasive pneumococcal disease were reported in a rural region of the state. The mean number of cases per year in the area is 2.8, according to the Centers for Disease Control and Prevention.
Serotype 12F, which is contained in the 23-valent pneumococcal polysaccharide vaccine, was the cause of disease in 9 of the 14 patients, and 6 of those 9 patients had a medical indication for vaccination (MMWR 2005;54:72-5).
The outbreak highlights the need for providing vaccination in both inpatient and outpatient settings at every opportunity. Because many people without a regular physician might seek care in an emergency department or urgent-care clinic, it is important for these types of facilities to also provide vaccination to those with a medical or age-related indication, the investigators said, noting that doing so could substantially reduce complications and deaths due to pneumococcal disease.
Barriers to vaccination should be identified, and standing orders programs should be implemented, they added.
MRSA Precautions
Single-room or cohort isolation of hospitalized patients with methicillin-resistant Staphylococcus aureus infection does not appear to reduce transmissions, a study suggests.
Admission and weekly screens were performed to determine the incidence of MRSA colonization during the prospective, 1-year study conducted in the intensive care units of two London teaching hospitals. For the middle 6 months of the study period, patients with MRSA were not isolated; during the first 3 months and last 3 months, MRSA-positive patients were isolated in single rooms or nursing cohorts. All 866 patients who needed ICU care for longer than 48 hours were included, Jorge A. Cepeda, M.D., of University College London Hospitals and his colleagues reported.
During the two periods of the study, patients had similar characteristics and MRSA acquisition rates. Use of standard precautions and hand-washing rates did not change between the two study periods. There was no evidence of increased MRSA transmission during the period when infected patients were not isolated, compared with the period when infected patients were moved to isolation rooms (hazard ratio 0.73), the investigators said (Lancet 2005;365:295-304).
Given these findings and the risks inherent in moving and/or isolating critically ill patients, isolation policies in intensive care units with endemic MRSA should be reevaluated, they concluded, adding that efforts to find more effective means of containing MRSA are needed.