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Central Africa was the epicenter of the HIV type 1 (HIV-1) pandemic. Understanding the early epidemic in the Democratic Republic of the Congo, formerly Zaire, could provide insight into how HIV evolved and assist vaccine design and intervention efforts. Using enzyme immunosorbent assays, we tested 3,988 serum samples collected in Kinshasa in the mid-1980s and confirmed seroreactivity by Western blot. Polymerase chain reaction of gag p17, env C2V3C3, and/or gp41; DNA sequencing; and genetic analyses were performed. Gene regions representing all the HIV-1 group M clades and unclassifiable sequences were found. From two or three short gene regions, 37% of the strains represented recombinant viruses, multiple infections, or both, which suggests that if whole genome sequences were available, most of these strains would have mosaic genomes. We propose that the HIV epidemic was well established in central Africa by the early 1980s and that some recombinant viruses most likely seeded the early global epidemic.

Up to now, all known env subtype E viruses (CRF01-AE) have had the same mosaic structure with subtype A, and no other env subtype E HIV-1 viruses with non-A subtypes in their genomes have been described. In this report we describe the full-length genome sequence of an env subtype E isolate with a recombinant genome different from the prototype CRF01-AE strains. The 97CD-KTB49 strain, obtained from a tuberculosis patient in Kinshasa, has a complex mosaic genome involving subtypes A, E, G, H, J, K, and several unknown fragments. The U sequences formed well-separated clusters together with previously described unknown fragments from CRF04-cpx (subtype I), and from Z321, the oldest intersubtype recombinant isolated in 1976 in the Democratic Republic of Congo. The complex recombinant virus from our study is not an isolated strain; partial sequencing of a second strain, 97CD-KFE45, confirmed the breakpoints observed in the 97CD-KTB49 strain in the regions sequenced. The complexity of these recombinant strains suggests a longstanding presence of subtype E in Central Africa.

The purpose of this study was to document the genetic diversity of human immunodeficiency virus type 1 (HIV-1) in the Democratic Republic of Congo (DRC; formerly Zaire). A total of 247 HIV-1-positive samples, collected during an epidemiologic survey conducted in 1997 in three regions (Kinshasa [the capital], Bwamanda [in the north], and Mbuyi-Maya [in the south]), were genetically characterized in the env V3-V5 region. All known subtypes were found to cocirculate, and for 6% of the samples the subtype could not be identified. Subtype A is predominant, with prevalences decreasing from north to south (69% in the north, 53% in the capital city, and 46% in the south). Subtype C, D, G, and H prevalences range from 7 to 9%, whereas subtype F, J, K, and CRF01-AE strains represent 2 to 4% of the samples; only one subtype B strain was identified. The highest prevalence (25%) of subtype C was in the south, and CRF01-AE was seen mainly in the north. The high intersubtype variability among the V3-V5 sequences is the most probable reason for the low (45%) efficiency of subtype A-specific PCR and HMA (heteroduplex mobility assay). Eighteen (29%) of 62 samples had discordant subtype designations between env and gag. Sequence analysis of the entire envelope from 13 samples confirmed the high degree of diversity and complexity of HIV-1 strains in the DRC; 9 had a complex recombinant structure in gp160, involving fragments of known and unknown subtypes. Interestingly, the unknown fragments from the different strains did not cluster together. Overall, the high number of HIV-1 subtypes cocirculating, the high intrasubtype diversity, and the high numbers of possible recombinant viruses as well as different unclassified strains are all in agreement with an old and mature epidemic in the DRC, suggesting that this region is the epicenter of HIV-1 group M.

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.

Treatment with high dose vitamin A has recently been recommended for children with measles in communities where vitamin A deficiency is a recognized problem. However, the relationship between vitamin A and measles mortality has not been clearly established. We studied serum vitamin A levels in 283 children less than or equal to 5 years of age admitted to Mama Yemo and Kalembe Lembe Hospitals in Kinshasa, Zaire, between January and March, 1987. Vitamin A levels were determined by high performance liquid chromatography. Vitamin A levels ranged from less than 5 to 63 micrograms/dl (median, 8). The overall case-fatality rate was 26 per cent. On univariate analysis, age less than 24 months, pneumonia on admission, lymphopenia (less than 2000/mm3), and lower vitamin A levels were associated with death during hospitalization. In a multivariate logistic regression model, a vitamin A level less than 5 micrograms/dl was associated with fatal outcome for children younger than 24 months old (relative risk = 2.9, 95 per cent CI 1.3, 6.8), but not for older children. Further studies are needed to determine whether low vitamin A levels predispose children to severe measles and the role of vitamin A supplements in the prevention of measles mortality.

A study of seroprevalence of the human immunodeficiency virus involving 2384 (96%) of Mama Yemo Hospital's (Kinshasa, Zaire) 2492 personnel found 152 (6.4%) to be seropositive. Prevalence was higher among women than among men (8.1% vs 5.2%); in women peak seroprevalence (13.9%) occurred in 20- to 29-year-olds. Workers most likely to be seropositive were those who were relatively young, those who were unmarried, those reporting a blood transfusion or hospitalization during the previous ten years, and those receiving medical injections during the previous three years. Medical, administrative, and manual workers had similar seroprevalence (6.5%, 6.4%, and 6.0%, respectively), and seropositivity was not associated with any measure of patient, blood, or needle contact. These findings are consistent with other hospital-based studies indicating low risks for occupational transmission of human immunodeficiency virus.

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.

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.

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.

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.

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 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.