Infectious Diseases – Flashcards
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Dental Caries |
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Caries (cavities) Primarily formed by streptococcus mutans Other bacteria attaches to strep mutans and creates a biofilm. Acid created by strep mutans leaches calcium, breaking down the hard tooth structure |
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Tooth and Gum Infections |
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If left undisturbed normal biota biofilm eventually contains anaerobic bacteria that can damage the soft tissues and bones. Intro of carbs to the oral cavity can result in breakdown of definition |
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Tooth Decay (dental caries) |
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Most common infectious disease of human beings. |
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Periodontitis |
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initial stage is gingivitis (swelling, loss of normal countour, patches of redness, and increased bleeding of gingival). If persists periodontitis develops. |
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Effects of Periodontitis |
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common disease, bacterial colonization results in inflammation of the gingiva and gingival damage through calculus production. Not caused by a single organism but multiple species in biofilms |
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Necrotixing ulcerative gingivitis and periodontitis |
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most destructive periodontal disease. Caused by poor oral hygiene, altered host defenses, or prior gum disease. Synergistic infectiosn involving treponema vincentii, prevotella intermedia, and fusobacterium species. Together they produce several invasive factors that cause rapid advancement into periodontal tissues. Common in aids patients |
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Mucus |
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discourages adherence of microorganisms |
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Peristalsis |
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keep things moving, including microorganisms |
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Bile acids |
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antimicrobial |
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Digestive enzymes |
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lysozyme, lactoferrin, pepsin |
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GALT |
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gut associated lymphoid tissues. Tonsils, appendix, adenoids all contain immune system cells. |
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IgA |
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coats most surfaces |
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Commensal organisms |
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microbial antagonism |
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Normal Biota of the Gastrointestinal Tract |
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large variety of normal biota. Mouth has more that 550 kinds, gram positives, gram negatives, anaerobes, yeasts, and some protozoa |
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Mycoplasma Pneumoniae |
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walking pneumonia. Atypical pneumonia sytoms do not resemble other more serious forms. Transmitted by droplets quarters, such as families, schools, military, etc. |
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Symptoms of Mycoplasma Pneumoniae |
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initially causes fever, malaise, sore throat, headache, after 2-3 weeks progresses to unproductive cough and earache. |
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Hantavirus |
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may 1993 in the four corners area of southwest US, affecting healthy young adults. Zoonosis- reservoir is deer mice. Transmission is rodent feces |
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Symptoms of Hantavirus |
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fever, lung edema, respiratory distress, hypotension. 33% fatal. |
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Histoplasmosis |
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Histoplasma capsulatum. Dimorphic fungus. Grows in nitrogen rich soils (bird/bat droppings) Worldwide distribution. Common in the Ohio River valley. Only about 1% infected become ill |
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Pneumocystic carinii jirveci |
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pneumocystic pneumonia. Most common opportunistic disease in AIDS patients, also affects the elderly and premature infants. Produces inflammation in the lungs. Traditional anti-fungal meds are inefective |
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Extrapulmonary Tuberculosis |
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M. Tuberculosis infection outside of the lungs. More common in immunosuppressed patients and young children. Organs most commonly involved are regional lymph nodes, kidneys, long bones, genital tract, brain, and meninges. Complications are usually grave. |
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Diagnosing tuberculosis |
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Tuberculin skin test, chest x ray, acids fast stain of sputum, sputum culture, vaccine adjuvants may give false positives. |
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Pneumonia |
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Inflammatory condition of hte lung in which fluid fills the aveoli. Can be caused by a wide variety of different microorganisms. Viral pneumonias are usually milder. Headache is common, fever is often present. |
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Streptococcus Pneumoniae |
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Pneumococcus- gram positive dipolococcus, normal biota in 5-50% of healthy people. Most common cause of bacterial pneumoniae. Capsule is main virulence factor, also produces an endotoxin. Vaccine available (pneumovax) |
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Legionella Pneumophilia |
