ddodell@stjhmc.fidonet.org (David Dodell) (07/29/90)
I was planning on publishing this in this week HICNews, but due to the nature
of the release, I thought it would be best to post this right away to the net.
I didn't spend the time to spruce it up format wise.
Please read carefully before drawing any conclusions. As a practicing dentist,
I saw many inconsistencies between some of the claims, ie dentist claims he
stuck himself with needles previous, but is positive he didn't it on that day.
I find that hard to believe, since I can remember exactly what happens on every
patient I treat, no less someone from 2 years earlier. It also claims that the
dentist's records were sketchy, but I doubt he would have documented needle
sticks.
I'm afraid the media is blowing this up more then it is ... there are alot of
unanswered questions, and dentistry is getting a poor rap by the media ...
enough editorial, here is the MMWR
Morbidity and Mortality Weekly Report
Thursday July 26, 1990
Possible Transmission of Human Immunodeficiency Virus to a Patient
during an Invasive Dental Procedure
CDC received a case report of acquired immunodeficiency syndrome
(AIDS) in a young woman for whom an epidemiologic investigation had not
established a source for her human immunodeficiency virus (HIV)
infection (i.e., documented behavioral or other risk factors, including
intravenous (IV)-drug use, sex with an HIV-infected person, or receipt
of a blood transfusion or blood components). However, investigation
revealed that 24 months before her AIDS diagnosis she had two teeth
extracted by a dentist who had AIDS. Information on the dental procedure
was obtained from interviews with the patient and reviews of her dental
records and radiographs. This report summarizes the epidemiologic and
laboratory findings of the investigation.*
The patient had two maxillary third molars extracted under local
anesthesia in the dentist's office. The dentist had been diagnosed with
AIDS 3 months before performing the procedure. Written documentation of
the procedure was limited. Review of the radiographs indicated that the
maxillary third molars were not impacted in bone. The patient reported
that she received no general anesthetic or sedative and that during the
procedure the dentist wore gloves and a mask. She did not recall, nor
did review of the dental records reveal, any circumstances that would
have exposed her to the dentist's blood (i.e., an injury to the dentist,
such as a needlestick or cut with a sharp instrument). The patient had
not received dental care from this dentist before the dental extractions.
Four weeks after the dental procedure, the patient sought medical
evaluation for a sore throat. Review of her medical records revealed
that she was afebrile, with moderately enlarged tonsils with ulcerations
and moderately enlarged nontender anterior cervical lymph nodes. Rash,
generalized lymphadenopathy, or fatigue were not reported or noted on
the medical record. A "strep antigen" test was negative. The patient was
diagnosed with pharyngitis and aphthous ulcers. Seventeen months after
the procedure, she was diagnosed with oral candidiasis; 24 months after
the procedure, she was diagnosed with Pneumocystis carinii pneumonia and
was seropositive for HIV antibody. The patient reported no previous test
for HIV infection.
Multiple interviews of the patient and her family and friends by
health department staff and review of her medical and previous dental
records did not identify factors that may have potentially placed her at
risk for HIV infection. The patient reported no history of blood
transfusions, IV-drug use, acupuncture, tattoos, or artificial
insemination. Additionally, she denied a history of sexually transmitted
diseases or pregnancies. VDRL and hepatitis B serologies were negative.
The patient has never been employed in a health-care or other setting
where she could have been exposed to HIV-infected blood or other body
fluids. She reported two boyfriends before her diagnosis of AIDS; both
were tested for HIV infection and were seronegative.
Blood specimens were obtained from the patient and the dentist. To
determine the relatedness of the HIV strains from both persons, DNA was
extracted from their peripheral blood mononuclear cells (PBMC). HIV
sequences encoding the variable regions (V3, V4, and V5) and a constant
region (C3) of the major external glycoprotein gp120 were selectively
amplified using the polymerase chain reaction (PCR) (1). Amplified HIV
DNA was molecularly cloned, and nucleotide sequences of multiple clones
were determined. The relatedness of the sequences was analyzed by
several computer-based methods in collaboration with Los Alamos National
Laboratory.** This multifaceted analysis showed a similarity between the
sequences from the patient and the dentist that was comparable to what
has been observed for cases that have been epidemiologically linked (Los
Alamos National Laboratory, unpublished data). Although the viral
sequences from the dentist and the patient could be distinguished from
each other, they were closer than what has been observed for pair-wise
comparisons of sequences taken from the other North American isolates
studied (3).
