a8988495858337f7a0f5b0b2cb1efccf.ppt
- Количество слайдов: 39
Diseases of the Digestive System
Gingivitis • Gum disease generally doesn't hurt. You may have it for years before you feel discomfort. • Telltale signs and symptoms of gingivitis: · Tender, swollen or bleeding gums, particularly when you brush your teeth · A change in your gums' color from pink to dusky red
• Causes – Caused by plaque, a sticky, colorless film of bacteria that coats your teeth. If allowed to harden (calcify), the film turns into whitecolored tartar (calculus), which becomes darker with time. – If plaque and tartar build up, they can irritate the gingiva, the part of your gum around the base of your teeth. This buildup creates pockets of bacteria between your gum and teeth and can result in gums that become inflamed and bleed easily.
• Risk Factors – Everyone's susceptible to gum disease, and the most common contributing factor is a long-term lack of attention to proper oral hygiene. But these factors can increase your risk: · Genes. Bacteria that lead to gingivitis are more harmful to some people's gums than to others. Those who are susceptible have a hereditary predisposition to gum disease. · Medications. Some medications reduce saliva, causing a dry mouth. Without the cleansing effect of saliva, plaque and tartar can more easily build up. Hundreds of prescription and over-the-counter antidepressants and cold remedies contain ingredients that decrease your body's production of saliva. Alcohol also can decrease production of saliva.
· Smoking slows your gums' ability to heal themselves and replace tissue destroyed by bacteria. · Diabetes. People with uncontrolled or poorly controlled diabetes are more susceptible to gum disease. Diabetes may result in a thickening of your blood vessels, making them less able to carry nutrients to your gum tissue and remove wastes. This can leave your gums less healthy and more prone to infection. · Pregnancy. Hormone changes during pregnancy make your gums more susceptible to the damaging effects of plaque. · Decreased immunity. Illness can weaken your immune system. This makes you prone to infection, which can lead to gum disease.
· Treatment: Gingivitis usually clears up after a professional cleaning by a dentist or hygienist, followed by proper daily oral hygiene. · Causative Agents: streptococci, actinomycetes, and anaerobic G- bacteria predominate in these infections
Periodontitis • Periodontitis is an advanced stage of gum (periodontal) disease that can threaten the loss of your teeth. • Some form of gum disease affects about 75 percent of adults after age 35.
• Signs and symptoms of periodontitis may include: · Swollen or recessed gums · Unpleasant taste in your mouth · Bad breath · Pain in one of your teeth when eating hot, cold or sweet foods · Dull sound when one of your teeth is tapped · Loose teeth · Change in your bite · Drainage or pus around one or more teeth
• If plaque and tartar extend farther, beneath your gumline you may develop periodontitis. • Your gums gradually withdraw from around your teeth. Pockets of infection (pus) can form in this dark, airless region and destroy the tissue and bone supporting your teeth. • Untreated, periodontitis will lead to your teeth loosening and falling out.
• Treatment – If you have pockets between your gums and your teeth that are 5 millimeters or less in depth, your dentist may recommend one of the following nonsurgical treatments: · Scaling and root planing. Scaling removes tartar and bacteria from your tooth surfaces and beneath your gums. Sometimes, scaling is done with an ultrasonic device. Root planing smoothes the root surfaces, discouraging further accumulation of tartar. With good daily oral hygiene, scaling and root planing may be all the treatment you'll need. · Antibiotic therapy. Dentists can pinpoint the specific strains of bacteria that cause periodontal disease and prescribe antibiotics to deal with them.
– If you have advanced periodontitis — the depth of the pockets between your gums and teeth is more than 5 millimeters — you may need surgery. The options: · Flap surgery. If you have a deep infection pocket, your dentist can "fold up" a section of your gum surgically, exposing the roots for more effective scaling and planing. Antibiotics may help fight the infection. · Bone grafting. If the bone surrounding your tooth root is destroyed, your dentist can secure sterilized bone segments from a bone bank to fill the space and keep your tooth in place. · Guided tissue regeneration. This technique allows bone destroyed by bacteria to regrow. Your dentist places a special piece of biocompatible fabric between existing bone and your tooth. This material prevents unwanted tissue from entering the healing area, thereby encouraging the bone to grow back.
