Page 1 of3S3 L19: Rhabdoviridae by Dr. Bunyi D DDe e e c c c e ee m mmb bbe eer r r 1 11 , , , 2 22 0 0 0 1 11 0 0 0 RABIES viral infection of animals excreted in saliva of an infected animal almost always fatal once symptoms appearorder: Mononegavirales onon-segmented, negative stranded RNA genomes classified in the Rhabdoviridae family (“bullet shaped”)a) Lyssavirus– includes rabies virus b) Ephemovirus c)Vesiculovirus STRUCTURE Approximately 180nm long and 75nm wide Genome encodes 5 proteins a.Nucleoprotein (N) b.Phosphoprotein (P) c.Matrix protein (P)– associated with RNP & envelope d.Glycoprotein (G) e.Polymerase (L) 2 major structural components 1.Helical ribonucleoprotein core (RNP) 2.envelope EPIDEMIOLOGY Asia 3.1 B people potentially exposed to dog bites > 35,000 human rabies deaths 98% from rabid dog bites > 10 M PET annually > 40% < 15 yrs old Philippines 400 cases or 6M population annually dog bites > 98% of cases Almost 3,000 lab confirmed (+) in almost all islands of the country Region V (Central Luzon), Region II National Rabies Control and Eradication Program, 1994 Annual consultation of 400,000 cases 80% require PET (post exposure treatment) only 15% receive PET Dog: 98% responsible for all human rabies cases Cat: 1.3% Others: < 1% RITM (2001) dog bite: #1 consultation 1,500 new cases ; > 3,000 ff-up/mo 27%: <5 yrs 65.5%: <19 yrs Exposures Category III– 83% Category II– 16% Category I– 1% TRANSMISSION bites of rabid animals licking of mucosa or open wounds PERIOD OF COMMUNICABILITY Dogs and Cats: 3-5 days before the onset of symptoms until the entire course of the illness INCUBATION PERIOD 1 day to 5 years (8 weeks) Average IP: 10-90 days n = 707 71% cases < 1 month 87% cases < 3 months VARIATION severity of bite site of bite in relation to nerve supply and distance from CNS size of inoculum, protection offered by clothing age and immune status of the host CLINICAL MANIFESTATIONS Animal rabies: sudden change in behaviorcharacteristic hoarse howl watchful, apprehensive expression of eyes, staring, blank gaze drooling of saliva paralysis of lower jaw and tongue, inability to drink paralysis or uncoordinated gait in some cases, lies quiescent, biting when provoked marked excitability and restlessness: pacing in cage if restrained, attacks objects within range, bites cage if at large, runs aimlessly, biting anything in its way depraved appetite, self-mutilation snaps at imaginary objects sudden death without associated signs and symptoms Prodromal Symptoms: lasts from 2 to 10 days non-specific (malaise, fatigue, headache, anorexia, nausea & vomiting, restlessness, ill defined anxiety, sore throat, fever, pain or paresthesia close to the site of exposure) i I J l r J l l i J t J l i i r i ň r l i l i i i s i J i i
