YF: icosahedral capsid, RNA and lipid envelope; vector: mosquito saliva. Causes infections in the liver, kidney and other organs. No vaccine.
FLU: (airborne) enveloped virus with eight nucleocapsids and helical RNA; causes respiratory tract infections and sometimes lung involvement.
HEPATITIS B: double-stranded DNA, enveloped; causes general weakness, nausea, vomiting. Can be transmitted through the blood. No vaccine.
GENITAL HERPES: double-stranded DNA, icosahedral capsid and envelope; causes infections and blisters around the anus and urethra. Incurable, but acyclovir is often given.
MUMPS: transmitted through the air; causes upper respiratory tract infection and inflamed glands; treated with vaccine.
POLIOMYELITIS: (vehicle: water & food) with icosahedral capsid, RNA; initial infection in the pharynx and intestine. In severe cases causes stiff neck and paralysis of the legs. Has vaccine (shot).
RABIES: (skin & wound) enveloped RNA virus transmitted by dogs; attacks the nervous system. Symptoms appear 3–8 weeks and include fever, hallucinations and hydrophobia. Treated with fluid therapy and prevented by vaccine.
MEASLES: airborne, enveloped RNA virus; childhood disease with respiratory tract infection and involvement of other tissues.
AIDS (HIV): (sexual) enveloped RNA virus that attacks and destroys T cells, causing decreased immune defenses. Treated with antiretrovirals.
VARICELLA: airborne, double-stranded DNA, icosahedral nucleocapsid and enveloped; causes respiratory tract infection and lymph node involvement. Vaccine is not effective. VIRUELA
Bacteria
BOTULISM: disease caused by a neurotoxin produced by bacteria; food poisoning that acts on the nervous system's ability to control muscle contraction. Leads to double vision, difficulty speaking and diaphragmatic paralysis. Treated with antitoxin.
CHOLERA: (contaminated water) infection of the digestive tract causing severe diarrhea. Preventable.
DIPHTHERIA: infection of the throat and tonsils; treated with antitoxin and prevented by vaccine.
PHARYNGITIS: severe inflammation of the throat; treated with penicillin G.
GANGRENE: tissue degeneration caused by bacterial exotoxins (for example, phospholipases); requires removal of affected tissue (debridement), antibiotics and antitoxin where indicated.
GONORRHEA: can cause inflammation of the vaginal mucosa and may be asymptomatic in carriers; in men it commonly affects the urethra and causes purulent discharge. Treated with antibiotics.
PLAGUE: vector: rat fleas; infection of lymph nodes, may produce bleeding spots, delirium and shock. Treated with streptomycin; vaccine available.
PNEUMONIA: infection of the lungs; treated with penicillin. Prevention measures exist.
SYPHILIS: initial skin lesions on the genitals followed by widespread rash; if it spreads to the nervous system and blood vessels it causes systemic complications. Treated with penicillin.
Protozoa
Sleeping sickness: infection of the blood vessels (parasite).
