FAMILY EREONACEAE 



1251 



Thermal inactivation : At 56° C in 30 

 minutes. 



Filterability : Passes Berkefeld N, W, 

 Chamberland L2, Lg, and Seitz EK filters, 

 with ease. 



Literature: Kudo et al., Jour. Im- 

 munol., 32, 1937, 129-135; Smorodintseff 

 et al.. Arch. f. gesamt. Virusforsch., 1, 

 1940, 550-559 ; Webster, Jour. Exp. Med., 

 67, 1938, 609-618. 



5. Erro nili spec. nov. From Latin 

 Nilus, god of the Nile. 



Common name : West Nile encephalitis 

 virus. 



Hosts : HOMINIDAE— Homo sapiens 

 L., man (perhaps without inducing any 

 definite disease). Experimentally, also 

 rhesus monkey, mouse. 



Geograpliical distribution : Africa 

 (Uganda). 



Induced disease : In man, no details are 

 known ; virus was originally isolated from 

 blood of a woman native of Uganda ; at the 

 time the temperature of the patient was 

 100.6° F but she denied illness ; moreover, 

 two laboratory workers developed neu- 

 tralizing antibodies without recognizable 

 clinical disease. In mouse, experimen- 

 tally, after intracerebral inoculation, in- 

 cubation period to 4 or 5 days, then 

 hyperactivity and roughening of coat ; 

 later, weakness, hunched attitude, some- 

 times paralysis of hind quarters ; usually 

 coma before death. In rhesus monkey, 

 experimentally, after intracerebral or 

 intranasal inoculation, fever and en- 

 cephalitis. 



Serological relationships : No cross reac- 

 tions in complement fixation tests between 

 this and equine encephalitis virus, 

 Japanese B encephalitis virus, St. Louis 

 encephalitis virus, or lymphocytic chori- 

 omeningitis virus. Neutralization tests 

 show some common antigens in West Nile 

 encephalitis virus, Japanese B encepha- 

 litis virus and St. Louis encephalitis 

 virus ; antiserum to West Nile virus does 

 not neutralize either of the others but 

 antisera against St. Louis virus may 

 neutralize West Nile virus and antisera 



against Japanese B virus have some effec- 

 tiveness in neutralizing both West Nile 

 virus and St. Louis virus. 



Immunological relationships : Vaccina- 

 tion with this virus does not enhance 

 resistance to Japanese B or St. Louis 

 encephalitis viruses but only resistance 

 to the homologous virus. 



Thermal inactivation : At 55° C, not 

 at 50° C, in 30 minutes. 



Filterability: Passes Berkefeld V, N, 

 and W filter candles readily; also passes 

 Seitz EK asbestos pads and collodion 

 membranes 79, not 62, millimicrons in 

 average pore diameter. 



Other properties : Infective particle 21 

 to 31 millimicrons in diameter, as calcu- 

 lated from filtration experiments. Vi- 

 able at least 2 weeks at 2 to 4° C. Viable 

 after drying from the frozen state. 



Literature: Havens et al.. Jour. Exp. 

 Med., 77, 1943, 139-153; Smithburn, Jour. 

 Immunol., U, 1942, 25-31 ; Smithburn et 

 al.. Am. Jour. Trop. Med., 20, 1940, 471- 

 492. 



6. Erro scelestus spec. nov. From 

 Latin scelestus, infamous. 



Common name: St. Louis encephalitis 

 virus. 



Hosts : HOMINIDAE — Homo sapiens 

 L., man. A great number of mammals 

 and birds in endemic areas may have 

 antisera that neutralize the virus, indi- 

 cating that they are probably natural 

 hosts; among these are : ANATIDAE— 

 Anas plalyrhyncha L., Mallard and Pekin 

 ducks; Anser anser (L.), domestic goose. 

 BOVIDAE — Bos taurus L., cow; Capra 

 hircus L., goat; Ovis aries L., sheep. 

 CANIDAE — Canis familiaris L., dog. 

 COL UMBIDAE—Columba livia, domes- 

 tic pigeon ; Zenaidura macroura, western 

 mourning dove. EQUIDAE — Equus ca- 

 ballvs L., horse. FALCONIDAE— 

 Falco sparverius L., sparrow hawk. LE- 

 PORIDAE — Lcpiis californicus Gray, 

 jack rabbit ; Sylvilagus nuiialli, cotton- 

 tail rabbit. MELEAGRIDAE—Mele- 

 agris gallopavoh., turkey. MURIDAE 

 — Rattus norvegicus (Berkenhout), brown 



