Isolation of HTLV-III from cerebrospinal fluid and neural tissues of patients with neurologic syndromes related to the acquired immunodeficiency syndrome

We conducted virus-isolation studies on 56 specimens from the nervous system of 45 patients in order to determine whether human T-cell lymphotropic virus Type III (HTLV-III) is directly involved in the pathogenesis of the neurologic disorders frequently encountered in the acquired immunodeficiency syndrome (AIDS) and the AIDS-related complex. We recovered HTLV-III from at least one specimen from 24 of 33 patients with AIDS-related neurologic syndromes. In one patient, HTLV-III was isolated from the cerebrospinal fluid during acute aseptic meningitis associated with HTLV-III seroconversion. HTLV-III was also isolated from cerebrospinal fluid from six of seven patients with AIDS or its related complex and unexplained chronic meningitis. In addition, of 16 patients with AIDS-related dementia, 10 had positive cultures for HTLV-III in cerebrospinal fluid, brain tissue, or both. Furthermore, we cultured HTLV-III from the spinal cord of a patient with myelopathy and from the sural nerve of a patient with peripheral neuropathy. These findings suggest that HTLV-III is neurotropic, is capable of causing acute meningitis, is responsible for AIDS-related chronic meningitis and dementia, and may be the cause of the spinal-cord degeneration and peripheral neuropathy in AIDS and AIDS-related complex.

Neurological complications of acquired immune deficiency syndrome: analysis of 50 patients

Fifty patients with acquired immune deficiency syndrome had complications affecting the central or peripheral nervous systems or both. The patients were either male homosexuals, intravenous drug abusers, or recently arrived Haitian refugees. They ranged in age from 25 to 56. Central nervous system complications were of four kinds: (1) Infections included Toxoplasma gondii abscesses in 5 patients, progressive multifocal leukoencephalopathy in 2, cryptococcal meningitis in 2, Candida albicans in 1, and possible Mycobacterium avium intracellulare in 3. Eighteen patients suffered a subacute encephalitis possibly attributable to cytomegalovirus infection. (2) Tumors consisted of primary lymphoma of the brain in 3 patients and meningeal invasion by systemic lymphoma in 4. (3) Vascular complications included nonbacterial thrombotic endocarditis in 2 patients and cerebral hemorrhages in the setting of thrombocytopenia in 3. (4) Undiagnosed central nervous system problems were evidenced as focal brain lesions in 3 patients and self-limiting aseptic meningitis in 4. Peripheral neuropathy occurred in 8 patients.

HIV-1 infection associated with abnormal vaginal flora morphology and bacterial vaginosis

BACKGROUND

In-vitro research has suggested that bacterial vaginosis may increase the survival of HIV-1 in the genital tract. Therefore, we investigated the association of HIV-1 infection with vaginal flora abnormalities, including bacterial vaginosis and depletion of lactobacilli, after adjustment for sexual activity and the presence of other sexually transmitted diseases (STDs).

METHODS

During the initial survey round of our community-based trial of STD control for HIV-1 prevention in rural Rakai District, southwestern Uganda, we selected 4718 women aged 15-59 years. They provided interview information, blood for HIV-1 and syphilis serology, urine for detection of Chlamydia trachomatis and Neisseria gonorrhoeae, and two self-administered vaginal swabs for culture of Trichomonas vaginalis and gram-stain detection of vaginal flora, classified by standardised, quantitative, morphological scoring. Scores 0-3 were normal vaginal flora (predominant lactobacilli). Higher scores suggested replacement of lactobacilli by gram-negative, anaerobic microorganisms (4-6 intermediate; 7-8 and 9-10 moderate and severe bacterial vaginosis).

