Y khoa, dược - Hiv, hepatitis, and other blood - Borne pathogens

34HIV, Hepatitis, and Other Blood-Borne Pathogens34-2Learning Outcomes34.1 Describe ways in which blood-borne pathogens can be transmitted.34.2 Explain why strict adherence to Universal Precautions is essential in preventing the spread of infection.34.3 Describe the symptoms of hepatitis and AIDS.34.4 List and describe the blood tests used to diagnose HIV infection.34-3Learning Outcomes (cont.)34.5 Identify chronic disorders often found in patients who have AIDS. 34.6 Compare and contrast drugs used to treat AIDS/HIV infection.34.7 Describe the symptoms of infection by other common blood-borne pathogens.34-4Learning Outcomes (cont.)34.8 Describe the steps involved in reporting a communicable disease. 34.9 Explain how to educate patients about minimizing the risks of transmitting blood-borne infections to others.34.10 Describe special issues you may encounter when dealing with patients who have terminal illnesses. 34-5Introduction Chapter 34 expands on OSHA Blood-Borne Pathogen StandardHow to reduce your risk of exposureHIV, hepatitis, and other blood-borne infections Reporting guidelinesEducating patientsIssues associated with terminal illnesses such as AIDS34-6Transmission of Blood-Borne Pathogens Blood-borne pathogens are disease-causing microorganisms carried in the host’s blood.Transmission occurs from one host to another through contact with infected Blood Tissue Body fluids Mucous membranes 34-7Transmission (cont.)Cerebrospinal fluidSynovial fluidPleural fluidPeritoneal fluidPericardial fluidAmniotic fluidIdentified by the Centers for Disease Control and Prevention (CDC)Transmission agents for blood-borne diseasesBloodBlood productsHuman tissueSemenVaginal secretionsSaliva from dental procedures34-8Transmission (cont.)Transmission agent only if there is visible bloodFecesNasal secretionsPerspirationSputumTearsUrineVomitusSaliva34-9Transmission (cont.)Blood-borne pathogens may be introduced into a new host byNeedlesticks Cuts or abrasionsAny body openingTransfusion of infected blood34-10People at Increased RiskAnyone who comes in contact with substances that may harbor the pathogensHealth-care professionalsLaw enforcement officersMortuary or morgue attendantsFirefightersMedical equipment service techniciansBarbers and cosmetologists34-11People at Increased Risk (cont.)PathogensHepatitis B virus (HBV)Hepatitis C virus (HCV)HIV  AIDS34-12ResearchIncidence of many infectious diseasesReported to state health departmentsInformation then sent to CDCTrends in spread Identify control tacticsAllocate resources34-13Apply Your KnowledgeANSWER: Transmission occurs from one host to another through contact with infected blood, tissue, body fluids, and mucous membranes.How are blood-borne pathogens transmitted from host to host?Good Answer!34-14Universal PrecautionsThe most effective means of preventing the spread of HIV, hepatitis, and other blood-borne pathogens is to avoid contaminationUniversal Precautions are required by OSHA34-15Universal PrecautionsFor medical offices, includes allBody fluidsSecretionsExcretionsMoist body surfacesAssume every patient is contaminated34-16Apply Your KnowledgeANSWER: In medical offices, Universal Precautions apply to body fluids, secretions, excretions, and moist body surfaces. Assume every patient is contaminated and use Universal Precautions with everyone.In a medical office, to what items do Universal Precautions apply, and with which patients should you practice these precautions?Right!34-17Disease ProfilesKeep up-to-date so you canIdentify symptoms that may indicate that a patient has a blood-borne diseaseIdentify habits of your patients that increase risk of spreading the diseaseEducate patients to limit risks of contracting disease34-18HepatitisViral infection of the liver that can lead to cirrhosis and death Hepatitis A – spread by fecal-oral routeHepatitis B – blood-borne disease that spreads by contact with contaminated blood or body fluids or sexual contact34-19Hepatitis (cont.)Hepatitis C (non-A/non-B)Spread through contact with contaminated blood or body fluids and sexual contactNo cure Many people are carriersFlu-like symptoms, if any Damages liver; causing cirrhosis, liver failure, and cancer34-20Hepatitis (cont.)Hepatitis D (delta agent hepatitis)Occurs only in people that are infected with HBV May mimic symptoms of hepatitis B, but more severeAssociated with liver cancer Hepatitis E Caused by hepatitis E virus (HEV)Transmitted by fecal – oral route34-21Hepatitis (cont.)Risk factors – same for