| Type | Etiological Agent | Disease | Disease Comments | Treatment |
| Bacteria | Bacillus anthracis | Anthrax | Exotoxin, septicemia; cutaneous, gastrointestinal, and inhalational forms, inhalational is most dangerous form. | Ciprofloxacin or doxycycline plus additional agents; vaccine available but requires a series of six injections over 18 months. |
| Bacteria | Bacillus cerus | Gastroenteritis, Bacillus cereus | Heating doesn't always kill spores, B. cerus grows rapidly and produces toxins. Resembles C. perfringens intoxications | Usually self-limiting; oral rehydration |
| Bacteria | Bacteroides fragilis | Infections of puncture wounds or surgical incisions, peritonitis | imipenem (Primaxin), piperacillin-tazobactam (Zosyn), ampicillin-sulbactam (semi-synthetic penicillins ) +/- cephalosporins | |
| Bacteria | Bartonella henselae | Cat-scratch disease (fever) | Systematic infection, prolonged fever; usually self-limiting although may be fatal. | Azithromycin |
| Bacteria | Bordetella pertussis | Whooping cough | Endotoxin and exotoxin, inactivates cilia in upper respiratory tract, mucus accumulates, spasms of intense coughing to clear mucus. | Erythromycin, clarithromycin better tolerated |
| Bacteria | Borrelia burgdorferi | Lyme disease, relapsing fever | Immune responses responsible for second phase arthritis | Doxycycline or amoxicillin, ceftriaxone or cefotaxime for late complications |
| Bacteria | Borrelia species other than B. burgdorferi | Relapsing fever | Transmitted by soft ticks, characterized by high fever that lasts 3-5 days and may be in excess of 105 F. Three or four relapses may occur. | Penicillin, broad spectrum antibiotics |
| Bacteria | Branhamella (Moraxella) catarrhalis | Otitis media | Amoxicillin/clavulanate po; alternatives: trimethoprim-sulfamethoxazole (TMP-SMX), macrolides (erythromycin, clarithromycin or azithromycin), tetracycline - doxycycline, cephalosporins | |
| Bacteria | Brucella abortus | Brucellosis | Most common species in US, disease is usually mild and self-limiting. Formerly acquired mostly by ingesting cow or other milk. Now mostly by contact with animal carcasses. Pathogen grows within phagocytic cells. | Doxycycline + streptomycin or gentamycin |
| Bacteria | Brucella melitensis | Brucellosis (Undulant fever) | Most common species in the rest of the world, disease is severe, often resulting in disability or death. Fever typically spikes to about 104 F each evening, thus the name undulant fever. | Doxycycline + streptomycin or gentamycin |
| Bacteria | Brucella suis | Brucellosis | Occasional formation of destructive abscesses. | Doxycycline + streptomycin or gentamycin |
| Bacteria | Burkholderia cepacia | Nosocomial infections | Metabolizes accumulated lung secretions in persons with cystic fibrosis | Trimethoprim-sulfamethoxazole (TMP-SMX), cephalosporins, tobramicin (aminoglycosides) |
| Bacteria | Campylobacter jejuni | Gastroenteritis, Campylobacter | Microaerophilic pathogen found in animal intestinal tracts; very common cause of gastroenteritis. Linked to Guillain-Barre' syndrome (1 in 1000 cases) | Usually self-limiting; oral rehydration |
| Bacteria | Chlamydia pneumoniae | Pneumonia, bacterial (Chlamydial) | Atypical. Mild, resembles mycoplasmal pneumonia | Tetracycline |
| Bacteria | Chlamydia psittaci | Psittacosis (Ornithosis) | Transmitted by contact with bird droppings, forms elementary bodies | Tetracycline |
| Bacteria | Chlamydia trachomatis | Conjunctivitis (Inclusion) | Swelling of eyelid; mucus and pus formation; transmitted to infants during birth and is transmitted in unchlorinated swimming water. | Tetracycline (doxycycline) or a macrolide (azithromycin) |
| Bacteria | Chlamydia trachomatis | Lymphogranuloma venereum (LGV) | Swelling in lymph nodes in groin. | Tetracycline (doxycycline) or a macrolide (azithromycin) |
| Bacteria | Chlamydia trachomatis | Pelvic inflammatory disease (PID) | Chronic abdominal pain; possible infertility. | Tetracycline (doxycycline) or a macrolide (azithromycin) |
| Bacteria | Chlamydia trachomatis | Trachoma | Conjunctivitis causes scarring of eyelid that mechanically damages cornea, often causing secondary infections; transmitted by hands, fomites, and perhaps flies. | Tetracycline (doxycycline) or a macrolide (azithromycin) |
| Bacteria | Chlamydia trachomatis | Urethritis (nongonococcal) | Painful urination and watery discharge. In females, possible complications such as PID. | Ceftriaxone (Rocephin, a cephalosporin) or ciprofloxacin (fluroquinolone) + doxycycline |
| Bacteria | Clostridium botulinum | Botulism; wound botulism | Exotoxin preformed in foods, causes paralysis and respiratory failure; infant botulism due to production of toxin by ingested bacteria - normal intestinal flora not well established in children under 1 year of age, spores often found in honey | Antitoxin, antibiotics of almost no use because toxin is preformed |
| Bacteria | Clostridium perfringens | Gas gangrene | Exotoxin | Penicillin with antitoxin; surgical removal of necrotic tissue and amputation; may treat with hyperbaric oxygen. |
| Bacteria | Clostridium perfringens | Gastroenteritis, C. perfringens | Exotoxin, associated with meats or meat stews contaminated with intestinal contents of the animal during slaughter. | Usually self-limiting; oral rehydration |
| Bacteria | Clostridium tetani | Tetanus | Exotoxin, formed in contaminated wound causes uncontrolled muscle contractions, eventual respiratory failure. | Antitoxin, (Tetanus Immune Globulin, TIG) penicillin |
| Bacteria | Corynebacterium diptheriae | Diptheria | Exotoxin interferes with protein synthesis; damages heart, kidneys, and other organs. Membrane forms in throat. Cutaneous form also occurs. | Pencillin and erythromycin in conjunction with antitoxin |
| Bacteria | Coxiella burnetii | Q fever | Usually subclinical, not transmitted by insect or lice bites. | Tetracycline |