FINDINGS

HIV-1 frequency was 14.2% among women with normal vaginal flora and 26.7% among those with severe bacterial vaginosis (p < 0.0001). We found an association between bacterial vaginosis and increased HIV-1 infection among younger women, but not among women older than 40 years; the association could not be explained by differences in sexual activity or concurrent infection with other STDs. The frequency of bacterial vaginosis was similar among HIV-1-infected women with symptoms (55.0%) and without symptoms (55.7%). The adjusted odds ratio of HIV-1 infection associated with any vaginal flora abnormality (scores 4-10) was 1.52 (95% CI 1.22-1.90), for moderate bacterial vaginosis (scores 7-8) it was 1.50 (1.18-1.89), and for severe bacterial vaginosis (scores 9-10) it was 2.08 (1.48-2.94).

INTERPRETATION

This cross-sectional study cannot show whether disturbed vaginal flora increases susceptibility to HIV-1 infection. Nevertheless, the increased frequency of HIV-1 associated with abnormal flora among younger women, for whom HIV-1 acquisition is likely to be recent, but not among older women, in whom HIV-1 is likely to have been acquired earlier, suggests that loss of lactobacilli or presence of bacterial vaginosis may increase susceptibility to HIV-1 acquisition. If this inference is correct, control of bacterial vaginosis could reduce HIV-1 transmission.

Seropositivity for HIV and the development of AIDS or AIDS related condition: three year follow up of the San Francisco General Hospital cohort

The three year actuarial progression rate to the acquired immune deficiency syndrome (AIDS) in a cohort of men in San Francisco who were seropositive for the human immunodeficiency virus (HIV) was 22%. An additional 26 (19%) developed AIDS related conditions. Beta 2 Microglobulin concentration, packed cell volume, HIV p24 antigenaemia, and the proportion and number of T4 lymphocytes each independently predicted progression to AIDS. Beta 2 Microglobulin was the most powerful predictor. The 111 subjects tested who were normal by all predictors (40%) had a three year progression of 7%, and the 68 subjects who were abnormal by two or more predictors (24%) had a progression rate of 57%. Two thirds of all men who progressed to AIDS were in the last group. The median T4 lymphocyte count in subjects who did not progress to AIDS fell from 626 x 10(6) to 327 x 10(6)/l. HIV p24 antigenaemia developed in 7% of the subjects per year. The proportion who were abnormal by two or more predictive variables rose to 41%. At three years an estimated two thirds of the seropositive subjects showed clinical AIDS, an AIDS related condition, or laboratory results that were highly predictive of AIDS. It is concluded from the observed rates and the distribution of predictive variables at three years that half of the men who were seropositive for HIV will develop AIDS by six years after the start of the study, and three quarters will develop AIDS or an AIDS related condition.

The mortality and pathology of HIV infection in a west African city

BACKGROUND

HIV disease is epidemic in Africa, but associated mortality, underlying pathology and CD4+ T-lymphocyte counts have not previously been evaluated in a representative study. Such data help to determine the management of HIV-positive people. Both HIV-1 and HIV-2 infections are prevalent in Côte d'Ivoire, and the pathology of HIV-2 infection in Africa is unclear.

METHODS

Consecutive adult medical admissions to a large city hospital in Côte d'Ivoire were studied in 1991, and a sample of HIV-positive deaths autopsied.

RESULTS

Of 5401 patients evaluated, 50% were HIV-positive; 38% of these died, with a median survival of 1 week. At autopsy (n = 294, including 24% of HIV-positive deaths in hospital), tuberculosis (TB), bacteraemia (predominantly Gram-negative rods) and cerebral toxoplasmosis caused 53% of deaths. TB was seen in 54% of cadavers with AIDS-defining pathology and Pneumocystis pneumonia in 4%. The median CD4+ T-lymphocyte counts in those who died was < 90 x 10(6)/l. Compared with HIV-1-positives, patients with HIV-2-positivity had a greater frequency of severe cytomegalovirus infection, HIV encephalitis and cholangitis.

CONCLUSIONS

In this population, HIV-positive adults present to hospital with advanced disease associated with high mortality. The three major underlying pathologies (TB, toxoplasmosis and bacteraemia) are either preventable or treatable. TB is an underestimated cause of the 'slim' syndrome in Africa. The patterns of pathology in HIV-2-positive patients suggest a more prolonged terminal course compared with HIV-1. There is an urgent need for attention towards the issues of therapy and care for HIV disease in developing countries.

