Exposure Information and Courses from MediaLab, Inc.

Antibodies are immunoglobulin proteins secreted by B-lymphocytes after stimulation by a specific antigen. The antibody formed binds to the specific antigen in order to mark the antigen for destruction.The type of antigenic exposure occurring in the body determines if the antibody is a naturally occurring or immune antibody.Naturally occurring antibodies can be formed after exposure to environmental agents that are similar to red cell antigens, such as bacteria, dust or pollen. Sensitization through previous transfusions, pregnancy or injections is not necessary. These antibodies are usually IgM and react best at room temperature or lower. Most of these antibodies are not clinically significant with the exception of ABO antibodies. Examples of naturally occurring antibodies include anti-A, anti-B, anti-Cw, anti-M, and antibodies in the Lewis and P system.

Why our immune system malfunctions is not completely understood. One current hypothesis is that the following series of events occurs resulting in the initiation of an autoimmune reaction. Gender and Genetic PredispositionA predisposition is usually the first step toward the development of an autoimmune reaction. Women are more likely to develop a systemic autoimmune disease than men. For example in SLE the female to male ratio is 9:1. The genotype of some individuals predetermines that their immune system will be more prone to a break in tolerance. This genetic susceptibility appears to be linked to multiple genes rather than a single gene. This is supported by evidence that some autoimmune diseases are more frequently encountered in certain ethnic groups compared to others. For example in American women between the ages of 15 and 64, the prevalence of SLE is 1 in 700 for Caucasians while it is 1 in 245 for African-American women.(Ref1) Evidence in one recent study suggests that the genes that impart an increased resistance to malaria unfortunately produce an increased susceptibility to the systemic autoimmune rheumatic diseases.(Ref2)Triggering eventThe second step is the occurrence of a triggering event that leads to a break in tolerance. For some very susceptible individuals this event might be exposure to an environmental trigger. These environmental triggers could be ubiquitous such as exposure to the Epstein Barr virus (EBV), or very limited, such as the exposure to leaking silicon from a breast implant. In others, the triggering event might be a change in hormonal balance. Whatever the case, the triggering event initiates the break in tolerance and the cascade of immunological events that eventually lead to the formation of an autoimmune disease begins.Development of autoantibodiesThe third step is the development of autoantibodies and subsequent development of clinical symptoms. Studies have shown that this process can take 3 years or longer and unfortunately, by the time the diagnosis is made, substantial damage to the body may have already occurred.

Paraffin temperatures should be maintained within 2° C to 4° C of the melting point of the paraffin. The measure and control of the temperature that the paraffin media is exposed to during its use should be recorded in the quality control records. The consistent maintenance of temperatures in a controlled range will provide the best results and performance from any paraffin formula selected; since at both on the low and high end of the recommended temperature range, problems can occur. Sectioning of blocks will be easier if the paraffin is cooled at a consistent rate for even solidification of the molten paraffin into its final crystalline structure. Controlled cooling allows the formation of a uniform and homogenous matrix of crystals. Paraffin which cools too rapidly or unevenly can cause grainy textures which interfere with sectioning and may result in artifacts in the final tissue sections. On the other hand, overheating of the paraffin can result in deterioration of the components of the paraffin mixture, and some tissue specimens may become brittle or hardened by prolonged exposure to too hot paraffin.Some technical problems, which are assumed to be microtomy issues, are really problems with media selection or embedding technique, so it is worth the time to investigate.

Atherosclerosis is one of the leading causes of heart disease and its presence is an important risk factor for events leading to acute myocardial infarction (AMI). In the past, atherosclerosis was described as a cholesterol and lipid storage event. Now we know it is a chronic inflammatory disorder of the arterial vessels with lipid components. Atherosclerosis begins with damage to the cells that line the blood vessels. Some possible causes of this cell injury are bacterial infection, hyperlipidemia, hypertension, glycosylated products of diabetes, cytokines from adipose tissue, or exposure to toxins such as pollution and second-hand smoke. Monocytes and lymphocytes adhere to the injured site; macrophages enter and ingest proteins and, along with modified lipoproteins, create foam cells. An inflammatory milieu results as cytokines and other inflammatory molecules become involved; foam cells and white blood cells begin secreting cytokines and metalloproteinases. Myeloperoxidase is also released by degranulated white blood cells and macrophages. As inflammation and accumulation of these products continues, fatty dots and streaks are formed on the vessel lining and the formation of plaque begins. As the atherosclerotic process continues, involved cells proliferate forming a complex extracellular matrix and a fibrous cap. If development continues, possibly over decades, the plaque formations are distributed throughout various vessels, become calcified or collagenized and make the vessel walls rigid. The risk to patients with significant atherosclerosis is that eventually a narrowing of the artery (stenosis) can cause a reduction in oxygen delivery to tissues and plaque rupture can lead to an acute coronary event.

