West Nile fever in Israel 1999-2000: from geese to humans.

West Nile virus (WNV) caused disease outbreaks in Israel in the 1950s and the late 1970s. In 1998 an outbreak of WNV in goose farms and evidence of infection in dead migratory birds were reported. Consequently, human diagnostic services for WNV were resumed, including virus isolation, serology, and RT-PCR. Risk factors for infection were assessed by a serological survey in 1999, which revealed a seroprevalence of (a) 86% in people who had close contact with sick geese, (b) 28% in people in areas along bird migration routes, and (c) 27% in the general population. Following two fatal cases in Tel Aviv in September 1999 and one encephalitis case in the southern Eilot region, a regional serological survey was initiated there. The survey revealed two more WNV-associated acute encephalitis cases, an IgG seroprevalence of 51%, and an IgM seroprevalence of 22%. In the summer of 2000, acute cases of WN disease were identified in the central and northern parts of Israel, involving 439 people. The outbreak started in mid-August, peaked in September, and declined in October, with 29 fatal cases, primarily in the elderly. During the outbreak, diagnosis was based on IgM detection. Four virus isolates were subsequently obtained from preseroconverted frozen sera. Sequence and phylogenetic analysis of 1662 bases covering the PreM, M, and part of the E genes revealed two lineages. One lineage was closely related to a 1999 Israeli bird (gull) isolate and to a 1999 New York bird (flamingo) isolate, and the other lineage was closely related to a 1997 Romanian mosquito isolate and to a 1999 Russian human brain isolate.

Electro-encephalography spectral analysis of heroin addicts compared with abstainers and normal controls.

UNLABELLED: Previous studies have shown that opiates slow the EEG and, in high doses, reduce the threshold of seizure activity. The present work looks at computerized EEG analyses (in the Fast Fourier Transform-FFT-method) of heroin addicts, recent abstainers and normal controls, with the aim of comparison and delineation of group characteristics. Examinations of 60 taped EEG recordings were performed: 20 subjects were current heroin users, 20 were recent abstainers and 20 were normal controls. Statistical analysis was performed for the relative frequency of wave bands. To amplify the known findings of slowing in heroin users, specific ratios were calculated: the alpha ratio (namely, the 8.0-9.5 Hz to 9.5-12.0 Hz ratio) and the delta to low alpha ratio. The specificity and sensitivity of the FFT method were evaluated through the use of discriminant analysis. The EEG was also recorded on conventional paper and evaluated by a neurologist. RESULTS: The addicts had a higher alpha ratio. The abstainers had a slowing of their alpha waves, a high incidence of delta waves and a delta to low alpha ratio that was relatively high. As a function of time from the beginning of abstinence, this ratio decreased. Abstainers for more than 80 days and controls had identical EEGs. The FFT method had 50% sensitivity for the addicts and 70% for the abstainers, while the specificity was 55%. In contrast, the neurologist's reading of the EEG had a very low sensitivity (25% for the addicts, 30% for the abstainers and 20% for the controls) and a 70% specificity.