Perinatal transmission of the human immunodeficiency virus type 1 to infants of seropositive women in Zaire

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.

Transmission of human immunodeficiency virus (HIV) by blood transfusions screened as negative for HIV antibody

Since early 1985, blood donations in the United States have been screened for antibody to human immunodeficiency virus (HIV). To identify instances of HIV transmission by antibody-negative donations, we investigated 13 persons seropositive for HIV who had received blood from 7 donors who were screened as negative for HIV antibody at the time of donation. Twelve of the 13 recipients had no identifiable risk factors for HIV infection other than the transfusions they had received. On evaluation 8 to 20 months after transfusion, HIV-related illnesses had developed in three recipients, and the acquired immunodeficiency syndrome had developed in one. All seven donors were found to be infected with HIV. On interview, six reported a risk factor for HIV infection, and five had engaged in high-risk activities or had had an illness suggestive of acute retroviral syndrome within the four months preceding their HIV-seronegative donation. Thus, these donors had apparently been infected only recently, and so were negative at the time of blood donation according to available antibody tests. We conclude that there is a small but identifiable risk of HIV infection for recipients of screened blood. To minimize this risk, the reasons for deferral of donation need to be communicated more effectively to blood donors who are at high risk of HIV infection, and new assays that detect HIV infection earlier should be evaluated for their effectiveness in screening donated blood.

Acquired immunodeficiency syndrome in infants

Fourteen infants with clinical and laboratory features of an acquired immunodeficiency syndrome were identified in a single metropolitan area from November 1980 to July 1983. Patients were predominantly of Haitian parentage, although two cases occurred in offspring of non-Haitian intravenous drug abusers. Only one patient had received a blood transfusion before the development of clinical findings. The predominant clinical findings included failure to thrive, persistent infection of the oral mucosa by Candida albicans, chronic pulmonary infiltrates, hepatosplenomegaly, lymphadenopathy, and diarrhea. Immunologic studies showed most of the infants to have inverted ratios of T-cell subsets, greatly increased immunoglobulin levels, and circulating immune complexes. Lymphopenia was not common, as it is in adult patients. Infectious agents responsible for opportunistic infections in this series included Pneumocystis carinii, herpesviruses, particularly cytomegalovirus, and C. albicans. Bacterial infections were common, and gram-negative sepsis was the major cause of death in the seven infants who have died. At autopsy, two infants had disseminated lymphadenopathic Kaposi's sarcoma. These observations suggest the likelihood of transplacental, perinatal, or postnatal transmission of an as yet unidentified infectious agent that causes this disease.

Intra-blood-brain-barrier synthesis of HTLV-III-specific IgG in patients with neurologic symptoms associated with AIDS or AIDS-related complex

Intra-blood-brain-barrier production of virus-specific antibody is good evidence of infection within the blood-brain barrier. Patients with the acquired immuno-deficiency syndrome (AIDS) have an increased incidence of neurologic abnormalities--i.e., unexplained, diffuse encephalopathy manifested clinically as chronic progressive dementia. To define the role of human T-cell lymphotropic virus Type III (HTLV-III), the etiologic agent of AIDS, in the pathogenesis of neurologic dysfunction, we compared cerebrospinal fluid and serum from patients with neurologic symptoms associated with AIDS and the AIDS-related complex for the presence of antibodies directed against HTLV-III. Antibodies directed against HTLV-III antigens were detected by four immunologic tests: a fixed-cell immunofluorescence assay, an enzyme-linked immunosorbent assay, immunoblots of viral lysates, and immunoprecipitation of cellular lysates. All patients were seropositive, and 22 of 23 (96 per cent) had HTLV-III-specific antibodies in their cerebrospinal fluid. Unique oligoclonal IgG bands were detected in the cerebrospinal fluid, and the rate of IgG synthesis within the blood-brain barrier was elevated. In eight of nine patients tested, the enzyme-linked immunosorbent assay showed that the percentage of HTLV-III-specific IgG in cerebrospinal fluid was higher than in serum, suggesting that HTLV-III infection of neurologic tissue occurs in the majority of patients with neurologic disease associated with AIDS or its related complex.

