exam 2

Question 0

Agent

Answer 0

A microbial organism with the ability to cause disease. The greater the organisms virulence (ability to grow and multiply), invasiveness (ability to enter tissue), and pathogenicity (ability to cause disease), the greater the possibility that the organism will cause an infection. Infectious agents can be bacteria, viruses, fungi, and parasites.

Question 1

Chain of Infection

Answer 1

Consists of the agent, reservoir, portal of exit, mode of transmission, portal of entry, and host.
Quiz Questions:
What is the difference between an insect vector that is a reservoir vs a mechanical carrier? In a reservoir vector the pathogenic organism is able to infect, develop, and multiply in the vector, whereas the mechanical carrier does not maintain the organism.
Chain of infection is the model of?

Question 2

Reservoir

Answer 2

The usual habitat in which the agent lives and multiplies. Can be humans, animals, and environment.
There are 2 types of human reservoirs and animal reservoirs; acute clinical cases (they are ill) and carriers (not ill).
Plants, soil, and water may serve as the reservoir for a variety of diseases.

Question 3

Types of Human Reservoir Carriers

Answer 3

Incubatory carriers: are people who are going to become ill, but begin transmitting their infection before their symptoms start. Ex. measles and HIV.
Inapparent infections: people with inapparent infections never develop an illness, but are able to transmit their infection to others. With some diseases, inapparent infections are more common than acute clinical cases. Ex. polio
Subclinical infections: With some diseases, the number of subclinical cases may be quite high before a single clinical case appears or is able to be diagnosed with specific clinical symptoms. Ex. meningococcal meningitis.
Convalescent carriers: people who continue to be infectious during and ever after their recovery from the illness. Ex. salmonella
Chronic carriers: people who continue to harbor infections for a year or longer after their recovery. Ex. Hep B

Question 4

Portal of Exit and Entry

Answer 4

How the agent exists the reservoir and enters the host. Entry and Exit are usually the same, but in some cases they are different.
Common portals: respiratory, genitourinary, alimentary, skin (superficial lesions and percutaneous), bloody and body fluids, transplacental.
Quiz Questions:
Which is not considered a portal of entry and exit?
If the portal of exit for the disease is blank then the portal of exit is blank Respiratory and Respiratory.

Question 5

Transmission

Answer 5

Necessary to bridge the gap between the portal of exit from the reservoir and the portal of entry into the host. How the agent moves from one system to another one.
There are 2 basic modes of transmission; direct and indirect.

Question 6

Direct Transmission

Answer 6

Direct: Occurs more or less immediately. Occurs when microorganisms are transferred from one infected person to another person without a contaminated intermediate object or person. Many diseases are transmitted by direct contact with the human, animal or environmental reservoir. Ex. STDs and enteric diseases.
Droplet: Considered direct transmission, but may be indirect also. Respiratory droplets carrying infectious pathogens transmit infection (about 3 ft). This happens when a person coughs, sneezes, or talks or during certain procedures.
Airborne: Occurs by dissemination of either airborne droplet nuclei or small particles in the respirable size range containing infectious agents that remain in the air over time and distance. Can be dispersed over long distance and can be transmitted to someone who has not had face-to-face contact with the infectious individual.
Quiz Question:
Which is not a form of direct transmission? Person A coughs on their hand, touches a pencil with infected sputum in hand, person B picks the pencil up. Person A has a disease, mosquito bites infected person A, mosquito then bites person B and transmits the disease.

Question 7

Indirect Transmission

Answer 7

May occur through animate or inanimate mechanisms.
Animate: involves vectors. Ex. flies, mosquitoes, ticks, or fleas.
Inanimate: when disease agents are spread by environmental vehicles or by air, this is referred to as indirect transmission by inanimate mechanisms. Anything may be a vehicle, including objects, food, water, milk, or biological products.

Question 8

How to break the links in the Chain of Infection.

Answer 8

Infectious agent: diagnosis/treatment.
Reservoir: education/policy, environmental sanitation, disinfection.
Exit: hand washing, control of excretion and secretions, trash and waste disposal.
Transmission: isolation, food handling, environmental sanitation, disinfection, hand washing.
Entry: first aid, personal hygiene, hand washing.
Host: treatment of underlying diseases, immunization.

Question 9

Host

Answer 9

A person who cannot resist a microorganism invading the body, multiplying, and resulting in infection due to a lack in immunity or physical resistance.

Question 10

Difference between Food borne illness and Food Poisoning

Answer 10

Food-borne illness: When you consume food and it has a preformed toxin, or it starts to form the toxin in the body after its consumed.
Food poisoning: endogenous toxins are already present in the food you consume.
Quiz Questions:
Food poisoning occurs because of toxins not inherent in food. FALSE
Food borne illness is synonymous with food poisoning. FALSE
In what ways can people be poisoned by food? food is ingested and illness occurs bc inherent toxin, ingestion of preformed toxin, ingestion of organisms themselves.
Rivals salmonella as the most common food borne illness. CAMPYLOBACTER ENTERITIS

Question 11

Staphylococcus Aureus

Answer 11

Most common cause of food poisoning in the U.S. Is a natural inhabitant of the human body. Short incubation period 30 min-7 hrs. Caused by food contamination with an infected lesion, or milk from infected cow.
Causes Folliculitis, Furuncles, and carbuncles, impetigo, osteomyelitis, toxic shock syndrome, and conjunctivitis.
Quiz questions:
What foods is staph aureus found in? cooked ham, milk, custards, cream fillings, salad dressing.
What diseases can staph aureus be an agent for? Folliculitis, furuncles, carbuncles, impetigo, osteomyelitis, toxic shock, and conjunctivitis.

Question 12

Definition of Arthropod

Answer 12

Insects that carry disease. Typically involved in transferring organisms from one reservoir to another. Most are parasitic. Some arthropods serve only as mechanical vectors rather than true reservoirs. Others become reservoirs if the organism infects them and is able to develop and multiply.

