Prevalence of Transfusion-Transmitted Viral Pathogens among Health-Care Workers and Risk Mitigation Programme in a Paediatric Tertiary Care Hospital

The health-care workers (HCWs) are at an occupational risk of exposure to blood-borne pathogens, mainly, HIV, hepatitis B virus (HBV) and hepatitis C virus. HBV is currently the only blood-borne virus for which a vaccine is available. All health-care institutions must encourage the HCWs to undergo screening for blood-borne pathogens.     

Hepatitis B virus (HBV) and hepatitis C virus (HCV) infections in health care workers (HCWs): guidelines for prevention of transmission of HBV and HCV from HCW to patients.

The transmission of viral hepatitis from health care workers (HCW) to patients is of worldwide concern. Since the introduction of serologic testing in the 1970s there have been over 45 reports of hepatitis B virus (HBV) transmission from HCW to patients, which have resulted in more than 400 infected patients. In addition there are six published reports of transmissions of hepatitis C virus (HCV) from HCW to patients resulting in the infection of 14 patients. Additional HCV cases are known of in the US and UK, but unpublished. At present the guidelines for preventing HCW to patient transmission of viral hepatitis vary greatly between countries. It was our aim to reach a Europe-wide consensus on this issue. In order to do this, experts in blood-borne infection, from 16 countries, were questioned on their national protocols. The replies given by participating countries formed the basis of a discussion document. This paper was then discussed at a meeting with each of the participating countries in order to reach a Europe-wide consensus on the identification of infected HCWs, protection of susceptible HCWs, management and treatment options for the infected HCW. The results of that process are discussed and recommendations formed. The guidelines produced aim to reduce the risk of transmission from infected HCWs to patients. The document is designed to complement existing guidelines or form the basis for the development of new guidelines. This guidance is applicable to all HCWs who perform EPP, whether newly appointed or already in post.     

Interventions to reduce needle stick injuries at a tertiary care centre

Background: Occupational exposure to blood/body fluids is associated with risk of infection with blood borne pathogens like human immunodeficiency virus (HIV), hepatitis B virus (HBV) and hepatitis C virus (HCV). Materials and Methods: We carefully document needle stick injuries (NSI) and implement post-exposure prophylaxis (PEP). We report a four-year continuing surveillance study where 342 healthcare workers (HCWs) sustained NSI. PEP was given to HCWs injured from seropositive sources. If the source was HbsAg positive, HCWs were given a hepatitis B immunization booster. If the HCW was antiHBs negative, both hepatitis B immunoglobulin (HBIG) and hepatitis B vaccine were administered. For HCWs who sustained injuries from HIV positive sources, antiretroviral therapy was started. Follow-up was done after three and six months of exposure. Recent interventions by the infection control committee at our hospital reduced NSI considerably during intravenous line administration and glucose monitoring. Results and Discussion: Of 342 injuries, 254 were from known sources and 88 from unknown sources. From known sources, 37 were seropositive; 13 for HIV, 15 for HCV, nine for HBV. Sixty six sharp injuries were sustained through garbage bags, 43 during IV line administration, 41 during injection administration, 35 during needle recapping, 32 during blood collection, 27 during blood glucose monitoring, 24 from OT instruments, 17 during needle disposal, 16 while using surgical blade, 7 during suturing and 34 from miscellaneous sources. Conclusion: No case of seroconversion has taken place, so far, as a result of needle stick injuries at our centre.     

Incidence of visits for health care worker blood or body fluid exposures and HIV postexposure prophylaxis provision at Rhode Island emergency departments

OBJECTIVES: To compare the incidence and types of emergency department (ED) visits for blood or body fluid exposures sustained by health care workers (HCWs) in Rhode Island and to identify factors predictive of HIV postexposure prophylaxis (PEP) utilization for these exposures. METHODS: A retrospective study of ED visits for blood or body fluid exposures to all Rhode Island EDs from January 1995 to June 2001 was conducted. Average incidence rates (IRs) of visits by HCW occupation and type of exposure were estimated and compared. Logistic regression models were created to determine which HCWs were more likely to be offered and to accept HIV PEP. RESULTS: Of 1551 HCW ED visits for occupational exposures, 72.5% sustained a percutaneous injury and only 2.5% were exposed to a source known to be HIV-infected. Hospital custodians had the highest IR of ED visits for percutaneous injuries (81 ED visits per year per 10,000 workers). Visits for all exposures increased over the study years and were most common during March, on weekends, and at 5:00 PM. Of all HCWs, 91.2% presented within 24 hours of their exposure and 98.2% presented within 72 hours. HIV PEP was offered to 469 HCWs and accepted 229 times. HCWs more likely to be offered HIV PEP were exposed to a known HIV-infected source (odds ratio [OR] = 6.38), sustained a significant exposure (OR = 4.98), presented to an academic hospital ED (OR = 2.60), were a member of the medical staff (OR = 2.02), and were exposed during the latter years of the study (OR = 1.23). HCWs were more likely to accept HIV PEP when it was offered if they were male (OR = 1.64) and presented to an academic hospital ED (OR = 2.72). CONCLUSIONS: The IRs of ED visits for exposures varied by occupation, and there were clear temporal trends for these visits. Despite the existence of federal guidelines for HIV PEP for occupational blood or body fluid exposures, factors other than characteristics of the exposure, such as type of hospital, occupation, and gender, may be influencing HIV PEP utilization.     