In order to ensure proper stability of the specimen and accurate test results, there are guidelines in place to aid in the appropriate urine processing and transportation. These guidelines include: Ensuring that all urine collection and/or transport containers should be clean and free of debris or interfering substances.Ensuring that the collection and/or transport container has a secure lid and is leak resistant. Leak-resistant containers reduce specimen loss and healthcare worker exposure to the specimen while also protecting the specimen from contaminants.Utilizing urine containers that are made of break-resistant plastic instead of glass.Utilizing urine containers that do not leach interfering substances into the specimen.Utilizing collection containers and/or transport tubes which will not leak within the pneumatic tube system (if one is used within the laboratory facility). A leak-proof device in this situation is paramount.Proper labeling and correct identification should be applied to the collection container or tubes. This includes noting the time the specimen was collected. Remember that urinalysis specimens must be analyzed within 2 hours of collection.Ensuring that there is sufficient volume to fill the tubes and/or perform the test.

Individuals with diabetes mellitus may excrete small amounts of protein in the urine which may signal the beginning of reduced glomerular filtration. Stabilizing the blood glucose level at this time may delay progression of diabetic nephropathy. Women in the last month of pregnancy may develop proteinuria as the first sign of impending eclampsia. Eclampsia is the gravest form of toxemia of pregnancy. The presence of protein in this situation must be evaluated by the physician in conjunction with other clinical symptoms.Benign transient proteinuria may be the result of: exposure to cold, strenuous exercise, dehydration, and/or high fever. Benign transient proteinuria may also occur during the acute phase of a severe illness.

No blood is found in the urine of healthy individuals although samples from menstruating females, frequently, but not always, test positive for blood. Hematuria is associated with renal or genital urinary disorders in which the bleeding is the result of irritation to the involved organs or trauma. Examples include renal calculi, pyelonephritis, glomerulonephritis, tumors, trauma or exposure to toxic chemicals or drugs and/or strenuous exercise. Hemoglobinuria may be due to the lysis of red cells within the urinary tract. If it is caused by intravascular hemolysis, the hemoglobin is then filtered through the glomeruli. In the normal individual, the hemoglobin molecule attaches to haptoglobin and in this way bypasses the kidney filtration system. When the hemoglobin/haptoglobin system is overwhelmed, as in cases of hemolytic anemia, severe burns, transfusion reaction, infection or strenuous exercise, hemoglobin passes into the urine.

Severe proteinuria (greater than 3.5 g/day) is characteristically seen in patients with glomerulonephritis, lupus nephritis, lipoid nephrosis, and severe venous congestion of the kidney. Moderate proteinuria (0.5-3.5g/day) is seen in nephrosclerosis, multiple myeloma, diabetes nephropathy, malignant hypertension, and pyelonephritis with hypertension. Mild proteinuria (less than 0.5 g/day) may be seen with polycystic kidneys, chronic pyelonephritis, benign orthostatic proteinuria, and some renal tubular diseases. Transient proteinuria can also be due to physiologic conditions such as stress, exercise, cold exposure, and fever, in the absence of renal disease.

It is important to remember that the collection of a specimen by dermal puncture may involve the potential of exposure to bloodborne pathogens as well as other safety considerations for both the phlebotomist and the patient. Some important safety reminders are listed in the table below. Safety Reminder Reason Comment Gloves are always necessary Blood contaminates the skin during a capillary blood collection. Gloves protect the phlebotomist from potential exposure to bloodborne pathogens. Gloves must remain intact to be an effective barrier against exposure to potential pathogens. Wear additional PPE, such as lab coat or gown when appropriate or required. Safety goggles and surgical mask may be needed if there is a potential for splashes or sprays of blood. May be needed to protect the phlebotomist or may be required to protect the patient from potential infection in some cases. Safety goggles and mask should both be worn to adequately protect the eyes and mucous membranes from exposure to bloodborne pathogens if there is the potential for splashes or sprays of blood. Only have the equipment needed for this procedure at hand and additional equipment out of reach of the patient. Protects the patient from accidental injury Often, capillary procedures are performed on very young children who are curious and may grab something that could cause injury.

Advantages of utilization of HbA1C over blood glucose measurement include: Fasting is not required Greater specimen stability Less fluctuations in day-to-day levels caused by stress and illness Disadvantages of utilization of HbA1C over blood glucose measurement include: Cost per test is higher than blood glucose. Conditions that shorten red blood cell (RBC) survival e.g., hemolytic anemia, homozygous sickle cell trait, pregnancy, or recent significant blood loss, will reduce exposure of RBCs to glucose, thereby lowering the HbA1C test value. Specimens with >10% fetal hemoglobin (HbF) may have a falsely decreased HbA1C test result. If onset of diabetes is rapid, blood glucose levels will more correctly reflect glycemia than HbA1C levels.

Chemical burns occur when caustic or corrosive chemicals come into contact with the skin.Act immediately, since the longer the exposure, the worse the injury.

