Mary E. Chamberland

Acquired immunodeficiency syndrome (AIDS) associated with transfusions.

Of 2157 patients with the acquired immunodeficiency syndrome (AIDS) whose cases were reported to the Centers for Disease Control by August 22, 1983, 64 (3 per cent) with AIDS and Pneumocystis carinii pneumonia had no recognized risk factors for AIDS. Eighteen of these (28 per cent) had received blood components within five years before the onset of illness. These patients with transfusion-associated AIDS were more likely to be white (P = 0.00008) and older (P = 0.0013) than other patients with no known risk factors. They had received blood 15 to 57 months (median, 27.5) before the diagnosis of AIDS, from 2 to 48 donors (median, 14). At least one high-risk donor was identified by interview or T-cell-subset analysis in each of the seven cases in which investigation of the donors was complete; five of the six high-risk donors identified during interview also had low T-cell helper/suppressor ratios, and four had generalized lymphadenopathy according to history or examination. These findings strengthen the evidence that AIDS may be transmitted in blood.

Risk and Management of Blood-Borne Infections in Health Care Workers

Exposure to blood-borne pathogens poses a serious risk to health care workers (HCWs). We review the risk and management of human immunodeficiency virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV) infections in HCWs and also discuss current methods for preventing exposures and recommendations for postexposure prophylaxis. In the health care setting, blood-borne pathogen transmission occurs predominantly by percutaneous or mucosal exposure of workers to the blood or body fluids of infected patients. Prospective studies of HCWs have estimated that the average risk for HIV transmission after a percutaneous exposure is approximately 0.3%, the risk of HBV transmission is 6 to 30%, and the risk of HCV transmission is approximately 1.8%. To minimize the risk of blood-borne pathogen transmission from HCWs to patients, all HCWs should adhere to standard precautions, including the appropriate use of hand washing, protective barriers, and care in the use and disposal of needles and other sharp instruments. Employers should have in place a system that includes written protocols for prompt reporting, evaluation, counseling, treatment, and follow-up of occupational exposures that may place a worker at risk of blood-borne pathogen infection. A sustained commitment to the occupational health of all HCWs will ensure maximum protection for HCWs and patients and the availability of optimal medical care for all who need it.

Transfusion-transmitted malaria in the United States from 1963 through 1999.

BACKGROUND Transfusion-transmitted malaria is uncommon in the United States. After the report of three cases of complicated Plasmodium falciparum infection acquired by transfusion, we reviewed all cases of transfusion-transmitted malaria reported to the Centers for Disease Control and Prevention (CDC) from 1963 through 1999. METHODS Information on the patients was from surveillance reports sent to the CDC. Information about the implicated blood donors came from the National Malaria Surveillance System. To determine whether donors should have been excluded from donating blood, we compared their characteristics with the exclusion guidelines of the Food and Drug Administration and the American Association of Blood Banks. RESULTS Of 93 cases of transfusion-transmitted malaria reported in 28 states, 33 (35 percent) were due to P. falciparum, 25 (27 percent) were due to P. vivax, 25 (27 percent) were due to P. malariae, 5 (5 percent) were due to P. ovale, 3 (3 percent) were mixed infections, and 2 (2 percent) were due to unidentified species. Ten of the 93 patients (11 percent) died. There were potentially 91 donors (in two cases, two patients received blood from the same donor), 67 of whom (74 percent) could be identified as infective. Of 64 implicated donors whose country of origin was reported, 38 (59 percent) were foreign born. Among those for whom complete information was available, 37 of 60 donors (62 percent) would have been excluded from donating according to current guidelines (in place since 1994), and 30 of 48 donors (62 percent) should have been excluded under the guidelines in place at the time of donation. CONCLUSIONS Careful screening of donors according to the recommended exclusion guidelines remains the best way to prevent transfusion-transmitted malaria.

West Nile virus infection transmitted by blood transfusion

BACKGROUND: A patient with transfusion‐transmitted West Nile virus (WNV) infection confirmed by viral culture of a blood component is described. A 24‐year‐old female with severe postpartum hemorrhage developed fever, chills, headache, and generalized malaise after transfusion of 18 units of blood components; a serum sample and the cerebrospinal fluid tested positive for the presence of WNV IgM antibodies. An investigation was initiated to determine a possible association between transfusion and WNV infection.

Preventing bloodborne pathogen transmission from health-care workers to patients. The CDC perspective.

The development of recommendations to manage the risk of bloodborne pathogen transmission from health-care workers to patients during invasive procedures has been difficult, primarily because of the limitations of available scientific data. Ultimately, both health-care workers and patients will be protected best by compliance with infection control precautions and by development of new instruments, protective equipment, and techniques that reduce the likelihood of intraoperative blood exposure without adversely affecting patient care.

Skin and mucous membrane contacts with blood during surgical procedures: risk and prevention.

