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1 Eastman Dental Institute, University College London, 256 Grays Inn Road, London WC1X 8LD, UK; and
2 University of California, San Francisco, USA
* corresponding author, c.scully{at}eastman.ucl.ac.uk
| ABSTRACT |
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KEY WORDS: HIV AIDS mouth dental transmission occupational
| INTRODUCTION |
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| HEALTH-CARE WORKERS WITH POSSIBLE OCCUPATIONALLY CONTRACTED HIV INFECTION |
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According to McCarthy, there are, worldwide, > 300 reports (102 confirmed) of occupational transmission to HCPs, including up to nine dental HCPs (unconfirmed) (McCarthy et al., 2002). Exposure to HIV has been reported by 0.5% dentists/year (McCarthy et al., 2002). There are few data from resource-poor countries or regions where the prevalence of HIV is, and risk of infection must be, higher.
| HEALTH-CARE PROFESSIONALS WITH HIV INFECTION OF UNKNOWN ORIGIN |
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| DENTAL STAFF WITH POSSIBLE OCCUPATIONALLY CONTRACTED HIV INFECTION |
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Dentist 1
The first case of a dental HCP reported with apparently occupationally contracted HIV was a male dentist in the USA (Klein et al., 1988). He lived among and treated New York City "Greenwich Village" patientsa high HIV/AIDS risk populationand he used protective equipment only intermittently, denied other high-risk behavior, and tested HIV-positive in a survey of 1309 dental HCPs (Klein et al., 1988). His HIV exposure could not be documented, and the CDC concluded that if the dentist did contract HIV occupationally, then standard infection control precautions would have prevented transmission to his patients.
Dentists 2 & 3
There is a reference to two HIV-seroconverted dental HCPs, among a group of 69 HCPs with no identifiable risk for infection (Neiburger, 2004). These dentists evidently worked in a correctional facility (treating high-risk patients), experienced needlesticks from equipment used on unidentified patients, and died before HIV-DNA studies and in-depth interviews could be done (Centers for Disease Control, 1992a).
There was little other information on these two dentists or any potential high-risk behavior.
Dentists 4, 5, & 6
The CDC, in several years of HIV/AIDS Surveillance Reports, indicated that there were seven dental HCPs who were possible cases of occupational HIV transmission, but this was later revised to six possible cases (Centers for Disease Control, 1993, 1997, 1999). Of these seven (or six) dental HCPs, three were general dental practitioners, two were dental students, one was a pedodontist, and one a periodontist. Dental HCPs in the UK have not been reported to have contracted HIV from HIV-infected patients (Public Health Laboratory Service, 2005).
| HIV TRANSMISSION FROM HCP TO PATIENT |
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In attempting to assess the risk, one must consider not only statistical data, but also the nature of the procedure being performed. Should the HIV-infected HCP incur a surgical accident or percutaneous injury in an exposure-prone procedure (EPP), there may be the potential for exchange of blood or other potentially infected fluid, such as saliva, but the susceptibility of oropharyngeal and other mucous membranes to transmission of HIV is unknown.
In only three reported instances (discussed below)the Florida dentist (Ciesielski et al., 1992), the French orthopedic surgeon (Lot et al., 1999), and the nurse (Goujon et al., 2000)have there been possible transmissions from an HIV-infected HCP to patients, but although genetic relatedness was demonstrated, only in the orthopedic case was the route of transmission clear.
Worldwide, all other retrospective studies of patients exposed to the potential risk of transmission of HIV during EPP have failed to identify any patients who have become infected by this route. Analysis of the data available from patient notification exercises also supports the conclusion that the overall risk of transmission of HIV from infected HCPs to patients is very low. Between 1988 and 2001 in the UK, there were 22 patient notification exercises, but no detectable transmission of HIV from an infected HCP to a patient, despite about 7000 patients having been tested (Public Health Laboratory Service, 2005).
| THE FLORIDA DENTIST CASE |
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The dentist then wrote to his former patients, which prompted 591 persons to be tested for HIV, when two patients (B and C) were found to be HIV-seropositive. Another patient (patient D) was identified as HIV-infected when the list of available names of the dentists former patients was matched with Floridas state AIDS surveillance records, and one more patient (E) contacted the CDC to report that she was HIV-infected and had been a former patient of the dentist. Of these four additional HIV-infected patients of the dentist, only two were infected with HIV strains closely related to those of the dentist and patient A, but not to strains from other persons residing in the same geographic area as the dental practice. Another 1100 persons who may have been patients of the dentist were contacted for counseling and HIV-antibody testing; of these persons, 141 were tested, but all were HIV-seronegative.