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Legionnaire's disease. Found in water supplies, pond, tap, cooling towers, resistant to chlorine. Spread in aerosols. Supermarket vegetable sprayers, hotel fountains. Can live inside amoebas. 3-30% fatal. usually affecting the elderly. Not transmitted person to person. |
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Lower respiratory tract diseases caused by microorganisms. |
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Diseases that affect the bronchi, bronchioles, and lungs. Tuberculosis and pneumonia |
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Tuberculosis |
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Humans are easily infected with mycobacterium tuberculosis but are resistant to the disease. Currently two billion people worldwide are infected with M. tuberculosis (1/3 of the population) |
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Stages of TB |
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primary tuberculosis, secondary tuberculosis, and disseminated tuberculosis. |
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About Tuberculosis |
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mycobacterium tuberculosis. Acid fast bacterium. Gram postive/gram negative? 15-20 hour generation time, up to 6 weeks for colony development. Droplet transmission. Not easily killed by phagocytes. |
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Primary Tuberculosis |
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Infectious dose: 10 bacterial cells. Bacteria ingested by macrophages and beings a period of hidden infection. After 3 to 4 weeks immune system mounts a cell mediated assault. Large influx of mononuclear cells into lungs. Tubercles form. Frequently the centers of tubercules break down into necrotic caseous lesions that gradually heal by calcification as normal lung tissue is replaced by calcium deposits. |
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Secondary (reactive) tuberculosis |
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Live bacteria can remain dormant and become reactivated weeks, months, or years later. Tubercles fill with bacteria expand and drain into bronchial tubes and upper respiratory tract. Untreated results in 60% mortality. |
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Influenza |
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Seasonal flue is the normal flu, sometimes more virulent stain emerges and causes a world wide pandemic |
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Symptoms of the Flu |
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begins in the upper respiratory tract, serious cases may also affect the lower respiratory tract. 1 to 4 day incubation period, then symptoms being very quickly: headache, chills, dry cough, body aches, fever, nasal discharge, and sore throat. Secondary bacterial infections are a possible result due to a weakened immune system. |
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Influenza virus |
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zoonosis- humans pigs birds horses. 3 viruses A B and C Enveloped RNA virus. Spike glycoproteins. Hemagglutinin (HA) Neuraminidase (NA) |
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HA of Influenza Virus |
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Influenza virus is known for its extreme variability. Constant genetic changes that alter the structure of its envelope glycoproteins. Low mutation rate for sites used to bind to hosts, high mutation rate for sites used for antibody binding to virus. Virus can continue to adheare to host cells, while decreasing the memory cells to recognize the virus. |
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Mechanisms of Variation |
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Antigenic drift. Mutation of genes, altered binding by antibodies, slower process Antigenic Shift gene reassortment coinfections rapid process. |
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Hemagglutinin |
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causes agglutination of red blood cells and aids in binding of virus to respiratory mucosa. Viral entry, 16 variants Human: H1,H2, H3 Swine: H1, H3 Equine: H3,H7 Avian: all |
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Neuraminidase |
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Breaks down mucous, assists viral budding and release, aids in host cell fusion. 9 variants Human: N1, N2 Swine: N1, N2 Equine: N7, N9 Avian: all |
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Influenza treatment |
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Amantadine- blocks replication Relenza and Tamiflu- blocks neuraminidase |
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Influenza Vaccination |
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Inactivated vaccine- injections Attenuated vaccine: nasal spray New trivalent vaccines each season because the flu antigens are always changing. Yearly vaccine is 70-90% effective |
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Whooping Cough |
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Bordetella pertussis, aerobic gram negative rod. Tussis= latin for cough. |
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Stages of whooping cough |
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Catarrhal stage: after incubation from 3 to 21 days. Bacteria in the respiratory tract cause what appear to be cold symptoms. Lasts 1 to 2 weeks. Paroxysmal stage Severe and uncontrollable coughing. Violent coughing spasms can result in burst blood vessels in the eyes or even vomiting. Followed by a long recovery (convalescent) phase. Complete recovery requires weeks or even months due to damaged cilia on respiratory epithelial cells. |
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Pathogenesis of whooping cough |
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Localized infection, toxin production, damage cilia. Acellular vaccine (TDaP) incidence increasing in teh US since the 1980s. |
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Respiratory Syncytial Virus (RSV) infection. |
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produces giant multinucleated cells in the respiratory tract. Highly contagious, spread by droplets and fomite. Most prevalent cause of respiratory infection in premature babies and babies up to 6 month, with nearly all children infected by age 2. |
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Symptoms of RSV |