Managing occupational risks for hepatitis C transmission in the health care setting

Hepatitis C virus (HCV) infection is a significant contemporary health problem in the United States and elsewhere. Because it is primarily transmitted via blood, hepatitis C infection presents risks for both nosocomial transmission to patients and occupational spread to health care workers. Recent insights into the pathogenesis, immunopathogenesis, natural history, and treatment of infection caused by this unique flavivirus provide a rationale for the use of new strategies for managing occupational hepatitis C infections when they occur. This article reviews this developing information. Recently published data demonstrate success rates in the treatment of "acute hepatitis C syndrome" that approach 100\%, and although these studies are not directly applicable to all occupational infections, they may provide important clues to optimal management strategies. In addition, the article delineates approaches to the prevention of occupational exposures and also addresses the difficult issue of managing HCV-infected health care providers. The article summarizes currently available data about the nosocomial epidemiology of HCV infection and the magnitude of risk and discusses several alternatives for managing exposure and infection. No evidence supports the use of immediate postexposure prophylaxis with immunoglobulin, immunomodulators, or antiviral agents. Based on the very limited data available, the watchful waiting and preemptive therapy strategies described in detail in this article represent reasonable interim approaches to the complex problem of managing occupational HCV infections, at least until more definitive data are obtained.     

HCV infection in medical environments

Since the discovery of the hepatitis C virus(HCV), it has become evident that this infectious agent is a primary cause of posttransfusion and sporadic non-A, non-B hepatitis. Populations at risk for HCV infection include health care workers, infants born to HCV-infected mothers, hemodyalysis patients, and intravenous drug abusers. Because there currently is no HCV vaccine or specific immunoglobulin against HCV, prevention of exposure remains the only possibility for reducing HCV transmission and prevalence. However, the percentage of individuals who are positive for HCV antibody among health care workers is not significantly high, suggesting that health care workers are not at very high risk of HCV infection. Too much fear of HCV infection among the health care workers should be avoided.     

Case report: risk of virus infection after accidental blood inoculation from a multi-infected AIDS patient

Infections caused by blood-borne viruses such as hepatitis B and C and the human immunodeficiency virus (HIV) are associated commonly with needlestick injuries, especially in a hospital setting. A prospective investigation was conducted on a medical doctor who suffered an accidental needlestick injury during blood collection from a patient with AIDS. The patient's blood contained 195,000 copies of HIV RNA, 1 × 10(6) IU hepatitis C virus (HCV) RNA, and >10(7) copies of parvovirus B19 DNA per 1 ml plasma. It was positive for cytomegalovirus virus and evidence of a resolved hepatitis B virus (HBV) infection was found. HCV viremia was detected in the physician 15 days later and was not resolved by seroconversion after 57 days. HIV infection was not transmitted, possibly because of the immediate use of anti-HIV prophylactic drugs after exposure. Parvovirus B19 infection was presumably prevented by pre-existing specific antibodies in the patient. Considering that many HIV carriers are coinfected with hepatitis B and C viruses, this case report support the knowledge that the risk of HCV transmission from a patient with AIDS is greater than that of HIV.     

