UNIT 9: DISEASES AND DISORDERS:

1. UNIT 9: DISEASES AND DISORDERS: An infection occurs when living agents enter tissue, multiply there and damage the tissue.

2. The General causative agents for disease include: • bacteria • viruses • fungus • Rickettsia • protozoan • arthropods (acting as vectors) • vermiform (various invertebrate worms)

3. STAPHYLOCCOCCAL INFECTIONS: (bacteria) • Staphyloccocci are spherical gram positive bacteria about .5 to 1.5 miccrometers in diameter. • They tend to form in irregular clusters like grapes • Staphylococcus aureus is the most pathogenic of the staphylococci (forms golden yellow colonies, almost all pathogenic and produces coagulase for blood clotting) • S. Aureus common problem in hospital s due to being carried on the skin of patients, visitors and the danger of infection of surgical wounds or skin breaks is high .

4. S. aureus is difficult to treat and is very resistant to many antibiotics…..mainly due to resistance to penicillinase. • S aureous often enters the body via natural openings in the skin barrier, hair follicles ect…, if through mouth (food poisoning) • Antibiotics do not penetrate abscesses well, thus making the infection more difficult to treat, often draining pus from abscess is one of the first steps of treatment…treat with penicillin or erythromycin.

5. Staph infections on newborns includes impetigo (vesicles on the skin rupture and crust over), or scalded skinsyndrome ( lesions on the nose and mouth, then bright red area appears, within 48 hr the skin of palms and soles peels off in sheet when touched…serious illness) • 30 to 50% health adults carry staph in their nose and 20% carry staph on their skin.. and the human immune system is good at combating staph infections ( most susceptible include infants, elderly drug users and immune impaired)

6. scalded skinsyndrome

7. The boils that Job scraped with broken pottery (Job 2:7-8) could only have been caused by staph

8. STREPTOCCOCAL INFECTION: including flesh-eating bacteria • Streptococci are gram positive spherical bacteria with cells growing in chains. • They are facultative anaerobes • Many are nonpathogenic and occupy the mouth, gastrointestinal tract and upper respiratory systems. • Some Streptococci are responsible for skin infections and secrete several enzymes including hemolysins (damages RBCs) • Impetigo is one disease caused by Strep infections (symptoms include: superficial skin infection, isolated pustules( round elevations full of pus) that become crusted and rupture

9. Impetigo is one disease caused by Strep infections

10. Strep also causes scarlet fever, infections of the throat • Steptococcus pneumonia most common cause of bacterial pneumonia…and also the cause of flesh-eating bacteria (necrotizing fasciitis ) • S. pneumoniais highly resistant and emits an enzyme able to destroy the fascia, or tissue that binds skin to muscle at a rate of an inch an hour…about 1500-2000 cases in USA per year with fatality rate of 30% in otherwise healthy adults.

11. necrotizing fasciitis

12. Jim Henson from muppets died of this bacteria in 1990 from a splinter cut on his finger (duration from time of splinter to death—6 weeks)

13. PSEUDOMONADS (bacteria) • Aerobic gram negative rods, widespread in soil and water, able to survive in any moist environment. • Cause otitis externa (swimmers ear) • Pseudomonas dermatitis causes rash outbreaks and is associated with swimming pools

14. Pseudomonas aeruginosa common and serious opportunistic pathogen in burn patients (esp 2nd and 3rd degrees), it is carried on flowers or plants sent by well-wishers, thus reason hospitals do not permit these patients to receive flowers. • Treatment with antibiotics gentamicin and carbenicillin, (Silver sulfadiazine used in burn victims)

15. WARTS: viral • Caused by Viruses that stimulate an uncontrolled but benign growth of skin cells, they can be transmitted from one person to another by contact. • Medical treatment includes applying extremely cold liquid nitrogen to them, drying them with electric current, or burning them off with acid. • Some skin or cervical cancers associated with this papillomarivius.

16. SMALL POX (VARIOLA VIRUS) • During middle ages 80% of population expected to contract small pox • Two basic forms of this disease: variola major (mortality rate 20%), and variola minor (mortality rate 1%) • Transmission and progression is via respiratory route, the virus infect many internal organs before eventually moving into the blood (viremia)…this leads to infection of the skin and the production of more recognizable symptoms ( virus in epidermal layers causes skin lesions that house the virus) .

