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P Piot

Publications and source records attributed to P Piot.

At least 73 records · Page 4Linked to original sources
PubMed1994

A socioeconomic, clinical and serological study in an African city of prostitutes and women still married to their first husband.

The aim of this paper was to compare women involved in prostitution with a group of women still married to their first husband and reporting having had only one sexual partner, in order to ascertain what factors if any contributed to women going into prostitution or staying still married to their first husband, their only sexual partner, and thereafter to compare clinical and serological aspects of the gynaecological conditions of the women in these two groups. The role of prostitutes in transmission of sexually transmitted diseases (STD) is widely recognised. Socioeconomic factors determining whether a woman will drift into prostitution or have a stable first marriage are largely unknown as are prevalence rates of STD, pelvic inflammatory disease (PID) and cervical cancer in these women. A socioeconomic, clinical and serologic study is reported for 2111 Ethiopian women attending teaching hospitals and maternal and child health clinics in Addis Ababa, analysing basic demographic data of three groups of women: (i) 278 engaged in prostitution, (ii) 730 still married to their one and only sexual partner, and (iii) 1103 single, widowed, divorced or married to their second or subsequent partner. Thereafter groups (i) and (ii) were compared and contrasted with regard to further socioeconomic, clinical and serological associations. The most significant socioeconomic associations for women in prostitution were low income (95% had < 50 Ethiopian birr [< U.S. $25] per month), ethnic group, and the timing of first coitus in relation to the menarche (81% were first married by age 15), in that order. Women still married to their first sexual partner had higher income, higher age at first marriage and longer duration of marriage. Sero-prevalence rates of STD in prostitutes were high: gonorrhoea 88%, genital chlamydiae 78%, syphilis (TPHA) 62%, HSV2 and HBV 46%, and chancroid 19%: 67% had PID and 2.9% cervical cancer. In comparison, rates for women married to their first and only sexual partner were: gonorrhoea 40%, genital chlamydiae 54%, syphilis (TPHA) 19%, HSV2 33%, HBV 35%, chancroid 13%, PID 47% and cervical cancer 1%. While the very high prevalence of STD in women involved in prostitution is not so unexpected, the high rate of STD in women still married to their first and only sexual partner is indicative of male promiscuity. Control of prostitution and diseases spread by it, together with education of both men and women is a national priority.

Adolescent↗
PubMed1994

Genetic and antigenic variability of HIV type 1 in Brazil.

Six Brazilian strains of human immunodeficiency virus type 1 (HIV-1) were isolated from infected individuals residing in different regions of Brazil between 1987 and 1989. Phylogenetic analysis based on an 860-base pair env fragment, including V3, V4, V5, and the beginning of gp41, classified the Brazilian strains significantly in genotype B, with interhost distances between 5.9 and 13.1% (mean value, 10%). Amino acid sequence analysis of the V3 loop revealed that three strains contained the North American/European GPGR motif as the tip of the loop whereas in the other three strains proline (P) was substituted by tryptophan (W), methionine (M), or phenylalanine (F). A consensus peptide, Bra-cons, was designed containing GWGR as the tip of the loop. Serological reactivity to the Bra-cons peptide and other V3 peptides (MN, SF2, HBX2, RF, MAL, ELI, Z6, and a Côte d'Ivoire peptide, CI-cons) was compared for 114 HIV-1-positive sera from Rio de Janeiro. Sixty-nine sera (60.5%) reacted with peptides belonging to genotype B, of which 10 sera also reacted with peptides belonging to genotype A (n = 7) and D (n = 3). Eighteen sera (15.8%) had binding antibodies to the Bra-cons peptide. A high number of sera (n = 43; 37.7%) had no antibodies to any of the V3 peptides tested. This result suggests that HIV-1 variants with aberrant V3 loops may circulate in Rio de Janeiro.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Isolation of simian immunodeficiency viruses from two sooty mangabeys in Côte d'Ivoire: virological and genetic characterization and relationship to other HIV type 2 and SIVsm/mac strains.

