The risk of infection after transplantation changes over time, particularly with modifications in immunosuppression. Unfortunately, no assays accurately measure a patient’s risk of infection. Currently, therefore, the clinician assesses a recipient’s risk of infection while considering the risk of allograft rejection, the intensity of immunosuppression, and other factors that may contribute to his or her susceptibility to infection. Prophylactic strategies are based on the patient’s known or likely exposures to infection according to the results of serologic testing and epidemiologic history. The risk of infection in the transplant recipient is a continuous function of the interplay between these factors.

https://nuhem.com/emlinks/LLSA%20Articles%202013/Infection%20in%20solid%20organ%20transplant%20recipients.pdf

Infection in Solid-Organ Transplant Recipients

Mosquito-borne flaviviruses provide some of the most important examples of emerging and resurging diseases of global significance. Here, we describe three of them: the resurgence of dengue in tropical and subtropical areas of the world, and the spread and establishment of Japanese encephalitis and West Nile viruses in new habitats and environments. These three examples also illustrate the complexity of the various factors that contribute to their emergence, resurgence and spread. Whereas some of these factors are natural, such as bird migration, most are due to human activities, such as changes in land use, water impoundments and transportation, which result in changed epidemiological patterns. The three examples also show the ease with which mosquito-borne viruses can spread to and colonize new areas, and the need for continued international surveillance and improved public health infrastructure to meet future emerging disease threats.

/pdf/emerging-flaviviruses-the-spread-and-resurgence-of-japanese-1ac5t0dmfv.pdf

Emerging flaviviruses: the spread and resurgence of Japanese encephalitis, West Nile and dengue viruses

Many pandemics have been attributed to the ability of some RNA viruses to change their host range to include humans. Here, we review the mechanisms of disease emergence that are related to the host-range specificity of selected mosquito-borne alphaviruses and flaviviruses. We discuss viruses of medical importance, including Venezuelan equine and Japanese encephalitis viruses, dengue viruses and West Nile viruses.

/pdf/transmission-cycles-host-range-evolution-and-emergence-of-2j0r7khe5z.pdf

Transmission cycles, host range, evolution and emergence of arboviral disease.

Fifty years ago, the age-old scourge of infectious disease was receding in the developed world in response to improved public health measures, while the advent of antibiotics, better vaccines, insecticides and improved surveillance held the promise of eradicating residual problems. By the late twentieth century, however, an increase in the emergence and re-emergence of infectious diseases was evident in many parts of the world. This upturn looms as the fourth major transition in human-microbe relationships since the advent of agriculture around 10,000 years ago. About 30 new diseases have been identified, including Legionnaires' disease, human immunodeficiency virus (HIV)/acquired immune deficiency syndrome (AIDS), hepatitis C, bovine spongiform encephalopathy (BSE)/variant Creutzfeldt-Jakob disease (vCJD), Nipah virus, several viral hemorrhagic fevers and, most recently, severe acute respiratory syndrome (SARS) and avian influenza. The emergence of these diseases, and resurgence of old ones like tuberculosis and cholera, reflects various changes in human ecology: rural-to-urban migration resulting in high-density peri-urban slums; increasing long-distance mobility and trade; the social disruption of war and conflict; changes in personal behavior; and, increasingly, human-induced global changes, including widespread forest clearance and climate change. Political ignorance, denial and obduracy (as with HIV/AIDS) further compound the risks. The use and misuse of medical technology also pose risks, such as drug-resistant microbes and contaminated equipment or biological medicines. A better understanding of the evolving social dynamics of emerging infectious diseases ought to help us to anticipate and hopefully ameliorate current and future risks.

Social and environmental risk factors in the emergence of infectious diseases

Background During the 2002 West Nile virus epidemic in the United States, patients were identified whose West Nile virus illness was temporally associated with the receipt of transfused blood and blood components. Methods Patients with laboratory evidence of recent West Nile virus infection within four weeks after receipt of a blood component from a donor with viremia were considered to have a confirmed transfusion-related infection. We interviewed the donors of these components, asking them whether they had had symptoms compatible with the presence of a viral illness before or after their donation; blood specimens retained from the time of donation and collected at follow-up were tested for West Nile virus. Results Twenty-three patients were confirmed to have acquired West Nile virus through transfused leukoreduced and nonleukoreduced red cells, platelets, or fresh-frozen plasma. Of the 23 recipients, 10 (43 percent) were immunocompromised owing to transplantation or cancer and 8 (35 percent) were at lea...

https://www.nejm.org/doi/pdf/10.1056/NEJMoa030969

Transmission of West Nile virus through blood transfusion in the United States in 2002.

Background In August 2002, fever and mental-status changes developed in recipients of organs from a common donor. Transmission of West Nile virus through organ transplantation was suspected. Methods We reviewed medical records, conducted interviews, and collected blood and tissue samples for testing with a variety of assays. Persons who donated blood to the organ donor and associated blood components were identified and tested for West Nile virus. Results We identified West Nile virus infection in the organ donor and in all four organ recipients. Encephalitis developed in three of the organ recipients, and febrile illness developed in one. Three recipients became seropositive for West Nile virus IgM antibody; the fourth recipient had brain tissue that was positive for West Nile virus by isolation and nucleic acid and antigen assays. Serum specimens obtained from the organ donor before and immediately after blood transfusions showed no evidence of West Nile virus; however, serum and plasma samples obtained...

https://www.nejm.org/doi/pdf/10.1056/NEJMoa022987

Krista L Hillyer

Papers

Transmission of West Nile virus from an organ donor to four transplant recipients.