Genetic comparison of HIV-1 isolates from Africa, Europe, and North America.
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Africa↗
Biomedical subjects
P Piot
Publications and source records attributed to P Piot.
Isolation and characterization of a new chimpanzee lentivirus (simian immunodeficiency virus isolate cpz-ant) from a wild-captured chimpanzee.
OBJECTIVE: To assess the prevalence of infection with simian immunodeficiency virus (SIV) isolate cpz, a lentivirus closely related to HIV-1, in chimpanzees, and to obtain new SIVcpz isolates. METHODS: Forty-four wild-captured chimpanzees in Belgium and Côte d'Ivoire were tested for HIV and SIV antibodies. Virus was isolated from the peripheral blood lymphocytes of positive animals and characterized by electron microscopy, Western blot and radioimmunoprecipitation assay. RESULTS: One animal had antibodies that cross-reacted with HIV-1. A lentivirus was isolated and referred to as SIVcpz-ant. With regard to molecular weight patterns, SIVcpz-ant differs from SIVcpz-gab' an HIV-1-related virus isolated from a wild-captured chimpanzee in Gabon. The major core protein, the transmembrane and outer membrane glycoproteins of the SIVcpz-ant strain consistently had higher molecular weights. Significantly more HIV-1-positive sera reacted with the envelope proteins of the Gabonese SIVcpz-gab strain than with the SIVcpz-ant strain. CONCLUSIONS: This study shows that natural infection of wild-captured chimpanzees with an HIV-related virus may not be uncommon. The diversity of the two chimpanzee isolates, the different geographical origin and the absence of disease suggest that chimpanzees have not recently become SIVcpz-infected.
Animals↗
Association between HIV-2 infection and genital ulcer diseases among male sexually transmitted disease patients in The Gambia.
OBJECTIVE: To investigate whether genital ulcer diseases are cofactors which enhance the transmission of HIV-2 in West Africa. DESIGN: A cross-sectional study of 435 men presenting with a sexually transmitted disease (STD). SETTING: The outpatient clinic of the Medical Research Council Laboratories, a primary care facility in Fajara, a suburb of Banjul, the capital city of The Gambia (West Africa). PATIENTS, PARTICIPANTS: Six hundred and twenty-four men presenting with a genital complaint, of whom 443 had an STD. Eight of the men with an STD were excluded from further analysis because they were HIV-1-infected (five patients) or had indeterminate Western blot patterns (three patients). The remaining 21 HIV-2-infected and 414 seronegative men constituted our study-group. MAIN OUTCOME MEASURES: Participants were questioned about previous STD and behavioural and demographic characteristics. A physical examination was performed and serum collected for measurement of antibodies against Haemophilus ducreyi and Treponema pallidum. RESULTS: HIV-2-infected men were more likely than HIV-seronegative participants to have previously had a genital ulcer [odds ratio (OR), 3.00; 95% confidence interval (Cl), 1.18-7.60] and to have antibodies against T. pallidum (OR, 5.95; 95% Cl, 2.10-16.91), or H. ducreyi (OR, 4.59; 95% Cl, 1.71-12.33). Circumcised patients with residual foreskin were more likely to be HIV-2 infected than patients with complete circumcision. HIV-2-seropositive patients were six times more likely to have generalized lymphadenopathy than their seronegative counterparts. CONCLUSIONS: Our data suggest that genital ulcerative diseases, such as syphilis and chancroid, are probably cofactors that increase the transmission of HIV-2 in West Africa, and that HIV-2 infection frequently results in generalized lymphadenopathy.
Adolescent↗
Rapid increase of both HIV-1 infection and syphilis among pregnant women in Nairobi, Kenya.
OBJECTIVE: To determine the prevalence of HIV-1 and syphilis antibodies in a population of pregnant women in Nairobi, Kenya, between 1989 and 1991. METHODS: As part of an ongoing prospective study on the effect of HIV-1 infection and sexually transmitted diseases, 4883 pregnant women were screened for HIV-1 and syphilis antibodies in one health-centre in Nairobi. RESULTS: HIV-1 seroprevalence increased from 6.5 to 13.0% (P < 0.001) and syphilis seroreactivity from 2.9 to 5.3% (P = 0.002), while there was no change in gonococcal infection rates. The most rapid increase in HIV-1 prevalence was observed in women aged less than 25 years. There was no evidence of demographic fluctuations in the population during this time, or of changes in sexual behaviour, except that fewer women enrolled in 1991 reported having more than one sex partner, compared with women enrolled in 1989 (39.1 versus 20.0%; P = 0.0001). HIV-1-seropositive women were more likely to be seroreactive for syphilis than HIV-1-seronegative mothers (7.7 versus 3.2%; odds ratio = 2.5; 95% confidence interval, 1.7-3.8; P < 0.001), but there was no difference between the two groups in terms of gonorrhoea prevalence. CONCLUSION: These data confirm an association between HIV-1 and syphilis infection, and indicate that both are spreading rapidly among women in Nairobi outside high-risk groups. Increased efforts to control both infections are urgently required.