OBJECTIVE: To search for the presence of SIV in sooty mangabeys and other monkey species in Côte d'Ivoire, West Africa, and to compare viral isolates with HIV-2 strains from the same region. METHODS: Forty-three captive housed monkeys (28 African green monkeys, 6 sooty mangabeys, 6 baboons, and 6 patas monkeys) were tested for the presence of HIV and SIV antibodies. Virus was isolated from the peripheral blood lymphocytes of seropositive animals and from HIV-2 antibody-positive patients originating from Côte d'Ivoire, Ghana, Senegal, and Belgium. Viruses were characterized by Western blot and radioimmunoprecipitation assay. Proviral DNA was amplified by PCR, cloned, and sequenced to construct a phylogenetic tree. RESULTS: One African green monkey and three sooty mangabeys had antibodies that cross-reacted with HIV-2. From two mangabeys lentiviruses were isolated and designated as SIVsmCI2 and SIVsmCI8. Serological, virological, and sequence data showed that these isolates are members of the HIV-2/SIVsm/SIVmac group of primate lentiviruses. Furthermore, in the phylogenetic tree, these two new viruses form a distinct subgroup that is equidistant to the HIV-2 strains and the previously described SIVsm/SIVmac viruses. CONCLUSION: This study provides additional evidence that sooty mangabey monkeys can be infected with a lentivirus in their natural habitat. Within the SIVsm and SIVmac viruses extensive genetic variation is observed.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Mother-to-child transmission of human immunodeficiency virus type 1: report from the Nairobi Study.

Mother-to-child transmission of human immunodeficiency virus type 1 (HIV-1) is a significant problem in countries with endemic HIV-1 infection. Between 1986 and 1991, 365 children of HIV-1-infected mothers and 363 control children were studied in Kenya. The overall risk of transmission from mother to child, determined by serologic evidence of infection by age > or = 12 months and excess mortality in the HIV-1-exposed group, was 42.8% (range, 27.6%-62.2%). Marriage was the only maternal characteristic associated with transmission (odds ratio, 2.2; 95% confidence interval, 1.2-4.2; P < .05). Children who experienced growth failure were more likely to be infected. In 44% of children ultimately infected, the pattern of antibody response implied intrapartum or postnatal exposure to HIV-1. Of potential postnatal exposures examined, duration of breast-feeding beyond age 15 months and the mother being married were independently associated with increased risk of infection and seroconversion of children. The percentage of HIV infection attributable to breast-feeding > or = 15 months was 32%. The frequency of mother-to-child transmission of HIV-1 was high; a substantial proportion of infection occurred postnatally, possibly through breast-feeding.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Molecular phylogeny of part of the env gene of HIV-1 strains isolated in Côte d'Ivoire.

OBJECTIVES: To examine the genetic variation of HIV-1 isolates in Abidjan, Côte d'Ivoire, and to determine the extent to which phylogenetic trees based on sequence information of part of the env gene containing the principal neutralizing domain are representative for documenting genetic variability. DESIGN: Phylogenetic comparison of 13 HIV-1 strains isolated from patients in Abidjan with previously documented HIV-1 strains of different geographic origin. METHODS: To sequence a 900 base-pair fragment of the env gene containing V3, V4, V5 and the beginning of gp41 of three to four clones per isolate. Phylogenetic tree analysis was performed with the software package TREECON. RESULTS: Eleven HIV-1 isolates of Abidjan were classified as genotype A, while two were classed as genotypes B and D. Intra-genotype A distances at the nucleotide level were a maximum of 14.1%. Inter-genotype distances between genotype A and genotypes B, C, and D varied from 16.0 to 22.6%. Phylogenetic trees, based on sequence data of a 300 base-pair fragment containing the V3 loop, showed significant differences in tree topology and statistical confidence with phylogenetic trees based on sequence data of the 900 base-pair env fragment. CONCLUSIONS: Genotype A Côte d'Ivoire HIV-1 strains, which comprise 11 out of 13 isolates, predominate in Abidjan, which may indicate a local burst of particular variants. Phylogenetic trees should be interpreted with caution when based on a more limited number of nucleotides, such as the V3 region.

Base Sequence↗
PubMed1994

Cross-neutralizing antibodies to HIV-1ANT70 and HIV-1IIIB in sera of African and Belgian HIV-1-infected individuals.