As discussed earlier, a break in the vessel endothelium leads to exposure of collagen and the vessel's subendothelial layer. Ruptured endothelial cells leak ADP and serotonin, the chemical triggers that induce platelet adhesion, which is the next step in the sequence of hemostatic events. Circulating platelets are drawn to the area by those liberated chemical signals and begin to physically attach themselves to the rough, damaged surfaces of the damaged vessel wall. Once platelets begin adhering to the damaged area of the vessel wall, the platelets start to change their shape and functionality through a process called platelet activation. The activated platelets undergo various changes, including the alteration of their surface receptors as they prepare to create a primary platelet plug. At this time, the platelets also release the contents of their granules through a process called platelet secretion which helps to attract more platelets to the site of injury as a positive feedback mechanism. As platelets continue to arrive and bind to the exposed collagen and basement membrane, a rudimentary barrier begins to form, as the platelets themselves serve to fill in the breached vessel wall. The process by which platelets bind to one another is referred to as platelet aggregation. Platelet aggregation is vital because it allows for a primary platelet plug to be formed. The platelet plug is the structure responsible for plugging the hole in the vessel wall, preventing further blood loss. The formation of the platelet plug signals the end of primary hemostasis, and serves to initiate upcoming processes associated with secondary hemostasis.

Since anti-D produces the most severe HDFN and was once relatively common, let's begin by reviewing how anti-D is produced.Immunization to D may occur when Rh-negative individuals are exposed to the D antigen, but developing anti-D varies greatly from person to person. Some individuals produce anti-D after being exposed to a small volume of D-positive red cells (e.g., 0.1 mL). For others, a relatively large volume of D-positive cells is required. Yet other persons will never produce anti-D, regardless of exposure.

Exposure to D+ red cells: Anti-D is red cell immune. The usual route of exposure to the D antigen is during pregnancy. Fetal bleeds into the mother occur more commonly at delivery but some may occur antenatally due to small lesions in the placenta or due to placenta previa, amniocentesis, abdominal trauma, abortion, ectopic pregnancy, etc. Transfusion is a relatively rare route of exposure since Rh-negative individuals normally receive only Rh-negative donor red cells. However, Rh-negative transfusion recipients may be exposed to small volumes of D-positive red cells in Rh-positive platelet concentrates. Also, there are rare reports of fresh frozen plasma, not normally matched for Rh(D), causing anti-D production.Volume of fetal bleed: In general, the larger the fetal bleed, the more likely the mother is to produce anti-D. Approximately 1 pregnancy in 400 result in a fetomaternal hemorrhage (FMH) of 30 mL or greater. ABO incompatibility between mother and fetus: If fetal red cells are ABO incompatible with the mother, maternal anti-A or anti-B will rapidly remove fetal cells from the circulation before anti-D can be produced. This protection decreases the chance of anti-D being produced but does not eliminate it entirely.

Sample Type Required: Deparaffinized and re-hydrated tissue sections on positively charged slides. Fixative: 10% Neutral Buffered Formalin Step Reagent Time Technical Notes 1 Periodic Acid 0.5% Solution 5 Minutes 2 Distilled Water 3 Changes 3 Schiff Reagent 15 Minutes Gluteraldehyde should be avoided as a tissue fixative since it is a dialdehyde that will react with this reagent and give false-positive PAS staining. 4 Potassium Metabisulfite 0.55% Solution 1 Minute in 2 Changes While some technicians omit this reagent step in the protocol with no problems, metabisulfite rinses may be necessary to remove any excess leucofuchsin left over after exposure to the Schiff reagent. Highly chlorinated water can cause these excess molecules to nonspecifically stain other tissue elements in the section. 5 Running Tap Water Up to 10 Minutes Warm to hot running water develops the PAS stain and gives a more intense staining reaction than cold water. Expected ResultsThe following elements will show positive PAS (Rose Red) staining: Glycogen Neutral mucins Some epithelial mucins Basement membranes Fungal wallsPost Staining Procedure: Tissue sections should be rinsed well in distilled water, dehydrated with 95% and absolute alcohols, cleared, and cover-slipped.

While microwave use in the laboratory is considered to be relatively safe, the following safety precautions should be taken to prevent high doses of exposure to microwaves and personal injury: Periodically inspect and clean door seals and hinges. Use a microwave leakage detector to check for microwave leakage from the door seals on a regular basis. Always handle containers with potholders or thermal mitts. Never operate the microwave without a minimum volume of microwave-absorbing material inside the container. Never heat food in a microwave oven used for laboratory procedures.

While microwave use in the laboratory is considered to be relatively safe, the following safety precautions should be taken to prevent high doses of exposure to microwaves and personal injury:Periodically inspect and clean door seals and hinges.Use a microwave leakage detector to check for microwave leakage from the door seals on a regular basis.Always handle containers with potholders or thermal mitts.Never operate the microwave without a minimum volume of microwave-absorbing material inside the container.Never heat food in a microwave oven used for laboratory procedures.

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.

The follow-up to a healthcare work HIV exposure includes: psychological counseling medical evaluation postexposure testing at baseline, 6 weeks, 12 weeks, and 6 months.

Give first aid. Wash needlesticks and cuts with soap and water. Flush splashes to the nose, mouth, or skin with water. Irrigate eyes with clean water, saline, or sterile irrigants. Report exposure to supervisor.

Prevention of HIV exposure is the best line of defense to prevent occupational transmission of HIV as there is no vaccine available to develop specific immunity and the postexposure prophylaxis is toxic. Following appropriate workplace practices in the laboratory focus on preventing needlesticks or other sharps injuries and exposure of mucous membranes and abraded skin to HIV-infected blood or body fluids.

