Hospital-based enhanced surveillance for West Nile virus neuroinvasive disease.
Accurate data on the incidence of West Nile virus (WNV) disease are important for directing public health education and control activities. The objective of this project was to assess the underdiagnosis of WNV neuroinvasive disease through laboratory testing of patients with suspected viral meningitis or encephalitis at selected hospitals serving WNV-endemic regions in three states. Of the 279 patients with cerebrospinal fluid (CSF) specimens tested for WNV immunoglobulin M (IgM) antibodies, 258 (92%) were negative, 19 (7%) were positive, and two (1%) had equivocal results. Overall, 63% (12/19) of patients with WNV IgM-positive CSF had WNV IgM testing ordered by their attending physician. Seven (37%) cases would not have been identified as probable WNV infections without the further testing conducted through this project. These findings indicate that over a third of WNV infections in patients with clinically compatible neurological illness might be undiagnosed due to either lack of testing or inappropriate testing, leading to substantial underestimates of WNV neuroinvasive disease burden. Efforts should be made to educate healthcare providers and laboratorians about the local epidemiology of arboviral diseases and the optimal tests to be used in different clinical situations.
Arboviral Diseases Branch,Centers for Disease Control and Prevention,Fort Collins,CO,USA.
N P
NP
Lindsey
Arboviral Diseases Branch,Centers for Disease Control and Prevention,Fort Collins,CO,USA.
M
M
Fischer
Foodborne, Waterborne, Vectorborne, and Zoonotic Diseases Section,Minnesota Department of Health,St Paul,MN,USA.
D
D
Neitzel
Foodborne, Waterborne, Vectorborne, and Zoonotic Diseases Section,Minnesota Department of Health,St Paul,MN,USA.
E
E
Schiffman
Viral and Rickettsial Disease Laboratory,California Department of Public Health,Richmond,CA,USA.
M L
ML
Salas
Viral and Rickettsial Disease Laboratory,California Department of Public Health,Richmond,CA,USA.
C A
CA
Glaser
Maricopa County Department of Public Health,Phoenix,AZ,USA.
T
T
Sylvester
Maricopa County Department of Public Health,Phoenix,AZ,USA.
M
M
Kretschmer
Maricopa County Department of Public Health,Phoenix,AZ,USA.
A
A
Bunko
Arboviral Diseases Branch,Centers for Disease Control and Prevention,Fort Collins,CO,USA.
J E
JE
Staples
D000293:Adolescent; D000328:Adult; D000368:Aged; D000914:Antibodies, Viral / Q000134:cerebrospinal fluid; D001130:Arizona / Q000453:epidemiology; D002140:California / Q000453:epidemiology; D002648:Child; D018792:Encephalitis, Viral / Q000134:cerebrospinal fluid / Q000453:epidemiology* / Q000821:virology; D005260:Female; D006761:Hospitals; D006801:Humans; D015994:Incidence; D008297:Male; D008587:Meningitis, Viral / Q000134:cerebrospinal fluid / Q000453:epidemiology* / Q000821:virology; D008875:Middle Aged; D008910:Minnesota / Q000453:epidemiology; D011159:Population Surveillance; D014901:West Nile Fever / Q000134:cerebrospinal fluid / Q000150:complications / Q000453:epidemiology*; D014902:West Nile virus / Q000302:isolation & purification*; D055815:Young Adult
D000914:Antibodies, Viral
Arbovirus; West Nile virus; encephalitis; meningitis; surveillance