| Bacteria | Ehrlichia spp. | Ehrlichiosis | Two forms: Human graulocytic erlichiosis (HGE) and human moncytic ehrlichiosis (HME). Tickborne diseases with a reservoir of infection in animals. | Doxycycline |
| Bacteria | Enterobacter species | Pneumonia, bacterial | Atypical. | Piperacillin/tazobactam + tobramycin (penicillin + aminoglycoside)
or Clindamycin + ciprofloxacin (lincosamide -
like a macrolide + fluoroquinolone) or Ceftazidime or Imipenem +/- aminoglycoside (cephalosporin or penicillin +/- aminoglycoside) |
| Bacteria | Enterococcus faecalis | Sepsis, Gram-positive | Nosocomial | Nafcillin + gentamicin or Nafcillin + ciprofloxacin; Vancomycin for resistant organisms; Synercid for VRE; Zyvox for Synercid resistant organisms |
| Bacteria | Enterococcus faecium | Sepsis, Gram-positive | Nosocomial | Nafcillin + gentamicin or Nafcillin + ciprofloxacin; Vancomycin for resistant organisms; Synercid for VRE; Zyvox for Synercid resistant organisms |
| Bacteria | Escherichia coli | Cystitis | Difficulty or pain in urination | Cephalosporins, chloramphenicol, gentamicin |
| Bacteria | Escherichia coli | Endotoxin shock | Endotoxin | Cephalosporins, chloramphenicol, gentamicin |
| Bacteria | Escherichia coli | Gastroenteritis, enteroinvasive | Shigella-like dysentery | Usually self-limiting; oral rehydration |
| Bacteria | Escherichia coli | Gastroenteritis, enterotoxigenic; Traveler’s diarrhea/Montezuma’s revenge | Exotoxin (enterotoxin); Watery diarrhea that resembles mild form of cholera | Usually self-limiting; oral rehydration |
| Bacteria | Escherichia coli | Pneumonia, bacterial | Atypical. | Piperacillin/tazobactam + tobramycin (penicillin + aminoglycoside)
or Clindamycin + ciprofloxacin (lincosamide -
like a macrolide + fluoroquinolone) or Ceftazidime or Imipenem +/- aminoglycoside (cephalosporin or penicillin +/- aminoglycoside) |
| Bacteria | Escherichia coli | Pyelonephritis | Fever, back or flank pain. | Trimethoprim-sulfamethoxazole (TMP-SMX), cephalosporins, gentamicin (aminoglycosides) |
| Bacteria | Escherichia coli O157:H7 | Gastroenteritis, enterohemorrhagic | Adherence to intestinal mucosa and production of shiga toxin causes hemorrhagic colitis and hemolytic uremic syndrome | Antibiotics, dialysis, transplants (severe hemolytic uremic syndrome) |
| Bacteria | Francisella tularensis | Tularemia (rabbit fever, deer fly fever) | Results from infection from handling small animals such as rabbits; enters by skin abrasions, ingestion, inhalation, bites. Ulceration, conjunctivitis, may cause sepsis and multiple organ infection. Can cause pneumonia when inhaled. | Streptomycin |
| Bacteria | Fusobacterium nucleatum | Occurs in cases of trench mouth along with spirochetes | ||
| Bacteria | Gardnerella vaginalis | Vaginitis | Fish odor, frothy vaginal discharge, presence of clue cells. | Metronidazole (Flagyl) (eliminates anaerobes but allows lactobacilli to repopulate) |
| Bacteria | Haemophilus aegyptus | Conjunctivitis (Contagious) | Along with Haemophilus influenzae, staphylococci and streptococci one of the most common etiological agents of conjuctivitis; transmission is by contact. | Erythromycin, sulfacetamide, tobramycin or gentamycin ointment |
| Bacteria | Haemophilus ducreyi | Chancroid (soft chancre) | Painful ulcers of genitals, swollen lymph nodes in groin. | Ceftriaxone (Rocephin, a cephalosporin) or Erythromycin, trimethoprim-sulfamethoxazole |
| Bacteria | Haemophilus influenzae | Acute epiglottitis | Most dangerous - epiglottis swells and blocks airway | Hib vaccine available, infants don’t respond; Rifampin; chloramphenicol or ampicillin, both in serious infections; second generation cephalosporins |
| Bacteria | Haemophilus influenzae | Meningitis, bacterial | Most common cause of bacterial meningitis before Hib vaccine became available in 1988, occurs primarily in children under age 4. | Hib vaccine available, infants don’t respond; Rifampin; chloramphenicol or ampicillin, both in serious infections; second generation cephalosporins |
| Bacteria | Haemophilus influenzae | Nasopharyngitis | Diseases occur mostly children, adults usually immune. | Hib vaccine available, infants don’t respond; Rifampin; chloramphenicol or ampicillin, both in serious infections; second generation cephalosporins |
| Bacteria | Haemophilus influenzae | Otitis media | Hib vaccine available, infants don’t respond; Rifampin; chloramphenicol or ampicillin, both in serious infections; second generation cephalosporins | |
| Bacteria | Haemophilus influenzae | Pneumonia, bacterial (Haemophilus influenzae) | Atypical. Symptoms resemble pneumococcal pneumonia | Hib vaccine available, infants don’t respond; Rifampin; chloramphenicol or ampicillin, both in serious infections; second generation cephalosporins |
| Bacteria | Helicobacter pylori | Ulcer (Gastric and duodenal), stomach cancer | Erodes gastric mucosa | Bismuth +Metronidazole (Flagyl) + tetracycline (triple therapy); Rantidine bisuth sulfate + clarithromycin is newer and better; dual therapy with antibiotics and proton pump inhibitors may be even better |
| Bacteria | Klebsiella pneumoniae | Pneumonia, bacterial | Atypical. | Piperacillin/tazobactam + tobramycin (penicillin + aminoglycoside)
or Clindamycin + ciprofloxacin (lincosamide -
like a macrolide + fluoroquinolone) or Ceftazidime or Imipenem +/- aminoglycoside (cephalosporin or penicillin +/- aminoglycoside) |
| Bacteria | Legionella pneumophila | Pneumonia (Legionellosis) | Atypical. Poterntially fatal pneumonia that tends to affect older males who drink or smoke heavily. | Erythromycin |
| Bacteria | Leptospira interrogans | Leptospirosis (kidney infection) | Headaches, muscular aches, fever; kidney failure a possible complication | Erythromycin, penicillin, tetracycline |
| Bacteria | Listeria monocytogenes | Listeriosis | Usually transmitted by contaminated food. Main danger is to fetus. | Penicillin G |