Question 13

Definition of Zoonoses

Answer 13

Infectious diseases of animals that can be transmitted to humans.

Question 14

Sinusitis

Answer 14

Acute or chronic inflammation of the mucous membranes of the paranasal sinuses. Can become chronic from allergies and/or persistent infections. Most frequently reported chronic disease in U.S. Caused by several disease agents.
Transmission: natural inhabitant of the human body (auto-infection). Airborne droplets or secretions of nose and throat.
Symptoms: fever, congestion, sore throat, thickened discolored nasal discharge, cough, tooth pain, tenderness and swelling of sinuses.
Prevention: healthy lifestyle
Control: careful personal hygiene, disposing of contaminated tissues, hand washing, wash drinking and eating utensils thoroughly.
Treatment: antibiotics
Quiz Question:
Which is associate with allergies? SINUSITIS

Question 15

Streptococcal Sore Throat (Pharyngitis)

Answer 15

An acute or chronic inflammation or infection of the pharynx. Caused by S. Pyogenes, 20% school children carriers, otitis media or acute sinusitis most common complication, rheumatic fever, glomerulonephritis, rheumatic heart disease may occur later.
Transmission: direct or intimate contact with individual who has active pharyngitis or a carrier. Ingestion of contaminated food.
Symptoms: temp of 101-104, severe sore throat, swollen glands and tonsils, malaise, weakness, anorexia, symptoms in children may be inapparent.
Treatment: penicillin or erythromycin for 10 days, early treatment, bed rest.
Prevention/control: children should be seen by a doc if they have consistent sore throat, avoid close contact with infected people, proper food handling, determine source, antibiotics prophylactically.

Question 16

Rheumatic Fever

Answer 16

Childhood disease always preceded by another strep infection. A systemic inflammatory and autoimmune disease involving the joints and cardiac tissue. Cause of rheumatic heart disease, causative factors include low resistance and hyper-sensitivity, most prevalent in lower income groups.
Transmission: No person to person, but transmission of strep organism is possible.
Symptoms: fever and migratory joint pain, abdominal pain, rash nodules,cardiac involvement, chorea (involuntary movements of limbs and face).
Treatment: antibiotics penicillin and erythromycin.
Prevention/Control: education of public, immediate antibiotic treatment, find carriers, check for contaminated foods or milk.
Quiz Question:
Which of the following of theses does not have a vaccine available? RHEUMATIC FEVER.

Question 17

Scarlett Fever

Answer 17

Generally proceeded by strep, erythrogenic toxin produced by S. Pyogenes, many are immune, no longer communicable after 24-48 hrs. of antibiotic treatment.
Transmission: droplet spread, direct and indirect, including contaminated milk or food.
Symptoms: sore throat, rash, nausea, vomiting, fever, strawberry tongue, flushed cheeks, shedding of skin (desquamation).
Treatment: penicillin, erythromycin, and clindamycin for 10 days.
Prevention/control: same as other strep diseases.

Question 18

Pneumonia

Answer 18

An infective inflammation of the lungs, may be caused by bacteria, virus, fungus, or protozoa, there are 2 types. Classified by disease agent, location, and type, one of the top 10 causes of death in the U.S.
Pneumococcal pneumonia: most common type, more common among very young and very old, common cause of death among alcoholics, 1-3 day incubation, antibiotic therapy, noninfectious within 24-48 hrs.
Transmission: direct or indirect contact with respiratory discharges.
Symptoms: sudden onset of chills, fever, chest pain, difficult breathing and cough, bright red or rusty sputum, older people may be asymptomatic.
Prevention/Control: vaccine for those at high risk, avoid crowds.
Mycoplasmal Pneumonia: causes 20% of all pneumonias, “walking pneumonia”, may last a month or more, light or asymptomatic in children under 5.
Transmission: direct or indirect contact with respiratory secretions.
Symptoms: sudden or insidious onset, headache, malaise, cough, substernal pain.
Prevention/Control: no vaccine, avoid crowds, contact investigation, proper sanitary methods.

Question 19

Legionnaires disease

Answer 19

Acute respiratory tract infection that produces severe pneumonia-like symptoms, milder form called Pontiac Fever. Outbreaks traced to faulty cooling systems or excavation sites, unrecognized cause of pneumonia for many years, mortality rates as high as 15% of hospitalized patients.
Transmission: Legionella bacterium lives in soil and water, infection by inhalation of airborne particles, no evidence of person to person transmission.
Symptoms: sudden or gradual onset, diarrhea, anorexia, malaise, myalgia, weakness, headache, high fever, chills, nonproductive cough, grayish blood-streaked sputum, nausea, vomiting, disorientation, pleurisy, and bradycardia, Complications; congestive heart failure, acute respiratory failure, renal failure and shock.
Prevention/Control: no vaccine available, implicated cooling systems and water supplies need to be disinfected, dust control at excavation sites.
Quiz Question:
The organism for the disease exist in soil what is the name of the bacterial infection acquired through the respiratory route. LEGIONNAIRES

Question 20

Pertussis (whooping cough)

Answer 20

A highly contagious infection of the respiratory tract. Childhood disease is violent coughing with high-pitched inspiratory whoop and vomiting of thick mucus. Has decreased since vaccinations began, but increased in recent years, caused by Bordetella pertussis, mortality usually result of secondary pneumonia in children under one and elderly, highly communicable during late incubation and catarrhal stage, communicable only 5-7days with antibiotics, 31% of adults with a chronic cough can be carriers.
Transmission: direct by droplets, indirect by contact with contaminated objects.
Symptoms: catarrhal- inflammation of the mucus membrane, insidious onset, may include irritating cough, anorexia, sneezing, listlessness, infected conjunctiva, low-grade fever.
paroxysmal- spasmodic and recurrent coughing that may expel tenacious mucus, cough ends in light high inspiratory whoop, vomiting, nose bleed, detached retina, hernia. Secondary infections; otitis media, encephalopathy, pneumonia.
convalescent- cough may last 1-2 months and be triggered again by upper respiratory infection.
Treatment: infants hospitalized, fluids and electrolytes, nutritional supplements, mild sedation, oxygen, antibiotics not very effective, but shorten communicability.
Prevention/Control: vaccination at 2-3 months, isolation of suspected cases, vaccination for those unvaccinated, gamma globulin prophylactically.

