Yellow Fever Virus Encephalitis in South American Monkeys
Wray Lloyd AND
H. A. Penna
From the Yellow Fever Laboratory of the International Health Division of The Rockefeller Foundation, Bahia, Brazil
1. Neurotropic yellow fever virus contained in Berkefeld N filtratesof infectious brain material was transferred by direct brainto brain inoculation through four passages in Saimiri sciureus,producing in each animal a well marked encephalitis characterizedby a uniform clinical course and definite pathological lesions.The virus recovered from the brain of the last monkey in theseries could be positively identified as yellow fever virusby passive immunity tests in mice.
2. A clinically and pathologicallycharacteristic encephalitiswas produced in Ateleus monkeysby the intracerebral inoculationof neurotropic yellow fevervirus. The virus could be recoveredfrom the brain or sciaticnerve at the death of the monkey and,when injected intracerebrallyinto a rhesus monkey or into mice,produced typical yellow fevervirus encephalitis.
3. Neurotropic yellow fever virus containedin Berkefeld N filtratesof infectious cerebral tissues wascarried by intracerebralinoculation through two passages inCebus frontatus, causingin each animal an encephalitis whichran a typical clinicalcourse and produced characteristic lesions.The virus couldbe isolated from the brain and adrenal glandat the time ofthe death of the monkey.
4. Neurotropic yellowfever virus, contained in Berkefeld Nfiltrates of infectiousbrain substance, was transferred byintracerebral inoculationthrough three passages in Callithrixmonkeys, with the productionof a uniformly fatal encephalitis.
5. The intracerebral inoculationof Leontocebus ursulus withneurotropic yellow fever virus wasfollowed by a febrile reactionand in some instances by neurologicalsymptoms and death, withthe presence of small perivascularinfiltrations in the brain.No success was attained in a limitedattempt to transfer thevirus in series in L. ursulus.