| Bacteria | Mycobacterium bovis | Tuberculosis of bone (spine) and/or lymphatics | Tuberculosis of cattle transmitted to humans; Attenuated strain is used for BCG vaccine | Isoniazid, rifampin, ethambutol |
| Bacteria | Mycobacterium leprae | Leprosy (Hansen's disease) | Bacteria grow in PNS; eventually cause extensive tissue damage. | Dapsone, rifampin, and clofazimine in combination; vaccine available as adjunct to chemotherapy; BCG vaccine is also somewhat protective |
| Bacteria | Mycobacterium tuberculosis | Tuberculosis | Systemic (milliary TB) infection, consumption | Isoniazid, rifampin, ethambutol |
| Bacteria | Mycoplasma pneumonia | Pneumonia, bacterial (Mycoplasmal) | Primary atypical or walking pneumonia | Cephalosporin +/- Macrolide: erythromycin, clarithromycin, or azithromycin |
| Bacteria | Neisseriae gonorrhoea (gonococcus) | Gonorrhea | Invasive; males experience painful urination and discharge of pus; females exhibit few symptoms but possible complications such as PID may occur. | Ceftriaxone (Rocephin, a cephalosporin) |
| Bacteria | Neisseriae gonorrhoea (gonococcus) | Neonatal gonorrheal ophthalmia | Acute infection with much pus formation; if treatment is delayed, ulcers form on cornea; transmission is from an infected mother to an infant during its passage through the birth canal. | Silver nitrate, tetracycline, or erythromycin for prevention |
| Bacteria | Neisseriae gonorrhoea (gonococcus) | Pelvic inflammatory disease (PID) | Chronic abdominal pain; possible infertility. | Ceftriaxone (Rocephin, a cephalosporin) |
| Bacteria | Neisseriae meningitidis (meningococcus) | Meningitis, bacterial (meningococcal) | Affects mostly children under age 2. Group A causes widespread epidemics inAfrica; group C in US vcauses local outbreaks. Invasive | Ampicillin, ceftriaxone (Rocephin), chloramphenicol for patients allergic to penicillin |
| Bacteria | Nocardia asteroides | Mycetoma | Localized destructive infection of the feet or hands | Sulfonamides, TMP/SMX, minocycline |
| Bacteria | Pasteurella multocida | Sepsis | Transmitted by animal bites | Penicillin and tetracycline |
| Bacteria | Propionibacterium acnes | Acne | Inflammatory lesions originating with accumulations of sebum that rupture a hair follicle | Benzoyl peroxide, isotretinoin, azelaic acid |
| Bacteria | Proteus species | Food Poisoning | Polymixins, nitrofurantoin | |
| Bacteria | Proteus species | Urinary tract infections | Opportunistic; Endotoxin | Polymixins, nitrofurantoin |
| Bacteria | Pseudomonas aeruginosa | Burn infections | Opportunistic, resistant to many antibiotics and disinfectants; Several exotoxins, endotoxin. Infections have a characteristic blue-green pus caused by the pigment pyocyanin. | Fluoroquinolones (ciprofloxacin), Aztreonam (a monobactam), Carbenicillin (a carboxypenicillin), Gentamicin; silver sulfadiazine to treat burn infections |
| Bacteria | Pseudomonas aeruginosa | Dermatitis | Superficial rash, however Pseudomonas is opportunistic, resistant to many antibiotics and disinfectants; Several exotoxins, endotoxin | Usually self-limiting |
| Bacteria | Pseudomonas aeruginosa | Otitis externa | Superficial infection of external ear canal, however Pseudomonas is opportunistic, resistant to many antibiotics and disinfectants; Several exotoxins, endotoxin | Fluoroquinolones (ciprofloxacin), Aztreonam (a monobactam), Carbenicillin (a carboxypenicillin), Gentamicin |
| Bacteria | Pseudomonas aeruginosa | Pneumonia, bacterial | Atypical. Opportunisitic | Piperacillin/tazobactam + tobramycin (penicillin + aminoglycoside)
or Clindamycin + ciprofloxacin (lincosamide -
like a macrolide + fluoroquinolone) or Ceftazidime or Imipenem +/- aminoglycoside (cephalosporin or penicillin +/- aminoglycoside) |
| Bacteria | Pseudomonas aeruginosa | Wound infections | Opportunistic, resistant to many antibiotics and disinfectants; Several exotoxins, endotoxin. Infections have a characteristic blue-green pus caused by the pigment pyocyanin. | Fluoroquinolones (ciprofloxacin), Aztreonam (a monobactam), Carbenicillin (a carboxypenicillin), Gentamicin |
| Bacteria | Rickettsia prowazekii | Typhus, epidemic | Transmitted by lice (Pediculus humanus corporis); high fever, high mortality rate. | Tetracycline, chloramphenicol |
| Bacteria | Rickettsia rickettsii | Rocky Mountain spotted fever | Transmitted by ticks (Dermacentor species); rash, fever, headache, high mortality rate. | Tetracycline, chloramphenicol |
| Bacteria | Rickettsia tsutsugamushi | Typhus, scrub | Tetracycline, chloramphenicol | |
| Bacteria | Rickettsia typhi | Typhus, endemic murine | Rodents are commonly hosts, transmitted by the rat flea Xenopsylla cheopis; resembles epidemic typhus buyt mortality rate is low. | Tetracycline, chloramphenicol |
| Bacteria | Salmonella enterica | Food Poisoning (Salmonellosis) | Infection type (enterotoxin produced in bowel); Inhabit animal intestinal tracts, contaminate foods. Invade and multiply in intestinal epithelial cells. Do not invade neighboring cells but can enter the bloodstream, causing nausea and diarrhea. | Antibiotics not useful; oral rehdyration therapy |
| Bacteria | Salmonella typhi | Typhoid fever | Invasive, can multiply in macrophages; Shed in human feces; incubation period is about 2 weeks, symptoms include high fever, disseminated infection, significant mortality rate. | Ceftriaxone (Rocephin) or other 3rd generation cephalosporins |
| Bacteria | Shigella dysenteriae | Dysentery (Shigellosis) | Shed in human feces, invade and multiply in intestinal epithelial cells. Infection spreads to neighboring cells, causing tissue damage and dysentery. Shiga toxin causes severe dysentery and prostration | Fluoroquinolones (Ciprofloxacin) |
| Bacteria | Shigella sonnei | Dysentery (Shigellosis) | Invasive and exotoxin, relatively mild dysentery | Usually self-limiting |