Acquired immunodeficiency syndrome in a heterosexual population in Zaire

38 patients with the acquired immunodeficiency syndrome (AIDS) were identified in Kinshasa, Zaire, during a 3 week period in 1983. The male to female ratio was 1.1:1. The annual case rate for Kinshasa was estimated to be at least 17 per 100 000. Opportunistic infections were diagnosed in 32 (84%) patients, disseminated Kaposi's sarcoma (KS) with opportunistic infection in 5 (13%), and disseminated KS alone in 1 patient. Immunological characteristics of these patients were as reported for cases in the USA and Europe, but immunological abnormalities were also found in 6 controls with infectious diseases but no symptoms of AIDS. Female AIDS cases were younger than male patients with AIDS (mean ages 28.4 vs 41.1 years, respectively), and were more often single (14/18 vs 2/20). Homosexuality, intravenous drug abuse, and blood transfusion did not appear to be risk factors in these patients. The findings of this study strongly argue that the situation in central Africa represents a new epidemiological setting for this worldwide disease--that of significant transmission in a large heterosexual population. Two instances of clusters of AIDS (not included in the above series) involving males and females with frequent heterosexual contact further implicate heterosexual transmission.

Slim disease: a new disease in Uganda and its association with HTLV-III infection

A new disease has recently been recognised in rural Uganda. Because the major symptoms are weight loss and diarrhoea, it is known locally as slim disease. It is strongly associated with HTLV-III infection (63 out of 71 patients) and affects females nearly as frequently as males. The clinical features are similar to those of enteropathic acquired immunodeficiency syndrome as seen in neighbouring Zaire. However, the syndrome is rarely associated with Kaposi's sarcoma (KS), although KS is endemic in this area of Uganda. Slim disease occurs predominantly in the heterosexually promiscuous population and there is no clear evidence to implicate other possible means of transmission, such as by insect vectors or re-used injection needles. The site and timing of the first reported cases suggest that the disease arose in Tanzania.

Resistance to HIV-1 infection among persistently seronegative prostitutes in Nairobi, Kenya

BACKGROUND

There is indirect evidence that HIV-1 exposure does not inevitably lead to persistent infection. Heterogeneity in susceptibility to infection could be due to protective immunity. The objective of this study was to find out whether in highly HIV-1-exposed populations some individuals are resistant to infection.

METHODS

We did an observational cohort study of incident HIV-1 infection-among 424 initially HIV-1-seronegative prostitutes in Nairobi, Kenya, between 1985 and 1994. 239 women seroconverted to HIV-1 during the study period. Exponential, Weibull, and mixture survival models were used to examine the effect of the duration of follow-up on incidence of HIV-1 infection. The influence of the duration of exposure to HIV-1 through prostitution on seroconversion risk was examined by Cox proportional hazards modelling, with control for other known or suspected risk factors for incident HIV-1 infection. HIV-1 PCR with env, nef, and vif gene primers was done on 43 persistently seronegative prostitutes who remained seronegative after 3 or more years of follow-up.

FINDINGS

Modelling of the time to HIV-1 seroconversion showed that the incidence of HIV-1 seroconversion decreased with increasing duration of exposure, which indicates that there is heterogeneity in HIV-1 susceptibility or acquired immunity to HIV-1. Each weighted year of exposure through prostitution resulted in a 1.2-fold reduction in HIV-1 seroconversion risk (hazard ratio 0.83 [95% CI 0.79-0.88], p < 0.0001). Analyses of epidemiological and laboratory data, show that persistent seronegativity is not explained by seronegative HIV-1 infection or by differences in risk factors for HIV-1 infection such as safer sexual behaviours or the incidence of other sexually transmitted infections.