Antibodies, Viral↗
Prevention of blood-borne HIV transmission using a decentralized approach in Shaba, Zaire.
OBJECTIVE: To prevent blood transfusion-acquired HIV infection with a decentralized approach to HIV screening of blood donors, using an instrument-free rapid test. SETTING: Shaba province, Zaire (496,877 km2). METHODS: The programme consisted of training health-care workers, distribution of a rapid HIV-antibody test (DuPont's HIVCHEK) for screening of all blood donations, and quality control of testing by a regional reference centre. RESULTS: Over a 2-year period, 11,940 rapid tests were distributed to 37 hospitals, covering 75% of all hospital beds outside the copper mine's health system in Shaba. Eighty-five per cent of the tests were used to screen blood donors (5.4% positive test rate) and 13% to test patients (39.7% positive test rate). At least 265 cases of HIV-positive blood donation were prevented, at an estimated cost of 137-279 ECU per case. Only 26% of initially positive specimens reached the central laboratory for supplemental testing, and sterile transfusion equipment and blood-grouping reagents were frequently unavailable. The lack of transport and communications and a deteriorating health system were major constraints. CONCLUSIONS: District hospitals in Africa are often long distances from major cities, difficult to reach for most of the year, and perform a small number of transfusions. In this context a classical centralized regional blood bank may not be a feasible option to ensure safe blood transfusions. However, safe blood transfusion can be achieved with a decentralized approach using a rapid test, provided that minimum standards of health-care services are available.
Blood Banks↗
Shigella and gonococcal vulvovaginitis in prepubertal central African girls.
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Adolescent↗
Antigenic diversity in Haemophilus ducreyi as shown by western blot (immunoblot) analysis.
The antigenic diversity within a panel of 63 Haemophilus ducreyi isolates was examined by Western blot (immunoblot) analysis with a pool of 238 well-characterized human antisera. When a serum pool adsorbed on a mixture of Haemophilus influenzae, H. parainfluenzae, and H. parahaemolyticus was used, the immunoprofiles suggested that prominent antigenic proteins involved in the human immune response have apparent molecular masses of 63, 42, 34 to 30, and 28.5 to 28 kDa. Preliminary subcellular localization revealed that these antigens are associated with the cellular membrane. Two subsets of antigens were discriminated by detergent extraction. There was no evidence that the antigen composition is altered by changing the growth conditions. With a serum pool adsorbed on the Haemophilus spp. mixture supplemented with Actinobacillus actinomycetemcomitans, Pasteurella ureae, Neisseria gonorrhoeae, and Escherichia coli, antigenic determinants more specific for H. ducreyi were identified. An immunodominant 28.5- to 28-kDa protein was expressed by all H. ducreyi isolates. In the range from 34 to 30 kDa, 56 isolates revealed a dominant protein with variable molecular mass. By using both proteins (28.5 to 28 kDa and 34 to 30 kDa) as immunotypic markers, seven different immunopatterns were identified. Antigenic diversity among isolates from different geographical origins as well as from a single area was observed.
Adsorption↗
Standardization of an enzyme immunoassay for human antibody to Haemophilus ducreyi.
We standardized a serologic enzyme immunoassay (EIA) for human immunoglobulin G and M antibodies against Haemophilus ducreyi. We evaluated the performance of this test with respect to the time from acute chancroid and coinfection with human immunodeficiency virus (HIV). Antibody to a crude, soluble bacterial antigen of one H. ducreyi strain was detected in a panel of serum samples from clinically and microbiologically confirmed cases of chancroid and from controls. Test interpretation was standardized for optimal sensitivity and specificity. Performance of the EIA was enhanced in the period of early convalescence from acute primary chancroid and was not diminished in the presence of HIV coinfection. The EIA performed adequately as a serologic screening test for field evaluation and epidemiologic application in conjunction with sexually transmitted disease and HIV detection and control efforts.
