| Review 2 Low JC. Donachie W.:
A review of Listeria monocytogenes and listeriosis.
Veterinary Journal. 153:9-29, 1997Following the initial isolation and description in 1926, Listeria monocytogenes has been shown to be of world-wide prevalence and is associated with serious disease in a wide variety of animals, including man.Our knowledge of this bacterial pathogen and the various forms of listeriosis that it causes has until recently been extremely limited, but recent advances in taxonomy, isolation methods, bacterial typing, molecular biology and cell biology have extended our knowledge. It is an exquisitely adaptable environmental bacterium capable of existing both as an animal pathogen and plant saprophyte with a powerful array of regulated virulence factors.Most cases of listeriosis arise from the ingestion of contaminated food and in the UK the disease is particularly common in ruminants fed on silage.Although a number of forms of listeriosis are easily recognized, such as encephalitis, abortion and septicaemia, the epidemiological aspects and pathogenesis of infection in ruminants remain poorly understood. The invasion of peripheral nerve cells and rapid entry into the brain is postulated as a unique characteristic of its virulence, but relevant and practical disease models are still required to investigate this phenomenon. | View Page |
| Review 2 Low JC. Donachie W.:
A review of Listeria monocytogenes and listeriosis.
Veterinary Journal. 153:9-29, 1997Following the initial isolation and description in 1926, Listeria monocytogenes has been shown to be of world-wide prevalence and is associated with serious disease in a wide variety of animals, including man.Our knowledge of this bacterial pathogen and the various forms of listeriosis that it causes has until recently been extremely limited, but recent advances in taxonomy, isolation methods, bacterial typing, molecular biology and cell biology have extended our knowledge. It is an exquisitely adaptable environmental bacterium capable of existing both as an animal pathogen and plant saprophyte with a powerful array of regulated virulence factors.Most cases of listeriosis arise from the ingestion of contaminated food and in the UK the disease is particularly common in ruminants fed on silage.Although a number of forms of listeriosis are easily recognized, such as encephalitis, abortion and septicaemia, the epidemiological aspects and pathogenesis of infection in ruminants remain poorly understood. The invasion of peripheral nerve cells and rapid entry into the brain is postulated as a unique characteristic of its virulence, but relevant and practical disease models are still required to investigate this phenomenon. | View Page |
| Most Eikenella cellulitis infections result from: | View Page |
| We can conclude from Robinson & Kourtis' "Tale of the Toothpick", that, "it is unwise to place a used toothpick in your pocket." | View Page |
| Which of the following properly describes use of needles? | View Page |
| Potentially infectious body fluids These substances are considered potentially infectious for an occupational exposure: blood cerebrospinal fluid synovial fluid pleural fluid peritoneal fluid pericardial fluid amniotic fluid any body fluid visibly contaminated with blood semen or vaginal fluid tissues removed during surgery. | View Page |
| Face and Eye Protection Face shields, masks, and safety glasses protect your eyes and the mucous membranes of your nose and mouth.They must be worn whenever it is reasonably anticipated that splashing or spraying of blood or other contaminated materials may occur.Employees who wear prescription eyewear may be protected with a face shield, goggles, or with side shields attached to their glasses. | View Page |
| Gloves Gloves must be worn: when there is a reasonable chance of exposure to blood, other infectious body fluids, mucous membranes, or nonintact skin. during vascular access procedures, including phlebotomy. when handling contaminated items or surfaces.Wear only flat rings under gloves as large rings may tear gloves.Replace gloves: Between patient contacts If they are damaged or contaminated Before leaving the work area. Wash hands after removing gloves.Never wash disposable gloves. | View Page |
| Agent: Botulism (bacterium) Most likely means of dissemination: Aerosol (eating contaminated food)Primary route of entry: Inhalation (oral)General signs and symptoms: Difficulty with speaking, swallowing, or blurred or double vision, drooping eyelids (ptosis), dilated pupils, dry mouth, decreased gag reflex, weakening of the reflexes (hyporeflexia), abnormal sensations such as numbness, prickling, tingling, and arm or leg weakness.Botulism is caused by a neurotoxin and technically could be classified as a chemical WMD. For our discussion it is placed under biological agents because the toxin is derived from a bacterium. Botulism is potentially life-threatening, producing a characteristic clinical picture of muscular paralysis leading to respiratory failure. Photo courtesy of the CDC archives. | View Page |
