An ABC for West Nile virus

West Nile Virus: A Challenge for Transplant Programs

West Nile virus is a new challenge for transplant programs worldwide. It is a mosquito-borne disease, which has become increasingly prevalent in North America since it was first recognized in New York in 1999. A review of a case study and the literature shows that the morbidity and mortality associated with West Nile virus infection and transplant recipients are alarmingly high. Treatment options are limited because of transplant programs' limited experience in working with this virus. Transplant programs must develop action plans for education on West Nile virus and its prevention to decrease the risk of infection among their transplant recipients.

The epidemiology of acute encephalitis

Encephalitis means inflammation of the brain matter. Despite being a rare condition, encephalitis is of public health importance worldwide because it has high morbidity and mortality. Yet, many details about its epidemiology have yet to be elucidated. This review attempts to summarise what is known about the epidemiology of the infective causes of encephalitis and is based on a literature search of the Medline archives. Infection is the most common cause identified, with viruses being the most important known aetiological agents. Incidence varies between studies but is generally between 3.5 and 7.4 per 100,000 patient-years. Encephalitis affects peoples of all ages; however, incidence is higher in the paediatric population. Although both sexes are affected, most studies have shown a slight predominance in males. Encephalitis occurs worldwide; some aetiologies have a global distribution (herpesviruses) while others are geographically restricted (arboviruses). Although definite epidemiological trends are evident, it is difficult to make generalisations as few population-based studies exist, most cases are not reported to health authorities, and many possible pathogens are implicated but in most cases a cause is never found. A better understanding of the epidemiology of this devastating disease will pave the way for better prevention and control strategies.

Methylene blue photoinactivation of RNA viruses

We present a review of the current status of the use of methylene blue (MB) photoinactivation of viruses starting with the first early observations up to its current use to inactivate HIV-1 in blood products. Basic mechanism of action studies conducted with model bacteriophages indicate that MB-photomediated viral RNA-protein crosslinkage is a primary lesion and that oxygen, specifically singlet oxygen, is very important also. Basic studies on the mechanism of action with HIV are lacking; however, we do show new data illustrating that viral reverse transcriptase inactivation per se cannot account for MB-mediated photoinactivation. We also show data illustrating that MB photomediates the inactivation of West Nile Virus, a flavivirus, which poses a significant new threat to the continental US. MB photoinactivation of viruses show significant promise because the technology not only offers significant potency but the history of safe MB use in human therapy makes it attractive also.