Antibodies, Bacterial↗
Antimicrobial susceptibility of Neisseria gonorrhoeae in Zaire: high level plasmid-mediated tetracycline resistance in central Africa.
OBJECTIVE: To determine the in vitro antimicrobial susceptibility of gonococcal strains isolated in 1988 among female prostitutes in Kinshasa, Zaire and to characterise strains with high level tetracycline resistance. METHODS: Minimal inhibitory concentrations of 8 antimicrobials were measured by agar dilution technique. Plasmid-profiles and serovars were determined. RESULTS: Two hundred and thirteen strains of Neisseria gonorrhoeae were tested of which 59% were beta-lactamase producers and an additional 21% showed intermediate or chromosomal resistance to penicillin (MIC = 0.5-8 mg/l). Eleven percent of the strains were resistant to the combination sulfamethoxazole-trimethoprim (MIC greater than 8 mg/l) and 57% of the isolates showed decreased susceptibility to thiamphenicol (MIC = 1-4 mg/l). All strains were sensitive to spectinomycin, norfloxacin and ceftriaxone and moderately sensitive to kanamycin. Chromosomal resistance to tetracycline was observed in 45% of strains (MIC = 2-8 mg/l). Ten percent were highly resistant to tetracycline (TRNG, MIC = 16-128 mg/l) and were shown to carry a plasmid borne Tet M determinant; such strains were not found in Kinshasa in 1985. TRNG belonged to 4 different serovars, which were also the dominant serovars in non-TRNG. CONCLUSION: These findings illustrate the high frequency of multiresistant gonococci in Zaire and suggest that high level tetracycline resistant strains of N. gonorrhoeae have become endemic in Central Africa.
Anti-Bacterial Agents↗
Laboratory techniques in the investigation of chancroid, lymphogranuloma venereum and donovanosis.
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Chancroid↗
Neurological complications of HIV-1-seropositive internal medicine inpatients in Kinshasa, Zaire.
Because little was known about the prevalence of neurological complications of human immunodeficiency virus type 1 (HIV-1) infection in Africa, we conducted a cross-sectional study among consecutive admissions to the internal medicine wards of Mama Yemo Hospital in Kinshasa, Zaire. Of the 196 patients studied, 104 (53%) were HIV-1 seropositive, of whom 50 (48%) had stage 3 and 49 (47%) had stage 4 HIV-1 infection according to the provisional WHO staging criteria for HIV infection. Neuropsychiatric abnormalities were present in 43 (41%) of 104 HIV-1-seropositive patients. Of the HIV-1-seropositive patients, 9 (8.7%; 95% confidence interval, 4-16%) were diagnosed as having possible HIV-1-associated dementia complex, 1 (1%) as having possible HIV-1 myelopathy, and 3 (2.7%) as having possible HIV-1-associated minor cognitive/motor disorder. Definitive diagnoses could not be made because there were no facilities for neuroimaging and neuropathology. Meningitis caused by cryptococcus was diagnosed in six (5.6%) and by Mycobacterium avium in two (2%) of the HIV-1 seropositive patients. Acute onset hemiplegia, believed to be due to stroke, was present in four (4%) of the HIV-1-seropositive patients. The prevalence of other central nervous system opportunistic infections and mass lesions, especially toxoplasmic encephalitis, could not be assessed. In this population of Zairian inpatients, the prevalence of neurological complications of HIV-1 infection was similar to that observed in industrialized countries among patients with advanced HIV disease.
Adult↗
HIV screening and confirmation: a simplified and less expensive testing algorithm.