| Agent: Tularemia (bacterium) Most likely means of dissemination: Solid or aerosolPrimary route of entry: Inhalation, absorption, or ingestionGeneral signs and symptoms: Sudden fever, chills, headaches, muscle aches, joint pain, dry cough, progressive weakness, and pneumonia.The disease is not transmissible through human contact. When used as a WMD, infection would be acquired by handling infected material, eating or drinking contaminated food or water or by breathing in the bacterium. | View Page |
| In Case of a Dirty Bomb Attack Stay inside or get inside quickly. Find a “Shelter-in-place”. To “shelter in” is a way to make the building you are in safe as possible to protect yourself until help arrives. You should not try to “shelter in” in a vehicle unless you have no other choice. The best room to use is one with as few windows and doors as possible. Be sure to close all windows and doors, and turn off the furnace, air conditioners, and exhaust systems. As best as possible, seal all openings in windows and doors. Monitor your radio for instructions from authorities. If you believe you’ve been exposed and you can’t get to a hospital, shed all your clothes as quickly as possible. Don’t take the clothes inside because you may spread contamination. Go straight to the shower and thoroughly wash all body parts with a coarse soap. It is important not to ingest radiation by eating contaminated food or even chewing on contaminated fingernails. Also, certain types of radioactivity can be flushed from the body by drinking large amounts of water. After an attack don’t travel through heavily contaminated areas. If you can get out of the general area through an uncontaminated route, do so—otherwise, stay indoors until assistance arrives. | View Page |
| How can HBV be prevented? You can avoid exposure to Hepatitis B by taking the appropriate precautions, such as: Receiving the immunization against Hepatitis B. Following standard precautions. Maintain proper work practices. Using proper techniques when handling materials which may be contaminated with blood or other potentially infected body fluids. | View Page |
| How is HBV Spread? The virus is spread when body fluids from an individual with the Hepatitis B virus are introduced into the body of a susceptible person.This contact may occur during introduction of blood or potentially infectious body fluid: Through an opening or sore in the skin. Via a puncture with a contaminated sharp such as a needle. Through direct contact with mucous membranes that line the insides of the mouth, nose, eyes, and the genital organs. HBV is not spread through casual contact, such as handshake, or through sweat. | View Page |
| Body Fluids Most Likely To Transmit HBV Body fluids most likely to transmit HBV are: Blood Semen Vaginal Secretions Pleural Fluid Peritoneal Fluid Pericardial Fluid Cerebrospinal Fluid Synovial Fluid Amniotic Fluid Blood contaminated saliva in dental procedures Any fluid visibly contaminated with blood Sweat uncontaminated by blood is not considered infectious. | View Page |
| Spread of HBV In The Community HBV is spread in the community through: Sexual contact. Drug abusers sharing contaminated needles. An infant's exposure to its mother's body fluids. | View Page |
| How is HIV spread? HIV is spread in the community just like HBV. Sexual contact Via a puncture with a contaminated sharp such as a needle. Through direct contact with mucous membranes that line the insides of the mouth, nose, eyes, and the genital organs. From a mother to her child | View Page |
| Transmission of Hepatitis B can be prevented by: | View Page |
| Transmission of the hepatitis B virus (HBV) can occur from all of the following EXCEPT: | View Page |
| Biohazard Labeled Container If the outside of a sealed specimen container is contaminated, the standard requires that the specimen be placed in a secondary red/orange or biohazard labeled container.All biohazardous materials must be identified with the international biohazard sign.The sign must be visible on all sides of the container. | View Page |
| Contaminated Wastes It is important to always dispose of contaminated wastes properly!Examples of contaminated wastes: Microbiology waste and pathology waste All body fluids, such as pleural fluid Contaminated sharps and blood specimens | View Page |
| Contaminated Wastes (continued) Contaminated sharps must be placed in puncture resistant, leak-proof, closable, biohazard labeled containers.These must be closed when only three quarters full, to prevent sharps from sticking out of the opening, and must be disposed of properly.Like specimen containers, they must be clearly marked with the biohazard symbol. | View Page |
| Biohazard Labeled Bags Put contaminated wastes which do not have the potential to puncture in a red or orange leakproof biohazard labeled bag. If the external surface of this bag is contaminated, place it within a secondary leakproof bag. | View Page |
| Contaminated Laundry Remove contaminated personal garments as soon as possible. Contaminated garments must be laundered by your employer, and your employer must provide you with clean clothes to wear. Handle contaminated laundry as little as possible. | View Page |
| Garments worn as Personal Protective Equipment Garments worn as personal protective equipment must meet the American Society for Testing and Materials (ASTM) standards. This will ensure that the wearer will not be contaminated if there is a splash or splatter.Scrub suits do not offer adequate protection.Regular cotton lab coats do not offer adequate protection.Spun man-made fibers such a olifin or plastics are excellent as they prevent absorption. | View Page |