• Prevention – The best means of preventing gum disease is good dental hygiene, including regular brushing and flossing of your teeth and periodic professional cleaning to prevent buildup of plaque and tartar. • Causative Agent: Porphyromonas species
Diseases of Lower Digestive System • Two types: infection and intoxication – infection: pathogen enters GI tract and multiplies – intoxication: ingestion of pre-formed toxin – Both types of infection often cause diarrhea. • Dysentery: sever diarrhea accompanied by blood or mucus – Both types of infection are frequently accompanied by abdominal cramps, nausea, and vomiting
– Gastroenteritis: general term for diseases causing inflammation of the stomach and intestinal mucosa. • Most common causative agents: rotavirus, some Ecoli species and Shigella species.
Staphyloccocal Food Poisoning • Leading cause of gastroenteritis – an intoxication caused by ingesting toxin produced by S. aureus – Highly resistant to heat, drying, radiation and osmotic presures
• Process of infection
• Toxin quickly triggers brain’s vomiting reflexcenter; abdominal cramps and usually diarrhea ensue – Recovery is usually complete within 24 hours – Mortality rate is almost zero among healthy people
• Shigellosis: – a severe form of diarrhea caused by group of facultative anaerobic G- rods of the genus Shigella • Most common species in the US is S. sonnei (traveler’s diarrhea) • Infection with S. dysenteriae often results in severe dysentery and prostration – Shiga toxin responsible for inhibition of protein synthesis – Bacteria not really affected by stomach acidity – Cause damage to intestinal mucosa resulting in fluid loss and inability to absorb fluid from the intestines.
• Treatment: anitibiotic therapy and oral rehydration – Generally self-limiting. (In other words, all the fluid that is lost from the body during the disease helps to wash out the bacteria from the body. )
• Salmonellosis: – Causative agent: Salmonella enterica – Every year, approximately 40, 000 cases of salmonellosis are reported in the United States. – Because many milder cases are not diagnosed or reported, the actual number of infections may be twenty or more times greater. – Children are the most likely to get salmonellosis. – Young children, the elderly, and the immunocompromised are the most likely to have severe infections. – It is estimated that approximately 1, 000 persons die each year with acute salmonellosis.
– Incubation period of 12 -72 hours – Lasts for 4 -7 days – Invade intestinal mucosa first and multiply there – Sometimes manage to pass through intestinal mucosa and invade lymphatic and cardiovascular systems – Symptoms: • • Fever Nausea Abdominal pain and cramps diarrhea
• Treatment: – Antibiotics are not usually necessary unless the infection spreads from the intestines, then it can be treated with ampicillin, gentamicin, trimethoprim/sulfamethoxazole, or ciprofloxacin. – Unfortunately, some Salmonella bacteria have become resistant to antibiotics, largely as a result of the use of antibiotics to promote the growth of feed animals
• Transmission: – Salmonella live in the intestinal tracts of humans and other animals, including birds. – Salmonella are usually transmitted to humans by eating foods contaminated with animal feces. – Contaminated foods usually look and smell normal. – Contaminated foods are often of animal origin, such as beef, poultry, milk, or eggs, but all foods, including vegetables may become contaminated. – Many raw foods of animal origin are frequently contaminated, but fortunately, thorough cooking kills Salmonella. – Food may also become contaminated by the unwashed hands of an infected food handler, who forgot to wash his or her hands with soap after using the bathroom.
– Salmonella may also be found in the feces of some pets, especially those with diarrhea, and people can become infected if they do not wash their hands after contact with these feces. – Reptiles are particularly likely to harbor Salmonella and people should always wash their hands immediately after handling a reptile, even if the reptile is healthy. – Adults should also be careful that children wash their hands after handling a reptile.
• Prevention: – There is no vaccine to prevent salmonellosis. – Since foods of animal origin may be contaminated with Salmonella, people should not eat raw or undercooked eggs, poultry, or meat. – Raw eggs may be unrecognized in some foods such as homemade hollandaise sauce, caesar and other salad dressings, tiramisu, homemade ice cream, homemade mayonnaise, cookie dough, and frostings. – Poultry and meat, including hamburgers, should be well -cooked, not pink in the middle. – Persons also should not consume raw or unpasteurized milk or other dairy products. – Produce should be thoroughly washed before consuming.