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fever that lasts approximately 3 days, rhinitis, pharyngitis, and otitis. Most serious infections give rise to symptoms of croup, coughing, wheezing, dyspnea, and rales. No vaccine. |
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HPV |
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Human papillomavirus (HPV) Causitive agents of genital warts. An individual can be infected with HPV without having warts. |
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Molluscum Contagiosum |
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Unclassified virus of the pox family. Can take the form of skin lesions. Wartlike growths on the mucous membranes or skin of the genital area. |
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HPV |
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Genital warts. Over 100 types virus. Sexually transmitted 15% of people between 15 and 49 are carriers. |
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Characteristics of HPV |
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benign warts. Cervical carcinoma- production of proteins that cause uncontrolled cellular division. Once infected it is incurable. Gardasil vaccine. |
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Group B Streptococcus Colonization |
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10% to 40% of women in the US are colonized asymptomatically by group B strep. When these women become pregnant about half of their infants become colonized by the bacterium during passage through the birth canal. Small percentage of infected infants experience life threatening bloodstream infections, meningitis, or pneumonia. |
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Chancroid |
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Caused by pleomorphic gram negative rode Haemophilus ducreyi. Transmission by direct contact, usually sexually. |
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Chancroid signs and prevention |
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Prevention is condoms. No system wide effects. Infection usually beings as a soft papule at the point of contact. Develops into a soft chancre (painful in men, but may be unnoticed in women) Lymph nodes can become swollen and tender. Associated with prostitutes and poor hygiene. Some may be asymptomatic. |
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Genital Herpes |
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caused by herpes simplex viruses (HSVs) Much more common that most people think. |
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Symptoms of genital herpes |
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No symptoms or single or multiple vesicles on the genitalia, perineum, thigh, and buttocks. Lesions from initial infection can be accompanied by malaise, anorexia, fever, and bilateral swelling and tenderness of the groin. May have recurrent episodes of lesions;generally less severe (4-5 per year) |
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Neonate and fetus herpes |
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In the neonate and fetus HSV infections are transmitted just before or during birth, are very destructive, and can be fatal. Mothers are screened for herpes and any sign in the last four weeks of pregnancy are delivered using cesarean section. |
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Herpes Virus |
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HSV 1: usually associated with the mouth and face. HSV 2: usually associated with the genital tract. Latency period is in the nerve ganglion. 20% of adults have genital herpes two thirds of them are asymptomatic carriers. |
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Female Condom |
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the female condom covers a large portion of the external female genitalia which helps control the spread of herpes. People infected with the herpes virus should always use barrier protection when having sex due to virus shedding even when no lesions are visible. |
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Genital ulcer diseases |
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three common infectious conditions resulting in lesions on a persons genitals: syphilis, chancroid, genital herpes. Having one of these diseases increases the chances of infection with HIV because of the open lesions. |
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Syphilis |
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Treponema pallidum. Gram negative spirochete. Fastidious killed by heat, drying, disinfectants, soaps, pH shifts... Only survives a few minutes to hours outside of the host. Risk of infection from sex with an infected partner is 12-30% encounter. Prevention: condoms, reporting to CDC and treatment. |
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Symptoms of Syphilis |
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appear in three distinct clinical stages: primary, secondary, and tertiary. Latent periods of varying duration also occur. Transmission during the primary and secondary stages and the early latency period between secondary and tertiary. Largely notransmissable during late latent and tertiary stages. |
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Primary Syphilis |
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appearance of painless chancre with firm edges and ulcerated central crater at the site of entry of pathogen (after an incubation period of 9 days to 3 months) Lymph nodes draining the affected region become enlarged and firm. Chancre filled with spirochetes. Chancre heals spontaneously in 3 to 6 weeks but by then the spirochete has moved into the circulation. |
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Secondary syphilis |
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Secondary stage. 3 weeks to 6 months after initial chancre heals (many body systems infected due to the pathogen entering and multiplying in the blood) -headache -lymphadenopathy (infection of the lymph nodes) -Skin rash (red brown) -loss of hair -malaise, mild fever Disappears spontaneously in a few weeks. Major complications of this stage occuring in the bones, hair follicles, joints, liver, eyes, brain etc... can linger for months or years. |
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Tertiary Syphilis |
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Latent period up to 20 years. Antibodies present, but no trepanema detected. Final stage of disease: tertiary phase. Rare today due to antibiotics. Permanent damage: Cardiovascular syphilis Gummas- painful swollen tumors in the liver, skin, bone, and cartilage. Neurosyphilis- causes severe headaches, convulsions, blindness, dementia. |