| Gloves Gloves made of either latex or a latex equivalent material such as nitrile must be worn whenever there is a risk of contact with blood or other body fluids.Keep hand jewelry worn under gloves to a minimum to protect their integrity.Replace gloves: Between patient contacts If they are damaged or contaminated Before leaving the work area. Perform hand hygiene after removing gloves. Disposable gloves cannot be washed.Utility gloves or heavy-duty rubber gloves are useful when cleaning up spills or when there is a risk of damage from equipment handling.Utility gloves may be decontaminated and reused if their integrity has not been compromised. They should be inspected regularly, and must be replaced if damaged. | View Page |
| Gloves Must be Worn When there is a reasonable chance of exposure to blood, other infectious body fluids, mucous membranes, or nonintact skin. During vascular access procedures, including phlebotomy. When handling contaminated items or surfaces. | View Page |
| Types of gloves To protect the worker from blood borne pathogens, either latex or a latex like product such as nitrile must be worn when handling specimens or other items possibly contaminated with blood.Utility gloves or heavy-duty rubber gloves are useful when cleaning up spills or when there is a risk of damage from equipment handling. | View Page |
| Face and Eye Protection The following protect your eyes and the mucous membranes of your nose and mouth: Face shields Masks and safety glasses They must be worn whenever it is reasonably anticipated that splashing or spraying of blood or other contaminated materials may occur.Employees who wear prescription eyewear may be protected with a face shield, goggles, or with side shields attached to their glasses. | View Page |
| Which of the following vectors has/have the capability of serving as a transport host for both the amebae and the flagellates? | View Page |
| The intestinal amebae are primarily transmitted by: | View Page |
| Match each parasite listed here with its corresponding infective stage: | View Page |
| Arrange the following phases of the hookworm life cycle in order beginning with human contact: | View Page |
| Which of the parasites listed here is/are transmitted via ingestion of contaminated pork? | View Page |
| Which of the following parasites may be contracted by swimming in contaminated water? | View Page |
| Houseflies are a possible transmission for which of these categories of parasites? | View Page |
| Arrange the following life cycle phases of Diphyllobothrium latum in order beginning with human transmission: | View Page |
| Contact with infected cat feces is responsible for the transmission of: | View Page |
| Match each vector listed here with its respective parasite: | View Page |
| Match each parasite listed here with its respective mode of human transmission: (answers may be used more than once) | View Page |
| Match each parasite listed below with its corresponding respective associated condition: | View Page |
| Arrange the basic steps in the intestinal ameba life cycle in order starting with transmission to a human host: | View Page |
| Dracunculus medinensis belongs to this category of parasites: | View Page |
| Label the morphologic structures on this parasite form: | View Page |
| A 35 year old male presented to the local clinic complaining of abdominal cramps, severe diarrhea, and intestinal gas discomfort. A stool was collected for parasite examination. It was foul-smelling and light colored in nature. This suspicious form was recovered and measured 10 µm by 12 µm. The patient is infected with: | View Page |
| A 43 year old female presented to her doctor for a routine check-up. Her only complaint was that she had been experiencing watery stools that occasionally contained pus and blood. Examination revealed tenderness in her abdomen. A stool for parasite study was sent to the lab. Two suspicious forms were seen. The oblong form on measured 53 µm by 60 µm whereas the rounder form measured 45 µm by 37 µm. Use the pulldown boxes to identify each picture: | View Page |
| A 16 year old male champion athlete went to his doctor complaining of a persistent cough, fever, bloody diarrhea and overall weakness. Upon questioning the patient, it was learned that he had recently competed in a freshwater swimming competition in the Caribbean. Examination revealed a dermatitis on the patient's right calf. A battery of tests were ordered including a CBC, chemistry profile, and a stool for culture and parasitic examination. The CBC revealed the presence of eosinophilia. The other hematology and chemistry tests were unremarkable. The culture was negative. This suspicious form was seen on all parasite preparations made from the stool sample submitted. This form measures 165 µm by 68 µm. This patient is most likely suffering from an infection with: | View Page |