| Bacteria | Spirillum minor | Rat-bite fever (Spirillar fever, Asian rat-bite fever, Sodoku) | Fever, headche, muscle aches, inflammation at bite site, complications include endocarditis. | Penicillin |
| Bacteria | Staphylococcus aureus | Carbuncles (abscesses) | Exotoxins | Oral:
Cephalexin, dicloxacillin, clindamycin, amoxicillin/clavulanate; Clindamycin,
TMP-SMX, minocycline, linezolid for
resistant strains. |
| Bacteria | Staphylococcus aureus | Endocarditis, Acute bacterial | Exotoxins | IV: Oxacillin, nafcillin, w or wo gentamicin; vancomycin w gentamicin and rifampin for penicillin-resistant strains |
| Bacteria | Staphylococcus aureus | Folliculitis | Infection of hair follicle; Exotoxins | Drain pus; Oral: Cephalexin, dicloxacillin, clindamycin, amoxicillin/clavulanate; Clindamycin, TMP-SMX, minocycline, linezolid for resistant strains. |
| Bacteria | Staphylococcus aureus | Food Poisoning | Toxin type (enterotoxins produced in the food) | Nafcillin, oxycillin; vancomycin for penicillin-resistant strains |
| Bacteria | Staphylococcus aureus | Furuncles (Boils) | Exotoxins | IV: Oxacillin, nafcillin; vancomycin for penicillin-resistant strains |
| Bacteria | Staphylococcus aureus | Impetigo of the newborn | Highly contagious superficial skin infection; Symptoms - thin-walled vesicles that rupture and crust over; transmission by contact | Hexachlorophene skin lotions |
| Bacteria | Staphylococcus aureus | Otitis media | Build up of pus in middle ear puts painful pressure on eardrum | Nafcillin, vancomycin for resistant organisms |
| Bacteria | Staphylococcus aureus | Pimples | Exotoxins | Oral:
Cephalexin, dicloxacillin, clindamycin, amoxicillin/clavulanate; Clindamycin,
TMP-SMX, minocycline, linezolid for
resistant strains. |
| Bacteria | Staphylococcus aureus | Pneumonia, bacterial | Atypical. | Nafcillin (a penicillin); vancomycin for penicillin-resistant strains |
| Bacteria | Staphylococcus aureus | Scalded skin syndrome | Exfoliative toxins | Oral:
Cephalexin, dicloxacillin, clindamycin, amoxicillin/clavulanate; Clindamycin,
TMP-SMX, minocycline, linezolid for
resistant strains. |
| Bacteria | Staphylococcus aureus | Sties | Exotoxins | Oral:
Cephalexin, dicloxacillin, clindamycin, amoxicillin/clavulanate; Clindamycin,
TMP-SMX, minocycline, linezolid for
resistant strains. |
| Bacteria | Staphylococcus aureus | Toxic shock syndrome | Fever, rash, shock; Exotoxins | Penicillin; Cephalosporins or macrolides (Azithromycin, Clarithromycin [Biaxin], Telithromycin [Ketek]); vancomycin for penicillin-resistant strains |
| Bacteria | Streptobacillus moniliformis | Rat-bite fever (streptobacillary r | Fever, headche, muscle aches, inflammation at bite site, complications include endocarditis. | Penicillin |
| Bacteria | Streptococcus (α-hemolytic) | Endocarditis, Subacute bacterial | Commonly found in oral cavity; Lodge in pre-existing lesions, form clot nuclei | Ampicillin, ceftriaxone (Rocephin), chloramphenicol for patients allergic to penicillin; vancomycin for penicillin-resistant strains |
| Bacteria | Streptococcus agalactiae (group B) | Sepsis, Gram-positive | Most common cause of life-threatening infections in newborns. | Nafcillin + gentamicin or Nafcillin + ciprofloxacin |
| Bacteria | Streptococcus mutans | Dental Caries | Accumulations of plaque allow localized acid production by bacteria, forming hole in tooth. | Drill it and fill it. |
| Bacteria | Streptococcus pneumoniae | Pneumonia, bacterial (Pneumococcal) | Typical. Infected alveoli fill with fluids; interferes with oxygen uptake | Nafcillin (a penicillin); vancomycin for penicillin-resistant strains |
| Bacteria | Streptococcus pneumoniae | Meningitis, bacterial (pneumococcal) | Occurs in children under age 4 and hospitalized elderly. Highest mortality rate of bacterial meningitis since Hib vaccine became available. | Ampicillin, ceftriaxone (Rocephin), chloramphenicol for patients allergic to penicillin; vancomycin for penicillin-resistant strains |
| Bacteria | Streptococcus pneumoniae | Otitis media | TMP-SMX po | |
| Bacteria | Streptococcus pyogenes (group A beta-hemolytic streptococci) | Erysipelas | Reddish patches on skin, often with high fever; Invasive, autoimmune cross-reactivity | Oral:
Cephalexin, dicloxacillin, clindamycin, amoxicillin/clavulanate; Clindamycin,
TMP-SMX, minocycline, linezolid for
resistant strains. |
| Bacteria | Streptococcus pyogenes (group A beta-hemolytic streptococci) | Impetigo | Symptoms - thin-walled vesicles that rupture and crust over; transmission by contact | Oral:
Cephalexin, dicloxacillin, clindamycin, amoxicillin/clavulanate; Clindamycin,
TMP-SMX, minocycline, linezolid for
resistant strains. |
| Bacteria | Streptococcus pyogenes (group A beta-hemolytic streptococci) | Otitis media | Oral:
Cephalexin, dicloxacillin, clindamycin, amoxicillin/clavulanate; Clindamycin,
TMP-SMX, minocycline, linezolid for
resistant strains. |
|
| Bacteria | Streptococcus pyogenes (group A beta-hemolytic streptococci) | Puerperal sepsis | Life threatening complication of childbirth or abortion | Nafcillin or oxycillin; vancomycin for penicillin-resistant strains |
| Bacteria | Streptococcus pyogenes (group A beta-hemolytic streptococci) | Rheumatic fever | Invasive, autoimmune cross-reactivity | Nafcillin or oxycillin; vancomycin for penicillin-resistant strains |
| Bacteria | Streptococcus pyogenes (group A beta-hemolytic streptococci) | Strep throat (may be accompanied by scarlet fever) | Inflammed mucous membranes of the throat. Invasive, autoimmune cross-reactivity | Amoxicillin, ampicillin; vancomycin for penicillin-resistant strains |
| Bacteria | Streptococcus pyogenes (group A beta-hemolytic streptococci) - erythrogenic toxin producing strains | Scarlet fever | Streptococcal exotoxin (erythrogenic toxin) causes skin and tongue reddening, peeling of affected skin. Invasive, autoimmune cross-reactivity | Nafcillin or oxycillin; vancomycin for penicillin-resistant strains |