Hepatitis C virus infection among transmission-prone medical personnel

Hepatitis C virus (HCV)-infected physicians have been reported to infect some of their patients during exposure-prone procedures (EPPs). There is no European consensus on the policy for the prevention of this transmission. To help define an appropriate preventive policy, we determined the prevalence of HCV infection among EPP-performing medical personnel in the Academic Medical Center in Amsterdam, the Netherlands. The prevalence of HCV infection was studied among 729 EPP-performing health care workers. Serum samples, stored after post-hepatitis B virus (HBV) vaccination testing in the years 2000-2009, were tested for HCV antibodies. Repeat reactive samples were confirmed by immunoblot assay and the detection of HCV RNA. The average age of the 729 health care workers was 39?years (range 18-66), suggesting a considerable cumulative occupational exposure to the blood. Nevertheless, only one of the 729 workers (0.14%; 95% confidence interval [CI]: <0.01% to 0.85%) was tested and confirmed to be positive for anti-HCV and positive for HCV RNA, which is comparable to the prevalence of HCV among Amsterdam citizens. Against this background, for the protection of personnel and patients, careful follow-up after needlestick injuries may be sufficient. If a zero-risk approach is desirable and costs are less relevant, the recurrent screening of EPP-performing personnel for HCV is superior to the follow-up of reported occupational exposures.     

Healthcare workers' compliance with universal precautions in Turkey

Blood-borne pathogens (BBP) represent remarkable occupational risks for healthcare workers (HCWs). Avoiding occupational blood exposure is a basis of prevention of the blood-borne pathogens (BBP). The effectiveness of the prevention strategies depends on the compliance and adherence to the program by healthcare-facility personnel. The aim of this study was to evaluate Turkish HCWs' compliance with Universal Precautions (UP). An analytic, cross-sectional, countrywide survey study was performed in hospital settings, (n = 5145) in 30 hospitals in 19 cities. In total, 1726 of the 5143 (33.6%) participants' behaviors were accepted as satisfactory for compliance with UP. The hepatitis knowledge levels of 2,650 (51.5%) participants were found to be satisfactory. In the multivariate analysis, working at a surgical site (P = 0.004), living in a rich region (P = .007) and the existence of a health office for HCWs (p = .000) were found to be contributor factors for HCWs' compliance with UP. Conversely, being a nurse (P = .000) and HBV/HCV carrier status (P = .039) were significant preventing predictors for HCWs' compliance with UP. Along with the other well-known predictive factors, regional economic status and a health office for HCWs are contributors for compliance with UP.     

HBV and HCV infection in Japanese dental care workers

Protective measures against occupational exposure to the hepatitis B virus (HBV) and hepatitis C virus (HCV) must be taken in order to prevent infection in dental care workers. To determine the best way to protect these workers, our study examined viral hepatitis infection in dental care workers in regions with a high prevalence of HCV infections in Japan. In total, 141 dental care workers (including dentists, dental hygienists and dental assistants) were enrolled. After a questionnaire to elicit demographic information was administered by an oral surgeon, hepatitis B surface antigen (HBsAg), antibody to HBs (anti-HBs), antibody to hepatitis B core antigen (anti-HBc) and antibody to HCV (anti-HCV) were measured. When necessary, HBeAg, anti-HBe, levels of HBV DNA, anti-HBc IgM and HCV RNA in serum were measured. Of the dental care workers included, 68 (48.2%) had been immunized with a HBV vaccine. Only 9 wore a new pair of gloves for each new patient being treated, 36 changed to a new pair only after the old gloves were torn and 24 did not wear any gloves at all. No one was positive for HBsAg or anti-HCV, though 73 (51.8%) and 17 (12.1%) workers were respectively positive for anti-HBs and anti-HBc. The positive rate of anti-HBc varied directly with worker age and experience. Of the 68 workers immunized with HBV vaccine, 51 (75%) were positive for anti-HBs. Of the 63 workers who were not so immunized, 17 (27%) were positive for anti-HBs and 15 of these were also positive for anti-HBc. Immunized workers were more protected against HBV infection than non-immunized workers, indicating that HBV vaccine was a useful measure for protection against the infection. The anti-HBc positive rate was significantly higher among dental care workers than general blood donors, suggesting that frequency of exposure to HBV was greater in dental care workers. HBV vaccination should be made compulsory for all dental care workers who handle sharp instruments.     