17. Rameses V (1156B.C.) showed evidence of small pox rash, Pocahontas (1617) died of small pox

18. Last outbreak in the USA was in 1947, routine vaccinations for small pox were discontinued in the United States in 1971 when it was deemed that the vaccination posed a greater threat that did contracting • Ali Maow Maalin

19. Ali Maow Maalin The last known case of wild smallpox occurred in Somalia in 1977

20. HERPES SIMPLEX: (VIRUS) • Greek meaning to “creep” • both types of herpes simplex viruses may spread to the brain and cause herpes encephalitis, type 2 = 70% mortality if untreated • About 90% of the population of the United States has been infected with the herpes simplex virus…initial infection usually during infancy, and often subclinical. • About 15% of the cases develop lesions known as cold sores or fever blisters (usually occurring in oral or nasal mucous membranes)… these lesions heal and the infection subsides but recur when the infection strengthens again ( due to hormonal, emotional stress or drop in immune system)

21. Between recurrences, herpes simplex type 1 viruses are latent in the trigeminal nerve ganglia communication between the face and the central nervous system. • Herpes simplex 2 virus is transmitted via sexual contact (lesions appear after incubation period of 1 week and cause a burning sensation, after which vesicles appear) urination can be painful, and walking uncomfortable. ( vesicles heal in a couple of weeks and contain the virus)( location of vesicles in female: external genitals, males: base of penis)

22. Herpes simplex 2has latent periods and active periods…varying per person…it can cross placental barriers and affect fetus…birth is via c section to prevent spread of disease to baby if the disease has not spread thru placenta • There is no cure for genital herpes, however Acyclovir can be administered topically or orally.

23. Shakespeare wrote of this unsightly curse in Romeo and Juliet: “ O’er ladies’ lips, who straight on kisses dream/Which oft the angry Mab with blisters plagues,/Because their breaths with sweetmeats tainted are”

24. MEASLES (RUBEOLA VIRUS) • Extremely contagious disease that spread by the respiratory route. • Person with measles is infectious before symptoms appear, thus quarantines not effective • Humans are the only reservoir for measles, although monkeys are also susceptible. • Law requires immunization for school…vaccines being 95% effective.

25. Development and progression of rubeola begins in the upper respiratory system…incubation period of 10-12 days, symptoms develop including sore throat, headache, and cough, followed by a papular rash appearing on the skin, lesions of the oral cavity include Koplik spots ( tiny red patches with central white specks (helpful for diagnostics) on the oral mucosa opposite the molars • Measles is extremely dangerous disease, especially in very young or elderly. …(1 in 3000 cases fatal in infants, complications such as encephalitis occur, if at all, about a week after the rash appears) and can cause severe birth defects if an expecting mother contracts german measles

26. Koplike patches indicating measles

27. SCABIES: arthropod • Infection of the human skin caused by the mite Sarcoptes scabiei, a parasitic arthropod. • The disease is most common among school children and is also found in adults…sometimes occurring as a nosocomial infection. • The fingers, wrist, and elbows are the most frequent sites of infection. • The mite burrow into the skin and fill the tunnel with their eggs and feces. • The eggs hatch, and new mites mature, mate and lay more eggs, perpetuating the life cycle.

28. Symptoms are the result of hypersensitivity reactions to the mites, and first occur 2 to 6 weeks after the initial infection…. • main symptom is itching especially when the skin is warm (ex in bed at night), a red raised lesions (erythematous papules) develop, which may become infected with bacteria through scratching. • Diagnosis is made by examination of the skin with a 10X hand lens to id burrows, sometimes the mites can be picked out with a needle for microscopic examination. • Treatment is by a topical application of gamma benzene hexachloride (kwell) , with bedding and other personal objects sanitized.

29. Scabies

30. CUTANEOUS MYCOSES: (fungal) ringworms and athletes foot • Fungi that colonized the hair, nails and outer layer of the epidermis are called dermatophytes and their infection are called dermatomycoses. • Dermatophytes grow on the karatin present in those locations, causing ringworms ( most being asymptomatic and removed for cosmetic reasons, named from Greek time period who believed the infection to be caused by worms)

31. Dogs and cats are frequently infected with ringworms, as well as humans, if ring worms are in the groin region it is called jock itch, if on the feet it is athlete’s foot • Treatment is of a variety of topical medications including: miconazole, or clotrimazole, or with oral medication such as griseofulvin.

32. Ring worms Athletes foot

33. CANDIDIASIS: Fungi • The infection of the mouth with the fungi Candida albicans, which is not affected by antibacterial drugs, and will sometimes overgrow the mucosal tissue when normal bacterial flora are suppressed. • Newborns infants, whose normal flora have not yet established are often afflicted with candidiasis of the oral cavity called thrush • Elderly, diabetics, and cancer patients can be afflicted with candida in the mucosal tissues of the vaginitis. • Treatment is usually with a topical application of miconazole, clotrimazole, or nystiatin.

