Human immunodeficiency virus type 1 (HIV-1) transmission from infected patients to health-care workers has been well documented, but transmission from an infected health-care worker to a patient has not been reported. After identification of an acquired immunodeficiency syndrome (AIDS) patient who had no known risk factors for HIV infection but who had undergone an invasive procedure performed by a dentist with AIDS, six other patients of this dentist were found to be HIV-infected. Molecular biologic studies were conducted to complement the epidemiologic investigation. Portions of the HIV proviral envelope gene from each of the seven patients, the dentist, and 35 HIV-infected persons from the local geographic area were amplified by polymerase chain reaction and sequenced. Three separate comparative genetic analyses--genetic distance measurements, phylogenetic tree analysis, and amino acid signature pattern analysis--showed that the viruses from the dentist and five dental patients were closely related. These data, together with the epidemiologic investigation, indicated that these patients became infected with HIV while receiving care from a dentist with AIDS.

No abstract

This section looks back to some ground-breaking contributions to public health, reproducing them in their original form and adding a commentary on their significance from a modern-day perspective. To complement the theme of this month's Bulletin, Thomas C. Quinn reviews the paper he co-authored in

Following its recognition in 1981, the HIV/AIDS epidemic has evolved to become the greatest challenge in global health, with some 34 million persons living with HIV worldwide. Early epidemiologic studies identified the major transmission routes of the virus before it was discovered, and enabled the implementation of prevention strategies. Although the first identified cases were in MSM in the United States and western Europe, the greatest impact of the epidemic has been in sub-Saharan Africa, where most of the transmission occurs between heterosexuals. Nine countries in southern Africa account for less than 2% of the world's population but now they represent about one third of global HIV infections. Where broadly implemented, HIV screening of donated blood and antiretroviral treatment (ART) of pregnant women have been highly effective in preventing transfusion-associated and perinatally acquired HIV, respectively. Access to sterile equipment has also been a successful intervention for injection drug users. Prevention of sexual transmission has been more difficult. Perhaps the greatest challenge in terms of prevention has been in the global community of MSM in which HIV remains endemic at high prevalence. The most promising interventions are male circumcision for prevention of female-to-male transmission and use of ART to reduce infectiousness, but the extent to which these interventions can be brought to scale will determine their population-level impact.

To examine perinatal transmission of the human immunodeficiency virus type 1 (HIV-1) in Zaire, we screened 8108 women who gave birth at one of two Kinshasa hospitals that serve populations of markedly different socioeconomic status. For up to one year, we followed the 475 infants of the 466 seropositive women (5.8 percent of those screened) and the 616 infants of 606 seronegative women matched for age, parity, and hospital. On the basis of clinical criteria, 85 of the seropositive women (18 percent) had the acquired immunodeficiency syndrome (AIDS). The infants of seropositive mothers, as compared with those of seronegative mothers, were more frequently premature, had lower birth weights, and had a higher death rate in the first 28 days (6.2 vs. 1.2 percent; P less than 0.0001). The patterns were similar at the two hospitals. Twenty-one percent of the cultures for HIV-1 of 92 randomly selected cord-blood samples from infants of seropositive women were positive. T4-cell counts were performed in 37 seropositive women, and cord blood from their infants was cultured. The cultures were positive in the infants of 6 of the 18 women with antepartum T4 counts of 400 or fewer cells per cubic millimeter, as compared with none of the infants of the 19 women with more than 400 T4 cells per cubic millimeter (P = 0.02). One year later, 21 percent of the infants of the seropositive mothers had died as compared with 3.8 percent of the control infants (P less than 0.001), and 7.9 percent of their surviving infants had AIDS. We conclude that the mortality rates among children of seropositive mothers are high regardless of socioeconomic status, and that perinatal transmission of HIV-1 has a major adverse effect on infant survival in Kinshasa.

Background Black/white disparities in HIV incidence and prevalence among men who have sex with men (MSM) in the United States remain largely unexplained. We examined the impact on HIV prevalence and incidence of interventions that decrease disparities in HIV care. Deciding which interventions have most impact on reducing disparities is critical. Methods Using available US Centers for Disease Control and Prevention (CDC) estimates, we constructed HIV care continua for black and white MSM for 2009-2010. These estimates were used as parameters in a deterministic model to yield estimated race-specific transmissions, transmission rates, incidence rates, and rate-ratios (RR). We examined the impact of changes in the care continuum for black MSM on transmission and incidence rates. Findings Marked disparities were found throughout the care continuum: ultimately, 16% of black and 34% of white MSM achieved viral suppression. Based on these care continua, 9,833 and 9,710 new HIV transmissions were estimated annually respectively from HIV-positive black and white MSM (transmission RR=1·36 and incidence RR=7·92). In a model where black and white MSM have identical care outcomes, transmission RR=1·00 and incidence RR=5·80. Scenarios of 95% diagnosis, 95% retention, and concurrent 95% diagnosis and 95% retention respectively yield transmission RR=1·00, 1·02, 0·56, and incidence RR=5·81, 5·93, 3·28. Interpretation Disparities in HIV transmission rates may be reduced by improving the HIV care continuum outcomes, but existing racial disparities in HIV prevalence will likely continue to drive higher incidence among black MSM for decades to come.

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.

To clarify risk factors for infection with the human immunodeficiency virus (HIV) we selected at random 785 homosexual men who had participated in studies of hepatitis B in San Francisco in 1978-80 for a follow-up study of the acquired immunodeficiency syndrome. Although most had not been contacted in over five years, 492 (63 per cent) were located and enrolled. The 240 (67 per cent) who had developed antibodies to HIV, as measured by an enzyme-linked immunosorbent assay (ELISA), were compared IntroductionSince initial reports of the acquired immunodeficiency syndrome (AIDS) in homosexual (gay) men, several investigations have attempted to define behavioral risk factors for