Question 21

Dipththeria

Answer 21

Acute communicable disease that causes necrosis of the mucus membrane in the respiratory tract. Generally a childhood disease. Once a leading cause of death, caused by corynebacterium diphtheriae stays in upper respiratory region produces deadly exotoxin which irritates tissue producing a pseudomembrane, reservoir is humans, an attack does not always confer immunity.
Transmission: direct by droplets or indirect by contact with contaminated articles.
Symptoms: thick, patchy grayish green membrane over mucous membranes of pharynx, larynx, tonsils, soft palate, and nose. Fever, sore throat, rasping cough, hoarseness, difficulty breathing, complications; myocarditis, neurologic involvement, kidney involvement.
Treatment: Diphtheria antitoxin, antibiotics.
Prevention/Control: active vaccination with diphtheria toxoid according to schedule, usually 2-3 months.

Question 22

Tuberculosis

Answer 22

A chronic acute or subacute infectious and inflammatory disease of the lungs. Cause by mycobacterium tuberculosis, 1900s 2 of every 1,000 died, now 30,000 cases/ year, 10 million infected. Primarily a disease of the lungs, can invade blood stream and infect liver, brain, urogenital tract, and bone. Illness and death rates increase with age. Higher rates among poor, non-whites, and in cities. Primary reservoir is humans and cattle. In 1993 declared a global emergency.
Transmission: direct or indirect, usually by inhalation of airborne droplets, prolonged exposure to an active case is necessary, more likely in family situation, army barracks, college dorm.
Symptoms: usually none at first, fatigue, weakness, anorexia, weight loss, night sweats, low grade fever, organisms are encapsulated in lungs, reactivation occurs late in life or at a time when the immune system is compromised, cough and pus, chest pain, occasionally bloody sputum.
Treatment: isoniazid combined with rifampin or other drugs, 9 months of therapy
Prevention/Control: vaccination with BCG, but not routinely used in U.S. , improved social conditions, education of public, appropriate chemotherapeutic methods.
Quiz Question:
Which is necessary to have prolonged exposure to an active case to become infected? TUBERCULOSIS

Question 23

Clostridium (C.) Perfringens

Answer 23

Milk with short duration, incubation is usually 10-12 hrs but could be from 6-24 hrs, occurs worldwide.
Transmission: food contaminated by soil or feces, most outbreaks from inadequately heated meats and meat gravies, often restaurants or food prep businesses with inadequate cooking and/or refrigeration facilities.
Symptoms: mild sudden cramps, diarrhea, nausea, seldom vomiting or fever. Last a day or less, rarely fatal.
Treatment: necessary only if dehydration occurs.
Prevention/Control: educate food handlers in large batch food prep, hot dishes cooled rapidly for storage, thorough reheating, source identified and eliminated.

Question 24

Botulism

Answer 24

Very serious and life threatening (affects the CNS). Ingested toxin results in paralysis of cranial and peripheral nerves, infant botulism, wound botulism, home canning, preserving, commercially canned, incubation usually 12-36 hrs, shorter incubation leads to more severe illness, case fatality under 15% with treatment, 1/3 die within 3-7 days without treatment. Is used in Botox.
Transmission: inadequately cooked foods, most often home canned fruit and vegetables in U.S., smoked or preserved meat in Europe and fish in japan.
Symptoms: dizziness, difficulty swallowing, double vision, nausea, vomiting, diarrhea, descending paralysis, death.
Treatment: botulinum antitoxin.
Prevention/Control: effective control of processing and preparation of commercially canned and preserved foods, education of others involved in food canning and preservation, bulging cans or jars should not be used, early detection, and elimination of source, boil food before discarding, sterilize contaminated utensils.
Quiz Question:
What infectious disease is a life-threatening illness that affects the CNS? BOTULISM

Question 25

E. Coli

Answer 25

Normal inhabitant of the intestines, suppresses growth of harmful bacteria in the body, 3-8 day incubation, serious in children, children under 5 less likely to develop hemolytic uremic syndrome.
Transmission: food, water, person to person (in feces) many different foods.
Symptoms: severe cramping, diarrhea that becomes bloody, occasional vomiting and low grade fever.
Treatment: fluid replacement for dehydration, antibiotics may increase risk of complications.
Prevention/Control: “ten golden rules” and typhoid prevention, antibiotics prophylactically for travelers, identification and elimination of source.

Question 26

Shigellosis

Answer 26

Shigella, bacillary= infection by an organism from one of four groups of shigella dysentery= diarrhea, abdominal cramping, and tenesmus. Endemic in N. Am, Europe, and the tropics, reservoir is human intestinal tract, 1-3 day incubation, communicable up to 4 weeks, drinking or infestion of 10 organisms can cause it, with treatment 1% fatal, more reported cases than campylobacter or salmonellosis.
Transmission: direct fecal-oral, indirect with contaminated objects, unwashed hands or unclean fingernails after defecation, flies, dogs who ingest human feces.
Symptoms: in children; diarrhea, tenesmus, high fever, nausea, vomiting, abdominal pain with distention, irritability and drowsiness, pus, mucus and blood in stools. Adults; same except for fever. Electrolyte imbalance and shock rare but can be fatal.
Treatment: Many strains resistant to antibiotics, antidiarrheal drugs prolong symptoms and communicability, control of dehydration most important.
Prevention/Control: control of human reservoir, adequate treatment of water, sewage, fly control, protection of food, water, milk.