This investigation strongly suggests that at least three (possibly six) patients of the Florida dentist with AIDS were infected with HIV during their dental care, since they had no other confirmed exposures to HIV, all had had invasive procedures performed by the HIV-infected dentist, and DNA sequence analyses of the HIV strains indicated a high degree of similarity of these strains to each other and to the strain that had infected the dentist. These HIV strains were also distinct from strains from patient D (who had known behavioral risks for HIV infection), from strains of the eight HIV-infected patients residing in the same geographical area, and from the 21 other North American HIV isolates. The precise mode of HIV transmission to patients A, B, and C remains uncertain, though all three had invasive dental procedures at times when the dentist was known to be HIV-infected and would have had high blood viral titers, and patients B and C had multiple invasive procedures.
Although barrier precautions were reportedly used in the Florida dental office, they were neither consistent nor in compliance with recommendations. Transmission might also have occurred by the use of instruments or other dental equipment that had been previously contaminated with blood from either the dentist or an infected patient.
There have been continued controversy and speculation over this case, and the truth will probably never be established, since the dentist has died.
| OTHER REPORTS FROM THE USA ON PATIENTS TREATED BY HIV-POSITIVE HCPs |
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The 37 HIV-infected persons in the same study (Centers for Disease Control, 1992a), for whom investigations were in progress, were patients treated by three HCPs, two of whom were dentists. Dentist 1 practiced in an area with high background prevalence of HIV infection, and, of 1162 patients tested, 29 were HIV-infected. Established risk factors could not be identified for 17 of these 29 patients, but epidemiologic investigations determined that many may have had opportunities for exposure to HIV (e.g., multiple sex partners and/or exchange of sex for drugs or money). HIV genetic sequence analysis results do not appear to have been published. More than 800 patients of Dentist 2 were tested, and five proved to be HIV-positive. Three of these patients had established risk factors identified. Eighteen months after the last visit to the dentist, a fourth patient was documented to be seronegative but was seropositive when re-tested 2 years later. No risk factors were identified for the remaining patient, who had visited the dentist only once, for an examination.
As of 1 January 1995, information about investigations of 64 HCPs infected with HIV had been reported to the CDC, with HIV test results available for 22,171 patients of 51 of these HIV-infected HCPs (Robert et al., 1995). For 37 of the 51 HCPs, no HIV-seropositive patients were reported among 13,063 patients tested. For the remaining 14 HIV-infected HCPs, 113 seropositive patients were reported among 9108 patients. However, epidemiologic and laboratory follow-up did not show any HCPs to have been a source of HIV for any of the patients tested (Robert et al., 1995).
Data from the above investigations, as well as risk estimates from modeling techniques, continue to indicate that the risk for HIV transmission from an HIV-infected HCP, whether dental or other, to a patient during an invasive procedure is very small.
| THE FRENCH ORTHOPEDIC SURGEON |
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This seems to confirm transmission of HIV from the HCP.
| THE FRENCH NURSE |
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| TRANSMISSION OF OTHER VIRAL INFECTIONS IN DENTAL PRACTICE |
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The current level of risk of transmission, however, is debatable. Dental HCPs do not now seem to be particularly at risk for occupational acquisition of blood-borne hepatitis viruses transmissible by percutaneous injuries or blood products, such as either hepatitis C virus or transfusion-transmitted virus.
| UNIVERSAL AND STANDARD INFECTION CONTROL PROCEDURES |
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| COMPLIANCE WITH INFECTION CONTROL PROCEDURES IN DENTAL PRACTICE |
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| PERCUTANEOUS INJURIES IN DENTAL HEALTH-CARE PROFESSIONALS |
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Blood is effectively removed from many hollow needles or suture needles when the needle passes through one or more layers of latex or vinyl gloves before coming into contact with the skin (Mast et al., 1993).
