chapter 22

Chapter 22

Microbial Diseases of the Nervous System

Structure and function of the nervous system

• Central nervous system

• Peripheral nervous system

• Blood-brain barrier

Bacterial diseases of the nervous system

• Meningitis

Bacterial diseases of the nervous system

• Meningitis– Haemophilus influenza– Neisseria sp.– Streptococcus pneumoniae

Bacterial diseases of the nervous system

• Meningitis

• Listeriosis

• Tetanus– Clostridium tetani– Neurotoxin blocks relaxation signal to muscle– Prevent with tetanus toxoid– Treat symptoms with antitoxin

Bacterial diseases of the nervous system

• Meningitis

• Listeriosis

• Tetanus

• Botulism– Clostridium botulinum– Neurotoxin blocks release of acetylcholine– Infant botulism– Wound botulism

Bacterial diseases of the nervous system

• Meningitis

• Listeriosis

• Tetanus

• Botulism

• Leprosy– Mycobacterium leprae

Viral diseases of the nervous system

• Polio– Higher incidence in summer– Virus has high affinity for motor nerves– Salk vaccine in 1954– Sabin vaccine in 1963

Viral diseases of the nervous system

• Polio

• Rabies– Virus multiplies in PNS and migrates to CNS– Long incubation period– Furious rabies– Paralytic rabies– Prevention

• Vaccination

Viral diseases of the nervous system

• Polio

• Rabies

• Arboviral encephalitis– Transmitted by mosquitoes– Disease can result in permanent neurological

damage– Prevent by controlling vectors

Prion diseases of the nervous system

• Sheep scrapie

• Creutzfeldt-Jacob disease

• Bovine spongioform encephalopathy