HBV and HCVOccupation that requires exposure to blood and body fluidsHigh-risk sexual activityIV drug useHemophilia Travel to areas with high incidenceBlood transfusions prior to screenHemodialysisLiving with partner with hepatitis B or hepatitis CMultiple sexual partners34-22Hepatitis (cont.)Risk in medical communityHIV Approximately 0.5% from a single needlestick Hepatitis B 6% to 33% from single needlestick The primary risk factor for HBV and HCV infection is occupational exposure to the virus.34-23Hepatitis (cont.)Infection progressionAcute illness lasts about 16 weeksProdromal stage – general malaise, maybe nausea or vomiting, or no symptoms Icteric, or jaundice, stage – yellowing of the skin, eyes, and mucous membranesAppears 5 – 10 days after initial infectionConvalescent (after acute stages) – can last 2 to 3 weeks34-24Hepatitis (cont.)SymptomsJaundiceDecreased appetiteFatigueNausea and vomitingJoint pain/tendernessStomach painGeneral malaiseDiagnosisInvestigation ofRisk factorsExposure incidentsBlood testsAntigen-antibody systems Determine stage of disease34-25Hepatitis (cont.)Preventive measuresAvoid contact with contaminated substancesUse Universal Precautions with all patientsVaccination is available to prevent HBV infectionsWill not protect you from other strains of hepatitisCDC recommends routine vaccination for everyoneHBIG for postexposure inoculation34-26AIDS/HIV InfectionVirus that infects and destroys components of the immune systemHIV infection develops into AIDSPathogen destroys Helper T cells – white blood cells that are a key component of immune systemNeurons, causing demyelinationPatients develop opportunistic infections34-27AIDS/HIV Infection (cont.)Risk factorsUnprotected sexual activitySharing needles used by IV drug users Passes from mother to fetus during pregnancy or to infant during delivery or breastfeedingIncubation period of 8 to 15 years34-28AIDS/HIV Infection (cont.)Risk in medical communityPercutaneous exposure – exposure through a puncture wound or needlestick Mucocutaneous exposure – exposure through a mucous membrane34-29Progression of AIDS/HIVThree main stagesInitial infection Can occur years before symptoms appearVirus enters cell and makes copiesHelper T cells dieImmune system respondsCleans the blood supply of the virusVirus enters an inactive phase34-30Progression of AIDS/HIV (cont.)Incubation periodVirus genetic material incorporated into the genetic material of the helper T cellsHIV becomes active again and continues to attack and kill helper T cellsVirus trapped in lymph systemAs helper T cells decrease, patients are more prone to opportunistic infectionsIncubation period can be 8 to 15 years34-31Progression of AIDS/HIV (cont.)Full-blown AIDS200 or fewer helper T cells/mL blood indicates full-blown AIDSOpportunistic infections and neurological deterioration34-32Diagnosis of AIDS/HIVEnzyme-linked immunosorbent assay (ELISA)Confirms presence of antibodies in response to HIV85% accurate – cross-reactivity with other virusesWestern Blot Test or immunofluorescent antibody (IFA) Confirms positive ELISA test Specific to individual virusesAccurate diagnosis – ELISA plus one of the other twoHome tests available – may give false results34-33Symptoms of AIDS/HIVSystemic Respiratory Oral – hairy leukoplakia Gastrointestinal Peripheral nervous systemSkin-relatedKaposi’s sarcoma 34-34Prevention of AIDS/HIVSexual contactUse protection Avoid multiple partnersUse condoms correctly IV drug usersAvoid sharing or reusing needlesMedical proceduresUniversal PrecautionsWash hands EducationDangers of HIV/AIDSHow HIV/AIDS is spread and not spreadPreventive measures34-35Apply Your KnowledgeWhich statements are true and which are false?____ Risk factors are the same for HBV and HCV.___ Hepatitis A is spread via contaminated blood or body fluids.____ Helper T cells are red blood cells and are a key component of immune system.