Fatal transplant-associated west nile virus encephalitis and public health investigation-california, 2010.

BACKGROUND: In December 2010, a case of West Nile virus (WNV) encephalitis occurring in a kidney recipient shortly after organ transplantation was identified. METHODS: A public health investigation was initiated to determine the likely route of transmission, detect potential WNV infections among recipients from the same organ donor, and remove any potentially infected blood products or tissues. Available serum, cerebrospinal fluid, and urine samples from the organ donor and recipients were tested for WNV infection by nucleic acid testing and serology. RESULTS: Two additional recipients from the same organ donor were identified, their clinical and exposure histories were reviewed, and samples were obtained. WNV RNA was retrospectively detected in the organ donor's serum. After transplantation, the left kidney recipient had serologic and molecular evidence of WNV infection and the right kidney recipient had prolonged but clinically inapparent WNV viremia. The liver recipient showed no clinical signs of infection but had flavivirus IgG antibodies; however, insufficient samples were available to determine the timing of infection. No remaining infectious products or tissues were identified. CONCLUSIONS: Clinicians should suspect WNV as a cause of encephalitis in organ transplant recipients and report cases to public health departments for prompt investigation of the source of infection. Increased use of molecular testing and retaining pretransplantation sera may improve the ability to detect and diagnose transplant-associated WNV infection in organ transplant recipients.

Infants hospitalized in intensive care units with 2009 H1N1 influenza infection, California, 2009-2010.

BACKGROUND: The 2009 H1N1 influenza virus emerged in April 2009 and primarily affected children and young adults. Few reports describe 2009 H1N1 influenza infection in infants. This report describes the clinical and epidemiologic features of 2009 H1N1 influenza in critically ill infants younger than 1 year of age. METHODS: Laboratory-confirmed cases were reported to the California Department of Public Health as part of public health surveillance for 2009 H1N1 influenza. Data were collected using standardized report forms and medical-chart abstractions. RESULTS: From April 23, 2009 through May 1, 2010, 82 cases of infants hospitalized in the intensive care unit with 2009 H1N1 influenza were reported in California. Medical charts were available for 77 of the infants, whose median age was 109 days (range: 1-361 days). Twenty-seven (35%) infants had a gestational age of 36 weeks or less. More than half (46; 60%) of the infants had at least 1 reported chronic medical condition. Thirty-five (45%) infants required mechanical ventilation; 7 (9%) died. Five infants were hospitalized since birth and acquired influenza infection during their admission; 2 (40%) of these infants died. CONCLUSIONS: Infants who are premature or with chronic conditions seem to be at increased risk for developing severe 2009 H1N1 influenza infection. We encourage clinicians to maintain high suspicion for influenza in infants when influenza viruses are circulating. Vaccination should be encouraged among contacts of infants <6 months of age, who are too young to be immunized or treated with licensed antivirals. Infection control measures should also be implemented in hospital settings to reduce nosocomial transmission.