| Bacteria | Streptococcus pyogenes (invasive group A beta-hemolytic streptococci) | Cellulitis | Invasive, attacks solid tissue, exotoxin A acts a superantigen causing immune cross-reactivity. | Nafcillin or oxycillin; vancomycin for penicillin-resistant strains |
| Bacteria | Streptococcus pyogenes (invasive group A beta-hemolytic streptococci) | Myositis | Invasive, attacks muscle, exotoxin A acts a superantigen causing immune cross-reactivity. | Nafcillin, oral dicloxacillin, clindamycin for penicillin allergy |
| Bacteria | Streptococcus pyogenes (invasive group A beta-hemolytic streptococci) | Necrotizing fascititis | Invasive, attacks muscle covering (fascia), exotoxin A acts a superantigen causing immune cross-reactivity.; Extensive tissue destruction | Surgical removal of tissue; Penicillin + clindamycin + aminoglycoside (or ciprofloxacin) |
| Bacteria | Streptococcus species | Pericarditis | ||
| Bacteria | Treponema pallidum | Syphilis | Initial sore at site of infection, later skin rashes and mild fever. Final stages may be severe lesions, damage to cardiovascular and nervous systems. Tertiary symptoms due to cell-mediated hypersensitivity and inflammatory responses of phagocytes although few progress to tertiary stage today. | Penicillin |
| Bacteria | Vibrio cholerae | Gastroenteritis, Vibrio Non-O1 | Mild diarrhea | Usually self-limiting; oral rehydration |
| Bacteria | Vibrio cholerae O:1 and O:139 | Cholera, Asiatic | Exotoxin causes diarrhea with large loss of water and electrolytes; no invasion of tissue. | Tetracycline (doxycycline); oral rehydration more important |
| Bacteria | Vibrio parahaemolyticus | Gastroenteritis | Exotoxin causes choleralike diarrhea, but generally milder. | Usually self-limiting; oral rehydration |
| Bacteria | Vibrio vulnificus | Gastroenteritis, sepsis | Dangerous to people suffering from liver disease. | Doxycycline |
| Bacteria | Yersinia enterocolitica | Gastroenteritis, Yersinia (yersinosis) | Endotoxin; Inhabits animal intestinal tracts, grows slowly at refrigerator temperatures. Symptoms are abdominal pain and diarrhea, usually mild. May be confused with appendicitis. | Usually self-limiting; oral rehydration |
| Bacteria | Yersinia pestis | Plague | Endotoxin, septicemia; Clasically transmitted by fleas from a reservoir in rats; in western US endemic in rodents. | Streptomycin |
| Bacteria | Yersinia pseudotuberculosis | Gastroenteritis, Yersinia (yersinosis) | Endotoxin | Clinically ill patients & septicemia: ampic |
| Fungus | Aspergillus flavus | Aflatoxin poisoning | Aflatoxin may contribute to cirrhosis and liver cancer, likely to be found on many foods, particularly peanuts | In cases of ingestion, feeding large quantities of an adsorbent such as activated charcoal may be used. Antioxidants such as ellagic acid and inducers of some cytochromes P450, such as indole-3-carbinol, may give a protective effect. |
| Fungus | Blastomyces dermatidis | Blastomycosis | Spreads from lungs, causes abscesses, severe | Itraconazole (non-life threatening, non-meningeal); Amphotericin B for life threatening or CNS infections |
| Fungus | Candida albicans | Candidiasis | Severe vaginal itching, yeasty odor, yellow discharge. | Fluconazole po; miconazole, clotrimazole, and nystatin (topically) |
| Fungus | Candida albicans | Thrush | Opportunistic. Thrush is infection of oral mucosae. Symptoms vary with infection site; usually affects mucous membranes or moist areas of skin. | Fluconazole po; miconazole, clotrimazole, and nystatin (topically); ketoconazole (IV) for systemic candidiasis. |
| Fungus | Candida albicans | Vaginitis, Candidiasis | Opportunistic. Vaginitis is infection of vaginal mucosae. Symptoms vary with infection site (severe vaginal itching, yeasty odor, yellow discharge); usually affects mucous membranes or moist areas of skin. | Fluconazole po; miconazole, clotrimazole, and nystatin (topically); ketoconazole (IV) for systemic candidiasis. |
| Fungus | Claviceps purpurea | Ergot poisoning (ergotism) | Mycotoxins can restrict blood flow in limbs resulting in gangrene; may also cause hallucinations | Gastric lavage, activated charcoal, support for respiratory and renal failure. |
| Fungus | Coccidiodies immitis | Coccidioidomycosis | Progressive disease, resembles T.B. | Amphotericin B |
| Fungus | Cryptococcus neoformans | Cryptococcosis | Severe meningitis transmitted by inhalation of fungus, often from bird droppings | Amphotericin B and flucytosine in combination |
| Fungus | Epidermophyton spp. | Ringworm (tinea) | Skin lesions of highly varied appearance; on scalp may cause local loss of hair. | Griseofulvin (orally), miconazole, clotrimazole (topically) |
| Fungus | Histoplasma capsulatum | Histoplasmosis | Respiratory, usually subclinical, transmitted in bird droppings | Itraconazole (non-life threatening, non-meningeal); Amphotericin B for meningeal infections |
| Fungus | Microsporum | Ringworm (tinea) | Skin lesions of highly varied appearance; on scalp may cause local loss of hair. | Griseofulvin (orally), miconazole, clotrimazole (topically) |
| Fungus | Pneumocystis jiroveci (formerly P. carinii) | Pneumonia, pneumocystis | Atypical. Opportunistic. | Trimethoprim-sulfamethoxazole (TMP-SMX) |
| Fungus | Sporothrix schenckii | Sporotrichosis | Ulcer at site of infection spreading into nearby lymphatic vessels | Potassium iodide solution (orally). |
| Fungus | Trichophyton | Ringworm (tinea) | Skin lesions of highly varied appearance; on scalp may cause local loss of hair. | Griseofulvin (orally), miconazole, clotrimazole (topically) |
| Helminth | Ascaris lumbricoides | Ascariasis | Helminths live off undigested intestinal contents. Transmitte by ingesting eggs from feces. Usually few symptoms. | Mebendazole |
| Helminth | Diphyllobothrium latum (fish) | Tapeworm infection | Helminth lives off undigested intestinal contents with few symptoms. Usually transmitted by ingesting larvae in meats. | Praziquantel and albendazole |