Question 27

Salmonellosis

Answer 27

Over 1800 species, 10 common in U.S., infection ranges from carrier state to potentially fatal infections, named after Daniel salmon, most often salmonella enteritidis, rate of infection is highest for babies and young children, 12-36 hr incubation.
Transmission: ingestion of food from infected animal, food contaminated during storage by feces, food contaminated by an infected person, meat, poultry, sausages, foods containing dairy products, turtles.
Symptoms: sudden onset of nausea, vomiting, abdominal pain, diarrhea, fever, chills.
Treatment: only for dehydration, use of antibiotics may prolong carrier state.
Prevention/Control: protection of meats, eggs, stored foods, food handlers inspected by health departments, carriers restricted from food handling, education of public and food handlers, infection in domestic animals, fowl, and pets controlled.

Question 28

Campylobacter Enteritis

Answer 28

Campylobacter jejuni, responsible for 5-11% of all cases of diarrhea and dysentery in the U.S., common foodborne illness, thought to cause more illness than salmonella, 2-5 day duration, up to 10 days, relapse sometimes occurs, reservoir in animals, poultry, human, dogs, lasting immunity after infection.
Transmission: food or water contact with infected pet, wild animals, infected children.
Symptoms: diarrhea, abdominal pain, malaise, fever, nausea, vomiting, blood in stools, asymptomatic or very sick, sometimes resemble typhoid, rarely meningitis.
Treatment: rehydration and electrolyte replacement, antibiotics in special cases.
Prevention/Control: thorough cooking of food from animals and poultry, pasteurization of milk, purification of water supplies, recognition, control of infected pets, hand washing after contact with animals, people infected should be excluded from food preparation, identification, elimination, or isolation of source.

Question 29

Toxic Shock Syndrome

Answer 29

Characteristics: menstruating women under 30, super absorbent tampons provided conditions for organism to multiply, some cases linked to birth control devices or an infection in another part of the body, a few cases in boys, men, and non-menstruating women.
Agent: S. Aureus, penicillin resistant strains exist. S. Pyogenes, 1980 30-70% fatality rate with treatment.
Transmission: S. Aureus infection occurs when conditions inside the vagina are favorable, regular inhabitant of body. S. Pyogenes transmission is unknown.
Symptoms: S. Aureus- fever over 104, sunburn like rash, low BP, peeling of skin on palms and soles of feet. S. Pyogenes- pain (most common) usually involving an extremity, swelling and redness of tissue occurs in 80% of patients, possible necrotizing fasciitis.
Treatment: antibiotics and fluid replacement.
Prevention/Control: switch to less absorbent tampon and change them more frequently, removal of contraceptive devices as soon as directed on package, keep the immune system strong.
Quiz Question:
how can toxic shock be avoided? Switching to a less absorbent tampon, removing contraception devices as directed, and keeping the immune system strong and healthy.

Question 30

Meningitis

Answer 30

Characteristics: infectious of meninges, become inflamed as a result of infection with a pathogenic organism, many times it is the complication of bacterial infection at some other location in the body, can be caused by bacteria, viruses, fungi, and parasitic worms.
Agents: bacterial meningitis is the most common cause. Neisseria Meningitidis more in young adults. Step Pneumoniae more in infants, older adults, and alcoholics. Haemophilus influenzae more in children.
Transmission: varies with infecting organism, most forms transmitted by direct contact with respiratory secretions from the nose and throat of infected persons, 10% of pop in endemic countries may be asymptomatic.
Symptoms: Adults and older children; stiff neck, problems in leg extension and flexion, exaggerated deep tendon reflexes, back spasm. Babies; fontanelle not bulging, sign of intracranial pressure.
Treatment: antibiotics intravenously for at least 2 weeks, followed by oral antibiotics.
Prevention/Control: antibiotics prophylactically with trauma or surgery. Vaccine available for H. Influenzae recommended for children under 15 months. Vaccines for some forms of N. Meningitidis. Monitor other children in daycare center when cases present, isolation for 24 hrs after start of antibiotics, some physicians advise rifampin prophylactically for all household contacts and day-care centers. Vaccine required for entering college and university students.
Quiz Question:
which of the following involves inflammation of membranes and lining. meningitis and

Question 31

Syphilis

Answer 31

Characteristics: throughout history prevalence has fluctuated, played an important role in shaping history, incubation period is 10 days to 3 months, but typically 3 weeks, four stages; primary, secondary, latent, and tertiary (late).
Agent: Treponema Palladium, spirochete.
Transmission: major means of transmission is direct contact with body fluids containing the organism during sexual intercourse or other intimate contact. Can enter the body through mucus membranes, fetus may be infected through placental membrane, may be transmitted through blood transfusions, contact with contaminated articles is possible, but highly unlikely because the organism can only exist in a moist environment.
Symptoms: Primary- painless chancre at portal of entry, Secondary- lymph node enlargement, aches and pains in the bones, hair may fall out in clumps, meningitis may occur, Latent- no more symptoms, Tertiary (late)- only 30% progress to late stage, painless gumma, cardiovascular (aneurysm, heart valve disease), neuro (progressive brain damage, paralysis, tabes dorsalis (affects spinal cord)).
Treatment: Penicillin will sure syphilis in primary, secondary and latent stages, organ damage caused is irreversible, fetus can be cured in the womb if mother is treated in a timely manner.
Prevention/Control: monogamous relationships, use of condoms, immunity is slowly gained over time after infection, early treatment leads to reduced immunity, screenings.

