Studies on West Nile virus infection in Egypt.
We conducted a prospective cohort study to determine prevalence and incidence of West Nile virus (WNV) in Egypt. Cohorts were established in Upper (UE), Middle (ME), and Lower (LE) Egypt. Additionally, a cross-sectional serosurvey was performed in the North (NS) and South (SS) Sinai. Cohorts were bled initially and 1 year later. Sera were tested for WNV-IgG by ELISA and positive sera were confirmed by plaque reduction neutralization test (PRNT). Sentinel chicken flocks placed in the above sites were bled monthly for virus isolation and serology. Mosquitoes were collected monthly from the above sites and tested for WNV. Human seroprevalence rates were 35%, 27%, 14%, 1% and 7% in UE, ME, LE, NS and SS, respectively. Seroconversion rates were 18%, 17% and 7% in UE, ME and LE, respectively; 49% of the seroconverters reported undiagnosed febrile illness. Sentinel chickens showed seroconversion in all study sites. WNV was isolated from both sentinel chickens and mosquitoes in cohort sites. This study demonstrates that WNV was actively circulating during the study period in different areas in Egypt and causing febrile illness in a considerable proportion of individuals in the study sites.
Soliman
Atef
A
US Naval Medical Research Unit 3, Cairo, Egypt. atef.soliman.ctr.eg@med.navy.mil
Mohareb
Emad
E
Salman
Diaa
D
Saad
Magdi
M
Salama
Sameh
S
Fayez
Caroline
C
Hanafi
Hanafi
H
Medhat
Iman
I
Labib
Emad
E
Rakha
Magda
M
El-Sayed
Nasr
N
Yingst
Samuel
S
Tjaden
Jeffrey
J
Earhart
Kenneth
K
D000293:Adolescent; D000328:Adult; D000368:Aged; D000818:Animals; D000914:Antibodies, Viral / Q000097:blood*; D002645:Chickens / Q000276:immunology / Q000821:virology*; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D009033:Culicidae / Q000821:virology*; D004534:Egypt / Q000453:epidemiology; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D005191:Family Characteristics; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009500:Neutralization Tests / Q000662:veterinary; D011201:Poultry Diseases / Q000097:blood / Q000175:diagnosis* / Q000453:epidemiology / Q000276:immunology / Q000821:virology; D015995:Prevalence; D011446:Prospective Studies; D020133:Reverse Transcriptase Polymerase Chain Reaction; D018571:Sentinel Surveillance / Q000662:veterinary; D016036:Seroepidemiologic Studies; D014901:West Nile Fever / Q000097:blood / Q000175:diagnosis* / Q000453:epidemiology / Q000662:veterinary / Q000821:virology; D014902:West Nile virus / Q000276:immunology / Q000302:isolation & purification*; D055815:Young Adult
D000914:Antibodies, Viral