OBJECTIVES: To determine the neutralizing antibody patterns to HIV-1ANT70 (ANT70) and HIV-1IIIB (IIIB) in human sera obtained from HIV-1-infected individuals from different African countries and Belgium. Second, to correlate the presence of neutralizing antibodies in sera and their ability to bind to synthetic peptides derived from eight different HIV-1 V3 loop sequences. DESIGN AND METHODS: Forty sera from Belgium and 88 obtained from seven countries in Africa were tested for their ability to neutralize ANT70 (one of the most genetically divergent HIV-1 isolates documented), and IIIB. Sera found to cross-neutralize both viruses were further challenged with four HIV-1 field isolates. All sera were tested on a panel of V3 loop peptides obtained from different HIV-1 genotypes. RESULTS: Four patterns of sera were identified, including 33 (26%) sera not neutralizing any of the isolates, seven (5%) sera neutralizing only ANT70, 45 (35%) sera neutralizing only IIIB, and 43 (34%) sera cross-neutralizing both isolates. Sera capable of cross-neutralizing both ANT70 and IIIB consistently neutralized other field isolates tested, with a remarkable similarity in neutralizing antibody titre. A significantly higher number of sera cross-neutralizing both ANT70 and IIIB compared with sera lacking neutralizing antibodies, reacted simultaneously in enzyme-linked immunosorbent assays (ELISA) with three or more V3 loop peptides belonging to HIV-1 strains of different genotypes. However, none of the sera cross-neutralizing ANT70 and IIIB were reactive in ELISA with the ANT70 V3 loop peptide. CONCLUSION: These results suggest that despite pronounced genomic variation of the HIV-1ANT70 isolate, there are strongly conserved neutralizing epitopes situated outside the V3 loop that are shared by other HIV-1 isolates. These findings suggest that genetic variation might be surmountable in the design of a polyvalent HIV vaccine, if neutralizing antibodies are found to be correlates of protection in HIV infection.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Genotypic subtypes of HIV-1 in Cameroon.

OBJECTIVE: The only two HIV-1 strains (ANT70 and MVP5180) reported to date from Cameroon are members of the outlier clade (group O). In this study, we assessed the prevalence of group O viruses and other HIV-1 subtypes in Cameroon. DESIGN: A phylogenetic analysis of 18 HIV-1 strains isolated from seropositive individuals from Yaoundé and Douala, Cameroon. METHODS: A 900 base-pair fragment of the env gene coding for V3, V4, V5, and the beginning of gp41 of 17 out of 18 HIV-1 isolates from Cameroon was amplified, cloned and sequenced using polymerase chain reaction. A phylogenetic tree was constructed. RESULTS: The overall env nucleotide sequence divergence among the Cameroon isolates ranged from 6.1 to 27.5%. In a phylogenetic tree, six subtypes were identified when compared with 23 reference strains of different geographic origin. Of these 17 Cameroonian strains, 11 (61%) were of subtype A of which the interpatient distances at the sequence level varied from 6.1% to 18.3% (average, 11.9%). Three (17%) strains were of subtype F, and the other three strains (6% each) belonged to subtypes B, E and H, respectively. The remaining isolate was classified as belonging to group O, on the basis of the sequence of part of the pol gene. A very broad spectrum of different tetrameric amino-acid sequences was observed at the apex of the V3 loop. Eleven strains contained the tetrameric globally predominant GPGQ sequence at the tip of the V3 motif. Two strains had the GPGR sequence typical of the American and European HIV-1 strains. The remaining tetrameric sequences included GPGS, GSGQ, GRGQ, and GLGR. CONCLUSION: These findings on a limited number of viruses suggest extensive env gene diversity of HIV-1 strains from Cameroon, and could have implications for vaccine development in Africa.

Amino Acid Sequence↗
PubMed1994

Antibodies to V3 loop peptides derived from chimpanzee lentiviruses and the divergent HIV-1ANT-70 isolate in human sera from different geographic regions.

OBJECTIVE: To study the spread of antibodies to V3 loop peptides of two chimpanzee lentiviruses and the divergent HIV-1ANT-70 isolate (group O) in human sera from different geographic regions, and to compare this with reactions to peptides from known North American (subtype B) and Zaïrean (subtype D) strains. METHODS: A total 2495 HIV-1-antibody-positive sera from nine countries were tested by enzyme-linked immunosorbent assay for antibodies to the V3 loop of 10 HIV/SIV isolates (including MN, SF2, HXB2, RF, MAL, ELI, Z6 and ANT-70 for HIV-1, and cpz-gab and cpz-ant for SIV). RESULTS: In each country, the highest prevalences were observed against the MN peptide (58.8-91.7%). Seroreactivity to other peptides from subtype B were generally lower. Prevalences of antibodies to V3 peptides derived from Zaïrean strains belonging to subtype D were generally lower than to subtype B. Relative high prevalences of sera reactive with the SIVcpz-gab V3 peptide were observed. The lowest rates were seen in Brazil (4.2%) and Belgium (25.7%). Among the African countries, the prevalence rates varied between 30.1 and 67.6%. Prevalence to the V3 loop derived from the SIVcpz-ant strains was much lower. Prevalence of sera reactive to the ANT-70 V3 loop peptide was very low, and the highest rates were observed in Cameroon (10.2%), Niger (6%) and Gabon (4.6%). Only the sera reactive to the ANT-70 V3 loop peptide from Cameroon and Gabon were confirmed on a specific HIVANT-70 Western blot (i.e., presence of antibodies to the envelope protein gp 120). CONCLUSIONS: The extent to which different V3 peptide reactivity patterns reflect the circulation of different HIV-1 strains in a particular population is not yet clear. However, V3 peptide serology using the very specific V3 peptide of the HIVANT-70 is a good indicator of the very aberrant group O in a particular population.