In this study we investigated the performance of fourteen different assays capable of simultaneously detecting antibodies to HIV-1 and HIV-2, referred to as combined screening assays (CSAs), on a panel of 371 sera, with a prevalence of 51.5% and 1.3% for HIV-1 and HIV-2 antibodies respectively. The geographic distribution of the sera was as follows; Europe (121), Africa (203) and Latin America (47). These sera were collected from different clinical groups of patients; Asymptomatic (36), AIDS-Related Complex/AIDS patients (18), infected individuals with generalised lymphadenopathy (12), blood donors (149), and subjects with unknown clinical status (156). The Dupont Western blot (WB) kit for detection of HTLV-III antibodies and the Pasteur new Lav-Blot II kit were used for the confirmation of HIV-1 and HIV-2 infection respectively. Of the 14 tests studied, 9 were enzyme linked immunosorbent assays (ELISAs), and 5 were non-Elisa tests requiring visual reading. An alternative approach for HIV antibody testing was studied restrospectively, whereby sera positive in an initial CSA (A) were retested on a second CSA (B), that was different from the first. The use of WB was limited to sera that gave discrepant (A+B-) results in the two CSAs. A positive result in both CSAs was reported as anti-HIV positive. A negative result in the first CSA was reported anti-HIV negative. Sensitivity, specificity, cost, and the delta (delta) values (delta values of the ELISA assays) were taken into consideration when selecting suitable pairs of assays. All the ELISAs scored 100% sensitivity, but for the non-ELISAs, the sensitivity ranged from 96.0% to 100%. The specificity for the ELISAs and non-ELISAs varied from 87.4% to 100% and from 51.4% to 100% respectively. Delta (delta) values for the ELISAs ranged from 3.82 to 136.68 and from -1.15 to -3.08 for the anti-HIV positive and anti-HIV negative populations respectively. Of the 121 test combinations studied, 9 (7.4%) pairs yielded 100% sensitivity and specificity and 61 (50.4%) pairs of CSAs required further testing on WB. This implies 100% positive predictive value, at a cost that was on average 6 times less, and a testing time that was 5 times faster than the conventional algorithm. We conclude that there are several combinations of pairs of CSAs that can be used in the alternative algorithm that can provide accurate results at a much lower cost than the conventional algorithm requiring confirmation by WB of all initially reactive CSA results.(ABSTRACT TRUNCATED AT 400 WORDS)
AIDS Serodiagnosis↗
Gentian violet, ketoconazole and nystatin in oropharyngeal and esophageal candidiasis in Zairian AIDS patients.
A randomized un-blinded study on the treatment of oropharyngeal and esophageal candidiasis was conducted in Kinshasa (Zaire), among 141 inpatients with AIDS and oropharyngeal candidiasis, of whom 136 also had esophageal candidiasis. The study compared the efficacy of gentian violet mouth washes (1.5 ml 0.5% aqueous solution b.i.d.), oral ketoconazole (200 mg/day, after a meal) and nystatin mouth washes (200.000 U oral suspension q.i.d.). Patients treated with mouth washes swallowed their medication after mouth washing. Patients enrolled in this study had a very high mortality (probability of death: 41.6% after 14 days). After 14 days, 72 patients could be evaluated. At that time, oropharyngeal lesions had disappeared in similar proportions of patients treated with gentian violet (11/26, 42%) and ketoconazole (10/23, 43%), and in a lower proportion of patients treated with nystatin (2/23, 9%; p less than 0.05). In esophageal candidiasis, ketoconazole seemed more efficient than both other treatments: esophageal lesions had disappeared in 5 (24%) of the 21 patients on ketoconazole, compared to less than 10% of patients on both other treatments (p = 0.07). The suboptimal results observed with all 3 treatments could be explained by the profound immunosuppression of patients enrolled in the study. This study suggests that gentian violet is effective treatment for oropharyngeal candidiasis. As it is very cheap (0.5 US$/treatment course in Kinshasa), we suggest that its use should be assessed in larger studies.
Acquired Immunodeficiency Syndrome↗
Evaluation of a line immunoassay for simultaneous confirmation of antibodies to HIV-1 and HIV-2.
An anti-HIV-1/HIV-2 line immunoassay (LIA), using peptides and recombinant antigens was evaluated against commercially available Western blot tests for HIV-1 and HIV-2 antibodies. Two thousand one hundred and ten sera of European, African, and South American origin were used in the evaluation. The panel included 1066 sera with antibodies to HIV-1, 192 sera with antibodies to HIV-2, and 64 sera with antibodies to both. Using Western blot results interpreted according to the WHO criteria as a reference standard, the overall specificity obtained by this LIA was 100% and the sensitivity was 99.77% (97.51-100% for 95% confidence limits) when sera dually reactive in Western blot were included. Of the three sera negative in the LIA but positive in HIV-1 WB, two could be retested in a radioimmunoprecipitation assay and were negative. When dually reactive sera in the Western blot (WHO) were included, the LIA yielded 9.9% indeterminate results as compared with 15.5% for both assays (chi 2 = 29.30; p less than 0.001). Although only one HIV-2 specific peptide antigen (gp36) was used, the LIA yielded a specificity of 100% and a sensitivity of 100% as compared with the HIV-2 Western blot assay. When indeterminate results were included, the overall agreement between the LIA and the HIV-1 and HIV-2 Western blot (WHO criteria) was 89.9% and 90.1% respectively. These results indicate that the LIA provides reliable simultaneous detection of antibodies to HIV-1 and HIV-2, and at a cost which is substantially lower than the cost of Western blot tests.