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Congenital syphilis |
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Spirochete crosses the placenta and travels through fetal tissue. Consequences range from mild to stillbirths depending on the period of development when infection occurs. Snuffles- infants often have profuse nasal discharge. Bone deformation, nervous system abnormalities. Hutchinson's teeth. |
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Gonorrhea |
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Neisseria gonorrhoea. Also known as gonococcus. Gram negative diplococci. Virulent due to fimbriae and a protease that inactivates IgA. Sexually transmitted disease- survival (2 hours on fomites) portal of entry- genital or extragential (rectum, eye, throat) Treatment: antibiotics and surveillance of isolates for antibiotic resistance. |
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Gonorrhea symptoms (male) |
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Male symptoms Urethritis, painful urination and yellowish discharge. Chan occasionally spread from the urethra to the prostate gland and epididymis. Scar tissue in the spermatic ducts during healing can render a man infertile (rare) |
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Gonorrhea symptoms (female) |
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Mucopurulent (contains mucus and pus) or bloody vaginal discharge. Painful urination if urethra is affected. Pelvic inflammatory disease- infection of upper reproductive tract (fallopian tubes and ovaries) can cause sterility or ectopic pregnancies by scarring fallopian tubes. |
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Chlamydia |
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Chlamydia trachomatis is a small gram negative bacterium. Obligate intracellular parasites-need host cells for growth. |
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Chlamydia symptoms |
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Most common reportable infectious disease in the U.S. (1 million reported each year) Prevalence in young adults is 4% majority of these cases are asymptomatic. symptoms in males -inflammation in urethra -symptoms mimicking gonorrhea (discharge and painful urination) -untreated infections may lead to epididymitis. Symptoms in females -cervicitis -leading cause of PID (more likely to cause PID than gonorrhea) -asymptomatic (75%) so often no treatment. |
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Chlamydia's overall symptoms and how it affects babies |
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Certain strains can invade the lymphatic tissues Symptoms: Headache, fever, muscle aches. Lymph nodes fill with immune system cells and become enlarged and tender. Babies born to mothers with infections can develop eye infections and pneumonia. Annual screening suggested for young women. |
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Prostatitis |
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Inflammation of the prostate gland, caused by GI tract bacteria. Acute or chronic, both forms can be bacterial with chronic forms often being caused by biofilms-- resistance to antibiotic therapy. Patients very ill with acute form. Symptoms are lower back pain and pelvic area. Frequent urge to urinate; blood in the urine; and or painful ejaculation. |
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Discharge disease with major manifestations in the G.I. Tract |
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increase in fluid discharge in male and female reproductive tract. Examples include trichomoniasis, gonorrhea, and chlamydia infection. Transmitted when this fluid is transferred to a mucosal surface of a sexual partner. |
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Gardnella species |
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Infection called vaginosis rather than vaginities because inflammation in the vagina does not occur. Vaginal discharge with a very fishy odor, especially after sex (by products of microbial metabolism) Itching is common. Probalby a condition that involves multiple bacterial species. Not sexually transmitted but possibly influenced by sexual activity. |
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Trichomonas vaginalis |
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Trichomonas. Flagellated protozoa. Sexually transmitted. Has no cyst form, does not live outside of the host. Many people are asymptomatically infected (50% males and females) Causes vaginitis, increases susceptibility to other infections, premature labor and low birth weights. |
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Leptospirosis |
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Zoonosis associated with the urine of wild animals and domesticated animals. Can affect the kidneys, liver, brain and eyes. Major effects on the kidney and is shed into the environment through animal urine. |
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Leptospriorsis signs and symptoms |
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Leptospira interrogans, bacterial spirochete. Enters through breaks in the skin and mucous membranes. Two phases -early (leptospiremic) phase- sudden high fever, chills, headache, muscle aches, conjunctivitis, and vomiting. Second phase (immune phase) milder fever, headache, weil's syndrome, kidney invasion, hepatic disease, jaundice, anemia, and neurological disturbances.) Avoid natural water sources frequented by livestock, wear protective footwear and clothing when in farm settings.) |
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Urinary schistosomiasis |
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Schistosoma haematovium helminth lodges in the blood vessels of the bladder. May or may not result in symptoms. If symptoms occur: itchiness in the area where the worm enters the body, fever, chills, diarrhea, and cough. urinary tract symptoms occur later which may include blood int he urine and bladder obstruction. Lifecycle involves a snail that is not found in the US, so all cases here are imported. Usually found in cultures with poor sanitation practices. Disease spread through contaminated water. |
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Normal Biota in the urinary tract |
