Reports on HIV/AIDS: 1990

JULY 27, 1990, MMWR, Vol. 39, No. 29, pp. 489-493
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).

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