Dental HCPs are also at risk, but tend to under-report percutaneous injuries, particularly when there is potential HIV contamination (Ramos-Gomez et al., 1997). The CDC, from June, 1995, through August, 2001, reported 208 exposures199 percutaneous injuries, six mucous membrane exposures, and three skin exposuresin dental HCPs (Cleveland et al., 2002). One-third of these injuries were caused by small-bore hollow syringe needles, and most were moderately deep. Nearly half the devices involved were visibly bloody at the time of injury. Twenty-four (13%) of the known source patients were HIV-positive; 14 had symptomatic HIV infection or a high viral load. In this study, three of four dental HCPs exposed to an HIV-positive source warranted a three-drug post-exposure protocol (PEP) regimen. Twenty-nine (24%) dental HCPs exposed to a source patient, who subsequently was found to be HIV-negative, took PEP; six took PEP for 5 to 29 days. No exposures resulted in HIV infection (Cleveland et al., 2002).
Most dental HCPs appear to be careful to try to avoid injury during intra-oral procedures, but it is during extra-oral proceduressuch as laboratory work, operatory clean-up, and instrument preparation for sterilizationthat most percutaneous injuries occur (Porter et al., 1990; Cleveland et al., 1995; Gooch et al., 1995; McCarthy et al., 1999b).
Fortunately, the rate of occupational injuries among dental HCPs appears to have decreased over the last decade (Bednarsh and Klein, 2003). Post-exposure prophylaxis after percutaneous injuries reduced transmission by over 80% (Cardo et al., 1997), but prevention of injuries is much more important.
| PREVENTION OF OCCUPATIONAL TRANSMISSION OF PATHOGENS |
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Engineering controls to eliminate or isolate the hazard (e.g., puncture-resistant sharps containers or needle-retraction devices) are the primary strategies for protecting dental HCPs and patients. Where these are not appropriate or available, work-practice controls that result in safer behaviors, coupled with the use of personal protective equipment (PPE) (e.g., protective eyewear, gloves, and masks), can prevent or minimize exposure.
An effective sharps injury prevention program is also required. This includes two main components: organizational steps for developing and implementing a sharps injury program, and operational processes. A culture of safety, reporting injuries, analyzing data, and selecting and evaluating devices must be engendered. Instruments, rather than fingers, should be used to grasp needles, retract tissue, and load/unload needles and scalpels. Safer local anesthetic syringes and retractable scalpels are available. It is important that HCPs not pass any needles unsheathed, or recap needles using two hands. Use of a mechanical recapping device or a scoop technique is recommended. Sharps disposal containers and needles and other sharps devices with an integrated engineered sharps injury prevention feature are essential (Centers for Disease Control, 2004).
| PROTOCOLS FOR DEALING WITH PERCUTANEOUS INJURIES AND OTHER POSSIBLE OCCUPATIONAL EXPOSURES TO HIV INFECTION |
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CDC recommendations for PEP (Centers for Disease Control, 2005) for most HIV exposures include beginning, within hours, a basic four-week regimen of 2 anti-retroviral drugs, using 2 NRTIs, or one NRTI and one NtRTI. Regimens include zidovudine [ZDV] and lamivudine [3TC] or emtricitabine [FTC]; d4T and 3TC or FTC; and tenofovir [TDF] and 3TC or FTC. Where there is an increased risk for HIV transmission, an expanded drug regimen is recommended, which includes the addition of a third protease inhibitor [PI]-based drug, usually lopinavir/ritonavir [LPV/RTV]. When the source persons HIV is known or suspected to be resistant to one or more of the PEP drugs, then drugs to which the source persons virus is unlikely to be resistant are recommended. In addition, the CDC outlines several special circumstances (e.g., delayed exposure report, unknown source person, pregnancy in the exposed person, resistance of the source virus to antiretroviral agents, or toxicity of the PEP regimen) when consultation with local experts and/or the National Clinicians Post-Exposure Prophylaxis Hotline ([PEPline] 1-888-448-4911) is advised (Centers for Disease Control, 2005).