OBJECTIVE To study the epidemiology and preventability of blood contact with skin and mucous membranes during surgical procedures. DESIGN Observers present at 1,382 surgical procedures recorded information about the procedure, the personnel present, and the contacts that occurred. SETTING Four US teaching hospitals during 1990. PARTICIPANTS Operating room personnel in five surgical specialties. MAIN OUTCOME MEASURES Numbers and circumstances of contact between the patients blood (or other infective fluids) and surgical personnels mucous membranes (mucous membrane contacts) or skin (skin contacts, excluding percutaneous injuries). RESULTS A total of 1,069 skin (including 620 hand, 258 body, and 172 face) and 32 mucous membrane (all affecting eyes) contacts were observed. Surgeons sustained most contacts (19% had > or = 1 skin contact and 0.5% had > or = 1 mucous membrane-eye contact). Hand contacts were 72% lower among surgeons who double gloved, and face contacts were prevented reliably by face shields. Mucous membrane-eye contacts were significantly less frequent in surgeons wearing eyeglasses and were absent in surgeons wearing goggles or face shields. Among surgeons, risk factors for skin contact depended on the area of contact: hand contacts were associated most closely with procedure duration (adjusted odds ratio [OR], 9.4; > or = 4 versus < 1 hour); body contacts (arms, legs, and torso) with estimated blood losses (adjusted OR, 8.4; > or = 1,000 versus < 100 mL); and face contacts, with orthopedic service (adjusted OR, 7.5 compared with general surgery). CONCLUSION Skin and mucous membrane contacts are preventable by appropriate barrier precautions, yet occur commonly during surgery. Surgeons who perform procedures similar to those included in this study should strongly consider double gloving, changing gloves routinely during surgery, or both.

Emerging Infectious Agents: Do They Pose a Risk to the Safety of Transfused Blood and Blood Products?

The blood supply is safer than it has been at any other time in recent history, and, in the context of other health care-related adverse events, the risks associated with blood transfusion are extremely small. The current high level of safety is the result of successive refinements and improvements in how blood is collected, tested, processed, and transfused; nonetheless, blood and plasma products remain vulnerable to newly identified or reemerging infections. In recent years, numerous infectious agents-including several newly discovered hepatitis viruses, the agents of transmissible spongiform encephalopathies, and tickborne pathogens-have been identified as potential threats to the safety of blood and plasma. Continued vigilance is critical to protect the blood supply from known pathogens and to monitor for the emergence of new infectious agents. Recent terrorist activities in the United States add new considerations to maintaining the safety and supply of blood. Education of clinicians and patients regarding the benefits and risks associated with the judicious use of blood and blood products can assist in informed decision making.

Acquired immunodeficiency syndrome in the United States: an analysis of cases outside high-incidence groups

From 1 June 1981 through 31 January 1984, 201 cases of the acquired immunodeficiency syndrome were reported involving persons who could not be classified into a group identified to be at increased risk for this syndrome. Thirty-five had received transfusions of single-donor blood components in the 5 years preceding diagnosis of the syndrome and 30 were sexual partners of persons belonging to a high-risk group. Information was incomplete for most remaining patients, but because many of these patients were demographically similar to populations recognized to be at increased risk for the syndrome, previously identified risk factors may have been present but not reported for some of them. Additionally, a few persons who met the case definition for the syndrome probably had other reasons for their opportunistic disease and did not have the acquired immunodeficiency syndrome. The slow emergence of the acquired immunodeficiency syndrome in new populations is consistent with transmission mediated through sexual contact or parenteral exposure to blood.

Simian foamy virus infection in a blood donor.

BACKGROUND: Infections with simian foamy virus (SFV) are widely prevalent in nonhuman primates. SFV infection was confirmed in a worker, occupationally exposed to nonhuman primates, who donated blood after the retrospectively documented date of infection. Human‐to‐human transmission of SFV through trans‐ fusion and its pathogenicity have not been studied.

Use of the hepatitis-B vaccine and infection with hepatitis B and C among orthopaedic Surgeons

We used a questionnaire, with a guarantee of anonymity to the respondents, and conducted serological testing of 3411 attendees at the 1991 Annual Meeting of The American Academy of Orthopaedic Surgeons to evaluate the prevalences of infection with the hepatitis-B and C viruses and the use of the hepatitis-B vaccine among orthopaedic surgeons. There was evidence of infection with hepatitis B in 410 (13 per cent) of 3239 participants who had reported having no non-occupational risk factors; 2103 (65 per cent) reported that they had been immunized with the hepatitis-B vaccine. Of 3262 participants who reported having no non-occupational risk factors and who were evaluated for infection with hepatitis C, twenty-seven (less than 1 per cent) tested positive for the antibody to the hepatitis-C virus. The prevalence of previous infection with hepatitis B increased with increasing age; four (3 per cent) of 136 surgeons who were twenty to twenty-nine years old had evidence of infection, whereas ninety-six (27 per cent) of 360 surgeons who were sixty years old or more had evidence of infection. The prevalence of infection with hepatitis C also increased with increasing age; none of 135 surgeons who were twenty to twenty-nine years old had evidence of infection, and five (1 per cent) of 360 surgeons who were sixty years old or more had evidence of the virus. The prevalence of vaccination decreased steadily with age: 123 (90 per cent) of 136 surgeons who were twenty to twenty-nine years old reported that they had received the hepatitis-B vaccine, whereas 127 (35 per cent) of 360 surgeons who were sixty years old or more reported that they had received the vaccine. The prevalence of infection with hepatitis B or hepatitis C was not associated with the measured indices of exposure to the blood of patients (the number of cutaneous or mucosal contacts with blood that had occurred within the previous month or the number of percutaneous injuries that had occurred within the previous month or year, as recalled by the participants). In conclusion, the prevalence of immunization with the hepatitis-B vaccine was high among the orthopaedic surgeons studied. Although the prevalence of infection with the hepatitis-C virus was several times greater in the current investigation than has been reported in studies of blood donors in the United States, infection with this virus was not associated with the indices of occupational exposure to blood measured in this study.