Reported by: Div of HIV/AIDS and Hospital Infections Program, Center for
Infectious Diseases; Dental Disease Prevention Activity, Center for
Prevention Svcs; National Institute for Occupational Safety and Health,
CDC.
Editorial Note: The case reported here is consistent with transmission
of HIV to a patient during an invasive dental procedure, although the
possibility of another source of infection cannot be entirely excluded.
No case of such transmission has been previously described.
In this report, the possibility that the patient may have been
infected with HIV during the dental procedure is based on the following
considerations: 1) the patient had an invasive procedure performed by a
dentist with AIDS (such procedures have been associated with
transmission of hepatitis B virus, which is also a bloodborne pathogen,
to patients); 2) an epidemiologic investigation did not identify any
other risk factors or behaviors that may have placed the woman at risk
for HIV infection; and 3) viral DNA sequences from the patient and the
dentist were closely related. These three considerations are discussed
as follows.
First, although the dentist was infected with HIV, it is uncertain
whether the patient was exposed to the dentist's blood during the
extraction procedure. When interviewed more than 2 years after the
procedure, the patient recalled that the dentist wore gloves and a mask.
The dental records contained few details on the extraction procedure,
but there was no mention of any circumstances that may have exposed the
patient to the dentist's blood. Review of the dental records and
radiographs suggest that the extraction should have been uncomplicated.
The dentist recalled occasional needlesticks with narrow-gauge
needles used to administer local anesthetic. After the diagnosis of HIV
infection, however, the dentist did not recall sustaining a needlestick
or cut resulting in visible blood during a procedure. The dentist, who
is negative for hepatitis B surface antigen, is no longer in practice.
Although the dentist employed assistants, it could not be determined
whether or to what extent the dentist was assisted in the procedure
reported here; it is not known whether the assistants were tested for
HIV infection. Details of the disinfection and sterilization practices
of the dental office are unknown.
Second, although multiple interviews with this patient and other
persons did not identify any established risk factors for HIV infection,
such risk factors involve sensitive personal behaviors that may not
always be revealed during interviews. In addition, the patient's
HIV-infection status at the time of the dental procedure is unknown. The
possibility that the patient may have been infected through another mode
cannot be entirely excluded.
Third, the DNA sequence data indicate a high degree of similarity
between the HIV strains infecting the patient and the dentist. HIV-1
exhibits considerable genetic variability, particularly in the selected
regions of the envelope gene tested. This property may be helpful in
evaluating the relatedness of viral strains isolated from different
persons (2). However, use of DNA sequencing for this purpose is new, and
there is a paucity of sequence data pertaining to the HIV-1 viruses of
sex partners and other epidemiologically related patients. The
quantitative criteria for determining epidemiologic linkage based on HIV
sequences are just now being developed.
In addition, the occurrence of pharyngitis 4 weeks after the dental
procedure is consistent with an acute retroviral syndrome following HIV
infection. However, the symptoms in this patient did not include fever,
rash, or generalized lymphadenopathy, which have been described in most
cases of acute retroviral syndrome (4). Also, the time between the
dental procedure and the development of AIDS (24 months) was short; 1%
of infected homosexual/bisexual men and 5% of infected transfusion
recipients develop AIDS within 2 years of infection (5,6).
Prospective investigations of HIV transmission from patients to
health-care workers indicate that the risk for HIV transmission after
percutaneous exposure to HIV-infected blood averages 0.4% (7). Four
investigations have been reported that attempted to assess the risk of
HIV transmission from infected health-care workers to their patients
(8-11). In the largest study, 616 patients who underwent surgery by a
general surgeon during the 7 years preceding his diagnosis of AIDS were
tested for HIV antibody. One patient, an IV-drug user, was positive for
HIV antibody (8). Viral strains from the patient and the surgeon were
not characterized.