European guidelines suggest that PEP should be started as soon as possible with any triple combination of antiretroviral drugs approved for the treatment of HIV-infected patients; initiation of PEP is discouraged after 72 hours. Rapid HIV testing of the source could reduce inappropriate PEP. HIV testing should be performed at baseline, 4, 12, and 24 weeks, with additional clinical and laboratory monitoring of adverse reactions and potential toxicity at weeks 1 and 2. HIV resistance tests in the source and direct virus assays in the exposed HCP are not recommended routinely (Puro et al., 2004). Specific UK recommendations are also available (Department of Health, 2004, http://www.dh.gov.uk/PublicationsAndStatistics/Publications/PublicationsPolicyAndGuidance/PublicationsPolicyAndGuidanceArticle/fs/en?CONTENT_ID=4083638&chk=qtPweH). The UK Department of Health recommends zidovudine as first choice, with lamivudine and nelfinavir, and recommends that PEP be considered whenever there is significant exposure to high-risk body fluids. In an ideal situation, PEP should be commenced immediately, preferably within 1 hour, but starting PEP up to 2 weeks after exposure may still be beneficial.
| CONCLUSIONS |
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When percutaneous exposure to HIV is suspected, the application of post-exposure protocols for investigating the incident and protecting those involved from possible HIV infection further reduces the likelihood of HIV disease, as well as the associated stress and anxiety.
Received September 8, 2005; Accepted December 20, 2005
| REFERENCES |
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Bagg J, Sweeney CP, Roy KM, Sharp T, Smith A (2001). Cross infection control measures and the treatment of patients at risk of Creutzfeldt Jakob disease in UK general dental practice. Br Dent J 191:8790.[ISI][Medline]
Bednarsh HS, Klein B (2003). Legal issues for healthcare workers with bloodborne infectious disease. Dent Clin North Am 47:745756.[Medline]
Cardo DM, Bell DM (1997). Bloodborne pathogen transmission in health care workers. Risks and prevention strategies. Infect Dis Clin North Am 11:331346.[ISI][Medline]
Cardo DM, Culver DH, Ciesielski CA, Srivastava PU, Marcus R, Abiteboul D, et al. (1997). A case-control study of HIV seroconversion in health care workers after percutaneous exposure. Centers for Disease Control and Prevention Needlestick Surveillance Group. N Engl J Med 337:14851490.
Centers for Disease Control (CDC) (1990). Possible transmission of human immunodeficiency virus to a patient during an invasive dental procedure. MMWR Morb Mortal Wkly Rep 39:489493.[Medline]
Centers for Disease Control (CDC) (1991). Update: transmission of HIV infection during an invasive dental procedureFlorida. MMWR Morb Mortal Wkly Rep 40:2127, 33.[Medline]
Centers for Disease Control (CDC) (1992a). Update: investigations of patients who have been treated by HIV-infected health-care workers. MMWR Morb Mortal Wkly Rep 41:344346.[Medline]
Centers for Disease Control (CDC) (1992b). Surveillance for occupationally acquired HIV infectionUnited States, 19811992. MMWR Morb Mortal Wkly Rep 41:823825.[Medline]
Centers for Disease Control (CDC) (1993). Health-care workers with documented and possible occupationally acquired AIDS/HIV infection, by occupation. HIV/AIDS Surveillance Report 5:13.
Centers for Disease Control and Prevention (CDC) (1995). Case-control study of HIV seroconversion in health-care workers after percutaneous exposure to HIV-infected bloodFrance, United Kingdom, and United States, January 1988-August 1994. MMWR Morb Mortal Wkly Rep 44:929933.[Medline]
Centers for Disease Control (CDC) (1997). Health care workers with documented and possible occupationally acquired AIDS/HIV infection, by occupation. HIV/AIDS Surveillance Report 9:15.
