Asiatic or Epidemic Cholera Vibrio cholerae Asiatic or Epidemic Cholera
Readings Question #1 Describe the Vibrio cholerae bacterium. Where is it found?
Outbreaks no major outbreaks in U.S. since 1911 sporadic: 1973-1991 1991: South America – Peru 1,099,882 cases and 10,453 deaths (1991-95) 1992: new strain – Bangladesh and India 1 case in U.S.
Symptoms of Cholera “rice-water” stools viscous blood sudden onset, incubation: 6 hrs- 5 days violent vomiting No fever abdominal cramps, nausea, dehydration, shock 1 million organisms
Progression of Disease
Diagnosis isolated from feces recovered from foods pathogenic and non-pathogenic forms exist test for presence of cholera enterotoxin
Treatment of Cholera water and electrolyte replacement tetracycline oral rehydration therapy sodium chloride, sodium bicarbonate, potassium chloride and dextrose intravenous rehydration tetracycline untreated – 50% mortality rate death occurs from dehydration and loss of essential electrolytes
Bacillus anthracis 1877 isolated by Robert Koch Readings question #2: List 5 characteristics of the Bacillus anthracis bacterium.
People at Risk handle animals, hides, wool, and other animal products goat hair and handicrafts containing animal hides from the Middle East infection initiated by endospores 2 exotoxins: edema toxin and lethal toxin capsule does not stimulate a protective response
Readings Question #3 What are the 3 forms of anthrax that affect humans?
Treatment of Anthrax antibiotics ciprofloxacin and doxycycline preventive doses of antibiotics (60 days) vaccination of livestock live attenuated human vaccine: inactivated form 6 injections over 18 months Annual boosters
Diagnosis of Anthrax isolation and identification from a clinical speciman
Biological Weapons “the use of living pathogens for hostile purposes” 14th century: 1346 Tartar army at Kaffa began the plague pandemic for 1348 - 1350 1925: 100 countries Sino-Japanese War (1937-1945) canisters of fleas carrying Yersinia pestis dropped on China
U.S. Epidemic Intelligence Service formed in 1951 (after start of Korean War) early warning system important role in combating epidemics and tracking outbreaks of disease 1940s-1960s: research on biological weapons develop vaccines or treatments
“Operation Sea-Spray” September 27 and 27, 1950 Serratia marcescens over San Francisco and Florida (Panama City and Key West) non-pathogenic, reddish coloration September 29: 11 patients (1 died) Pneumonia January 2008: recall of pre-filled heparin-lock flush solution
Serratia marcescens production of red pigment damp conditions: bathrooms complete eradication is difficult dirt, “sterile places”, biofilm of teeth hospital settings: catheters, saline irrigation solutions, sterile solutions urinary and respiratory tract infections in hospitals conjunctivitis, keratitis, endophthalmitis, tear duct infections resistant to several antibiotics
Biological Weapons 1972: 100 countries 1979: Bacillus anthracis in Sverdlovsk explosion resulting in 100 deaths in 2 weeks 1984: The Dalles, Oregon Salmonella enterica 2001: U.S. Postal Service Bacillus anthracis “bioterrorism”
Bordetella Whooping Cough (Pertussis) 2 basic toxins: 1) tracheal cytotoxin - damages ciliated cells 2) pertussis toxin - systemic symptoms small children: violence of coughing can break ribs infants: irreversible damage to the brain occasionally occurs adults: misdiagnosed as bronchitis
Diagnosis of Pertussis clinical signs and symptoms throat swab culture culture on special media rapid tests available
Treatment of Pertussis Erythromycin Antibiotics render the patient noninfectious Immunity following recovery is good DTap Vaccine: 1996, minimal side effects lowered annual cases fewer than 10 deaths/year effectiveness wanes after 12 years of age elderly and infants
Enterics (Enterobacteriaceae) Genera: Escherichia, Klebsiella, Proteus, Salmonella, Shigella straight rods, simple nutritional requirements intestinal tracts of humans and animals fermenters of glucose and carbohydrates fimbriae sex pili proteins: lysis of closely related species
Readings Question #4 What is the most significant opportunistic pathogen of all the enterics? Where is it found? traveler’s diarrhea
Klebsiella pneumoniae normal flora of mouth and skin naturally occurs in soil new antibiotic resistant strains nosocomial infection: invasive treatments
Pathogenesis bacterial pneumonia severe, rapid onset high fever, chills, flu-like symptoms, cough “currant jelly” sputum mortality fairly high lung destruction and abcesses empyema bronchitis urinary tract and wound infections feces and contaminated instruments
Treatment resistant to penicillin and its derivitives two or more powerful antibiotics susceptible to aminoglycosides and cephalosporins culture: sputum, blood, and urine samples and swab of surgical site
Proteus Hospitals: colonizes skin and oral mucosa Rod-shaped, gram-negative bacilli Soil, stagnant and standing water, fecal matter, raw meats, dust Proteus mirabilis: 90% (community-acquired) highly motile, does not form regular colonies
Proteus “Swarming Colonies”
Pathophysiology Fimbriae attach to uroepithelial cells bloodstream: sepsis Long-term indwelling urethral catheters UTIs most common clinical manifestation Readings question #5: What is the significance of Proteus vulgaris to the embalmer?
Salmonella all members potentially pathogenic biochemical and serological tests common inhabitants of the intestinal tract of many animals, especially poultry and cattle contaminate food: unsanitary conditions gram-negative, facultatively anaerobic, non-endospore-forming rods
Salmonella enteritidis intestinal mucosa lymphatic and cardiovascular system less than 1% mortality rate normal recovery in a few days shed in feces for up to 6 months 40-50,000 reported cases; 2-4 million cases Sources: intestinal tracts of animals 1 in 20,000 eggs pet reptiles (90%)
Treatment antibiotic therapy is not useful oral rehydration therapy
Shigella facultatively anaerobic gram-negative rods pathogenic E. coli many cases of “traveler's diarrhea” may actually be mild forms of shigellosis small infective dose primary site: large intestine toxins, destroy tissue, dysentery rarely invade the bloodstream diagnosis: rectal swabs fluoroquinolones
Yersinia pestis Scratches and bites from domestic cats Flea bite – bloodstream- lymph and blood Survive and proliferate in phagocytic cells Fever “buboes”
“Septicemic Plague” septic shock “pneumonic plague”: 100% mortality rate spread by airborne droplets diagnosis: isolating bacterium treatment: streptomycin, tetracycline recovery confers reliable immunity vaccine