Migratory birds and spread of West Nile virus in the Western Hemisphere.

John Rappole

doi:10.3201/eid0604.000401

Abstract

West Nile virus, an Old World flavivirus related to St. Louis encephalitis virus, was first recorded in the New World during August 1999 in the borough of Queens, New York City. Through October 1999, 62 patients, 7 of whom died, had confirmed infections with the virus. Ornithophilic mosquitoes are the principal vectors of West Nile virus in the Old World, and birds of several species, chiefly migrants, appear to be the major introductory or amplifying hosts. If transovarial transmission or survival in overwintering mosquitoes were the principal means for its persistence, West Nile virus might not become established in the New World because of aggressive mosquito suppression campaigns conducted in the New York area. However, the pattern of outbreaks in southern Europe suggests that viremic migratory birds may also contribute to movement of the virus. If so, West Nile virus has the potential to cause outbreaks throughout both temperate and tropical regions of the Western Hemisphere.

Highlights

Rates To determine the expected demographics, rates of hospitalization, and international travel among patients with Salmonella Infantis infections compared with patients with infections caused by other common nontyphoidal Salmonella serotypes, we analyzed data collected through the Foodborne Disease Active Surveillance Network (FoodNet; https://www.cdc.gov/foodnet/index.html) during 2012–2015
The 2014 and 2015 St. Louis encephalitis virus (SLEV) isolates are genetically distinct from the 2003 Imperial Valley, California, strain that was isolated before the 11-year absence of SLEV activity in the state [49]. These results suggest there was likely a single introduction of SLEV into the United States from South America, and possibly Argentina, no later than November 2014, the earliest dated sample from which SLEV was isolated in Arizona and that the virus spread in the summer of 2015 from Arizona to California [49]
Investigation of Feeder Rats Owned by the Patient Because the patient kept feeder rats at home and these rats are a known source of Seoul virus (SEOV) infection, the rats were collected for source investigation

Summary

Introduction

Rates To determine the expected demographics, rates of hospitalization, and international travel among patients with Salmonella Infantis infections compared with patients with infections caused by other common nontyphoidal Salmonella serotypes, we analyzed data collected through the Foodborne Disease Active Surveillance Network (FoodNet; https://www.cdc.gov/foodnet/index.html) during 2012–2015. Begun in 1996, FoodNet has conducted active, population-based surveillance for culture-confirmed cases of infection caused by 9 pathogens transmitted commonly through food, including Salmonella. The FoodNet surveillance area includes 15% of the US population; these data are used to estimate the burden of US foodborne illnesses, hospitalizations, and deaths [1]. L(+) tartrate+, Blockley, Anatum, Mississippi, and Panama. These 20 serotypes represented 69% of nontyphoidal Salmonella isolates reported to FoodNet in 2015

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