Question 32

Folliculitis, Furuncles, and Carbuncles

Answer 32

Characteristics: folliculitis is infection of a hair follicle, furunculosis involves deep layers of skin, gland, or hair follicle, carbuncles encompass more than one hair follicle and invade deep tissue. Common in children during warm weather, can lead to other infections.
Transmission: Hands are most important mode, people are the reservoir, it inhabits in the nostrils, self infection is responsible for at least 1/3 of infections, person to person by contact with a pus containing lesion or with an asymptomatic carrier.
Symptoms: stye, red pustules, boils are hard painful nodules on neck, face, armpits, and buttock. Carbuncle painful deep abscess that drains through multiple openings.
Treatment: None other than keeping the area clean, antibiotic ointment, hot compress, surgical drainage.
Prevention/Control: good hygiene, educate children on hand washing, infants, the ill, and the elderly are more susceptible, don’t share personal items.
Quiz Question:
which of the following does not describe why auto infection plays a big part in folliculitis? Spread from person to person

Question 33

Impetigo

Answer 33

common in newborns, during hot humid weather, people are reservoir, 4-10 day incubation, agent is S. Aureus or S. pyogenes.
Transmission: direct and indirect contact, hands are main method, fomites, auto-infection (1/3 of cases).
Symptoms: small red spot on skin mostly on face, blisterlike vesicle, pustule, pustule ruptures and becomes crusted.
Treatment: antibiotics are not used unless fever, malaise, or other complications are present. Bacitracin and keep skin clean.
Prevention/Control: personal hygiene, children who have it should be excluded form school or daycare centers, people with diabetes and the elderly are more susceptible, frequent hand washing.

Question 34

Osteomyelitis

Answer 34

Infection of bone and bone marrow. Caused by S. Aureus, occurs more often in children than adults, more often in boys than girls, common sites are lower end of the femur and the upper end of the tibia, humerus, and radius, in adults the pelvis and vertebrae. Transmission: internal infection, person to person unlikely unless they have S. Aureus on their skin or mucus membranes and the infection travels to the bones.
Symptoms: abrupt onset sudden pain, tenderness, heat, swelling, restricted movement of bones, may be fever, tachycardia, nausea, and malaise.
Treatment: 4-8 weeks of antibiotic therapy, surgical debridement, drainage, analgesics for pain.
Prevention/Control: refrain from squeezing boils, risk factors include anything that compromises the immune system, check for penetration wound, sterile procedures for disposal of bandages and draining wound.

Question 35

Conjunctivitis

Answer 35

“pinkeyed”, caused by S. Aureus, 24-72 hr incubation, people are the reservoir, children under 5 are the most susceptible.
Transmission: contact with discharges, contaminated fingers, fomites, and insect vectors.
Symptoms: redness, itchiness, purulent discharge, and occasionally photophobia, eyelids can get stuck together.
Treatment: warm water, antibiotic ointment, eye drops, oral antibiotic.
Prevention/Control: personal hygiene, sanitary conditions, treat promptly.

Question 36

Lyme Disease

Answer 36

Characteristics: in all states but Montana, 7-32 day incubation, repeated infections can occur, highest rates in children 5-9 years and adults over 30, serious sequelae (condition that is the consequence of a previous disease or injury).
Agent: borrelia burgdorferi, spirochete carried by lxodes dammini (deer tick).
Transmission: bite of an infected tick, transmission to fetus, no person to person.
Symptoms: 3 stages. 1st stage- EM or erythema migrans, distinctive lesion, red macule or papule which expands, may be hot, sticky, becomes lighter in center. 2nd stage- neurological and/or cardiac abnormalities. 3rd stage- swelling and pain in knees and other large joints.
Treatment: cured by antibiotics in all 3 stages, reversal of arthritis only half the time, penicillin for children, tetracycline for adults, 10-20 days of antibiotics in early stages minimizes later symptoms.
Prevention/Control: wear long sleeves, long pants, boots, light colored clothing, and insect repellant, shower, towel down briskly, inspect each person and domestic animal for ticks when in an area where there is deer, vaccine for individuals who hike, work, or live in infested areas.

Question 37

Plague

Answer 37

Characteristics: came close to annihilating the human race, still dangerous today, exists in rodent populations, 3 forms bubonic, pneumonic, and septicemic, 2-6 day incubation, 60% mortality without treatment in bubonic, nearly 100% in the other 2, 18% with treatment.
Agent: yersinia pestis
Transmission: usually by the bite of a flea from an infected rat, domestic pets may carry, handling of tissues of infected animals, carelessness with lab cultures.
Symptoms: Bubonic- Hemorrhage in lymph nodes “buboes”. Septicemic- convulsions, prostration. Pneumonic- primary; productive cough with yellowish sputum, secondary; sputum turning to frothy pink or red.
Treatment: streptomycin within 8-24 hrs of onset, must start within 18 hrs to avoid deaths in septicemic and pneumonic.
Prevention/Control: elimination of rats and their fleas, education of people living in or near plague areas, vaccinations available, must be reported to gov, isolation of victims, disinfection of soiled articles, prophylactic treatment, isolation for 7 days.
Quiz Question:
identify 3 forms of plague. Bubonic, Pneumonic, Septicemic.

Question 38

Anthrax

Answer 38

Characteristics: Occupational disease, survivors develop resistance, feared biological weapon.
Agent: Bacillus Anthracis
Transmission: Cutaneous anthrax- contact with tissues of dying animals, animal products including bone meal, shaving brush bristles, soil associated with infected animals, biting fleas. Intestinal- eating undercooked meat. Inhalation- inhalation of spores. No person to person transmission.
Symptoms: Cutaneous- vesicle becomes larger, turns black “malignant pustule”. Inhalation- upper respiratory symptoms. Intestinal- septicemia, death in most cases.
Treatment: antibiotics, penicillin and tetracycline.
Prevention/Control: vaccine for animals and high risk persons, education for those in at risk occupations, special precautions, protective clothing and gloves for workers, dust control and masks in contaminated areas.
Quiz Questions:
what is distinct about anthrax lesion? It starts off as a red elevated area, within a day or two quickly becomes a vesicle, then it turns black “malignant pustule”.
why would anthrax be considered and occupational disease? Because you can get it through any work that is done with animals.