Amino Acid Sequence↗
PubMed1994

Maternal human immunodeficiency virus-1 infection and pregnancy outcome.

OBJECTIVE: To study the impact of maternal human immunodeficiency virus type 1 (HIV-1) infection on pregnancy outcome. METHODS: Between January 1989 and December 1991, 406 HIV-1-seropositive and 407 HIV-1-seronegative age- and parity-matched pregnant women from Nairobi, Kenya, all at less than 28 weeks' gestation, were recruited into a prospective study of HIV-1 infection in pregnant women and their offspring. Both groups were followed until 6 weeks postpartum. RESULTS: Three hundred fifteen HIV-1-seropositive women and 311 HIV-1-seronegative controls were followed until delivery. Seropositive women were younger at sexual debut and reported more lifetime partners and more sexually transmitted diseases (STDs) than the seronegative controls. The seropositive women had higher rates of genital ulcer disease (4.7 versus 2.0%; P = .08), genital warts (4.9 versus 2.0%; P = .03), and positive syphilis serology (7.9 versus 3.2%; P < .001), but there were no differences between the groups in isolation rates of Neisseria gonorrhoeae (6.8 versus 7.1%) and Chlamydia trachomatis (11.5 versus 9.0%). Maternal HIV-1 infection was associated with significantly lower birth weight (2913 versus 3072 g; P = .0003) and with prematurity (21.1 versus 9.4%; P < .0001), but not with small for gestational age size (4.2 versus 3.2%; P = .7). The stillbirth rate was higher in seropositive women, yet not statistically significant (3.8 versus 1.9%; P = .2). Women with a CD4 count lower than 30% had a higher risk of preterm delivery (26.3 versus 10.1%; P < .001). Postpartum endometritis was more common in HIV-1-infected women than in seronegative controls (10.3 versus 4.2%; P = .01) and was inversely correlated with the CD4 percentage. No histopathologic placental abnormalities attributable to HIV-1 were detected. CONCLUSION: Maternal HIV-1 infection was significantly associated with prematurity and postpartum endometritis, but not with fetal growth retardation. There was a trend toward a higher stillbirth rate in HIV-1-seropositive mothers.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Emergence of Haemophilus ducreyi resistance to trimethoprim-sulfamethoxazole in Rwanda.

The in vitro susceptibilities of 112 clinical isolates of Haemophilus ducreyi to six antimicrobial agents were determined. These isolates were obtained in Kigali, Rwanda, during three studies on genital ulcer disease performed in 1986 (18 isolates), 1988 (23 isolates), and 1991 (71 isolates). All H. ducreyi isolates were susceptible to azithromycin, ceftriaxone, ciprofloxacin, and erythromycin; all isolates obtained in 1986 were also susceptible to trimethoprim and to the combination trimethoprim-sulfamethoxazole. In contrast, 39 and 9% of the isolates obtained in 1988 and 59 and 48% of the isolates obtained in 1991 were resistant to trimethoprim (MIC, > or = 4.0 mg/liter) and trimethoprim-sulfamethoxazole (MIC, < or = 4.0/76 mg/liter), respectively. These data indicate that trimethoprim-sulfamethoxazole can no longer be recommended for use in the treatment of chancroid in Rwanda, and possibly elsewhere in Africa.

Anti-Bacterial Agents↗
PubMed1994

Detection of human immunodeficiency virus type 1 (HIV-1) in heel prick blood on filter paper from children born to HIV-1-seropositive mothers.

The human immunodeficiency virus type 1 (HIV-1) DNA PCR results of 94 dried blood spot (DBS) samples on filter paper and corresponding venous blood in EDTA obtained from infants born to HIV-1-seropositive mothers were compared. In addition, the results of HIV-1 DNA PCR on DBS and the HIV-1 RNA PCR from plasma of 70 paired samples were compared. A 100% specificity and a 95% sensitivity for HIV-1 DNA PCR on DBS compared with results for venous blood were observed for the 94 paired samples. The results of the DBS HIV-1 DNA PCR and HIV-1 RNA PCR of 70 corresponding plasma samples correlated perfectly (100%). The DBS HIV-1 DNA PCR method proved reliable for HIV-1 detection.