Rapid spread of hepatitis C virus among injecting-drug users in the Philippines: Implications for HIV epidemics

From the trends of human immunodeficiency virus (HIV) epidemics in South and Southeast Asia, it was postulated that an HIV epidemic would start as a blood-borne infection among injecting-drug users in the Philippines. In 2002, 560 individuals were recruited in Metro Cebu, Philippines and tested for HIV, hepatitis C virus (HCV), and hepatitis B virus (HBV) infections. The seroprevalence of anti-HCV among injecting-drug users (70.1%, 61/87) was significantly higher than those among inhalation drug users (16.3%, 7/43; P = 0.00; OR = 12), sex workers (0%, 0/130; P = 0.00; OR = infinity), antenatal clinic attendees (0%, 0/100; P = 0.00; OR = infinity), and students/health care workers (2%, 4/200; P = 0.00; OR = 115). The seroprevalence of HBsAg among injecting-drug users (10.3%, 9/87) was significantly higher than those among sex workers (2.3%, 3/130; P = 0.01; OR = 4.9), and antenatal clinic attendees (3%, 3/100; P = 0.04; OR = 3.7), but was not statistically different from those among inhalation drug users (9.3%, 4/43; P = 0.9) and students/health care workers (4.5%, 9/200; P = 0.06). None of the study population was reactive to anti-HIV antibody. The HCV strains obtained from the injecting-drug users belonged to either genotype 1a or 2b and the strains in each genotype clustered closely to each other. There was no dual infection with genotype 1a and 2b. These results suggest that the HCV infection in injecting-drug users may be emanating rapidly from limited number individuals in Metro Cebu, Philippines.     

Human immunodeficiency virus,hepatitis B virus and hepatitis C virus seroprevalence in critically ill emergency department patients at a Trauma Care Centre,India

Introduction: Human Immunodeficiency Virus (HIV), Hepatitis B virus (HBV) and Hepatitis C virus (HCV) are the most common occupationally acquired infections amongst the healthcare workers (HCWs) with critically ill patients attending the emergency department being the most common source of occupationally acquired infections. Therefore, the present study was conducted at a 165 bedded level-1 trauma centre of India to ascertain the seroprevalence rate of HIV, HBV and HCV; and thus the risk associated with the occupational exposure in a busy emergency setting of the developing world. Methodology: A retrospective, 7 years study (2007-2013) was carried out at the JPNA Trauma Centre of the 2,500 bedded All India Institute of Medical Sciences, New Delhi. Records of all patients whose serum samples were sent to the laboratory for viral markers testing were obtained and those falling in the red area were included. Results: A total of 11,630 patients were received in the red area; and samples from 7,650 patients were sent for testing. Seropositivity of HIV, HBV and HCV in these samples was 0.28%, 3.4% and 0.9% respectively. The number of samples received was lesser than the total number of patients received in the red area. Conclusion: Adopting Standard Precautions (SP) can be used as an easy method to decrease the risk of occupationally acquired infections.     

Seroprevalence of anti-HCV and hepatitis B surface antigen in HIV infected patients

Human immunodeficiency virus (HIV) is known to influence the natural history of infections with certain hepatitis viruses and interactions between HIV and hepatitis viruses may potentiate HIV replication. There is high degree of epidemiological similarity between hepatitis B virus and HIV as regard to high-risk group and route of transmission. Transmission of hepatitis C virus (HCV) through blood transfusion and intravenous drug abuse is well documented. Present study deals with the study of concurrent infection of HBV and HCV with HIV infection. In the study of 110 HIV seropositive patients, 34(30.4%) were positive for HBV and 8(7.27%) for HCV. The difference of concomitant infection was highly significant compared to controls. (p value < 0.0001). Heterosexual high risk behaviour was observed in 89(80.91%) of 110 HIV positive patients, out of which 23(25.8%) and 5(5.62%) were HBsAg and anti-HCV positive respectively. History of transmission was unclear in remaining patients. Concomitant infection of HIV and HBV was found to be significantly more in the symptomatic group (40.68%) compared to asymptomatic group (19.6%). As HIV infection is known to affect the natural history of both HBV and HCV infection, screening of their concurrent association is necessary.     

Seroprevalence of hepatitis B virus among health care workers in Korea

We studied the seroprevalence of HBsAg, anti-HBs and anti-HBc and the vaccination histories among health care workers (HCWs) at a large suburban referral hospital in Korea. The purpose of this study was to determine the immune status of HCWs against hepatitis B virus and we also wanted to prepare a practical guideline to protect HCWs from occupational exposure. During December, 2003, 571 HCWs (56 physicians, 289 nurses, 113 technicians and 113 aid-nurses) aged between 21 and 74 yr were included in the surveillance. The positive rates of HBsAg and anti-HBs were 2.4% (14/571) and 76.9% (439/571), respectively. The positive rate of anti-HBs was lower in the physician group, and this was associated with the male gender and older age. Of the 439 anti-HBs positive cases, 320 cases (73.1%) were anti-HBc negative and this was significantly associated with a past history of HBV vaccination. The distribution of the anti-HBs levels was not associated with age (except for HCWs in their sixties), gender or occupation. Our study revealed that the seroprevalence rates of HBsAg and anti-HBs in HCWs in Korea were not different from those of the general population. Based on this surveillance, we can make reasonable decisions in case of occupational exposure to hepatitis B virus.     