Question 39

Tetanus

Answer 39

Characteristics: More common in agricultural regions, underdeveloped areas, reservoir is the intestines of animals and man, 10 day incubation.
Agent: Clostridum tetani, anaerobic conditions promote growth.
Transmission: Spores common in dust of streets, soil, anything or place contaminated with fecal matter containing spores. Introduced into the body through any wound or abrasion usually a puncture wound. Presence of dead tissue, foreign bodies, favors growth. No person to person transmission.
Symptoms: Rigidity in abdomen or wound site, risus sardonicus- grinning expression, arched back rigidity if somatic muscles involved.
Treatment: tetanus antitoxin or tetanus immune globulin within 72 hrs, later tetanus toxoid, booster if needed. If tetanus develops airway maintenance, muscle relaxant, tracheostomy, mechanically assisted respiration, high-dose antibiotics, preferably penicillin for 10-14 days.
Prevention/Control: active immunization with tetanus toxoid, infants at 2-3 months, 10 year booster after initial series, source identification, report to local health authorities.

Question 40

Common Cold

Answer 40

Characteristics: most common of all communicable diseases, not serious but serious complications, nearly 200 cold viruses identified, more frequent in children, 48 hr incubation, communicable from 24 hrs before onset of symptoms and 5 days or more after onset.
Agent: over 100 different types of rhinovirus.
Transmission: direct or indirect, most often by hand-eye route, can exist on objects for some time, droplet route is possible as well.
Symptoms: Common symptoms- tickle in throat, watery discharge from nose, copious and causes irritation to the nose, sneezing. Secondary infection occurs when discharge thickens and becomes yellowish green.
Treatment: no cure, treatment for symptoms, plenty of liquid, extra rest, OTC products for temporary relief, reyes syndrome in children if given aspirin, antibiotics will not affect viral disease.
Prevention/Control: no scientific evidence that extra vitamins, orange juice will prevent colds, high degree of fitness may help, frequent hand washing, cold shot available for at risk individuals.
Quiz Questions:
Which is not a complication that occurs with the common cold? Fever
Which mode of transmission holds the greatest chance for acquiring a cold? Handling a contaminated object and then rubbing your eyes.

Question 41

Influenza

Answer 41

Characteristics: respiratory tract infection, can be dangerous and lead to pneumonia, epidemics in winter, 1-5 day incubation, communicable 3-5 days after first signs, 3 groups; A most common, B widespread or region epidemics, pandemics every 2-3 years, mixed A and B, C endemic scattered and minor.
Agent: virus is constantly changing, A and B are identified by location/infected population and letter and number ex H5N1.
Transmission: through the air person to person in crowded condition, droplets, indirect contact with contaminated object, virus able to survive for hours in dried mucus.
Symptoms: Sudden onset, chills, temp of 101-104, muscles aches, nonproductive cough, secondary infections may occur most often pneumonia.
Treatment: bed rest, analgesics, liquid, amantadine for high risk of developing pneumonia, antibiotics prophylactically to prevent secondary infection.
Prevention/Control: vaccination for people over 65, high risk (every year), 60-70% effective, at the least is lessens severity, no school closings its too late, education of public in personal hygiene.
Quiz Question:
Why has flu been a difficult disease to prevent? Because the virus changes very rapidly making everyone susceptible to new forms.

Question 42

Varicella (chicken pox)

Answer 42

Characteristics: mild, very contagious in childhood, severe effects in adults, birth defects, 13-17 days incubation, communicable 5 days before and 5 days after vesicles appear, immune after infection, organism stays in body, may cause shingles later.
Agent: human herpes virus 3 (varicella-zoster).
Transmission: direct contact with respiratory secretions and fluid from lesions, indirect contact with fomites.
Symptoms: anorexia, rash within 24 hr, small red spots on trunk or scalp become clear vesicles on red base (dewdrop on a petal), itchy and breaking, scarring, boils caused by staph aureus.
Treatment: bicarbonate of soda baths, calamine or antihistamine lotions to relieve pruritus, acyclovir.
Prevention/Control: Varicella Zoster immune globulin decreases severity if given within 96 hrs after exposure, vaccine available, children should be excluded from school for at least 5 days after first lesion appears or until all vesicles dry.
Quiz Question:
Dew drop on a rose petal is used to describe symptom of what disease? Varicella (chicken pox).

Question 43

Poliomyelitis

Answer 43

Characteristics: has produced more fear in the world than AIDS. Ranges from asymptomatic to paralysis, “iron lung” is an artificial respirator, symbolic of the paralytic form, used to be called infantile paralysis, 7-14 day incubation.
Agent: poliovirus, an enterovirus.
Transmission: direct contact with close association with someone who has the disease, fecal-oral main route if sanitation is bad, pharyngeal secretions main route in sanitation is good.
Symptoms: at least 90% asymptomatic, .1-2% paralysis occurs 3-4 days after minor illness has subsided, extent of paralysis varies depending on nerves involved-maybe only one leg or progressive, if progressive it will eventually effect vital organs resulting in death.
Treatment: no treatment, can treat symptoms as they appear, analgesics to relieve pain, physical therapy.
Prevention/Control: immunization beginning at 2 months, greatest risk of infection during prodromal period, isolation unnecessary but sanitary disposal of feces.
Quiz Question:
What is the iron lung? An artificial respirator (the first one ever built) used for polio virus.

Question 44

Hepatitis B

Answer 44

Characteristics: Caused by at least 5 different viruses, A (infectious) B (serum), slower onset than A, 60-90 day incubation, blood thought to be infective weeks before symptoms appear and through the carrier stage which may be for life.
Agent: Hep B virus
Transmission: blood, saliva, semen, vaginal fluids, contaminated needles, syringes, contamination of sores, blood transfusion, homosexual or heterosexual intercourse.
Symptoms: Insidious onset- anorexia, vague abdominal discomfort. Sometimes- Jaundice.
Treatment: treat symptoms only, interferon used to treat chronic HBV patients, this slows the progress of the disease in about 40% of patients treated.
Prevention/Control: vaccines recommended for those at risk of infection and newborns, continued screening of blood, sterilization of syringes, proper disposal of needles and syringes.