Adult↗
PubMed1994

Diagnosis of human immunodeficiency virus (HIV) infection: multicenter evaluation of a newly developed anti-HIV 1 and 2 enzyme immunoassay.

A new anti-human immunodeficiency virus type 1 and 2 (anti-HIV 1 and 2) test is described. It uses recombinant p24 and peptides covering gp32, gp41, and gp120 to identify HIV-1 and HIV-2 infections. This test has been shown to be specific (99.5%) and sensitive (99.8%). In this respect, the assay was equal or superior to anti-HIV 1 and 2 tests run as references. The test was able to discriminate sera from patients with HIV infections from those from uninfected individuals with excellence; it also exerted high intra- and interassay precisions. The "modular" concept of the test allows the use of single components (gp32 or gp41) to separate between HIV-2 and HIV-1 infections, respectively.

Diagnosis, Differential↗
PubMed1994

Comparison of E test with agar dilution for antimicrobial susceptibility testing of Neisseria gonorrhoeae.

A collection of 150 Neisseria gonorrhoeae isolates from Africa, where various resistance mechanisms among N. gonorrhoeae isolates are common, was used to the compare E test (AB Biodisk, Solna, Sweden) with agar dilution susceptibility testing. MICs obtained by the E test agreed within 1 log2 concentration by the agar dilution method for 97.5, 97.3, 96.6, 94, and 84.7% of the tested isolates for penicillin, ciprofloxacin, chloramphenicol, tetracycline, and trimethoprim-sulfamethoxazole, respectively. No significant difference in susceptibility categorization was observed between either method. The E test is an attractive alternative to the agar dilution technique and is a more appropriate method for N. gonorrhoeae susceptibility testing in developing countries.

Africa↗
PubMed1994

Quantification of human immunodeficiency virus in plasma by RNA PCR, viral culture, and p24 antigen detection.

A semiquantitative PCR technique for detecting human immunodeficiency virus type 1 (HIV-1) RNA in plasma was compared with quantitative viral culture and p24 antigen detection in plasma. Ninety-three samples from 20 symptomatic, 10 asymptomatic, and 10 seronegative individuals were tested. For most of the seropositive patients, consecutives samples were examined. Viral RNA was extracted from plasma by the method described by Boom et al. (R. Boom, C.J. A. Sol, M. M. M. Salimans, C.L. Jansen, P. M. E. Wertheim-van Dillen, and J. van der Noordaa, J. Clin. Microbiol. 28:495-503, 1990). The RNA PCR was the most sensitive method (100 and 74% sensitivity for symptomatic and asymptomatic patients, respectively) and produced less divergent results with the consecutive samples from individual patients compared with the other techniques. All samples positive by viral culture or p24 antigen assay were also positive in the RNA PCR. For each of the three assays, the number of positive results obtained correlated with the disease stage. The estimated mean number of HIV-1 RNA copies was significantly higher in symptomatic patients (22,750 copies per ml) than in asymptomatic patients (1,820 copies per ml). It was also higher in samples positive for viral culture than in culture-negative samples. No close correlation was found between the amount of HIV-1 RNA and the amount of p24 antigen or the titer of infectious virus in plasma or between this titer and the level of p24 antigen. The plasma RNA PCR may be a useful additional marker of disease progression and may be valuable for monitoring the effects of antiviral therapy.

Acquired Immunodeficiency Syndrome↗
PubMed1994

State of our knowledge: the epidemiology of HIV/AIDS.

The first part of this paper describes the current global situation of the AIDS pandemic, and the second part the dynamics of the heterosexual transmission of the HIV virus in a population. Risk factors for HIV infection are presented in three different categories: environmental risk factors, including all epidemiological and socio-economic variables which modify the HIV prevalence in a community and operate beyond the control of individuals taken separately; personal risk factors, including the behavioural variables which determine an individual's probability of being exposed to an HIV-positive sexual partner; and biological risk factors, including the known and putative variables which facilitate the transmission of the virus between two partners of differing serostatus. As preventive strategies should be targeted against risk factors which are both preventable and responsible for a large number of HIV transmissions, an attempt is made in this paper to identify in four different populations the risk factors which account for the largest proportion of HIV infections.

Acquired Immunodeficiency Syndrome↗