| Helminth | Echinonococcus granulosus | Hydatid disease | Larvae form in body; may be very large and cause damage. Transmitted by ingesting tapework eggs. | Surgical removal, albendazole to kill cysts |
| Helminth | Enterobius vermicularis | Pinworms | Itching around anus. | Pyrantel pamoate and mebendazole |
| Helminth | Necator americanus, Ancyclostoma duodenale | Hookworms | Larvae enter through skin. Large infections may result in anemia. | Mebendazole |
| Helminth | Schistoma larvae of nonhuman animals | Swimmers’s itch | Allergic reaction to the parasite in the skin | Most cases do not require medical attention. Topical use of corticosteroid cream may be used for relief. |
| Helminth | Schistosoma sp. | Schistosomiasis | Eggs lodge in tissue and induce inflammatory response. | Praziquantel and oxamniquine. |
| Helminth | Taenia soluim (pork) | Tapeworm infection | Helminth lives off undigested intestinal contents with few symptoms; pork tapeworm may cause larvae to form in many organs (neurocysticercosis) and cause damage; in this case the eggs are infectious - humans can be the intermediate host. When humans act as the primary host the worms are transmitted by ingesting larvae in meats. | Praziquantel and albendazole |
| Helminth | Taenia saginata (beef) | Tapeworm infection | Helminth lives off undigested intestinal contents with few symptoms. Usually transmitted by ingesting larvae in meats. | Praziquantel and albendazole |
| Helminth | Trichinella spiralis | Trichinosis | Larvae encyst in striated muscle. Transmitted by ingestion of larvae in meats. Usually few symptoms, but large infections may be fatal. | Mebendazole and corticosteroids |
| Parasite | Pediculus humanus capitis | Pediculosis (lice) | Itching, presence of nits | Topical insecticide preparations (1% permethrin or pyrethrin); removal of nits |
| Parasite | Pediculus humanus coporus | Pediculosis (lice) | Itching, presence of nits; transmits disease (epidemic typhus, Rickettsia prowazekii) | Topical insecticide preparations (1% permethrin or pyrethrin); removal of nits |
| Parasite | Pthirus pubis | Crabs | Itching, presence of nits | Topical insecticide preparations (1% permethrin or pyrethrin); removal of nits |
| Parasite | Scaroptes scabiei (mite) | Scabies | Papules due to hypersensitivity reaction to mites | Gamma benzene hexachloride, permethrin (topically) |
| Prion | Prion | Spongiform encephalitis (Creutzfeldt-Jakob disease) | Rare but fatal, spongiform encephalitis, has a heritable form. | None |
| Prion | Prion | Spongiform encephalitis (Kuru) | New Guinea tribes practicing ancestor worship by eating the brains of dead tribe members (not victims). | None |
| Prion | Prion | Spongiform encephalitis (Transmissible mink encephalitis) | None | |
| Prion | Prion | Spongiform encephalitis, Bovine (mad cow disease) | None | |
| Prion | Prion | Spongiform encephalitis, Gerstmann-Straussler-Scheinker syndrome (GSS) similar to CJD, inherited. | None | |
| Prion | Prion | Spongiform encephalopathy, (Scrapie) | Occurs in sheep | None |
| Protozoa | Acanthamoeba | Acanthamoeba keratitis | Corneal inflammation leading to blindness | Topical propamidine isethionate or miconazole; corneal transplant or eye removal surgery may be required. |
| Protozoa | Babesia microti | Babesiosis | A tick-borne disease that resembles malaria, usually subclinical. | Atovaquone and azithromycin in combination. |
| Protozoa | Balantidium coli | Dysentery, Balantidial | Transmitted in cyst stage from contaminated food or water. Pigs are a host. | Tetracycline, with metronidazole(Flagyl) and iodoquinol as alternatives |
| Protozoa | Cryptosporidium parvum | Cryptosporidiosis | Shed in animal feces, causes self-limiting diarrhea. Respiratory and gallbladder infections in immunocompromised patients | Oral rehydration |
| Protozoa | Cyclospora cayetanensis | Cyclospora diarrheal infection | Diarrhea associated with raspberries | Trimethoprim plus sulfamethoxazole (TMP-SMX) |
| Protozoa | Entamoeba histoltica | Dysentery, Amoebic | Lyses epithelial cells of intestine, causes abscesses; significant mortality rate. | Metronidazole (Flagyl) plus iodoquinol |
| Protozoa | Giardia lamblia | Giardiasis | Forms cysts; Adheres to intestinal wall, may inhibit nutritional absorption. Causes diarrhea. | Metronidazole (Flagyl) or quinacrine hydrochloride |
| Protozoa | Leishmania sp. | Leishmaniasis | Skin sores, damage to mucous membranes, systemic disease of deep body organs depending on species. Transmitted by sandfly. | Drugs containing the toxic metal antimony, amphotericin B, recently miltefosine. |
| Protozoa | Naegleria fowleri | Meningocephalitis, Naegleria | Usually classified as a free-living amoeba but has flagellated form as well, usually acquired by swimming in streams or ponds; infects nasal mucosa and later proliferates in brain. | Fatality rate is nearly 100%; Diagnosis is typically made at autopsy, however if caught in time amphotericin B is effective. |
| Protozoa | Plasmodium sp. (P.faciparum, P. vivax, P. malariae, P. ovale) | Malaria | A mosquito-borne disease, characterized by fever and chills at intervals. | Quinine and derivatives chloroquine, primaquine, and mefloquine. Malarone is a new combination drug, as effective as mefloquine and less toxic. Increasing use of artemisinin. |
| Protozoa | Toxoplasma gondii | Toxoplasmosis | Mild in immunocompromised adults, may cause sever fetal damage if initial infection occurs during pregnancy. | Pyrimethamine with sulfadimiazine. Doesn’t affect the chronic bradyzoite statge and is toxic. |
| Protozoa | Trichomonas vaginalis | Urethritis (nongonococcal) | Tinidazole or Metronidazole (Flagyl) | |
| Protozoa | Trichomonas vaginalis | Vaginitis, Trichomoniasis | No cysts, causes vaginitis (Vaginal itching, greenish-yellow discharge); usually nonsymptomatic in males. | Tinidazole or Metronidazole (Flagyl) |
