Volume 7, Number 4—August 2001
THEME ISSUE
West Nile Virus
West Nile Virus
West Nile Encephalitis in Israel, 1999: The New York Connection
Table 1
Antibodies to West Nile virus and clinically related flaviviruses in two encephalitis cases, Tel Aviv, 1999
Serum #1 | Serum #2 | CSF #1 | CSF #2 | |||||
---|---|---|---|---|---|---|---|---|
Case 1 | ||||||||
Days after onset | 9 | 35 | 3 | 14 | ||||
Antigen | IgMa | IgGa | PRNTb | IgM | IgG | PRNT | IgM | IgM |
WN | 13.8 | 1 | 10 | 13.7 | 3.6 | 640 | 0.9 | 21.6 |
Den 1-4 | 2.3 | 1.2 | <10 | 2.6 | 1.7 | <10 | 1 | 1.7 |
CHIK | 0.9 | 1.2 | 0.9 | 1.2 | 1.2 | 1 | ||
SIN | 1 | 1.2 | 1.1 | 1.2 | 1.1 | 1.1 | ||
POW/TBE | 1 | 1.1 | 1.2 | 1.8 | 0.9 | 0.8 | ||
JE | 2.8 | 0.8 | <5 | 6.2 | 0.8 | 20 | 1.5 | 1.7 |
Case 2 | ||||||||
Days after onset | 14 | NA | 7 | NA | ||||
Antigen | IgM | IgG | PRNT | IgM | ||||
WN | 13.5 | 3.1 | 80 | 25.3 | ||||
Den 1-4 | 1.7 | 1.3 | 1.4 | |||||
CHIK | 1 | 1.4 | 0.9 | |||||
SIN | 1.3 | 1.4 | 0.9 | |||||
POW/TBE | 1.1 | 1.4 | 1 | |||||
JE | 2.5 | 0.8 | 5 | 2.1 |
CSF = cerebrospinal fluid; CHIK, Chikungunya virus; Den 1-4 = dengue virus (types 1-4); JE = Japanese encephalitis virus; NA = not available; POW/TBE = Powassan virus tick-borne encephalitis virus; PRNT = plaque-reduction neutralization test; SIN = Sindbis virus; WN = West Nile virus.
aImmunoglobulin M (IgM) and IgG antibody levels were determined by enzyme immunoassay. Results are expressed as positive-negative absorbance ratios (P/Ns), determined by dividing the average optical density of the test sera by the average optical density measured for the negative control sera, with values >3.0 considered to be positive.
bResults of the PRNT are expressed as reciprocal antibody titers, with values 20 considered to be positive.