Centers for Disease Control (CDC) (1999). Health care workers with documented and possible occupationally acquired AIDS/HIV infection, by occupation, reported through June 1998. U.S. HIV/AIDS Surveillance Report 10:24.
Centers for Disease Control (CDC) (2001). http://www.cdc.gov/hiv/pubs/facts/hcwprev.htm.
Centers for Disease Control (CDC) (2002). Preventing occupational HIV transmission to healthcare personnel. http://www.cdc.gov/hiv/pubs/facts/hcwprev.htm.
Centers for Disease Control (CDC) (2004). Workbook for designing, implementing, and evaluating a sharps injury prevention program. http://www.cdc.gov/sharpssafety/wk_info.html.
Centers for Disease Control (CDC) (2005). Updated U.S. Public Health Service guidelines for the management of occupational exposures to HIV and recommendations for postexposure prophylaxis. MMWR Morb Mortal Wkly Rep 54:117. http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5409a1.htm
Ciesielski C, Marianos D, Ou CY, Dumbaugh R, Witte J, Berkelman R, et al. (1992). Transmission of human immunodeficiency virus in a dental practice. Ann Intern Med 116:798805.[ISI][Medline]
Cleveland JL, Lockwood SA, Gooch BF, Mendelson MH, Chamberland ME, Valauri DV, et al. (1995). Percutaneous injuries in dentistry: an observational study. J Am Dent Assoc 126:745751.
Cleveland JL, Barker L, Gooch BF, Beltrami EM, Cardo D, National Surveillance System for Health Care Workers Group of the Centers for Disease Control and Prevention (2002). Use of HIV postexposure prophylaxis by dental health care personnel: an overview and updated recommendations. J Am Dent Assoc 133:16191626.
Department of Health (DH) (2004). HIV post-exposure prophylaxis: guidance from the UK Chief Medical Officers Expert Advisory Group on AIDS. UK Department of Health. http://www.dh.gov.uk/PublicationsAndStatistics/Publications/PublicationsPolicyAndGuidance/PublicationsPolicyAndGuidanceArticle/fs/en?CONTENT_ID=4083638&chk=qtPweH.
Do AN, Ciesielski CA, Metler RP, Hammett TA, Li J, Fleming PL (2003). Occupationally acquired human immunodeficiency virus (HIV) infection: national case surveillance data during 20 years of the HIV epidemic in the United States. Infect Control Hosp Epidemiol 24:8696.[ISI][Medline]
Glennie Report (2004). NHS Scotland: Sterile Services Provision Review Group: survey of decontamination in general dental practice. ISBN:0-7559-4362-7. business.edinburgh{at}blackwell.co.uk
Gooch BF, Cardo DM, Marcus R, McKibben PS, Cleveland JL, Srivastava PU, et al. (1995). Percutaneous exposures to HIV-infected blood among dental workers enrolled in the CDC Needlestick Study. J Am Dent Assoc 126:12371242.
Gordon BL, Burke FJ, Bagg J, Marlborough HS, McHugh ES (2001). Systematic review of adherence to infection control guidelines in dentistry. J Dent 29:509516.[ISI][Medline]
Goujon CP, Schneider VM, Grofti J, Montigny J, Jeantils V, Astagneau P, et al. (2000). Phylogenetic analyses indicate an atypical nurse-to-patient transmission of human immunodeficiency virus type 1. J Virol 74:25252532.