Question 45

HIV/AIDS

Answer 45

Characteristics: impairs the immune system leading to opportunistic pathogen infections, originally linked to homosexuality and drug users, highest rates in white men with men.
Agent: Human Immunodeficiency Virus, destroys helper T cells.
Transmission: when infected blood, semen, or vaginal secretions are introduced into the bloodstream, blood transfusion, pregnant mother can pass virus to fetus, mother can pass to child when breastfeeding, women more susceptible than men.
Symptoms: asymptomatic, nonspecific symptoms 6 days to 6 weeks after infected, symptoms resolve spontaneously and are usually attributed to the flu, the virus can stay quietly in the body for up to 10 years without any symptoms, AIDS diagnosed- person with less than 200 CD4+ T- lymphocytes/uL, or a CD4+ T- lymphocyte percentage of total lymphsytes less than 14. Opportunistic infections appear; pneumocystis carinii, kaposis sarcoma.
Treatment: no cure, highly active antiretroviral therapy “AIDS cocktail” reduces the amount of the virus circulating and keeps the immune system at normal levels.
Prevention/Control: be sure of sexual partners status, refrain from oral, anal, and vaginal sex, use condoms, use sterile equipment during healthcare.
Quiz Question:
How does HIV aids cause damage to the immune system? takes over helper T cells and destroys them.

Question 46

HPV

Answer 46

Characteristics: infections are widespread, 6 mill new infections annually, 50% of men and women will get it at some point in their lives, highest rates are seen among women ages 20-24, highest rates among african american women.
Agent: 100s of strains, 4 major ones that cause problems are 16, 18, 6, 11. 16 and 18 are associated with 70% of cervical cancer cases. 6 and 11 are associated with 90% of genital warts cases.
Transmission: touching (hand/genital and genital/gential), women are at a higher risk because the cervix, it contains squamous cell and glandular cells, the place where these 2 cell types meet is called the transformation zone.
Symptoms: Males- may be asymptomatic, genital warts on penis, anus, scrotum, or groin, may lead to penile and anal cancer. Women- may be asymptomatic, genital warts on labia or groin, in the vagina, and on the cervix, linked with 95% of cervical cancer.
Treatment: most cases go away on their own 70% gone in one year, 90% gone in 2 years, 5-10% can develop into precancerous lesions, if cancer develops surgery, chemo, anticancer drugs, and radiation can be used. For genital warts there are many different methods to remove them, but theres a possibility they can come back, they may also disappear after several years.
Prevention/Control: monogamous relationships, practice safe sex, vaccination (gardasil for all 4 strains, glaxosmithklines for 16 and 18), for women ages 21-65 screen with cytology (Pap smear) every 3 years, Pap smear with HPV testing every 5 years.

Question 47

Ebola Virus

Answer 47

Characteristics: 1st appeared in africa in 1976, endemic to central africa, reservoirs in nature, acute and mostly fatal, causes blood vessel bursting, 2-21 day incubation, systemic, humans and non human primates.
Agent: Ebola virus, Human subtypes- ebola zaire, ebola sudan, ebola Ivory Coast, Nonhuman- ebola reston.
Transmission: direct contact with blood/secretions of infected person or dead person, may stay in semen for up to 3 months, may enter through broken skin or through mucus membranes, possible airborne among reston. Indirect contact with objects contaminated by infected persons fluids or secretions. Can only spread once symptoms are present.
Symptoms: early- red eyes, stomach pain. acute- bleeding/hemorrhaging from skin, orifices, internal organs, possible death
Treatment: no standard treatment, working quickly to create vaccine, supportive therapy such as treating infections, balancing fluids, and maintaining oxygen and BP, dependent on the persons immune system, patients who survive develop immunity which lasts 10 years.
Prevention/Control: Isolate patient for 21 days, medical staff training, infection-control measures, caution with fluids of the dead, incinerate all waste.

Question 48

Coccidioidomycosis (Valley Fever)

Answer 48

Characteristics: weather and increase in population are thought to be the cause, found in 2 forms; primary and progressive, located mostly California to southern Texas, 1-4 week incubation, disease is not communicable, immunity for life.
Agent: coccidioides immitis
Transmission: inhalation of the spores found in the soil, dry weather coupled with sparse foliage and high winds allows for spores to become airborne.
Symptoms: Primary- usually heals on its own within a few weeks, in 5% of people- tender nodules on legs especially shin, joint pain in knees and ankles.
Treatment: primary- bed rest, relief of symptoms. In severe cases and disseminated antifungal agents used.
Prevention/Control: dust control measures, careful selection of occupations, skin testing, dust masks should be worn.
Quiz Questions:
In the U.S. where is coccidiomycosis prevalent? California to southern Texas.
What is the reservoir for coccidiomycosis? Soil

Question 49

Candidiasis (moniliasis, thrush)

Answer 49

Characteristics: Opportunistic yeastlike fungal infection of the skin or mucus membranes, occurs in babies (diaper rash), mouth (thrush), and vulvovaginal area (moniliasis), occurs worldwide, natural inhabitant of the body, 2-5 day incubation, communicable as long as the lesions are present.
Agent: Candida albicans
Transmission: secretions or excretions of infected individuals or carriers, babies can get it while passing through the birth canal of the mother, sexual intercourse, endogenous infection when resistance is low.
Symptoms: skin- scaly red papular rash, often appearing in creases of skin. mouth- cream colored or blush white patches on the tongue, mouth, and pharynx. vagina- white or yellow cheesy discharge, itchy, vaginal wall develops white or grey raised patches.
Treatment: control the underlying condition, antifungal drugs are effective.
Prevention/Control: treatment of pregnant women, partner treatment, maintain a healthy lifestyle.
Quiz Question:
Candidiasis is most prevalent in which areas of the body? Mouth, areas where diaper covers, creased areas, vagina.