____ Percutaneous exposure occurs through a puncture wound or  needlestick.ANSWER:FTTFHepatitis A is spread by the fecal-oral route.Helper T cells are white blood cells.Right!34-36Patient ProfileNo one is immune to AIDS2005: 40.3 million men, women, and children were HIV-infected worldwide.People infectedHomosexual males (rate decreasing)Young people in large metropolitan areasIV drug usersWomen34-37Chronic Disorders of the AIDS PatientImpaired immune system permits opportunistic infectionsPneumocystis carinii pneumoniaProtozoal infectionOccurs in 75% of AIDS patientsKaposi’s sarcomaAggressive malignancyNon-Hodgkin’s lymphomaSecond most common malignancy associated with HIV infection34-38Chronic Disorders (cont.)TuberculosisOften drug-resistant Mantoux skin test often negative in AIDS patientsAnergic reaction – no response to any substances injected as a skin testMycobacterium avium complex (MAC) infections97% of nontuberculous bacterial infectionsMeningitisCan lead to AIDS dementia complex34-39Chronic Disorders (cont.)Candidiasis Oral – thrushVaginal – femalesHerpes simplex Infections caused by HSV can be mild to life-threateningHerpes zosterVirus that causes chickenpox becomes dormantReturns as herpes zoster, or shinglesLesions last longer in immunocompromised patients – patients with impaired or weakened immune systems34-40Treating Opportunistic InfectionsDrug side effects problematicPatients developAllergies to treatment Intolerance to medicationsPathogens become resistant to treatmentsTreatments may conflict with other treatments34-41Testing RegulationsCDC does not require mandatory HIV testing for health-care workersHealth-care workers’ chances of being infected by a patient are greater than a patient being infected by a health-care worker34-42Drug TreatmentsDrugsSlow reproduction of virus, no current cure List of FDA approved drugs – Table 21-2Treatment goalsIncrease the time between infection and symptomatic diseaseImprove quality of lifeReduce transmissionTo uninfectedMaternal-infantReduce HIV-related deaths34-43Drug Treatments (cont.)Treatment guidelinesPanel of Clinical Practices for Treatment of HIV InfectionsInitial and follow-up testingDrug resistance testingHAART – combination of drug treatmentInitiating therapyDecision made by patient and physicianAIDS diagnosis or CD4 T cell count is < 200cells/mm334-44Drug Treatments (cont.)Delayed treatmentBenefitsPostponement of drug-related adverse affectsDelayed development of drug resistancePreserving treatment options RisksIrreversible immune system damageIncreased risk of transmission of disease34-45Drug Treatments (cont.)Early treatmentBenefitsSuppression of viral replication (preserves immune function)Reduction in chance of transmissionHelps patient live symptom-free longerDisadvantagesDrug toxicityDrug resistanceAdverse effects on quality of lifeLoss of treatment options34-46Drug Treatments (cont.)Treating complicationsMust also treat opportunistic infectionsPatients more prone toBacterial infectionsProtozoal infectionsViral infectionsFungal infectionsMalignancies Continuing researchGlobal issueKeep informed of new treatments and prevention methods34-47Apply Your Knowledge Identify where these opportunistic infections affect the body.Herpes simplexPneumocystis cariniiKaposi’s sarcoma Tuberculosis MeningitisOral candidiasisANSWER:mouth, lips, genitalia lungsarms, legs, chest, neck, face, conjunctiva, palate lungsbrainmouth, tongueCORRECT!34-48Other Blood-Borne InfectionsCytomegalovirusAntibodies found in 80% of adultsErythema infectiosumParvovirus B19Fifth diseaseHuman T-cell lymphotropic virusHTLV-1Appears in IV drug users, among othersListeriosisCaused by bacteria Listeria monocytogenesFever, shock, rash, and achesAll are problematic for people with impaired immune systems.34-49Other Blood-Borne Infections (cont.)MalariaParasite enters bloodstream through mosquito’s biteCyclical symptomsSyphilisCaused by spirochete Treponema pallidumThree stagesDifficult to identify and treat in HIV-positive persons ToxoplasmosisCaused by Toxoplasma gondii in cat feces34-50Apply Your KnowledgeWhich blood-borne pathogen is found in 80% of adults and rarely causes noticeable symptoms?ANSWER: Cytomegalovirus (CMV) Good Job!34-51Reporting GuidelinesRequirements for reporting HIV infections and AIDS determined by stateFollow state and employer’s guidelines for reporting34-52Reporting Guidelines (cont.)State health department report formsDifferent for each diseaseInformation neededDisease identificationPatient identificationInfection historyInformation about reporting institution34-53Apply Your KnowledgeANSWER: Information needed includes: Disease identification Patient identification Infection history Information about reporting institutionWhat information is generally needed when making a report of an infectious disease?Excellent!34-54Patient EducationAn effective means of preventing disease transmissionAssess the patient’s understanding of the risk for infection Provide information about preventions and treatments34-55Patient Education (cont.)Clinical drug trialsRecognized research protocols designed to Evaluate the efficacy or safety of drugsProduce scientifically valid resultsInformation on trials available from