INTERPRETATION

We conclude that a small proportion of highly exposed individuals, who may have natural protective immunity to HIV-1, are resistant to HIV-1.

Postnatal transmission of AIDS-associated retrovirus from mother to infant

The third child of a previously healthy woman was delivered by caesarean section. Because of intraoperative blood loss, a blood transfusion was given after the delivery. The baby was breast-fed for 6 weeks. One unit of blood came from a male in whom the acquired immunodeficiency syndrome (AIDS) developed 13 months later. On recall, the mother proved to have lymphadenopathy, serum antibody to the AIDS virus, and a reduced T4/T8 ratio. The infant, who failed two thrive and had atopic eczema from 3 months, has likewise proved to have antibody to the AIDS virus. Since his mother was transfused after his birth, he is presumed to have been infected via breast milk or by way of some other form of close contact with his mother.

The association between maternal HIV infection and perinatal outcome: a systematic review of the literature and meta-analysis

OBJECTIVE

To investigate the association between maternal HIV infection and perinatal outcome by a systematic review of the literature and meta-analysis.

METHODS

Appropriate publications were identified using electronic and hand searching of relevant journals from 1983 to 1996. Studies were included in the review if they were prospective cohorts with pregnant women identified as being HIV-infected with a control group of pregnant women who were not infected with HIV. Methodological quality was assessed for each study. Data were extracted for pre-determined outcome measures. Sensitivity analyses were performed to explore the association between HIV infection and an adverse perinatal outcome for the following study characteristics: clinical setting (developed or developing countries), methodological quality (high or poor) and whether studies controlled for potential confounding.

RESULTS

Thirty-one studies were eligible to be included in the review. The summary odds ratio of the risk of pre-defined adverse perinatal outcomes related to maternal HIV infection were as follows: spontaneous abortion 4.05 (95% CI 2.75-5.96); stillbirth 3.91 (95% CI 2.65-5.77); fetal abnormality 1.08 (95% CI 0.7-1.66); perinatal mortality 1.79 (95% CI 1.14-2.81); neonatal mortality 1.10 (95% CI 0.63-1.93); infant mortality 3.69 (95% CI 3.03-4.49); intrauterine growth retardation 1.7 (95% CI 1.43-2.02); low birthweight 2.09 (95% CI 1.86-2.35) and pre-term delivery 1 83 (95% CI 1.63-2.06). Sensitivity analyses showed that the association between infant mortality and maternal HIV infection was stronger in studies conducted in developing countries when compared with developed countries [odds ratios (OR) 3.72 (95% CI 3.05-4.54) and 8.6 (95% CI 0.53-141.05), respectively]; studies of higher methodological quality compared with those of poorer quality [odds ratios 14.57 (95% CI 6.93-30.65) and 3.37 (95% CI 2.74-4.14), respectively] and studies which had used restriction or matching to control for potential confounding factors compared with those that had not [OR 11.60 (95% CI 5.71-23.58) and 3.35 (95% CI 2.73-4.12), respectively].

CONCLUSIONS

The findings of this review have implications for women infected with HIV who are planning a pregnancy or who find themselves pregnant. There appears to be an association, although not strong, between maternal HIV infection and an adverse perinatal outcome. This relationship may be due to bias including uncontrolled or residual confounding. There does, however, appear to be a real and large increase in the risk of infant death in developing countries associated with maternal HIV infection, especially so when there has been an attempt to control for confounding.

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.