Heptonstall J, Gill ON, Porter K, Black MB, Gilbart VL (1993). Health care workers and HIV: surveillance of occupationally acquired infection in the United Kingdom. Commun Dis Rep CDR Rev 3:R147R153.[Medline]
Ippolito G, Puro V, De Carli G (1993). The risk of occupational human immunodefienciency virus infection in health care workers. Italian Multicenter Study. The Italian Study Group on Occupational Risk of HIV Infection. Arch Intern Med 153:14511458.[Abstract]
Klein RS, Phelan JA, Freeman K, Schable C, Friedland GH, Trieger N, et al. (1988). Low occupational risk of human immunodeficiency virus infection among dental professionals. N Eng J Med 318:8690.[Abstract]
Kohn WG, Collins AS, Cleveland JL, Harte JA, Eklund KJ, Malvitz DM, et al. (2003). Guidelines for infection control in dental health-care settings2003. MMWR Recomm Rep 52(RR-17):161.[Medline]
Lot F, Séguier JC, Fégueux S, Astagneau P, Simon P, Aggoune M, et al. (1999). Probable transmission of HIV from an orthopedic surgeon to a patient in France. Ann Intern Med 130:16.
Marcus R (1988). Surveillance of health care workers exposed to blood from patients infected with the human immunodeficiency virus. N Engl J Med 319:11181123.[Abstract]
Mast ST, Woolwine J, Gerberding JL (1993). Efficacy of gloves in reducing blood volumes transferred during simulated needlestick injury. J Infect Dis 168:15891592.[ISI][Medline]
McCarthy GM, Koval JJ, MacDonald JK (1999a). Compliance with recommended infection control procedures among Canadian dentists: results of a national survey. Am J Infect Control 27:377384.[ISI][Medline]
McCarthy GM, Koval JJ, MacDonald JK (1999b). Occupational injuries and exposures among Canadian dentists: the results of a national survey. Infect Control Hosp Epidemiol 20:331336.[ISI][Medline]
McCarthy GM, Ssali CS, Bednarsh H, Jorge J, Wangrangsimakul K, Page-Shafer K (2002). Transmission of HIV in the dental clinic and elsewhere. Oral Dis 8(Suppl 2):126135.[Medline]
Neiburger EJ (2004). Dentists do not get occupational AIDS. J Am Assoc Forensic Dent 26:13.
OSHA (2002). http://www.osha.gov/OshDoc/data_BloodborneFacts/index.html.
Porter K, Scully C, Theyer Y, Porter S (1990). Occupational injuries to dental personnel. J Dent 18:258262.[ISI][Medline]
Public Health Laboratory Service (2005). http://www.hpa.org.uk/infections/topics_az/bbv/pdf/intl_HIV_tables_2005.pdf
Puro V, Cicalini S, De Carli G, Soldani F, Antunes F, Balslev U, et al. (2004). Post-exposure prophylaxis of HIV infection in healthcare workers: recommendations for the European setting. Eur J Epidemiol 19:577584.[ISI][Medline]
Ramos-Gomez F, Ellison J, Greenspan D, Bird W, Lowe S, Gerberding JL (1997). Accidental exposures to blood and body fluids among health care workers in dental teaching clinics: a prospective study. J Am Dent Assoc 128:12531261.
Robert LM, Chamberland ME, Cleveland JL, Marcus R, Gooch BF, Srivastava PU, et al. (1995). Investigations of patients of health care workers infected with HIV. The Centers for Disease Control and Prevention database. Ann Intern Med 122:653657.
Saag MS, Crain MJ, Decker WD, Campbell-Hill S, Robinson S, Brown WE, et al. (1991). High-level viremia in adults and children infected with human immunodeficiency virus: relation to disease stage and CD4+ lymphocyte levels. J Infect Dis 164:7280.[ISI][Medline]
Scully C, Porter SR, Epstein J (1992). Compliance with infection control procedures in a dental hospital clinic. Br Dent J 173:2023.[ISI][Medline]
Smith AJ, Cameron SO, Bagg J, Kennedy D (2001). Management of needlestick injuries in general dental practice. Br Dent J 190:645650.[ISI][Medline]
Tokars JI, Marcus R, Culver DH, Schable CA, McKibben PS, Bandea CI, et al. (1993). Surveillance of HIV infection and zidovudine use among health care workers after occupational exposure to HIV-infected blood. The CDC Cooperative Needlestick Surveillance Group. Ann Intern Med 118:913919.
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