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.

They can have a psychological impact.Biological WMD's could possibly have a psychological impact that will go far beyond their actual effect. The very thought of exposure to a biological agent may possibly cause many people to panic. Biological WMDs can tie up resources.Some biological agents can be a hazard for lengthy periods. The use of these agents may require tedious, time-consuming, resource-intensive decontamination and monitoring of facilities before they can be returned to service.Defense may be difficult.It is very difficult for civilian government agencies to prepare for biological terrorist incidents. While most civilian agencies have some kind of hazardous material or HAZMAT response teams; in the event of a biological terrorist incident, these teams are likely to be challenged beyond their capability in terms of human resources, and equipment.

At present, 5 laboratories participate in Level 1 activities. At this level, technical personnel are trained to detect exposure to an expanded number of chemicals in human blood and urine. This includes all Level 3 and 2 laboratory analyses, plus analyses for mustard agents, nerve agents, and other toxic chemicals.

Staphylococcus aureus, particularly methicillin resistant strains (MRSA), have represented a likely target for molecular development, particularly in blood cultures. As more institutions implement patient screening protocols for MRSA, replacement of routine culture methods with molecular assays has gained increasing attention.PNA-FISH assays provide for the definitive identification of Staphylococcus aureus from positive blood culture vials. Peptide nucleic acid fluorescent in-situ hybridization is a relatively straight forward procedure that does not involve amplification and has limited equipment requirements. Procedurally it is easy to perform with minimal hands on time.PNA is a synthetic imitator of a nucleic acid sequence in which the backbone is a pseudopeptide rather than a sugar. PNA behaves similarly to DNA and will bind to complementary nucleic acid strands. A PNA probe is constructed, utilizing a complementary, hybridizing sequence for a known nucleic acid target sequence. The probe is typically bound to a fluorescent protein as a means of visualizing/detecting the target. In one commercially available method, once a blood culture vial demonstrates gram-positive cocci in clusters, a drop of the blood culture broth is added to fixation solution on a slide. Heat or methanol is used to fix the smear. After fixation, probe that targets species-specific ribosomal RNA is added to the smear, which is then cover-slipped.Slides are then incubated at 55oC. Post incubation, slides are immersed in a preheated wash solution and coverslips gently removed. After incubation in the wash solution, smears are air dried; a drop of mounting medium is added and the slide is cover-slipped again.The slides are examined with a fluorescent microscope, utilizing specific filters. Green fluorescing cocci in clusters are identified as Staphylococcus aureus. This identification would be available, depending on the routine identification system utilized, potentially 24 hours earlier than the norm.A significant number of blood cultures that demonstrate gram-positive cocci in clusters yield coagulase negative staphylococci (CNS), which represent potential contaminants, rather than significant infection. What is the significance of differentiating blood cultures that contain S. aureus from those that are growing CNS in a much earlier timeframe?Studies have shown that IF the differentiation of CNS from S. aureus is effectively communicated to clinicians and pharmacy/antimicrobial stewardship teams, active assessment can occur utilizing defined exclusion criteria for those patients whose cultures yielded CNS rather than S. aureus. In scenarios where contamination rather than infection is indicated, vancomycin can be discontinued earlier, and length of hospital stay is also shortened. Reduced antibiotic exposure, reduced risk of development of resistance, and reduced cost are all potential benefits.

The first step in treating patients with CDAD is to discontinue the causative agent wherever possible. The choice for initial antibiotic therapy depends on the severity of disease. Oral vancomycin or metronidazole remain the mainstays of therapy for CDI, with vancomycin reserved for patients with more severe disease and/or those who have not responded to metronidazole. Metronidazole is currently favored in guidelines from the Centers for Disease Control and Prevention (CDC) on the basis of cost and concern that oral vancomycin promotes colonization with vancomycin-resistant Enterococcus. Oral fluids (water and electrolytes) may be necessary to counteract fluid loss as a result of excessive diarrhea, which can quickly lead to dehydration. Patients with fulminant disease and toxic megacolon may require colectomy. Recurrence of CDI is becoming an increasing problem. Most recurrences happen 7-14 days after completion of therapy, suggesting relapse rather than re-infection. If a patient develops a second episode of CDI following initial successful treatment, it is recommended that if possible, the same drug be used to treat the second episode. Contributing factors to recurrent CDI include:Continuing exposure to organisms either through re-infection (via contaminated environment or poor hand hygiene) or an endogenous source, such as C. difficile spores in GI tract. An inability to mount an adequate anti-Toxin A IgM and/or IgG antibody response (i.e., poor host immune response); a likely reason why CDI affects an increasingly elderly population. Unfortunately a vicious cycle can arise whereby the initial treatment prescribed, vancomycin or metronidazole, significally disrupts normal colonic flora reducing colonization resistance and leaving the patient vulnerable to the next recurrent episode.Other treatments, including the use of probiotics or anion-exchange resins to absorb toxins, may work in some cases but none work in every case.The goal of all treatment is to reestablish normal colonic flora so as to control C. difficile (over)growth.