Transmission of hepatitis B virus (HBV), which has epidemiologic
transmission patterns similar to HIV, from health-care workers to
patients during invasive medical (primarily gynecologic surgery) and
dental (primarily oral surgery) procedures has been reported (12-15).
The dental procedures in which HBV was transmitted involved oral
surgical procedures such as dental extractions. In these reported
instances, the dental workers did not routinely wear gloves and were
thought to have sustained puncture wounds or had skin lesions or
microlacerations that allowed virus to contaminate instruments or open
wounds of patients. Also, these health-care workers (when tested) have
been positive for hepatitis B e antigen, a marker that indicates very
high titers of virus in blood and correlates with increased
transmissibility of HBV.
Restrictions on patient care for health-care workers with HIV
infection have been considered by the American Medical Association (16),
the American Hospital Association (17), the American Dental Association
(18), the American College of Obstetricians and Gynecologists (19), the
British government (20), CDC (21), and other organizations. Although the
specific recommendations of these organizations vary to some extent,
these recommendations generally have stated that the risk, if any, of
HIV transmission from health-care workers to patients occurs during
invasive procedures and that decisions regarding restrictions of patient
care by infected workers who perform such procedures should be made on
an individual basis.
The epidemiologic and laboratory findings in this investigation
indicate possible transmission of HIV from the dentist to the patient.
Regardless of the interpretation of the findings in this investigation,
adherence to universal precautions, including prevention of blood
contact between health-care workers and patients and proper
sterilization and disinfection of patient-care equipment, is important
for prevention of transmission of bloodborne pathogens in health-care
settings (21-23). CDC is considering the implications of this case in
its review of the guidelines for prevention of transmission of HIV and
other bloodborne pathogens to patients during invasive procedures.
References
1. Ou CY, Kwok S, Mitchell SW, et al. DNA amplification for direct
detection of HIV-1 in DNA of peripheral blood mononuclear cells. Science
1988;239:295-7.
2. Burger H, Belman A, Grimson R, et al. Long HIV-1 incubation periods
and dynamics of transmission within a family. Lancet 1990;336:134-6.
3. Myers G, Rabson AB, Josephs SE, Smith TF, Berzofsky JA, Wong-Staal
F. Human retroviruses and AIDS, 1989. Los Alamos, New Mexico: Los Alamos
National Laboratory, Theoretical Division, 1989.
4. Cooper DA, Gold J, MacLean P, et al. Acute AIDS retrovirus
infection: definition of a clinical illness associated with
seroconversion. Lancet 1985;1:537-40.
5. Lifson AR, Hessol N, Rutherford G, et al. Natural history of HIV
infection in a cohort of homosexual and bisexual men: clinical and
immunologic outcome, 1977-1990 (Abstract). Vol 1. VI International
Conference on AIDS. San Francisco, June 20-24, 1990:142.
6. Ward JW, Bush TJ, Perkins HA, et al. The natural history of
transfusion-associated infection with human immunodeficiency virus:
factors influencing the rate of progression to disease. N Engl J Med
1989;321:947-52.
7. Marcus R, the CDC Cooperative Needlestick Surveillance Group.
Surveillance of health care workers exposed to blood from patients
infected with the human immunodeficiency virus. N Engl J Med
1988;319:1118-23.
8. Mishu B, Schaffner W, Horan J, Wood L, Hutcheson R, McNabb P. A
surgeon with AIDS: lack of transmission to patients. JAMA
1990;264:467-70.
9. Sacks JJ. AIDS in a surgeon (Letter). N Engl J Med 1985;313:1017-8.
10. Armstrong FP, Miner JC, Wolfe WH. Investigation of a health-care
worker with symptomatic human immunodeficiency virus infection: an
epidemiologic approach. Military Med 1988;152:414-8.
11. Porter JD, Cruickshank JG, Gentle PH, Robinson RG, Gill ON.
Management of patients treated by a surgeon with HIV infection (Letter).
Lancet 1990;335:113-4.
12. Welch J, Webster M, Tilzey AJ, Noah ND, Banatvala JE. Hepatitis B
infections after gynaecological surgery. Lancet 1989;1:205-7.