| A 17 year old female went to her doctor complaining of diarrhea. With the exception of seasonal allergies, she was in relatively good health. Patient history was unremarkable. A stool was submitted for culture and parasite examination. The culture was reported out as "no enteric pathogens isolated." This suspicious form was seen on wet preparation and permanent stain. It measures 27 µm. This patient is most likely suffering from which of the following conditions: | View Page |
| A 29 year old male steak house owner from Arizona presented to his doctor complaining of weight loss, abdominal pain and diarrhea. Patient history revealed that the man eats all of his meals at his restaurant and his favorite meat is rare sirloin steak. The man also noted that he had recently been on anti-parasitic medication. The doctor ordered a stool for parasitic examination. These two suspicious forms were seen. The patient is most likely suffering from an infection with: | View Page |
| This parasite, found in stool, measures 60 µm by 45 µm. Name that parasite! | View Page |
| A 35 year old man presented to his doctor with fever, diarrhea, abdominal pain and epigastric discomfort. Upon questioning the patient, it was learned that he travels extensively on business and loves to try new kinds of raw fish. The patient is most likely suffering from: | View Page |
| The common name for Taenia saginata is: | View Page |
| Discussion This phlebotomist violated hospital procedures in several ways that could adversely impact patient care:
Cleaning the site only with alcohol, not iodine, could result in a false-positive contaminated blood culture. This might result in the patient receiving unnecessary intravenous antibiotics, and could prolong the patients hospital stay unnecessarily.
Drawing both cultures at the same time lessens the chance of recovering a bloodstream organism.Drawing both cultures from the same site might result in both of them being contaminated, making it very difficult for the physician to distinguish contamination from a “real” bloodstream infection.Relevant topics:Blood cultures: introduction,
Avoid skin contamination, Blood culture site preparation 1, Blood culture site preparation 2 | View Page |
| Additional tips Contaminated blood cultures may have very serious consequences in terms of patient care.Always draw blood cultures prior to drawing other blood tubes to minimize the risk of contamination.
Do not draw blood cultures from a central line, unless cultures are being drawn to determine whether or not the line is contaminated. | View Page |
| What are bloodborne pathogens? Bloodborne pathogens are infectious micro-organisms which live in the bloodstream.You can be exposed to bloodborne pathogens if you are injured with a contaminated needle.You can also be exposed if your mucous membranes, including eyes, mouth, or the inside of your nose come into contact with contaminated body fluids.
| View Page |
| Hazardous waste disposal All needles & other sharps must be disposed of in approved sharps disposal containers.
Other contaminated waste must be discarded in an appropriate red biohazard bag or waste receptacle. | View Page |
| Protect Yourself The safety of both the phlebotomist and patient is of utmost concern at all times. In the unfortunate event of an accidental needlestick or if you get blood or other potentially infectious materials in your eyes, nose, mouth, or on broken skin, immediately flood the exposed area with water and clean any wound with soap and water or a skin disinfectant if available. Report this immediately to your employer and seek immediate medical attention. It is imperative that the phlebotomist follow facility protocol for reporting the incident. This ensures prompt treatment for the injury. The facility procedure must be followed whether the accidental puncture was from a clean or contaminated needle.The single most important element to prevent an accidental needlestick is for the phlebotomist to fully concentrate during every procedure. Keeping your mind on the task at hand contributes to a successful and safe result. | View Page |
| Tourniquets, Alcohol, and Gauze A tourniquet is used by the phlebotomist to assess and determine the location of a suitable vein for venipuncture. Single-use, latex-free tourniquets are preferred but reusable tourniquets are acceptable. However, if the reusable tourniquet becomes contaminated with blood or body fluid, it must be discarded immediately to avoid the spread of harmful contaminants to other patients. Follow the guidelines established by your facility for cleaning reusable tourniquets.Proper application of a tourniquet will partially impede venous blood flow back toward the heart and cause the blood to temporarily pool in the vein so the vein is more prominent and the blood is more easily obtained. The tourniquet is applied three to four inches above the needle insertion point and should remain in place no longer than one minute to prevent hemoconcentration. If the tourniquet is used during preliminary vein selection, it is best to release the tourniquet after assessing the vein and while you are assembling your supplies. Reapply the tourniquet just before starting the venipuncture; it should then be released soon after the needle has been inserted into the vein and the blood flows into the first tube. If collecting multiple tubes, the tourniquet may remain in place until blood enters the last tube. | View Page |