This course will provide you with basic information about bloodborne pathogens, the regulations that govern safe work practices when handling blood and other potentially infectious body fluids, and necessary precautions that must be taken to minimize your risk of exposure to these infections.

The Bloodborne Pathogens Standard includes these major components: Exposure control plan Preventive measures Hepatitis B vaccination Standard precautions Methods of control Engineering and work practice controls Personal protective equipment Housekeeping Labeling What to do if an exposure incident occurs

There are three exposure categories :Category I are those employees who, on a day-to-day basis, will come in contact with blood or body fluids as part of their normal job. This includes medical laboratory professionals, pathologists and operating room nurses.Category II are those employees who may come in contact with blood or body fluid during the course of their normal job. This includes housekeepers, transporters, and some technicians such as EKG techs.Category III are those persons who would not normally ever come in contact with blood or body fluids and generally includes secretaries, administrators, and gardeners.Persons may move from one category to another during the course of a workday.

Engineering controls are devices that isolate the worker from the hazard of exposure.Examples include: Self-sheathing needles (top image on the right)Sharps disposal containers (bottom image on the right) Disposable resuscitation bags Biological safety cabinets Hand washing facilitiesProper use of engineering controls in your workplace will help protect you from bloodborne pathogens.

After the exposure, there is an incubation period that lasts between 45 and 180 days, with an average of 90 days. Many individuals with acute HBV will have no symptoms at all. Some will have a mild illness with loss of appetite, nausea and vomiting, and fatigue. About 30% of infected individuals will develop clinical hepatitis with jaundice (yellow discoloration of the skin and eyes) due to liver dysfunction.

HBV is spread in society most often:Through shared needles used to inject drugsThrough sexual contactFrom mother to child before or during birth

Days to weeks after exposure, the patient may begin to complain of fever, headache, and fatigue. This may also be accompanied by a rash.For the first several months after the infection, the exposed individual may be HIV-antibody negative and the disease may not be detected. However, the individual is still infective and can transmit the disease during this period.The disease may remain silent in the patient for months to years, even with no treatment.When the immune system is weakened enough, the patient will develop opportunistic infections and be classified as having acquired immunodeficiency syndrome (AIDS).

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 when touching contaminated surfaces.

If an exposure occurs, wash the affected area immediately with soap and water.Contact your supervisor immediately, regardless of the situation or the time of day.

This program will provide you with basic information about bloodborne pathogens and vital precautions you must take to minimize your risk of workplace exposure to these infections.

Up to 1% of the U.S. population harbors the Hepatitis B virus in their bloodstream. In 1990, workplace exposure gave rise to an estimated 8,000 cases of HBV resulting in 200 to 300 deaths from acute and chronic HBV. So occupational exposure to HBV is a serious problem.

After an exposure to HIV by a contaminated needle, the chance of becoming infected is usually less than 1%.However, exposures from patients with high numbers of viral particles in their blood may be more hazardous.Because of the extremely serious nature of HIV, we must take every precaution to avoid workplace exposure.

In December of 1991, OSHA issued a standard to guard against occupational exposure to bloodborne pathogens.This standard, part 1910.1030 of the Code of Federal Regulations was published in the Federal Register.On November 27, 2001, OSHA published a compliance directive 2-2.69 that now includes the revisions to the original standard.These regulations are law!

Employers must develop and implement an exposure control plan to protect employees from exposure to bloodborne pathogens.This is a document that explains how the employer will implement the OSHA standard.It also specifies what to do if an exposure occurs.The Exposure Control Plan must include an Exposure Determination which lists jobs that will or may subject workers to occupational exposures.

Work Practice controls specify how to perform a task. Wherever there is a risk of exposure, they forbid:Smoking Eating or drinking Applying cosmetics or lip balm Handling contact lenses Mouth pipetting Food and drink in specimen refrigerators

Even after taking all the proper precautions there is still a small chance of an exposure incident.Exposure incident: Blood or another potentially infectious body fluid coming into direct contact with mucous membranes or nonintact skin.Parenteral exposure: Needle stick or being cut by a contaminated sharp.

Only you can protect yourself from bloodborne pathogens.Therefore... Use Standard Precautions, Get your Hepatitis B Vaccine, And always think about how to perform each task in a way that minimizes your risk of exposure to bloodborne pathogens.

1987 Haz-Com Standard (29 CFR 1910.1200) is designed to help control employee exposure to chemicals on the job. 1990 Chemical Hygiene Standard (29 CFR 1910.1450) is specifically designed to meet the needs of laboratories with large varieties of chemicals, and to require specific training for laboratory employees. 1992 Formaldehyde Standard (29-CFR 1910.1048) is designed specifically for employees who work with formaldehyde. The goal of this standard is to reduce the risk of formaldehyde overexposure by establishing safe exposure limits.

Respirators usually are not needed in a pathology laboratory. However, they are required if formaldehyde exposure exceeds the action level of 0.5 ppm. Respirators, if required, must be provided to you at no cost.Some OSHA-approved respirators include:Air-purifying full-facepiece or half mask respirator equipped with a canister or cartridge approved for protection against formaldehyde. If a half mask is used, gas-proof goggles must also be worn.Self-contained breathing apparatus operated in the demand mode or pressure-demand mode.