165例医务人员职业暴露分析

目的了解我院医务人员职业暴露情况。方法对我院2005-2009年职业暴露的人员结构、暴露源、暴露时的情况（暴露方式、暴露地点、暴露时防护措施）、暴露后处理（包括紧急处理、上报、预防用药、监测）等情况进行回顾性调查。结果共发生职业暴露165例,其中护士94例,医师59例,保洁人员12例。暴露源为艾滋病病毒/艾滋病（HIV/AIDS）64例,乙肝30例,丙肝5例,梅毒21例,狂犬病40例。暴露方式：锐器伤73例,完整皮肤60例,破损皮肤、粘膜32例。职业暴露发生于临床各科室。暴露时无任何防护措施101例,戴手套64例,穿隔离衣8例。紧急处理64例;立即上报58例。预防用药HIV/AIDS3例,乙肝13例,梅毒8例,狂犬病40例。定期检测HIV/AIDS42例,乙肝30例,丙肝5例,梅毒21例。目前无一例感染发生。结论职业暴露的高危人群主要是低年资、低职称、临床一线医务人员,暴露源以血源性传染疾病为主,暴露方式以锐器伤为主,ICU、手术室、呼吸内科等为血源性疾病职业暴露发生较多的科室,部分医务人员防护意识薄弱、未严格执行标准预防,正确处理是职业暴露后的重要补救措施。     

Blood-borne and sexual transmission of human herpesvirus 8 in women with or at risk for human immunodeficiency virus infection

BACKGROUND: Human herpesvirus 8 (HHV-8), the causal agent of Kaposi's sarcoma, is transmitted sexually among homosexual men, but little is known of its transmission among women. Although HHV-8 has been detected in blood, there has been no clear evidence of blood-borne transmission. METHODS: We identified risk factors for HHV-8 infection in 1295 women in Baltimore, Detroit, New York, and Providence, Rhode Island, who reported high-risk sexual behavior or drug use. HHV-8 serologic studies were performed with two enzyme-linked immunosorbent assays. RESULTS: In univariate analyses, HHV-8 was associated with black race, Hispanic ethnic background, a lower level of education, and infection with syphilis, the human immunodeficiency virus (HIV), hepatitis B virus (HBV), or hepatitis C virus (HCV). The risk of seropositivity for HHV-8 increased with the frequency of injection-drug use (P<0.001); HHV-8 seroprevalence among the women who used drugs daily was three times that among women who never injected drugs. Among the women with a low risk of sexual transmission, HHV-8 seroprevalence was 0 percent in those who had never injected drugs and 36 percent in those who had injected drugs (P<0.001). However, injection-drug use was linked less strongly to HHV-8 infection than to infection with HBV or HCV. In a multivariate analysis, independent predictors of HHV-8 seropositivity included HIV infection (odds ratio, 1.6; 95 percent confidence interval, 1.1 to 2.2), syphilis infection (odds ratio, 1.8; 95 percent confidence interval, 1.1 to 2.8), and daily injection-drug use (odds ratio, 3.2; 95 percent confidence interval, 1.4 to 7.6). CONCLUSIONS: Both injection-drug use and correlates of sexual activity were risk factors for HHV-8 infection in the women studied. The independent association of HHV-8 infection with injection-drug use suggests that HHV-8 is transmitted through needle sharing, albeit less efficiently than HBV, HCV, or HIV.     

Healthcare workers as vectors of infectious diseases

Nosocomial infections cause considerable morbidity and mortality. Healthcare workers (HCWs) may serve as vectors of many infectious diseases, many of which are not often primarily considered as healthcare-associated. The probability of pathogen transmission to patients depends on several factors, such as the characteristics of a pathogen, HCW and patient. Pathogens with high transmission potential from HCWs to patients include norovirus, respiratory infections, measles and influenza. In contrast, human immunodeficiency virus (HIV) and viral hepatitis are unlikely to be transferred. The prevention of HCW-associated transmission of pathogens include systematic vaccinations towards preventable diseases, continuous education, hand hygiene surveillance, active feedback and adequate staff resources.     

