Search

In this paper, we studied the variability of HIV-1 subtype F strains in Africa. For 11 viruses, mainly of Central African origin, different parts of the genome were genetically characterized. For all strains the V3-V5 region of the envelope gene was sequenced, and for 7 strains, the entire envelope gene was studied. For 10 strains, the p24 region of the gag gene was also sequenced. For each region studied, three subgroups in the F subtype were identified, F1, F2, and F3. These three subgroups were supported by high bootstrap values and the intra- and inter-subgroup F distances were comparable to those obtained for the known subtypes A, B, C, D, E, G, and H. In subgroup F1, some African strains clustered with previously described strains from Brazil and Romania, suggesting an African origin of the HIV-1 epidemic in these countries. A more detailed analysis of the gag and the envelope sequences allowed the identification of four recombinant viruses. Our data show a high diversity among subtype F strains, suggesting the presence of new subtypes in the regions studied. If biological differences exist among subtypes, it is important that these subtypes be well defined. The data from our study show that there is a need to clearly identify the different subgroups within the F subtype., (Copyright 1999 Academic Press.)

As a first step in designing an AIDS prevention program at a large factory in Kinshasa, Zaire, we collected information on attitudes towards human immunodeficiency virus (HIV) infection and acquired immunodeficiency syndrome (AIDS) from factory foremen and their wives. Trained moderators conducted twelve focus group discussions (from November through December 1987) that addressed knowledge, attitudes and beliefs about HIV infection and AIDS. In general, participants were familiar with HIV infection and AIDS and considered these conditions leading health problems in Kinshasa. Although participants had a fairly accurate understanding of the causes of HIV infection, modes of transmission and preventive measures, many myths and misconceptions existed. Many participants did not believe that condom use would consistently prevent infection through sexual intercourse. Participants strongly favored the counseling of seropositive persons but showed less consensus about whether the spouse of a seropositive person should be notified of the partner's test result. Participants predicted that couples in which one member is seropositive and the other is not would experience marital discord and friction with family, neighbors and co-workers. These findings were applied to the development of a counseling and educational program for seropositive factory employees and their spouses.

A provisional clinical case-definition for acquired immunodeficiency syndrome (AIDS) developed by the World Health Organisation (WHO) for use in Africa was tested on 174 inpatients at Mama Yemo Hospital, Kinshasa, Zaire. In this hospital population with a 34% infection rate of human immunodeficiency virus (HIV), the clinical case-definition had a specificity of 90%, a sensitivity of 59%, and a predictive value of 74% for HIV seropositivity. These results support the use of the WHO clinical definition for AIDS in Africa. However, since HIV prevalence and disease expression vary, similar evaluations should be carried out in different regions.

In Africa, female prostitutes represent a high risk group for HIV infection. In Kinshasa, Zaire, 101 (27%) out of 377 prostitutes were seropositive to HIV by ELISA and Western blot determination. Seropositivity was significantly associated with the number of lifetime partners with a median number of 600 partners, four seropositives and 338 for seronegative individuals (P = 0.02). Seropositivity was also significantly associated with a history of taking oral medications for the prevention of sexually transmitted diseases and/or pregnancy (odds ratio = 2.21, confidence interval = 1.2-4.2), and with the introduction of any product into the vagina for hygiene or other purposes (odds ratio = 2.3, confidence interval = 1.1-4.7). In addition, among 85 prostitutes reporting condom use by their sexual partners during the previous year, the use of condoms by 50% or more of partners was associated with a reduced risk of HIV seropositivity (P = 0.046). An increased risk of HIV seropositivity was not associated with fellatio, anal intercourse, or with any type of kissing. Twenty-nine per cent of prostitutes reported at least one symptom suggestive of HIV infection, and seropositivity was associated with weight loss, either with or without chronic diarrhea or pruritic dermatitis. These data confirm that African prostitutes are at high risk for HIV infection and that the number of lifetime sexual partners, and factors which interfere with the integrity of the vaginal or cervical mucosa, may be associated with an increased risk of HIV infection acquired through heterosexual contact.(ABSTRACT TRUNCATED AT 250 WORDS)

In 1985 we tested 659 human serum samples, collected in the remote Equateur province of Zaire in 1976, for antibody to human immunodeficiency virus (HIV). Five (0.8 percent) were positive, and HIV was isolated from one of these. Follow-up investigations in 1985 revealed that three of the five seropositive persons had died of illnesses suggestive of acquired immunodeficiency syndrome (AIDS), and two remained healthy but seropositive. In 1986, a serosurvey we conducted using a cluster-sampling technique in the same region showed a seroprevalence of 0.8 percent in 389 randomly selected residents. The seroprevalence in 283 prostitutes was 11 percent. Patients with AIDS were identified in various hospitals in the province. Risk factors for AIDS included a greater than average number of sexual partners and residence outside the area. We believe that the long-term stability of HIV infection in residents of rural Zaire suggests that social change may have promoted the spread of AIDS in Africa.