Formaldehyde exposure as low as 0.1 ppm (parts per million) may cause: Skin irritation Eye irritation Airway irritation Headaches and dizziness Symptoms possibly related to formaldehyde exposure should be reported immediately to management.

A monitoring badge is attached to your lab coat collar in the "breathing zone" for a specified length of time. This badge is then sent to an outside laboratory by your supervisor to determine your level of exposure to formaldehyde.

When monitoring results exceed the STEL or PEL, the employer must: Develop a written plan to reduce exposure to levels below the PEL and STEL. Provide written notice of corrective actions to employees.

1987 Haz-Com Standard is designed to help control employee exposure to chemicals on the job.1990 Chemical Hygiene Standard is specifically designed to meet the needs of laboratories with large varieties of chemicals, and to require specific training for laboratory employees.1992 Formaldehyde Standard is specifically for employees that work with formaldehyde. The goal was to reduce the risk of formaldehyde overexposure by establishing safe exposure limits.

Depending on the exposure level at your workplace, a medical surveillance questionnaire may need to be completed by you prior to your working with formaldehyde.This questionnaire helps determine your personal risk from exposure to formaldehyde.If your level of exposure is high enough, you may be required to complete this questionnaire annually.

When monitoring results exceed the STEL or PEL, the employer must: Develop a written plan to reduce exposure to levels below the PEL and STEL. Provide written notice of corrective actions to employees.

Respirators usually are not needed.However, they are required if exposure exceeds action level of 0.5 ppm.If you require respirators for your work, they will be provided at no cost to you.

Locate potentially hazardous chemicals in your workplace. Explain how to obtain a copy of a material safety data sheet (MSDS). Explain the information included on chemical labels. Identify exposure control measures.The intent of th to recognize potentially hazardous chemicals in the workplace, be able to locate the paper copies of material safety data sheets (MSDSs) in the laboratory, or know how to obtain an electronic copy of an MSDS when needed. The goals also include able to explain the information that is included on chemical labels and choose to use engineering controls, personal protective equipment and safe work practices to avoid exposure to hazardous chemicals.

This section includes important first aid information that you will need if you, or someone else, comes into contact with the chemical.

Certain chemicals in use in the laboratory, such as formaldehyde, are hazardous if your exposure to them is prolonged. The amount of the chemical to which you can be exposed before possible danger is called the threshold limit value. Monitoring badges are used from time to time to measure your exposure. These are worn in the "breathing zone" for a certain period of time--often eight hours (for long-term exposure) or fifteen minutes (for short-term exposure). Based on the results of this monitoring, additional personal safety measures, such as ventilation or face-fitted masks, may be implemented for your protection.

The training requirements that are stated in the US Code of Federal Regulations at 49 CFR 172.704 must be met by all personnel who are involved in shipping hazardous materials in the United States and training must be completed within 90 days of employment or performance of the required hazmat function (relevant documented training from a previous employer is acceptable).These requirements include: General awareness/familiarization training Function-specific training Safety training Security awareness training (Category A substances) Safety training, must be provided by the facility where the infectious materials are packaged and must include: Emergency response information Measures to protect the employee from the hazards associated with hazardous materials to which they may be exposed in the work place, including specific measures the hazmat employer has implemented to protect employees from exposure Methods and procedures for avoiding accidents, such as the proper procedures for handling packages containing hazardous materials OSHA bloodborne pathogens training is generally sufficient to meet this requirement for packaging and shipping infectious materials.

A category B infectious substance is not in a form generally capable of causing permanent disability or life-threatening or fatal disease in otherwise healthy humans or animals when exposure to it occurs. The proper shipping name and Identification number is:Biological substance, Category B, UN 3373

Blood collection tubes with Hemogard ™ (BD) closure protect you from blood which might splatter when the tube is opened. The rubber stopper is recessed inside the plastic shield, preventing exposure to blood present on the stopper. You will probably be using Hemogard or other tubes having protective devices.

The Occupational Health and Safety Administration (OSHA), of the federal government has mandated bloodborne pathogen training for all US workers who are at risk of exposure. The next few slides cover a few highlights of this training. You will receive complete OSHA bloodborne pathogens training before you begin work.

These agents are dangerous, highly virulent organisms that should NEVER be manipulated on an open bench! Laboratory infections can occur and the use of a class II, or higher, biological safety cabinets (BSC) is critical when aerosols are likely. The importance of following facility specific safety protocols and standard microbiology practices at ALL times cannot be understated. Agent Biosafety Level Laboratory Exposure Risk B. anthracis BSL-2 Low Y. pestis BSL-2 Medium F. tularensis BSL-2/3 High Brucella species BSL-2/3 High Burkholderia species BSL-2/3 High