Question 50

Dermatophytoses (tinea or ringworm)

Answer 50

Characteristics: common fungal infection, occurs anywhere on the skin, reservoir is usually people but can be animals and soil, incubations ranges based on the type of tinea but is typically 4-14 days, usually in warm moist places, communicable as long as lesions are present.
Agent: several different types of fungi. Barbae -beard, capitis- scalp, cruris- public area “jock itch”, pedis- foot, manuum- hands, unguium- nails.
Transmission: direct and indirect contact, contact with lesions or infected items.
Symptoms: capitis and barbae- small papules spread across the beard or head area, hair becomes grey lusterless and eventually falls out. cruris and corporis- red slightly elevated scaly oatches containing minute vesicles, patches are ring shaped, new patches arise of the periphery while central area clears up leading to the ringworm appearance, itching is usually considerable. pedis- scaling or cracking between the toes, watery blisters. unguium- thickening of infected nail, nail becomes discolored, nail becomes cheesy looking.
Treatment: hygiene, wash area throughly, disinfect, remove scabs or crust, fungicide, oral antifungals and antibiotics.
Prevention/Control: education about the fungus, dry areas well, regular use of antifungal powders, launder everything in hot water, frequent washing of recreational facilities.
Quiz Question:
Which is not a common site for tinea infections? Ears

Question 51

Toxoplasmosis

Answer 51

Characteristics: one of the most common infectious diseases, cats are the main host and get it from consuming infected birds or rodents, they excrete cysts containing the organisms eggs in their feces, 5-23 day incubation, 10-25% of lamb contains the organism.
Agent: toxoplasma gondii.
Transmission: transmitted to human through cysts, ingestion of under cooked pork and lamb, contaminated water supply, cat liter boxes and sand boxes with cat feces, placental transmission to fetus.
Symptoms: Acute- similar to mononucleosis, pregnant woman and child- in the first trimester baby is often stillborn, those who survive have hydrocephalus and hepatosplenomegaly.
Treatment: no treatment is necessary unless its developed during pregnancy.
Prevention/Control: all meals should be cooked throughly, feed cats commercially prepared food, clean litter boxes frequently, pregnant women should not clean litter boxes, protect sandboxes from stray cats, public education on the danger, contact investigation.
Quiz Question:
The existence of toxoplasmosis suggests that pregnant women should not do what while pregnant? Clean the litter box.

Question 52

Malaria

Answer 52

Characteristics: important disease hazard for americans traveling to other countries, prevalent in Asia, Africa, and Latin America, 12 day -10 month incubation, untreated people could be the source of mosquito infections for 1-3 years, 10% fatality rate for those untreated, people with certain genetic traits have immunity.
Agent: 4 species of plasmodium; vivax, malariae, falciparum, ovale.
Transmission: bite of a female anopheles mosquito, injection or transfusion of blood, congenital infection is rare.
Treatment: chloroquine is effective for all except falciparum, victum usually recovers in 3-4 days, quinine and other drugs are used for falciparum.
Symptoms: acute attacks- 3 stages, cold, hot , and wet. Cold- chills, shaking, last 1-2 hrs. Hot- fever up to 107, lasts 3-4 hrs. Wet- profuse sweating, lasts 2-4 hrs. Cycles of wellness and malaria attacks may continue for 50 years.
Prevention/Control: elimination of mosquito breeding grounds, use screens and nets on windows and doors, insecticides on skin, screening of blood donors, prophylactic drugs for those traveling, contact investigation and source identification.
Quiz Questions:
When a person with malaria begins to experience an acute attack of chills what has taken place in their body? Erythrocytes rupture releasing their components into the bloodstream.
How is malaria transmitted? bite of an infected female anopheles mosquito, injection or transfusion of infected blood, contaminated needles.

Question 53

Taeniasis (tapeworm disease)

Answer 53

Characteristics: various species, occurs worldwide, rare in U.S., 8-14 weeks before eggs appear in stools, everyone is susceptible.
Agent: tapeworm, there are many species, can be 20-30 ft long.
Symptoms: usually theres no symptoms other than mild abdominal discomfort and diarrhea. Pork tapeworm- embryos escape from eggs shells and penetrate intestinal walls, carried to various tissues where they develop into cysts and can cause dangerous systemic and CNS symptoms.
Transmission: Ingestion of undercooked beef, pork, and fish, hand to mouth contact, pork tapeworm is communicable from person to person, eggs are released into the environment for as long as they are in the intestines, they can remain infective in the environment for months.
Treatment: Drugs are available for treatment.
Prevention/Control: education of the public regarding proper cooking of meats and sanitary measures, freeze beef or pork for more than 4 days can destroy the organism, rigid sanitation methods should be taken, source identification and elimination.
Quiz Questions:
In which meat or meat substitute are tapeworms NOT generally found? Chicken, lamb, deer.
What is the intense nocturnal itching experienced with enterobiasis? Migration of pinworms to the perianal area at night to lay their eggs.

Question 54

Scabies

Answer 54

Characteristics: mites that burrow under skin and lay eggs, can occur anywhere, 2-6 week incubation, for people who have been infected before 1-4 day incubation, highly communicable, some people are more resistant than others, for those who have been infected before they don’t get it as easily the next time.
Agent: sarcoptes scabiei
Transmission: usually requires skin to skin contact, sexual relations
Symptoms: Itching that is greater at night, papules or vesicles or tiny burrow lines that appear between fingers, anterior surfaces of wrists and elbows, in armpit, at waistline, on nipples in females, and genitalia in males.
Treatment: soap and water bath, topical insecticide, itching persists for 1-2 weeks after treatment, all clothing, bedding, etc must be sterilized, all people that have come in contact with infected person need to be treated too.
Prevention/Control: public education, early diagnosis and treatment, contact investigation and source identification.
Quiz Question:
How is scabies generally transmitted to the host? Skin to skin contact.