13. Shaw FE Jr, Barrett CL, Hamm R, et al. Lethal outbreak of hepatitis
B in a dental practice. JAMA 1986;255:3260-4.
14. Kane MA, Lettau LA. Transmission of HBV from dental personnel to
patients. J Am Dent Assoc 1985;110:634-6.
15. Ahtone J, Goodman RA. Hepatitis B and dental personnel: transmission
to patients and prevention issues. J Am Dent Assoc 1983;106:219-22.
16. American Medical Association. Ethical issues in the growing AIDS
crisis: Council on Ethical and Judicial Affairs. JAMA 1988;259:1360-1.
17. American Hospital Association. Management of HIV infection in the
hospital. 3rd ed. Chicago: American Hospital Association, 1988.
18. American Dental Association. Report of the Council on Ethics,
Bylaws, and Judicial Affairs: American Dental Association annual reports
and resolutions. Chicago: American Dental Association, 1990:147-9.
19. Committee on Ethics, The American College of Obstetricians and
Gynecologists. Human immunodeficiency virus infection: physicians'
responsibilities. Obstet Gynecol 1990;75:1043-5.
20. Department of Health and Social Security. AIDS: HIV-infected health
care workers--report of the recommendations of the Expert Advisory Group
on AIDS. London: Her Majesty's Stationery Office, 1988.
21. CDC. Recommendations for prevention of HIV transmission in
health-care settings. MMWR 1987;36(no. 2S).
22. CDC. Update: universal precautions for prevention of transmission of
human immuno deficiency virus, hepatitis B virus, and other bloodborne
pathogens in health-care settings. MMWR 1988;37:377-82,387-8.
23. CDC. Guidelines for prevention of transmission of human
immunodeficiency virus and hepatitis B virus to health-care and public
safety workers. MMWR 1989;38(no. S-6).
* Single copies of this article will be available free until July 27,
1991, from the National AIDS Information Clearinghouse, P.O. Box 6003,
Rockville, MD 20850; telephone (800) 458-5231.
**Viral sequences obtained from the samples taken from the dentist and
the patient were shown to be distinct by the following criteria:
1. Each PBMC sample was split into two before extraction of DNA. PCR
amplification of human leukocyte antigen (DQ alpha) sequences was
performed on each sample. The sequences were the same between samples
from the same person, but the dentist and patient DNA samples were
clearly different.
2. The average difference (4.6%, range: 2.0%-7.2%) between all viral
V4-C3-V5 sequences present in the patient versus all those in the
dentist was higher than the average difference between the viral
sequences present within the dentist alone (3.5%, range: 1.2%-6.0%) and
within the patient alone (2.0%, range: 0.4%-3.6%).
3. Viral sequences in the patient possessed some unique substitutions
not found in the viral sequences from the dentist, and vice versa.
Viral sequences obtained from the samples taken from the dentist and
the patient were judged to be closely related by the following criteria:
1. Individual consensus sequences deduced from single base
substitutions (excluding insertions and deletions) in the patient's and
dentist's viral sequence sets over the V3-V4-C3-V5 regions of the
envelope gene differed by 1.2%. Corresponding DNA regions from 17 other
distinct North American isolates gave pair-wise differences to the
dentist's consensus viral sequence of 5.1%-10.2%, with an average of
8.1%. Similarly, comparison of the patient's consensus viral sequence to
these 17 gave pair-wise differences of 5.9%-10.7%, with an average of
8.8%. The range of all pair-wise differences among the 17 was
4.7%-12.9%, with an average of 9.2%.
2. Unique patterns of nucleotide substitutions not found in any other
virus isolate examined were shared between viral sequences found in the
dentist and patient.
3. The average difference (4.6%) between all of the patient's viral
sequences and all of the dentist's viral sequences over the V4-C3-V5
regions falls into a class of differences (3.4%-5.8%) similarly
determined for viruses from known epidemiologically linked cases (2; Los
Alamos National Laboratory, unpublished data). These include two
instances of sexual transmission, one instance of perinatal
transmission, and an instance in which a group of persons with
hemophilia became infected from a single batch of factor VIII
concentrate.
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