Brucella species: Brucella is distributed in nature worldwide and found in domesticated and wild animals, such as cattle, sheep, and pigs. Infection with Brucella species, known as brucellosis, is caused in humans by exposure to infected animal fluids or food products. This includes ingesting non-pasteurized dairy products, such as milk or cheese, inhaling aerosols, and skin contact with the fluids of infected animals. Brucellosis poses an increased risk of occupational exposure to laboratory, veterinary, and slaughterhouse workers. Brucella is the most commonly reported laboratory-associated bacterial infection.Burkholderia mallei and B. pseudomallei: Most Burkholderia are found in soil, but B. mallei is only found in mammals. B.mallei is the causative agent for Glanders which primarily affects animals such as donkeys, mules, and horses. Horses, the organism's natural host, are highly susceptible to infection. Human infection is rare and usually occurs in people working with infected animals or laboratory workers handling the organism. The organism is endemic in Africa, Asia, the Middle East, and Central and South America, and usually enters via the eyes, nose, mouth, abrasions or cuts in the skin, or through inhalation. B. pseudomallei is found in soil and water and can accidentally infect animals, plants, and rarely humans. It is the causative agent of melioidosis, which is endemic in areas of southeast Asia, Taiwan, and northern Australia. The organism generally enters through cuts in the skin, ingestion of contaminated water, or by inhalation of an aerosol.

Anthrax (B. anthracis): Inhalation of anthrax spores is virtually 100% fatal Spores can remain infectious for decadesBotulism: Most lethal toxic agent known Toxin could be used to contaminate food supplies Can be aerosolized in enclosed areasPneumonic Plague (Y. pestis): Aerosolized in large amounts Short incubation period, usually in less than three days, and invariably fatal without early and effective antimicrobial therapy Untreated, fatality rate exceeds 90% Disease is spread from direct exposure to respiratory droplets of infected humansSmallpox: Highly contagious and deliberate spread by aerosol is extremely infectious Mass panic would be createdTularemia (F. tularensis): Highly contagious and easily spread An aerosol containing as few as 25 organisms can cause infection Easily penetrates the smallest breaks in the skinViral Hemorrhagic Fever: Causes internal and external bleeding and would likely cause great panic and easily spread by direct contact with body fluids or respiratory droplets Outbreak due to bioterrorist attack could lead to mass illness and death

Stomatocytes are erythrocytes with a slit-like central pallor, given them the appearance of "coffee beans" or "kissing lips". In three dimensions, the stomatocyte is actually the shape of a bowl, as the cell has lost its biconcave morphology due to a membrane defect. Most cases of stomatocytosis are due to alteration in permeability, leading to an increase in red cell volume. Stomatocytes form at a low blood acidic pH as seen in exposure to cationic detergents, and in patients receiving phenolthiazine or chlorpromazine. Stomatocytosis can be an inherited or acquired condition.In hereditary stomatocytosis, mild anemia and findings of on-going hemolysis may be evident if the condition presents as a clinical problem at all. Individuals who possess the Rh null phenotype have osmotically fragile red cells, which take the form of stomatocytes. Individuals with this phenotype tend to experience varying degrees of chronic hemolytic anemia. Note: Unless 10% or more of the RBC's are stomatocytes, their presence is probably artifactual.

An issue related to reaction strength of RhIg in serologic tests is how long passive anti-D from RhIg can be detected post-injection. The half-life of IgG is 23 to 26 days. Following injection of RhIg, serologically detectable levels of anti-D peak within hours (IV injection) or days (IM injection).Although the half-life of passive anti-D from RhIg is approximately 3 weeks, it may be detectable by serologic tests for approximately 8 weeks by the indirect antiglobulin test (IAT) and up to 12 weeks or more by continuous flow analyzers used to quantify anti-D. Levels of passive anti-D will decrease over time.Immune anti-D becomes detectable later (e.g., ~4weeks after exposure to D+ red cells), and generally reaches a peak after 6–8 weeks. Levels of immune anti-D will remain constant for longer and will increase following exposure to another immunizing dose of fetal D+ cells. Depending on the many variables that can affect reaction strength (mentioned earlier), as detected serologically, passive anti-D from RhIg can be detected for about 8 weeks or longer by routine, sensitive antibody detection methods.Since RhIg is injected at about 28 weeks, it is routinely detected at delivery, which could occur well before the ~40 weeks considered to be normal gestation (37–42 weeks by the World Health Organization).

The Occupational Safety and Health Administration is an agency working within the United States Department of Labor. It was created in 1970 by congress under the Occupational Safety and Health Act. As the primary regulatory agency in the field of occupational safety and health, its mission is to prevent work-related injuries, illnesses, and deaths by issuing and enforcing standards for workplace safety and health. Several states have also implemented their own occupational safety and health programs. To qualify as a state plan, the state agency must promulgate regulations that are equal to or more stringent than the federal OSHA program. Some of the safety regulations brought about by OSHA that affect the laboratory are: Personal protective equipment (PPE)- primarily to prevent exposure to bloodborne pathogens. Lockout/tagout- securing energy sources in an "off" condition when performing repairs of maintenance. Hazard communications- requires developing and communicating information on hazards of chemical products used in the laboratory, such as material safety data sheets (MSDS). Bloodborne pathogens- a standard designed to prevent both employees and patients from being exposed to bloodborne pathogens.