Tuberculosis, atypical mycobacteriosis, and the acquired immunodeficiency syndrome among Haitian and non-Haitian patients in south Florida

To study the association between mycobacterial disease and the acquired immunodeficiency syndrome, we reviewed the records of all cases of tuberculosis and all cases of the syndrome reported in Dade County, Florida, from January 1980 through June 1983. Tuberculosis was diagnosed in 27 of 45 Haitians with the syndrome, but in only 1 of 37 non-Haitians with the syndrome (p less than 0.001). Among the 27 Haitians with the syndrome and tuberculosis, 19 had extrapulmonary tuberculosis, whereas among 286 Haitian patients with tuberculosis without the syndrome, only 56 had extrapulmonary tuberculosis (p less than 0.001). Tuberculosis preceded the syndrome by 1 to 17 months (mean, 6) in 22 patients. In 10 patients with the syndrome and positive sputum cultures who were treated with conventional antituberculosis drugs, the cultures became negative within 1 to 4 months and tuberculosis did not recur. The frequency of disseminated atypical mycobacteriosis or positive sputum cultures for atypical mycobacteria was not significantly different between Haitian (11.3%) and non-Haitian (8.3%) patients with the syndrome.

Immune activation is a dominant factor in the pathogenesis of African AIDS

The AIDS epidemic in Africa is very different from the epidemic in the West. As suggested here by Zvi Bentwich, Alexander Kalinkovich and Ziva Weisman, this appears to be primarily a consequence of the over-activation of the immune system in the African population, owing to the extremely high prevalence of infections, particularly helminthic, in Africa. Such activation shifts the cytokine balance towards a T helper 0/2 (Th0/2)-type response, which makes the host more susceptible to infection with human immunodeficiency virus (HIV) and less able to cope with it.

Diarrhea in developed and developing countries: magnitude, special settings, and etiologies

Diarrheal diseases are major causes of morbidity, with attack rates ranging from two to 12 or more illnesses per person per year in developed and developing countries. In addition, diarrheal illnesses account for an estimated 12,600 deaths each day in children in Asia, Africa, and Latin America. The causes of diarrhea include a wide array of viruses, bacteria, and parasites, many of which have been recognized only in the last decade or two. While enterotoxigenic Escherichia coli and rotaviruses predominate in developing areas, Norwalk-like viruses, Campylobacter jejuni, and cytotoxigenic Clostridium difficile are seen with increasing frequency in developed areas; and Shigella, Salmonella, Cryptosporidium species, and Giardia lamblia are found throughout the world. The rational management of infectious diarrhea requires the highly selective use of laboratory tests for these varied etiologic agents, depending on the clinical and epidemiologic setting. The purpose of this review is to provide an overview of the magnitude, special settings, and etiologies of diarrhea endemic to developed and developing countries. This information permits a practical approach to the diagnosis and management of common diarrheal illnesses in different settings.

Immunopathogenesis of the acquired immunodeficiency syndrome

Many abnormalities of humoral and cellular immunity associated with the acquired immunodeficiency syndrome can be explained by the preferential infection of the T4 lymphocyte subset with the etiologic retrovirus. Severe alterations in specific T4 functions, such as inadequate immune responsiveness to specific antigen, result in devastating morbidity and mortality. On the basis of accumulated scientific knowledge, we outline the immunopathogenesis of this syndrome.

A role for a new herpes virus (KSHV) in different forms of Kaposi's sarcoma

Kaposi's sarcoma (KS) is a previously rare, tumour-like lesion of controversial biological nature. KS has since the early 1980s become frequent in patients with AIDS, particularly in homosexuals. KS is also endemic in Central Africa predominantly in otherwise healthy men but also in women and children. Recently, evidence for the presence of novel, herpes virus DNA sequences in more than 90% of AIDS Kaposi lesions (AKS) was presented. This DNA was identified using representational difference analysis (RDA) generating short, unique sequences with variable homology to several herpes virus, but no intact virus was recovered. If these DNA-sequences are also present in other, non-HIV-associated forms of Kaposi's sarcoma this would strongly suggest a specific, aetiopathological involvement of this putative new herpes virus in the pathogenesis of Kaposi's sarcoma, rather than a contamination of yet another opportunistic virus in immunosuppressed AIDS patients.

