A Seroprevalence Study of West Nile Virus Infection in Solid Organ Transplant Recipients

Abstract

West Nile virus (WNV) causes severe neurological disease in less than 1% of infections. However, meningoencephalitis may be more common in immunosuppressed transplant patients. In 2002, a WNV outbreak occurred in our region. To determine the spectrum of disease of community acquired WNV infection and assess public health behavior patterns in transplant recipients, we carried out a seroprevalence study. Patients were enrolled from outpatient transplant clinics in October 2002 and sera were screened for WNV. Questionnaires about WNV were provided to patients. Eight hundred sixteen organ transplant patients were enrolled. The seroprevalence of WNV IgM was 2/816 (0.25%; 95% CI 0.03-0.88%). By extrapolation to our entire transplant population of 2360 patients, and using data from hospital-based surveillance, the risk of meningoencephalitis in a transplant patient infected with WNV is estimated to be 40% (95% CI 16-80%). With regards to knowledge and behavior, 56% patients knew of and 47% used at least one protective measure against WNV. Only 33% used insect repellent. The risk of meningoencephalitis in transplant recipients is much higher than in the general population. There is incomplete knowledge and poor rates of compliance amongst patients with regards to WNV prevention.

Transmission of Tropical and Geographically Restricted Infections during Solid-Organ Transplantation

“…In addition, transplant recipients should be educated regarding the risk of WNV infection and the use of preventive measures, especially as a recent study performed in Canada found poor rates of compliance among SOT recipients with regard to WNV protection (214).…”

West Nile virus meningoencephalitis

“…28 People over 50 years of age (particularly those of 60-89 years of age) are at highest risk (20-fold increase) for developing meningo encephalitis, with a slightly higher incidence among males ( Figure 3). 3,29,31 Immunosuppressed recipients of transplanted organs have an increased risk of developing neuroinvasive disease (estimated at up to 40-fold increase in some studies), 18,32 and when disease develops it is often more severe than in immunocompetent individuals. 33 Other immunosuppressed individuals might be at higher risk, but this has not been shown conclusively.…”

Complications of Kidney Transplantation: Effects of Over-Immunosuppression

“…Compared with the general population, where the infection rate for WNV was 5 per 100,000, the rate in transplant recipients was 200 per 100,000 (P < .001) [99]. A seroprevalence study found a 0.25% seroprevalence and a resultant 40% risk of meningoencephalitis in a transplant patient with community acquired WNV [100]. Similar studies of immunocompetent persons estimate the risk of meningoencephalitis to be less than 1%.…”