Risk management is the process by which the laboratory becomes aware of risk that can cause potential loss exposure. Loss could result from a variety of circumstances and, depending upon the circumstances, can be insignificant to catastrophic. Therefore, in addition to identifying the risk, it is also important to establish the severity of the risk by determining the probability of loss if the risk is not controlled. There are a variety of ways the laboratory can identify potential risks. The following methods are generally considered among the more effective methods. Evaluating complaints from patients and clients Reviewing incident reports Evaluating deficiencies cited by accreditation or governmental inspections (external assessments) Reviewing proficiency testing results However, it is important to be sensitive to events or trends that may alert you to risk potential. For example, although continually monitoring the number of phlebotomies that are performed in a day may not be a normally effective method for evaluating risk, if there is a sudden staff shortage of phlebotomists or a sudden increase in hospital census, it may be worth evaluating the number of phlebotomies that are done because the risk potential may increase if the phlebotomy staff is overworked.

Specimen collection and handling information should be recorded and included with the semen analysis report, including:The time of collectionDays of abstinenceLocation at which specimen was collected: clinic or homeCollection or transport problems (e.g., incomplete specimen, specimen exposure to cold temperatures)Method of collectionAbnormalities of liquefactionTime of specimen receipt and analysisA sample supplemental information collection form is shown below:

Susceptibility to an influenza virus strain is dependent on the immune status of the human host, since our bodies become immune only to the strains that we have been exposed to previously (either naturally or by vaccination). The lack of previous exposure to this subtype resulted in the rapid spread and increased number of infections, especially in the younger population. Respiratory infections occurred, even among those individuals who had received the seasonal flu vaccine because that vaccine was not formulated to protect against the influenza A 2009 H1N1 subtype.

Hematoxylin is the most widely used natural dye. However, it has little natural affinity for tissues, and needs to be oxidized to encourage tissue staining. The oxidation product of hematoxylin is hematein. This conversion process is called "ripening" and can occur naturally or chemically.The natural oxidation process takes place upon exposure to air and light and can take as long as 3-4 months before ripening is complete. However, the end product retains its staining ability for a long period of time.Chemical oxidizing agents convert the hematoxylin to hematein almost instantaneously. However, the resultant solution has a shorter shelf-life.

TB infection is usually followed by an immune response and latency after exposure. In about 5-10% of cases, the latent period progresses to an active infection.Infection occurs when a susceptible person inhales droplet nuclei containing Mycobacterium tuberculosis and the organism reaches the alveoli of the lungs. The minimal infectious inoculum may be as low as one viable organism.About 2-12 weeks after infection, the immune system limits multiplication of additional bacteria and the immunological test becomes positive.Latent tuberculosis infection (LTBI) is the stage when the viable organism remains in the body; the individual has no symptoms and is noninfectious.Most persons infected with M. tuberculosis do not experience clinical illness and are noninfectious. About 5-10% of persons who are infected and are not treated will develop active TB during their lifetime. The risk for progression is highest during the first several years after infection.Most often, M. tuberculosis infects the lungs. However, it can infect almost any organ in the body, including bones and joints. Tuberculosis meningitis is a TB infection that occurs outside the lungs with devastating consequences, most often in young children and patients with AIDS.

Geographic areas with high incidence of tuberculosis include Africa, Asia, eastern Europe, Latin America, and Russia. Persons at higher risk for exposure to and infection from Mycobacterium tuberculosis include: Frequent travelers to areas of the world where tuberculosis is endemicResidents and employees of high-risk congregate settings such as correctional facilities, long-term care facilities, and homeless sheltersHealth care workers who serve high-risk patients or have unprotected exposureMedically underserved and low-income populationsInfants, children, and adolescents exposed to adults in high-risk categories

The CDC recommend that all health care facilities develop a TB exposure control plan. The plan should include an exposure determination at defined intervals for all employees who may have occupational exposure to tuberculosis. Additionally, it should provide for engineering controls and work practice controls for procedures that potentially may aerosolize Mycobacterium tuberculosis, including these procedures:BronchoscopyEndotracheal intubationSuctioningOther respiratory proceduresOpen abscess irrigationSputum inductionAerosol treatments that induce coughingFor laboratory workers, procedures that are at high-risk of producing aerosols include:Handling unfixed tissues in surgical pathology or autopsiesProcessing specimens in the microbiology section from patients with suspected or confirmed tuberculosis

Respirators are used in situations that pose a high-risk for exposure to infectious aerosols. The most commonly used respirator in the health care facility is the N95 respirator, shown in the image on the right. An N95 respirator should be used when collecting specimens from patients with known or suspected cases of active tuberculosis. In a microbiology laboratory, a respirator should be used when it is probable that aerosols might be released in the biosafety cabinet at substantial levels as a result of the manipulation of the potentially infectious specimen. Health care workers (HCW) are screened for medical conditions by a physician prior to using respiratory protection.Annual fit-testing and training on proper usage of the N95 respirator is required. Fit testing ensures a good face seal can be achieved. Each time the respirator is worn, the wearer performs a user-seal check to ensure adequate respiratory protection. HCW who, for medical reasons, cannot use N95 respirators and men with beards or other facial hair that would interfere with the seal between the face and the respirator must use a different type of respirator that offers sufficient aerosol protection but does not require fit-testing. However, annual training on proper usage is required.