34. Thrush

35. Caused by Hemophilus aegytius, and is transmitted by hand contact or by flies. Treatment topical application of antibiotics (vary) CONTATGIOUS CONJUNCTIVITIS: pinkeye bacteria

36. BACTERIAL MENINGITIS: • An inflammation of the meninges caused by gram negative bacteria. • Most patients suffering from any type of meningitis complain of headache and have symptoms of nausea and vomiting, convulsions and coma accompany the infection in many cases. • Mortality rate varies with pathogen but is generally high for an infectious disease today…many survivors suffer from various neurological damage.

37. Meningitis caused by different types of pathogens (viruses, bacteria, fungi, protozoan) • There are 3 major types of bacterial meningitis: • meningococcal meningitis: caused by Neisseriameningitides mortality rate 27% • pneumococcal meningitis caused by Streptococcuspneumonia mortality rate 11% • Hemophilus influenza mortality rate 43% most common • Diagnosis is via analysis of cerebral spinal fluid and blood. • Treatment is though a strengic regime of various antibiotics including Rifampin, penicillin and ampicillin

39. TETANUS: bacteria • Causitive agent is Clostridium tetani, an obligate, anaerobic,endospore-forming, gram positive rod that is common in soil contaminated with animal feces. • Symptoms are caused by an extremely potent neurotoxin (tetanospasmin) that is released upon the dath and lysis of the growing bacteria.( potent enough that the amount of toxin in the ink of one . could kill 30 people) • In normal muscle operations, one muscle contracts and the opposing muscle relaxes

40. This neurotoxin blocks the relaxation pathway so that both the muscles contract, resulting in characteristic muscle spasms (if in the jaw…lock jaw) • Mode of transmission is improperly cleaned deep puncture wounds, especially those with little or no bleeding, immunization is 100% effective and boosters of every 10 years maintains immunity..(DPT: diphtheria, pertussis, tetanus) • Recovery does not confer immunity, an d about 560,000 babies die each year in Asia and Africa because their umbilical cords are cut with filthy instruments or the stump is packed with dirt.

41. Tetanus

42. BOTULISM: Bacteria • Caused by Clostridium botulinum, an obligately anaerobic, endospore-forming, gram-positive rod that is found in soil and many freshwater sediments. • Ingesting the endospore usually does no harm, however in anaerobic environments, ex sealed cans, the microorganisms produces an exotoxin that is highly potent. • Persons suffering from botulism undergo progressive flaccid paralysis for 1-10 days and may die from respiratory and cardiac failure.

43. Symptoms include nausea, but no fever, varying neurological safe), difficulty swallowing ,general weakness, blurred Recovery does not confer immunity • First described 1800s with blood sausage (blood and ground meat tied in pig stomach and incubated) • Botulin toxin not formed in foods with acidity below ph 4.7 ( ex tomatoes • Mortality rate 25 to 40% • Treatment relies heavily on supportive care, antibiotics of no use because toxin is preformed • Diagnosis by inoculation of mice with samples from patients serum, stool, or vomitus

45. LEPROSY: BACTERIA • Causitive agent Mycobacterium leprae, an acid-fast rod, with an optimum growth temperature of 30 C • first isolated and identified about 1870. • Sometimes called Hansen’s disease (avoid term leprosy)

46. Two main forms: • tuberculoid (neural) form characterized by regions of skin that have lost sensation and are surrounded by a boreer of nodules…. Recovery sometimes spontaneously • lepromatous (progressive) form: skin cells are infected and disfiguring nodules form all over body…mucous membrane of nose affected, deformation of hand into clawed form and necrosis of tissue

47. Both forms are spread by transfer of bacteria from lesions or inanimate objects exposed to lesion discharge • Patients can be made noncommunicable within 4-5 days by administration of sulfone drugs • National leprosy hospital in Carville Lousiana reports about 200 cases a year. • No vaccine for leprosy currently exists

48. POLIOMYELITIS: Virus • Causitive agent: poliomyelitis virus • Best known as a cause of paralysis, however, only about 10% of infected people develop identifiable symptoms, and the paralytic form probably affects less that 1% of those infected. • Symptoms often asymptomatic or mild and may include headache, sore throat, fever and nausea. • Humans only known natural host • Primary mode of transmission is ingestion of water that is contaminated with feces containing virus

49. Occurrence more often in summer months in temperate regions • Predilection sites: tonsils, lymph nodes of neck and ileum • Diagnosis based on isolation of virus from feces and throat secretions • Preventives: Salk vaccine and Sabin vaccine (more common in USA, less expensive and oral medication of orange flavored medicine)

50. Polio