www.ClinicalTrial.gov 34-56Patients with Special ConcernsTeenagersDangers of HIV and AIDSEstablish trust and provide factsPatients about to be dischargedPatient must understand the importance ofReturning for follow-up Reporting any adverse reactionsWatching for signs and symptoms that need to be reportedMulticultural concernsHigh-risk groups based on CDC reportsWritten information available in appropriate language34-57Apply Your KnowledgeWhat guidance could you give a patient with AIDS or hepatitis who requests more information about the disease?ANSWER: Suggest that the patient contact government agencies such as the CDC or the Consumer Information Center by mail or on the Internet. In addition, there may be local support groups and resource organizations available in your area.Impressive!34-58Special Issues with Terminal IllnessTerminal – fatal Reactions will varyHelp by Supporting and accepting patient regardless of reaction Encouraging patient to express feelingsCommunicating respect through nonverbal communicationMeeting reasonable needs and demandsProviding referrals to hospices34-59Apply Your KnowledgeMr. Andrews recently learned his HIV status has progressed to AIDS. When he comes into the office for an appointment, his mood swings from anger to crying. What should you do to help him?ANSWER: You should show support and acceptance of Mr. Andrews regardless of his reactions, encourage him to express feelings, and show respect for him. If his demands are reasonable, attempt to meet them. At this time, you should not refer him to a hospice because there may still be treatment options available.Great!34-60In Summary34.1 Blood-borne pathogens can be transmitted by exposure to blood and body fluids, including blood products, human tissue, semen, vaginal secretions, saliva from dental procedures, cerebrospinal fluid, synovial fluid, pleural fluid, peritoneal fluid, pericardial fluid, and amniotic fluid.34.2 Strict adherence to Universal Precautions by treating all individuals as if they are potentially infected with blood-borne pathogens is essential in preventing the spread of infection. Protecting oneself from exposure through the use of appropriate personal protective equipment is the best way to prevent the spread of infection.34-61In Summary (cont.)34.3 The general symptoms of hepatitis include jaundice, diminished appetite, fatigue, nausea, vomiting, joint pain or tenderness, stomach pain, and general malaise. The initial symptoms of AIDS are usually severe flu-like symptoms followed later by systemic (weight loss, fatigue, night sweats), respiratory, oral, gastrointestinal, nervous system, and skin complaints. 34.4 The tests used to diagnose HIV infection include the Rapid test, enzyme-linked immunosorbent assay (ELISA) test, Western blot, and immunofluorescent antibody (IFA) test.34-62In Summary (cont.)34.5 AIDS/HIV patients develop chronic disorders including Pneumocystis carinii pneumonia (PCP), Kaposi’s sarcoma, non-Hodgkin’s lymphoma (NHL), tuberculosis, Mycobacterium avium complex (MAC), meningitis, oral and vaginal candidiasis, herpes simplex, and herpes zoster.34.6 FDA-approved pharmaceutical agents used in the treatment of HIV/AIDS are divided into four classes; fusion inhibitors, nonnucleoside reverse transcriptase inhibitors (NNRTIs), nucleoside reverse transcriptase inhibitors (NRTIs), and protease inhibitors (PIs).34-63In Summary (cont.)34.7 Several other common blood-borne pathogens are of importance especially to patients who are immunocompromised. It is important that the medical assistant be able to recognize the symptoms of these infections, which include cytomegalovirus (CMV), erythema infectiosum (fifth disease), human T-cell lymphotrophic virus (HTLV-1), listeriosis, malaria, syphilis, and toxoplasmosis. 34.8 The steps involved in reporting a communicable disease include obtaining the correct form, filling in the appropriate blanks on the form, and submitting the form to the physician prior to mailing it to the appropriate agency.34-64In Summary (cont.)34.9 Medical assistants can assess patients’ understanding of their risk for infection, the measures patients must take to eradicate an infection, the potential dangers posed by treatments, and the methods for controlling an infection’s spread.34.10 Patients will have a variety of reactions to the news that they are dying. Some become angry, some will deny that they are dying, and some will get depressed. 34-65Thought is an infection. In the case of certain thoughts, it becomes an epidemic. ~ Wallace Stevens End of Chapter 34