Blotting, Western↗
Cofactors in male-female sexual transmission of human immunodeficiency virus type 1.
In a study of human immunodeficiency virus type 1 (HIV-1)-uninfected African prostitutes, 83 (67%) of 124 seroconverted to HIV-1. Oral contraceptive use (odds ratio [OR], 3.1; 95% confidence interval [CI], 1.1-8.6; P less than .03), genital ulcers (mean annual episodes, 1.32 +/- 0.55 in seroconverting women vs. 0.48 +/- 0.21 in seronegative women; P less than .02) and Chlamydia trachomatis infections (OR, 3.6; CI, 1.3-11.0; P less than .02) were associated with increased risk of HIV-1 infection. Condom use reduced the risk of HIV-1 infection (OR, 0.11; CI, 0.05-0.27; P less than .0001). Stepwise logistic regression analysis confirmed independent associations between HIV-1 infection and oral contraceptive use, condom use, genital ulcers, and C. trachomatis. The presence of other sexually transmitted diseases may in part explain the heterosexual HIV-1 epidemic in Africa and may represent important targets for intervention to control HIV-1 infection.
Adult↗
Association of cervical ectopy with heterosexual transmission of human immunodeficiency virus: results of a study of couples in Nairobi, Kenya.
To identify risk factors involved in heterosexual transmission of human immunodeficiency virus (HIV), a cross-sectional study of HIV-seropositive men and their spouses was conducted in Nairobi, Kenya. Of 70 spouses, 40 (57%) were seropositive and 30 (43%) were seronegative for HIV. In univariate analysis, the presence of cervical ectopy (odds ratio, 4.7; P = .006) was the only statistically significant variable associated with HIV infection in women. After controlling for possible confounding variables using multivariate logistic regression analysis, the presence of cervical ectopy (odds ratio, 5.0; P = .007) remained the only independent predictor of HIV seropositivity. These findings suggest that cervical ectopy may be a newly identified risk factor for heterosexual transmission of HIV.
Adult↗
Oral manifestations of HIV-1 infection in Zairian patients.
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Cross-Sectional Studies↗
Comparison of five commercial enzyme-linked immunosorbent assays and Western immunoblotting for human immunodeficiency virus antibody detection in serum samples from Central Africa.
Detection by five different enzyme-linked immunosorbent assays (ELISAs) of antibody to human immunodeficiency virus (HIV) in sera from three Zairian populations consisting of 1,998 individuals with various risks for HIV infection was evaluated. Sera that were reactive by at least one assay and 10% of the nonreactive serum samples were analyzed by Western blot (immunoblot) by using U.S. Public Health Service interpretation criteria. Sera which were positive by ELISA for detection of antibody to HIV-1 and HIV-2 and negative or indeterminate by HIV-1 Western blot were also analyzed by HIV-2 Western blot. Overall, 443 (22.2%) serum specimens were HIV-1 Western blot positive, 390 (19.5%) had indeterminate HIV-1 Western blot patterns, and no samples were HIV-2 Western blot positive. The sensitivity of the ELISAs ranged from 97.5 to 99.8%, and the specificity ranged from 51.7 to 98.4%. By population group, the negative predictive value ranged from 97.1 to 100%, in contrast to the positive predictive value, which varied from 6.6 to 100%. Follow-up results for sera which were indeterminate for antibody to HIV-1 documented only four seroconversions (6.0%) among 67 individuals at high risk for HIV-1 infection and no seroconversions among 202 individuals at relatively low risk for HIV-1 infection. This study demonstrates the importance of evaluating commercial ELISAs with sera from appropriate geographical regions in order to select the most cost-effective and practical assay for use in that region. Furthermore, the high frequency of indeterminate Western blots for African sera emphasizes the continual need for improved confirmatory assays and interpretation criteria.
Blotting, Western↗