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outer region of the urethra harbors some normal biota. Nonhemolytic stretococci, staphylococci, cornebacteria, and some lactobacilli. Same biota for the male genital tract. The female genital tract harbors lactobacillus and candida albicans. |
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Urinary Tract diseases caused by microorganisms |
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Urinary tract infections (UTIs) urine is a good growth medium for many microorganisms. Reduced urine flow or accidental introduction of bacteria into the bladder can result in cystitis (infection of the bladder) If the infection also affects the kidney it is called pyelonephritis. An infection only in the urethra: urethritis. |
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Urinary Tract Infections |
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UTI: can involve any portion of the urinary tract. Cystitis: common bladder inflammation. E. coli is most common cause Urethritis: inflammation of the urethra Pyelonephritis: kidney infection. E coli is the most common cause. |
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Cystitis |
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A sudden onset of symptoms. Pain the pubic area, frequent urges to urinate even when the bladder is empty. Burning pain accompanying urination (dysuria), cloudy urine, orange tinge to the urine, fever and nausea, back pain indicates kidneys may also be involved. Prevention is emptying the bladder frequently and for females wiping from front to back after a bowel movement (good hygiene), drink cranberry juice. |
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Liver and intestinal disease |
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Opisthorchis sinensis and clonorchis sinensis. Chinese liver flukes. Complete their sexual development in mammals intermediate development in snail and fish hosts. Ingest in inadequately cooked or raw freshwater fish. Larvae hatch and crawl into the bile duct. Symptoms are slow but include thickening of the lining of hte bile duct and possible granuloma formation in the liver. |
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Fasciola hepatica |
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occasionally transmitted to humans, common in sheep, cattle, goats, another other mammals. Complex life cycle. Symptoms of vomiting diarrhea, hepatomegaly, and bile obstruction. |
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Muscle and neurological symptoms |
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Trichinosis. caused by trichonella. Life cycle spent entirely within the body of a mammalian host. Human eats undercooked pork or bear, cyst envelope digested in the stomach and small intestine, and larvae is liberated. Final development occurs when the coiled larvae are encysted in the skeletal muscle.Symptoms may be unnoticeable or life threatening depending on how many larvae were ingested. |
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Liver Disease: schistosomiasis |
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First symptoms: itchiness in the area where the worm enters the body. Followed by fever, chills, diarrhea, and cough. Chronic infection can lead ot the hepatomegaly and liver disease and splenomegaly. |
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Life cycle of liver worms |
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Infected humans release eggs into the irrigated fields or ponds through fertilization, defecation, or urination. Egg hatches in water and swims to a snail. Multiples into a larger larvae called cercaria. Infected snails give off thousands of cercariae into the water. Cercaria attach themselves to human skin and penetrate into hair follicles. Pass into small blood and lymphatic vessels. Carried to the liver where they achieve sexual maturity and mate in permanently attached pairs. |
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GI tract disease caused by helminths |
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Helminths are multicellular animals that parasitize humans and are very diverse, ranging from barely visible round worms to huge tapeworms. |
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Three Groups Of Worms |
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Nematodes: roundworms Cestodes: tapeworms trematodes: flukes |
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General clinical considerations |
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Pathogenesis and virulence factors -most do not have a specific virulence factor. -have numerous adaptations that allow them to survive in their host. -specialized mouthparts -enzymes -cuticle or other covering Damage caused to host is usually the result of the host's response to the presence of the worm. many have more than one host. |
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Definite Host |
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The host in which the adult worm is found |
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Diagnosis of Helminths |
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Differential blood count showing eosinophilia. Serological tests indicating sensitivity to helminthic antigens. Intestinal distess as the primary symptom. Discovery of eggs, larvae, or adult worms in stools or other tissue. |
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Prevention and treatment of helminths |
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Prevention- minimizing human contact with parasite or interrupting its life cycle. Treatment-antihelminthic drugs or in some cases removal of the worms or larvae. |
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Easiest way to prevent rhinitis |
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wash hands frequently |
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The most common viral cause of the common cold |
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Rhinovirus |
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Organisms that cause sinusitis |
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S. pneumonia, s. aureus, haemophilus influenza, s. pyrogenes. (E.Coli does not cause sinusitis) |
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Virulence factors of sinusitis |
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there are none |
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Most common cause of pharyngitis |
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streptococcus pyrogenes |
