West Nile Virus and Other Nationally Notifiable Arboviral Diseases - United States, 2016.

Alexis Burakoff,J Erin Staples,Nicole P Lindsey,Marc Fischer,Jennifer Lehman

doi:10.15585/mmwr.mm6701a3

Abstract

Arthropod-borne viruses (arboviruses) are transmitted to humans primarily through the bites of infected mosquitoes and ticks. West Nile virus (WNV) is the leading cause of domestically acquired arboviral disease in the continental United States (1,2). Other arboviruses, including La Crosse, Powassan, Jamestown Canyon, St. Louis encephalitis, and eastern equine encephalitis viruses, cause sporadic cases of disease and occasional outbreaks. This report summarizes surveillance data reported to CDC for 2016 for nationally notifiable arboviruses. It excludes dengue, chikungunya, and Zika viruses, as these are primarily nondomestic viruses typically acquired through travel. Forty-seven states and the District of Columbia (DC) reported 2,240 cases of domestic arboviral disease, including 2,150 (96%) WNV disease cases. Of the WNV disease cases, 1,310 (61%) were classified as neuroinvasive disease (e.g., meningitis, encephalitis, acute flaccid paralysis), for a national incidence of 0.41 cases per 100,000 population. After WNV, the most frequently reported arboviruses were La Crosse (35 cases), Powassan (22), and Jamestown Canyon (15) viruses. Because arboviral diseases continue to cause serious illness, maintaining surveillance is important to direct prevention activities.

Highlights

Meningitis, acute flaccid paralysis, or other neurologic manifestations were categorized as neuroinvasive disease
South Dakota (4.04 per 100,000), North Dakota (3.17), Nebraska (1.84), Wyoming (1.37), and Colorado (1.06) had the highest incidence rates (Table 2) (Figure).The largest number of cases were reported from California [335], Texas [252] and Illinois [98], which together accounted for just over half of neuroinvasive disease cases (52%)
Twenty-two Powassan virus disease cases were reported from nine states (Connecticut, Maine, Massachusetts, Minnesota, New Hampshire, New York, North Carolina, Rhode Island, and Wisconsin)

Summary

Introduction

West Nile virus (WNV) is the leading cause of domestically acquired arboviral disease in the continental United States [1,2]. Forty-seven states and the District of Columbia (DC) reported 2,240 cases of domestic arboviral disease, including 2,150 (96%) WNV disease cases. Of the WNV disease cases, 1,310 (61%) were classified as neuroinvasive disease (e.g., meningitis, encephalitis, acute flaccid paralysis), for a national incidence of 0.41 cases per 100,000 population.

Results

Conclusion