Self-reported symptoms associated with West Nile virus infection in RNA-positive blood donors
ABSTRACT In 2003, West Nile virus (WNV) nucleic acid amplification testing (NAT) was implemented to detect potentially infected donors. Of more than 5.3 million donations screened prospectively by the American Red Cross during the epidemic periods of 2003 and 2004, 974 were NAT-reactive and 519 confirmed-positive. A subset of both the confirmed-positive and the false-positive groups was assessed for demographic characteristics, symptoms, and symptom reporting relative to date of donation.
All donors with initial WNV NAT-reactive results were invited to participate in a study that included a demographic, symptom, and date-of-symptom questionnaire. WNV confirmed-positive cases were compared to false-positive controls for comparison of frequency of symptom reporting before, on the day of, and after donation.
Enrolled cases and controls were similar in all characteristics except cases were more likely to live in rural areas. Symptoms were reported by 61 percent of cases versus 20 percent of controls, with 74 percent of symptoms reported by cases within the 14 days after donation. The frequency of headache and fever reported together in the 7 days before donation was not significantly different between cases and controls; only the individual frequencies of headache, eye pain, and new rash during this time were significantly different. The most commonly reported symptoms, after adjustment for symptom reporting by controls, were headache, new rash, and generalized weakness; these symptoms were reported by 25 percent of cases.
The demographic characteristics of infected donors reflected the rural nature of the 2003 to 2004 WNV epidemics. This study suggests that asking donors about predonation headache and fever had no detectable contribution to blood safety.
Conference Paper: On lattice-form algorithms for adaptive IIR filtering[Show abstract] [Hide abstract]
ABSTRACT: Lattice-form algorithms are described for adaptive IIR (infinite-impulse-response) filtering that are based on the Gauss-Newton search method. Several approximations of the Hessian matrix that have different levels of computational complexity are considered, and the results are compared to a previous IIR lattice algorithm. Computer simulations in a system-identification configuration illustrate their convergence properties. Algorithms for the two-multiplier lattice with distinct coefficients in each section, and the one-multiplier form, are outlinedAcoustics, Speech, and Signal Processing, 1988. ICASSP-88., 1988 International Conference on; 05/1988
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ABSTRACT: National blood donor screening for West Nile virus (WNV) RNA using minipool nucleic acid amplification testing (MP-NAT) was implemented in the United States in July 2003. We compiled national NAT yield data and performed WNV immunoglobulin M (IgM) testing in 1 WNV-epidemic region (North Dakota). State-specific MP-NAT yield, antibody seroprevalence, and the average time RNA is detectable by MP-NAT were used to estimate incident infections in 2003. WNV donor screening yielded 944 confirmed viremic donors. MP-NAT yield peaked in August with >0.5% of donations positive for WNV RNA in 4 states. Peak IgM seroprevalence for North Dakota was 5.2% in late September. The average time viremia is detectable by MP-NAT was 6.9 days (95% confidence interval [CI] 3.0-10.7). An estimated 735,000 (95% CI 322,000-1,147,000) infections occurred in 2003, with 256 (95% CI 112-401) infections per neuroinvasive case. In addition to preventing transfusion-transmitted WNV infection, donor screening can serve as a tool to monitor seasonal incidence in the general population.Emerging infectious diseases 04/2006; 12(3):395-402. DOI:10.3201/eid1205.051287 · 7.33 Impact Factor
- Transfusion 08/2006; 46(7):1069-71. DOI:10.1111/j.1537-2995.2006.00887.x · 3.57 Impact Factor