Household members of 46 patients with confirmed acquired immunodeficiency syndrome (AIDS) and 43 human T-cell lymphotropic virus type III/lymphadenopathy-associated virus (HTLV-III/LAV)-seronegative controls from Kinshasa, Zaire, were identified and sought for serologic testing for evidence of HTLV-III/LAV infection. Twenty (9.8%) of 204 case-household members and three (1.9%) of 155 control-household members were HTLV-III/LAV seropositive (relative risk = 5.1; 95% confidence interval, 1.7 to 15.2). Eleven (61.1%) of 18 spouses of patients with AIDS were HTLV-III/LAV seropositive, compared with one (3.7%) of 27 control spouses (relative risk = 16.5; 95% confidence interval, 3.7 to 75.0). Except for spouses, the rate of HTLV-III/LAV seropositivity did not differ significantly between case and control households. Furthermore, for adults in case households who were not spouses, the number seropositive for HTLV-III/LAV was identical to that predicted from sex- and age-specific HTLV-III/LAV seroprevalence rates. These data from Zaire confirm the results of US and European studies of household contacts of infected hemophiliacs and pediatric patients with AIDS.

To better define the interrelationship of infection with human immunodeficiency virus (HIV) and tuberculosis (TB), we conducted three HIV serosurveys of inpatients and outpatients with confirmed or suspected TB in Kinshasa, Zaire. HIV seroprevalence in hospitalized sanatorium patients did not change significantly in serosurveys conducted in 1985 and 1987 (92/231 [40%] versus 85/234 [36%]). These proportions were significantly higher than the 17% HIV seroprevalence observed in a 1987 serosurvey of 509 consecutive patients with an initial diagnosis of pulmonary TB seen at an outpatient TB diagnostic center in Kinshasa (p less than 0.001). HIV seroprevalence was higher in sanatorium patients with extrapulmonary TB (22/46 [48%]) and suspected pulmonary TB (60/132 [45%]) than in patients with bacteriologically confirmed pulmonary TB (94/287 [33%]) (p less than 0.02). Mycobacterium sputum isolation rates were similar in HIV-seropositive (28/34 [82%]) and HIV-seronegative patients (135/159 [85%]). All isolates were Mycobacterium tuberculosis. Eighteen (21%) of 84 HIV-seropositive sanatorium patients in 1987, who were followed for two months after admission, had died, compared with 11 (9%) of 128 HIV-seronegative patients (p less than 0.01). However, clearance rates of acid-fast bacilli from sputum after standard therapy were equally good in HIV-seropositive and HIV-seronegative survivors. With the growing AIDS problem, the serious TB burden in sub-Saharan Africa may become even more onerous and may critically overload the stressed African health care systems.

The clinical case definition for AIDS proposed by WHO for use in Africa was evaluated against HIV antibody status in 72 patients in rural Zaire. Twenty-one (29%) of the patients were antibody-positive. For diagnosing anti-HIV seropositivity, the case definition had a sensitivity of 52%, a specificity of 78%, a positive predictive value of 50% and a negative predictive value of 80%. Calculation of the positive predictive value at different levels of prevalence of HIV infection suggests that the case definition operates at maximum reliability in selected high-risk groups. Modifications to the case definition should be evaluated to try and improve its sensitivity and positive predictive value.

The natural history of human immunodeficiency virus (HIV) infection in Zaïre was determined by identifying in October, 1984, 125 seropositive hospital personnel without signs or symptoms and 145 age and sex matched seronegative controls from the same population. Between July, 1985, and February, 1986, 67 seropositives, including 38 men and 29 women, and 113 seronegatives were interviewed and examined by an observer who did not know their serological status. The acquired immunodeficiency syndrome (AIDS) had developed in 1 seropositive and no seronegatives (rate difference, 1.3/100 person-years [py]; 95% confidence interval 0-3.3/100 py); AIDS-related complex or generalised lymphadenopathy had developed in 8 seropositives (12%) and 1 seronegative (1%) (rate ratio, 13.2; 95% confidence interval 1.3-134.6); and minimal lymphadenopathy had developed in 19 seropositives (28%) and 8 seronegatives (7%) (rate ratio, 3.9; 95% confidence interval 1.8-8.4). These data provide the first estimates for rates of progression to AIDS or AIDS-related conditions among healthy HIV seropositive heterosexual adults. Rates observed in this study are similar to those reported in US or European homosexual or bisexual men.

Surveillance for acquired immunodeficiency syndrome (AIDS) in Kinshasa, Zaire, was initiated in July 1984, using a modified version of the case definition developed by the Centers for Disease Control. During the first eight months, 332 patients met all clinical and laboratory criteria; surveillance information was available for 295 (89%) of these patients. Of the sera tested from these patients, 99% had antibodies to human T-cell lymphotropic virus type III/lymphadenopathy-associated virus by both enzyme-linked immunosorbent assay and Western blot procedures. The male-female case ratio was 1:1.1; the mean age of patients was 33.6 years (median, 32 years; range, 1.5 to 64 years); and men were significantly older than women (mean, 37.4 vs 30.0 years). The estimated incidence rate for adults in Kinshasa is 380 cases per 1 million people per year. Peak age-specific incidence rates for men and women occurred among the 30- to 39-year age group, although the rate for men in this age group was 24% higher than the rate for women (786 vs 601 per 1 million). A reasonable estimate of the current annual incidence of AIDS is 550 to 1,000 cases per 1 million people. Surveillance of AIDS in Zaire provides important information on transmission patterns and rates in Africa.