Avian hosts for West Nile virus in St. Tammany Parish, Louisiana, 2002.
West Nile virus (WNV) infections in free-ranging birds were studied in Slidell, St. Tammany Parish, Louisiana, after a human encephalitis outbreak peaked there in July 2002. Seroprevalence in resident, free-ranging wild birds in one suburban site was 25% and 24% in August and October, respectively, indicating that most transmission had ceased by early August. Mortality rates, seroprevalence rates, host competence, and crude population estimates were used in mathematical models to predict actual infection rates, population impacts, and importance as amplifying hosts for several common passerine birds. Northern cardinal (Cardinalis cardinalis) and house sparrow (Passer domesticus) were the principal amplifying hosts, but blue jay (Cyanocitta cristata) and northern mockingbird (Mimus polyglottos) also contributed. The blue jay population was reduced by an estimated 47%. A variety of passerine bird species combined to play an important role as amplifying hosts in the WNV transmission cycle.
Komar
Nicholas
N
Division of Vector-Borne Infectious Diseases, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Fort Collins, Colorado 80522, USA. nkomar@cdc.gov
Panella
Nicholas A
NA
Langevin
Stanley A
SA
Brault
Aaron C
AC
Amador
Manuel
M
Edwards
Eric
E
Owen
Jennifer C
JC
D000818:Animals; D001717:Birds / Q000145:classification / Q000821:virology*; D004196:Disease Outbreaks; D004197:Disease Reservoirs / Q000145:classification / Q000821:virology*; D018792:Encephalitis, Viral / Q000453:epidemiology* / Q000209:etiology / Q000635:transmission / Q000821:virology; D006801:Humans; D008145:Louisiana / Q000453:epidemiology; D014901:West Nile Fever / Q000453:epidemiology* / Q000209:etiology / Q000635:transmission / Q000821:virology; D014902:West Nile virus / Q000302:isolation & purification*