| Protozoa | Trypanosoma brucei rhodesiense, T.b. gambiense | African trypanosomiasis | Transmitted by tsetse fly bites, affects CNS, leads to coma and death | Suramin and pentamidine moderately effective, don’t alter disease’s course. Melarsoprol alters course of disease but is very toxic. Eflornithine, introduced in 1992, is so effective even late that it is referred to as the resurrection drug; more effective against T. b. gambiense, melarsoprol still recommended for T.b. rhodesiense |
| Protozoa | Trypanosoma cruzi | Chagas’ disease (American trypanosomiasis) | Transmitted by reduviid bug, damages cardiac muscle or smooth muscle in esophagus and colon | Difficult to treat due to low efficacy and toxicity of drugs available. Benznidazole or nifurtimox effective when given in acute stage, chronic stage requires management strategies. |
| Virus | Alphavirus (Arbovirus) | Encephalitis, arboviral; eastern equine encephalitis (EEE), western equine encephalitis (WEE), St. Louis encephalitis (SLE), and West Nile encephalitis. | Transmitted by mosquitoes. | Prevention: vaccination and control of mosquito population. |
| Virus | Coronavirus | Upper respiratory infections, common cold. | None | |
| Virus | Coxsackie B virus | Myocarditis | None | |
| Virus | Coxsackie B virus | Post-viral fatigue syndrome (PVFS), chronic fatigue syndrome | None | |
| Virus | Cytomegalovirus (HHV-5) | Cytomegalic inclusion disease | Usually inapparent, chronic, latent. Estimated 80% of the population carries the virus. Disease appears usually when host is immunocompromised and severity of disease correlates with severity of immunosuppression. Symptoms include pneumonia, hepatitis, mononucleosis, and arthritis. Risk of graft rejection increases significantly with CMV infection. | None |
| Virus | Dengue Fever Virus (an arbovirus) | Hemorrhagic fever, viral; Dengue Fever | A classic viral hemorrhagic fever, relatively mild, similar to yellow fever, transmitted by Aedes aegypti mosquito | |
| Virus | Ebola virus (a filovirus) | Hemorrhagic fever, viral | Same as Marburg virus, an emerging viral hemorrhagic fever. Ebola has a mortality rate of close to 90%. | |
| Virus | Epstein-Barr virus (HHV-4) | Burkitt’s lymphoma | Infects B cells and is associated with nasopharyngeal carcinoma. | None |
| Virus | Epstein-Barr virus (HHV-4) | Infectious mononucleosis | Infects B cells, symptoms include malaise and lethargy, pharyngitis, lymph node enlargement, spleenomegaly, fever. | None |
| Virus | Hepatitis A virus | Hepatitis, infectious | Acute hepatitis, mild disease, mostly malaise, often subclinical. 90% recovery, fecal-oral inoculation. | |
| Virus | Hepatitis B virus | Hepatitis, serum | Transmitted by blood and other body fluids, including sexual activity. Severe disease likely to cause liver damage; about 10% of cases become chronic. | |
| Virus | Hepatitis C virus | Hepatitis, serum | Blood-borne non-A non-B hepatitis, similar to HBV but more likely to become chronic | |
| Virus | Hepatitis D virus | Hepatitis | Severe liver damage with high mortality rate. Must be coinfected with HBV | |
| Virus | Hepatitis E virus | Hepatitis, serum | Enterically transmitted non-A, non-B hepatitis; similar to hepatitis A, pregnant women may have high mortality rate. | |
| Virus | Hepatitis F virus | Not characterized yet | ||
| Virus | Hepatitis G virus | Not characterized yet | ||
| Virus | Hepatitis H virus | Not characterized yet | ||
| Virus | Herpes simplex 1 | Cold Sores | Cold sores– usually oral transmission may be respiratory, lesions on upper body. | Acyclovir may modify symptoms |
| Virus | Herpes simplex 1 | Genital herpes | Usually transmitted genitally, oral-genital contact may be a factor. Lesions appear as sores after cell lysis. Virus persists in latent state and is fairly easily reactivated (UV exposure, fever, radiation, stress). | |
| Virus | Herpes simplex 1 | Herpetic keratitis | May progress to corneal ulcers and severe damage | Trifluridine may be effective |
| Virus | Herpes simplex 2 | Genital herpes | Usually transmitted genitally, infections of lower body. Lesions appear as sores after cell lysis. Virus persists in latent state and is fairly easily reactivated (UV exposure, fever, radiation, stress). | |
| Virus | HTLV I, HTLV II | |||
| Virus | Human Immunodeficiency virus (HIV) | AIDS | Immunosuppression | Anti-retrovirals and protease inhibitors |
| Virus | Human parvovirus B19 | Erythema infectiosum, fifth disease | From a 1905 list of skin rash diseases: 1. measles 2. scarlet fever 3. rubella 4. Filatow-Dukes disease 5. erythema infectiosum 6. Roseola infantum; Mild flu-like symptoms, facial rash, maculopapular rash on trunk and limbs. | None |
| Virus | Influenza viruses | Influenza | Types A, B, and C. Segmented genome allows extensive recombination leading to antigenic changes. Transmitted by inhalation, infects respiratory mucosa, allows secondary bacterial infections to occur after epithelial denudation. | Tamiflu early may be helpful. Vaccines are type specific. |
| Virus | Lassa fever virus (an arenavirus) | Hemorrhagic fever, viral; Lassa Fever | Like Ebola, spread among humans by contact with body fluids. | |
| Virus | Lassa-like viruses (arenaviruses) | Hemorrhagic fever, viral; Argentine and Bolivian hemorrhagic fevers | Emerging viral hemorrhagic fevers | |
| Virus | Marburg virus (a filovirus) | Hemorrhagic fever, viral | An emerging viral hemorrhagic fever; initiates from contact with infected monkeys or tissues, may be passed secondarily by contact with secretions or unsterilized instruments. Human-human contact inefficient. Acute fever, muscle pain, abdominal pain, rash, severe gastrointestinal bleeding, generalized hemorrhage, shock, death. | |
| Virus | Mastadenovirus | Respiratory infections in humans, some cause tumors in animals. | ||