Molecular and epidemiological characteristics of blood-borne virus infections among recent immigrants in Spain

The increased immigration from developing regions to Western countries raises public health concerns related to blood-borne viruses. The prevalence of human immunodeficiency virus (HIV), hepatitis B virus (HBV), hepatitis C virus (HCV), and human T-lymphotropic virus (HTLV) infections among recent immigrants attending several Spanish diagnostic centers in years 2002 and 2003 was examined. Genetic characterization of viral subtypes and its relationship with distinct at-risk populations was carried out. A total of 1,303 immigrants were identified. They originated in Latin America (46.9%), Sub-Saharan Africa (23.7%), Eastern Europe (9.4%), and the Maghreb (9.2%). Seroprevalence rates were as follows: HIV-1 4.2%, HBV 4.1%, HCV 2.9%, and HTLV-1 0.8%. All patients with HIV-1 non-B subtypes, HBV genotypes E and A3, and HCV genotype 4 were sub-Saharan Africans, and had been infected mainly through heterosexual contacts. In contrast, Latin American homo/bisexual men carried HIV-1 subtype B most likely acquired after their arrival to Spain. In conclusion, while Sub-Saharan Africans carry wide diverse genetic variants of blood-borne viruses, the absence of high-risk practices in most cases could limit the spread of these variants. In contrast, Latin Americans with high-risk sexual practices may be a particularly vulnerable collective to acquire blood-borne viruses in the receptor country.     

上海市男性同性恋HIV感染者中乙型肝炎、丙型肝炎病毒的合并感染情况横断面研究

目的 探讨男性同性恋HIV感染者中乙型肝炎病毒（HBV）、丙型肝炎病毒（HCV）的合并感染情况。方法 选择2016年1月~2018年1月在本区域内进行治疗的男性同性恋HIV感染者157例,以横断面调查的方法进行研究,收集所有入组患者的性别、年龄、文化程度、感染途径等资料。对所有患者HBV抗体、HCV抗体进行检测。结果 不同感染途径人群合并感染发生率对比,差异具有统计学意义（P＜0.05）:同性性行为患者单纯HIV感染发生率最高,吸毒患者HIV+HBV感染率最高,输血患者HIV+HCV感染率最高,HIV+HBV+HCV感染率最高者为吸毒患者。不同学历合并感染发生率对比,差异具有统计学意义（P＜0.05）:大专及以上的患者以HIV单纯感染为主,高中及中专患者以HIV和HIV+HBV为主,初中及以下的患者则以合并感染为主。不同职业合并感染发生率对比,差异具有统计学意义（P＜0.05）:单纯HIV感染患者以自由职业及职员为主,职员在HIV+HBV感染发病率高于自由职业者及农民,农民在HIV+HCV及HIV+HBV+HCV的发病率均高于其他职业患者。结论 男性同性恋HIV感染者中乙型肝炎病毒、丙型肝炎病毒合并感染发生率均较高,患者感染途径、文化程度及职业的不同,合并感染情况均有显著差异。     

Occupational risk of the acquired immunodeficiency syndrome among health care workers

In August 1983, we initiated nationwide prospective surveillance of health care workers with documented parenteral or mucous-membrane exposures to blood or other body fluids of patients with the acquired immunodeficiency syndrome (AIDS) or AIDS-related illnesses. The purpose of the surveillance project is to quantitate prospectively the risk to health care workers of acquiring the AIDS virus, human T-cell lymphotropic virus Type III/lymphadenopathy-associated virus (HTLV-III/LAV), as a result of occupational exposures. By December 31, 1985, 938 health care workers were being followed in the surveillance project. The mean length of follow-up was 15 months (range, 0 to 56) and 531 health care workers (57 percent) had been followed for more than one year. Needlestick injuries and cuts with sharp instruments accounted for 76 percent of the exposures. Over 85 percent of all exposures were to blood or serum. None of the health care workers have acquired signs or symptoms of AIDS. Analyses of T-lymphocyte subsets were performed for 341 (36 percent) of the exposed health care workers, and tests for antibody to HTLV-III/LAV were performed for 451 (48 percent). Seven health care workers who had low helper/suppressor T-lymphocyte ratios on initial testing were retested; only three had persistently low ratios. Only two health care workers tested were seropositive for antibody to HTLV-III/LAV. The results of this surveillance project, thus far, suggest that the risk to health care workers of occupational transmission of HTLV-III/LAV is low (the upper bound of the 95 percent confidence interval for the seroprevalence rate among workers with greater than or equal to 3 months of follow-up with HTLV-III/LAV antibody testing is 1.65 percent) and appears to be related to parenteral exposure to blood.