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Incubation period of pharyngitis |
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2-5 days |
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Diptheria |
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Cornebacterium diptheria |
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Virulence factor of diptheria |
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exotoxin |
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Whooping cough |
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also known as pertussis |
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Recovering phase of whooping cough |
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Convalescent |
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Flu pandemic that all others are measured against |
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1918-1919 |
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Treatment of influenza virus |
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amatadine, relenza, tamiflu |
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tuberculosis transmitted |
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respiratory droplets |
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Types of tuberculosis |
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Primary tb, secondary tb, and disseminated tb. |
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Bacterial pneumonia |
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an inflammatory condition of the lung in which fluid fills the alveoli |
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Pneumonia classification |
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lower respiratory tract disease. |
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Causative agent of viral pneumonia |
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hantavirus |
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Viral pneumonia prevalence in the U.S. |
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eastern and central parts |
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Best prevention of mumps |
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MMR vaccine |
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Most common symptom of mumps |
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swelling of the salivary glands |
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Most common bacterial causative agent of gastritis |
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heliobacter pylori |
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most common mode of transmission of gastritis |
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person to person |
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Causative agent of food poisoning |
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staph aureus, bacillus cereus, clostridium perfringens. |
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Symptoms in the gut caused by |
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preformed toxin |
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Causative agents of hep B |
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enveloped DNA virus |
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virulence factors of hep c |
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core proteins suppresses immune function and produces various cytokines. |
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Mode of transmission of gonorrhea |
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vaginal, anal, or oral sex. |
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Another name of gonorrhea |
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the clap |
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If left untreated chlamydia can cause |
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infertility |
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chlamydia can't be caused by |
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kissing |
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Syphilis causitive agent |
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treponema pallidum |
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disease that can be prevented by introducing patients to malaria |
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syphilis |
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strand of herpes that causes genital herpes |
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hsv-2 |
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percentage of the popl that has been infected with herpes |
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98-100% |
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Most common std |
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human papillomavirus |
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treatment for individuals that contract HPV |
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no known treatment |
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Enterobius Vermicularis |
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often called a pinworm. Most common worm of children in temperate zones. Pronounced anal itching when the mature female emerges from the anus and lays eggs. Eggs have a sticky coating causing them to stick to fingers and fomites for transmission. Usually asymptomatic, but patient can suffer from disrupted sleep, nausea, abdominal discomfort, and diarrhea. |
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Taenia solium |
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tapeworm with hooklets and suckers to attach to intestinal walls. Transmission through pig contact or consumption of pork. Adults- large length (5 m) few symptoms. occasionally proglottids in the stool sometimes vague abdominal pain and nausea. |
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Intestinal distress accompanied by migratory symptoms |
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some helminths enter the body as eggs or larvae and mature adult worms in the intestine. These worms then migrate to the circulatory and lymphatic systems, traveling to the heart and lungs. They then migrate up the respiratory tree to the throat and are swallowed, sending them back to the intestines to complete the cycle. Cause inflammatory reactions along these migratory routes Can result in eosinphilia and pneumonia. |