| Virus | Measles virus | Measles, red (rubeola) | Skin rash of reddish macules first appearing on face and spreading to trunk and extremities. Transmission by inhalation usually, spreads to lymph nodes, infects T-cells. Antibody titer rises, rash appears (probably immune complex mediated hypersensitivity), fever, cough, conjunctivitis. Recovery is usually rapid, complete, and imparts lifelong immunity. | Vaccination provides effective long-term immunity. |
| Virus | Measles virus | Subacute sclerosing panencephalitis | A rare complication of measles that occurs mostly in males 1-10 years after recovery from infection. Sever neurological symptoms and death within a few years. | Vaccination provides effective long-term immunity. |
| Virus | Mumps virus | Mumps | Half of infections are inapparent. Invades upper respiratory tract and lymph nodes, spreads to target organs (most common is parotid gland). Can cause orchitis (testicular inflammation) in post-pubescent males, may result in sterility. | Vaccine available. |
| Virus | Norwalk Agent (Noroviruses, Norwalk-like viurses) | Gastroenteritis | Immunity is poor. | Self-limiting |
| Virus | Papillomavirus spp. | Genital warts | Warts in genital area. HPV-16 associated with close to 90% of cervical cancers, especially serious in South Carolina. | May be removed by liquid nitrogen, cryotherapy, electrodesiccation, acids, or lasers. |
| Virus | Papillomavirus spp. (Papovaviruses) | Warts | A horny projection of the skin, formed by proliferation of cells. Some warts are sexually transmitted. | May be removed by liquid nitrogen, cryotherapy, electrodesiccation, acids, or lasers. |
| Virus | Poliovirus | Poliomyelitis | Transmitted mainly with ingested water. About 1% of cases result in at least partial paralysis. Loss of anterior horn cells (motor neurons) causes flaccid paralysis, sometimes of diaphragm (thus the use of the iron lung). Three different serotypes of the virus. | Vaccination – Salk vaccine developed in 1954 is a formalin inactivated vaccine (IPV – inactivated polio vaccine), requires repeated injection, may be as high as 90% effective. Sabin vaccine introduced in 1963 contains 3 living attenuated strains of the virus, taken orally (OPV – oral polio vaccine); immunity resembles natural immunity but attenuated strains may revert to virulence. |
| Virus | Rabies virus (Lyssavirus) | Rabies | Zoonotic, transmission by contact with infected animals. Virus spreads from wound to brain along neurons. Incubation is 1 week to 1 year depending on site of wound. Symptoms include cerebral hyperirritability, rage, pharyngeal muscle spasm, alternating mania and coma until death, usually by respiratory failure (destruction of respiratory center. | Vaccine available, treatment includes injection with immune globulin and vaccine. |
| Virus | Respiratory syncytial virus (RSV) | Pneumonia, viral (RSV disease) | Atypical. A serious respiratory disease of infants and the elderly. Viral pneumonia may also be a complication of influenza, measles, or chickenpox; may be caused by a number of different kinds of viruses, including parainfluenza viruses (measles and mumps viruses) and adenoviruses. | |
| Virus | Rhinovirus | Common cold | Over 300 different viruses, makes vaccine development impractical. | None |
| Virus | Roseolovirus (HHV-6) | Roseola infantum (sixth disease, exanthem subitum) | High fever, generalized rash, rapid and complete recovery | None |
| Virus | Rotavirus | Gastroenteritis | Immunity acquired to most strains after initial infection, makes incidence of infection in adults less common than in children. New vaccine approved in Feb. 2006. | Self-limiting |
| Virus | Rubella virus | Congenital rubella syndrome | Congenital rubella syndrome can affect a fetus when a woman contracts rugella during the first trimester of her pregnancy. Damage from congenital rubella syndrome includes stillbirth, deafness, eye cataracts, heart defects, and mental retardation. | |
| Virus | Rubella virus | Measles, German (Rubella) | A red rash and light fever might occur in an infected individual; the disease can be asymptomatic. Respiratory transmission, imparts long-lasting immunity. | |
| Virus | Sin Nombre hantavirus | Hantavirus pulmonary syndrome | Frequently manifests as a fatal pulmonary infection, spread by aerosols from field mouse excretions. | |
| Virus | Varicella zoster (HHV-3) | Chicken Pox (varicella) | Vesicles in most cases confined to face, throat, and lower back. Primary infection is chicken pox, may be accompanied by pneumonia and encephalitis in immuno-compromised children; more severe in adults, usually accompanied by pneumonia. Transmission is respiratory. | Acyclovir for immunocompromised patients, vaccine available. |
| Virus | Varicella zoster (HHV-3) | Shingles (herpes-zoster) | Vesicles similar to chickenpox; typically on one side of waist, face and scalp, or upper chest.Virus remains dormant in dorsal root or cranial nerve ganglia, reactivated by stress, travels down nerve fiber and causes painful blisters in the relevant dermatome. Unexposed people can contract chicken pox from zoster lesions but not vice versa; primary exposure imparts immunity to exogenous infection. | Acyclovir for immunocompromised patients. |
| Virus | Variola major | Smallpox, (pox – vesicopustular skin eruptions). | Pustules that may be nearly confluent on skin; systemic viral infection affects many internal organs. Transmission is respiratory. | None |
| Virus | Yellow Fever Virus (Flavivirus, an arbovirus) | Hemorrhagic fever, viral; Yellow Fever | A classic viral hemorrhagic fever transmitted by mosquito bites. Hepatic necrosis, jaundice, fever, vomiting, diarrhea, mortality rate of 80%; Yellow fever prohibited significant colonization of large parts of South and Central America until controlled (elimination of mosquito population); Panama canal was discontinued until the disease was controlled. | Vaccine is now available. |