– Cross-contamination of foods should be avoided. – Uncooked meats should be keep separate from produce, cooked foods, and ready-to-eat foods. – Hands, cutting boards, counters, knives, and other utensils should be washed thoroughly after handling uncooked foods. – Hand should be washed before handling any food, and between handling different food items. – People who have salmonellosis should not prepare food or pour water for others until they have been shown to no longer be carrying the Salmonella bacterium. – People should wash their hands after contact with animal feces. – Since reptiles are particularly likely to have Salmonella, everyone should immediately wash their hands after handling reptiles. – Reptiles (including turtles) are not appropriate pets for small children and should not be in the same house as an infant.
Cholera • Causative Agent: Vibrio cholerae – Outbreaks caused by temporary lapses in sanitation practices – Cholera bacteria commonly associated with brackish (salty) waters – Under unfavorable conditions, the bacterial cell shrinks drastically into a nonculturable, spherical, dormant state • sporelike state without formation of a true spore coat
– Both sporelike and vegetative forms are infectious. • Grows in small intestine and produce an enterotoxin that results in the secretion of chlorides, bicarbonates, and water. • Excess water and mineral electrolytes are excreted taking on the appearance of “rice water stools” – Sudden loss of fluids and electrolytes causes shock, collapse, and often death (3 -5 gallons/day are lost. )
– Loss of fluid causes blood to become so viscous that vital organs are unable to function properly • Vaccine available but only produces short term immunity • Treatment: tetracycline and replacement of lost fluids – 50% mortality rate
Diseases of the Urinary Reproductive Systems • Cystitis: inflammation of urinary bladder – Signs and Symptoms: dysuria (Painful or difficult urination. This includes burning on urination. ), pyuria (presence of leukocytes in urine) – 2 most common causative agents: E-coli and S. saprophyticus – Rx. : Trimethoprim-sulfamethoxazole
• Pylonephritis: progression of cystitis to inflammation of one or both kidneys – Signs and Symptoms: fever and flank or back pain. – Causative agent: E-coli – Complications: development of scar tissue forms in kidneys and impairs their function – Rx: intravenous, broad-spectrum antibiotics (cephalosporins)
• Leptospirosis: disease of domestic or wild animals that can pass to humans and cause severe kidney or liver disease – Causative agent: Leptospira interrogans, spirochete, obligate aerobe – Transmission: shed in urine for extended periods. Humans become infected upon contact with urinecontaminated water, soil or animal tissue – Signs and Symptoms: Incubation period or 1 -2 weeks. Fever, chills, headaches, muscular aches. Several days later, second episode of fever – Rx. : Body fights off. Antibiotics not very effective – Complications: can cause kidney failure
• Gonorrhea: one of most common communicable diseases – Causative agent: Neisseria gonorrhoeae – Transmission: attachment of organism to mucosal cells of epithelial wall – Signs and Symptoms: • Males: painful urination, discharge of puscontaining material from urethra • If untreated, can result in sterility if testes are infected • Females: only cervix infected • Some abdominal pain later in infection due to subsequent Pelvic Inflammatory Disease
• Complications: can become systemic infection • Transmission: any type of sexual contact • Rx: typically penicillin used but increases resistance – Current drug of choice is cephalosporin: Ceftriaxone
• Pelvic Inflammatory Disease: bacterial infection of female pelvic organs (uterus, cervix, uterine tubes, or ovaries) – Causative agent: N. gonorrhoeae, Chlamydia – Signs and Symptoms: severe abdominal pain – Transmission: bacterial attachment to sperm cells – Rx. : combination of doxycycline and cefoxitin
Syphilis • Causative agent: Treponema pallidum • Symptoms: – Primary stage: • small, hard based sore (at site of infection) • serous exudate forms in center (highly infectious) • lesion disappears w/in few weeks – Secondary stage: • skin rashes of varying appearance (widely distributed on skin, mouth, throat, cervix • lesions of rash are very infectious
• • loss of patches of hair generally lasts a few weeks becomes latent After latency for 2 -4 years, not usually infectious – Tertiary stage • usually 10 or more years after onset of latent phase • most symptoms due to immune system • cause gummas, rubbery masses of tisse that appear in many organs and sometimes on external skin • can cause extensive tissue damage • Not generally infectious • most infections today don’t progress to this stage
• Rx: Benzathine penicillin: long acting formulation that remains effective in body for about 2 weeks