Lack of transmission of HTLV-III/LAV infection to household contacts of patients with AIDS or AIDS-related complex with oral candidiasis

To determine the risk of transmission of human T-cell lymphotropic virus Type III/lymphadenopathy-associated virus (HTLV-III/LAV) to close but nonsexual contacts of patients with the acquired immunodeficiency syndrome (AIDS), we studied the nonsexual household contacts of patients with AIDS or the AIDS-related complex with oral candidiasis. Detailed interviews, physical examinations, and tests for serum antibody to HTLV-III/LAV were performed on 101 household contacts of 39 AIDS patients (68 children and 33 adults), all of whom had lived in the same household with an index patient for at least three months. These contacts had shared household items and facilities and had close personal interaction with the patient for a median of 22 months (range, 3 to 48) during the period of presumed infectivity. Only 1 of 101 household contacts--a five-year-old child--had evidence of infection with the virus, which had probably been acquired perinatally rather than through horizontal transmission. This study indicates that household contacts who are not sexual partners of, or born to, patients with AIDS are at minimal or no risk of infection with HTLV-III/LAV.

Hormonal contraception, vitamin A deficiency, and other risk factors for shedding of HIV-1 infected cells from the cervix and vagina

BACKGROUND

Factors that influence shedding of HIV-1 infected cells in cervical and vaginal secretions may be important determinants of sexual and vertical transmission of the virus. We investigated whether hormonal contraceptive use, vitamin A deficiency, and other variables were risk factors for cervical and vaginal shedding of HIV-infected cells.

METHODS

Between December, 1994, and April, 1996, women who attended a municipal sexually transmitted diseases (STDs) clinic in Mombasa, Kenya, and had previously tested positive for HIV-1, were invited to take part in our cross-sectional study. Cervical and vaginal secretions from 318 women were evaluated for the presence of HIV-1 infected cells by PCR amplification of gag DNA sequences.

FINDINGS

HIV-1 infected cells were detected in 51% of endocervical and 14% of vaginal-swab specimens. Both cervical and vaginal shedding of HIV-1 infected cells were highly associated with CD4 lymphocyte depletion (p = 0.00001 and p = 0.003, respectively). After adjustment for CD4 count, cervical proviral shedding was significantly associated with use of depot medroxyprogesterone acetate (odds ratio 2.9, 95% CI 1.5-5.7), and with use of low-dose and high-dose oral contraceptive pills (3.8, 1.4-9.9 and 12.3, 1.5-101, respectively). Vitamin A deficiency was highly predictive of vaginal HIV-1 DNA shedding. After adjustment for CD4 count, severe vitamin A deficiency, moderate deficiency, and low normal vitamin A status were associated with 12.9, 8.0, and 4.9-fold increased odds of vaginal shedding, respectively. Gonococcal cervicitis (3.1, 1.1-9.8) and vaginal candidiasis (2.6, 1.2-5.4) were also correlated with significant increases in HIV-1 DNA detection, but Chlamydia trachomatis and Trichomonas vaginalis were not.

INTERPRETATION

Our study documents several novel correlates of HIV-1 shedding in cervical and vaginal secretions, most notably hormonal contraceptive use and vitamin A deficiency. These factors may be important determinants of sexual or vertical transmission of HIV-1 and are of public health importance because they are easily modified by simple interventions.

Relation between perceived vulnerability to HIV and precautionary sexual behavior

Although virtually all major theories of health-protective behavior assume that precautionary behavior is related to perceived vulnerability, the applicability of this assumption to human immunodeficiency virus (HIV) preventive behavior has recently been called into question. This article uses qualitative and quantitative methods to review and integrate the literature relevant to the relation between perceived vulnerability to HIV and precautionary sexual behavior. Specifically, the purpose of the article is to determine whether the extent research supports 2 hypotheses regarding this relation; (a) Perceptions of personal vulnerability to HIV are reflections of current and recent risk and precautionary behavior, and (b) these perceptions motivate precautionary sexual behavior. In addition, it examines the conceptual and methodological strengths and weaknesses of the empirical literature on these questions and provides recommendations for future research.