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Ascaris Lumbricoides |
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giant intestinal roundworm. Most common helminth infection. Larvae and adult stages in humans. Eggs released in feces, spread, consumed, and eggs hatch in intestines. Larbae then penetrate intestinal wall, enter the lymphatic and circulatory systems, sweep into the hear, and arrive at the capillaries of the lungs. The larvae migrate up the respiratory tree to the pharynx. Worms are swallowed and returned to the small intestines, reach adulthood, and reproduce. Can also invade the liver and gallbladder, and sometimes emerge from the nose and mouth. Severe inflammatory reactions mark the migratory route. |
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Hookworms |
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necator americanus. Called the hookworms due to the hooks it uses to attach to the intestine. larvae penetrate skin, not transmitted through egg ingestion. Invade to lungs. develop in intestine. eggs shed in feces. |
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Acute diarrhea caused by e coli |
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enterotoxigenic- ETEC (produces 2 toxins) enteroinvasive- EIEC (invades gut mucosa) enteropathogenic-EPEC (similar to EHEC but no shiga toxin, so no systemic effects) |
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ETEC |
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traveler's diarrhea. Voluminous watery diarrhea, A-B toxin like cholera. Heat stable toxin |
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EIEC |
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diarrhea with pus, similar to shigella, no toxin produced. |
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EPEC |
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profuse watery diarrhea, fever and vomiting also common, produce effacement of gut surfaces. |
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EAEC |
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can cause chronic diarrhea in young children and AIDS patients. |
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Campylobacter |
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most common bacterial cause of diarrhea in the U.S. Bacteria burrow into the walls of the ileum to multiply. Frequent watery stools, fever, vomiting, headaches, and severe abdominal pain. Symptoms may last beyond 2 weeks. |
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Campylobacter profile |
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Camplyobacter jejuni. Curved or spiral gram negative bacteria. Transmission through contaminated beverages and food. |
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Guillain Barre syndrome |
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acute paralysis (usually temporary) Autoimmune reaction. 20-40% were preceeded by C. jejuni infection. |
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yersinia species |
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y. enterocolitica and y. pseudotuberculosis- are gram negative bacteria commonly found in the gut of farm and domestic animals, often the gut of farm and domestic animals, often spread by handling raw food and indirect contact. Uncommon in the U.S. Inflammation of the ileum and mesenteric lymph nodes gives rise to severe abdominal pain (often misdiagnosed ans appendicitis) Infectional occasionally spreads to the blood stream. |
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acute diarrhea caused by clostridium dificile |
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gram positive forming rod, part of normal biota of intestine. Causes pseudomembranous colitis. Major cause of diarrhea in hospitals. Able to superinfect the large intestine when broad spectrum antibiotics have disrupted the normal biota. produces two enterotoxins (toxin a and b) that cause areas of necrosis in the wall of the intestine. Diarrhea severe cases exhibit abdominal cramps, fever, and leukocytosis. |
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Clostridium dificile |
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normal intestinal microbiota. Antibiotic resistant. Over growth during chemotherapy. Toxin mediated damage. Pseudomembranes slough off and untreated eventually perforate the intestine. |
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Vibrio Cholera |
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usually seen after natural disasters. Incubation period of a few hours to days. Symptoms begin with vomiting. Followed by copious amounts of watery feces called secretory diarrhea. Can lose up to 1 liter of fluid an hour in severe cases. Loss of fluids causes sunken eyes, acidosis, hypotension, tachycardia, cyanosis, collapse from shock within 18-24 hours, death within 48 hours if untreated. |
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Vibrio Cholerae profile |
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comma shaped gram negative bacteria. Contaminated water. Cholera toxin A-B enterotoxin. Secretion of water/electrolytes into lumen. Rice water stools. Severe dehydration. Oral rehydration therapy. |
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Cryposporiduium |
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Headache, sweating, vomiting, severe abdominal cramps, and diarrhea. In AIDS patients may develop into chronic persistent cryptosporidial diarrhea. |
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Cryptosporidium profile |
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Protozoa. Zoonotic disease. Ingestion of oocysts in contaminated food or water. Chlorine resistant. Outbreak in Milwaukee. Other outbreaks include swimming pools and local water supplies contaminated. May cause chronic infections in AIDS patients. |
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Rotavirus |
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Globally the primary viral cause of mortality from diarrhea. 1 million cases a year. Damages intestinal epithelia. Watery diarrhea with fever and nausea. Spread oral fecal route. Primarily in children. Worse on babies 6-24 months. |
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Noroviruses |
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Norwalk like viruses. Gastroenteritis. Fecal oral route of transmission. Nausea, vomiting, and diarrhea with cramps. Primarily affects adults. Epidemic outbreaks in schools and cruise ships. |