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Biomedical subjects

P Piot

Publications and source records attributed to P Piot.

At least 91 records · Page 5Linked to original sources
PubMed1994

Teenage obstetric and gynaecological problems in an African city.

OBJECTIVE: To measure the prevalence of sexually transmitted diseases (STD), pelvic inflammatory disease (PID), cervical cancer, pregnancy and use of contraception in teenagers, and to determine socioeconomic factors associated with these conditions to aid planners of medical services and promotion of sexual health. SUBJECTS: 181 Ethiopian teenagers and 1,845 women aged 20 to 45 years for comparison. SETTING: Gynaecological outpatient department, antenatal, postnatal and family planning clinics, in two teaching hospitals and a mother and child heath centre in Addis Ababa, Ethiopia. METHODS: Results of serologic tests for STD, clinical evidence of PID, and cervical cytology were analysed against socio-economic factors. RESULTS: In teenagers early age at first marriage/coitus, more common in those of rural origin, was associated with poverty, a greater number of lifetime sexual partners, and prostitution: 40 pc were first sexually active before the menarche. Prevalence of seropositivity to specific STD pathogens was; Treponema pallidum (TPHA) 21 pc, Neisseria gonorrhoeae (gonococcal antibody test: GAT) 40 pc, genital chlamydiae 51 pc, hepatitis B virus 36 pc, herpes simplex virus (HSV-2) 32 pc, and Haemophilus ducreyi 16 pc: 92 pc of teenagers were seropositive to one or more STD's. STD seroprevalence was higher in those with more than one sexual partner, those sexually active by age 15 (very high in those sexually active by age 12), those involved in prostitution and those attending the family planning clinic. Forty three pc had clinical evidence of PID; one married at age 10 had invasive cervical cancer by age 18; 40 pc of teenagers were pregnant compared with 25 pc of those aged 20 to 45; 21 pc attended for family planning; of regular FPC attenders 81 pc were GAT seropositive. CONCLUSION: Despite legislation early age of sexual debut is common, STD and PID are widely prevalent, the pregnancy rate in adolescents is high and contributes to the national population growth rate. Action is required at family, medical and governmental level to encourage cultural acceptance that marriage and sexual activity should not occur before the age of 16 years, with education appropriate to culture to prevent STD. Similar studies are recommended in other countries to establish a baseline for informed strategy regarding prevention of STD and health education.

Adolescent↗
PubMed1994

Rapid plasma reagin card test: evaluation of a hand-rotation procedure and stability of the RPR antigen.

Reported are the results of a comparative study of two procedures for the rapid plasma reagin (RPR) test for syphilis serology: in one approach a mechanical rotator was used and in the other, hand rotation was employed. Both procedures were performed on 327 sera. The agreement between both was 98.8%. Three sera that exhibited minimal reactivity (titre = 1) in the mechanical-rotation RPR were nonreactive in the hand-rotation RPR. RPR antigen was stored for 3 months at room temperature (mean, 21 degrees C) and 30 degrees C. There was no difference in the reactivity of 62 sera (50 positive, 12 negative) that were tested using either adversely stored antigens or antigen stored at 4 degrees C. In poorly equipped settings at the primary health care level, the hand-rotation RPR is a practical alternative to mechanical rotation. Also, the stability of the antigen under adverse storage conditions is an additional advantage of RPR for use in tropical areas.

Antigens, Bacterial↗
PubMed1993

HIV infection and AIDS in the tropics.

One decade after the first description of the acquired immunodeficiency syndrome (AIDS), the epidemic has become a world-wide public health problem. Infection with the human immunodeficiency virus (HIV) is now spreading most rapidly among the poorer populations in the industrialised world and in the developing world. It has become the most important cause of death among adults in the major African cities and it absorbs an ever increasing proportion of health care budgets. On a global scale heterosexual intercourse is now the most common mode of transmission of HIV, resulting in a growing problem of transmission of the virus from mother to child. As a result of the AIDS epidemic, the incidence of tuberculosis is rising in virtually all populations. Developing countries face a double, gigantic challenge in an unfavourable economic and political climate: caring for those infected with HIV and preventing new infections.

Acquired Immunodeficiency Syndrome↗
PubMed1993

Non-Hodgkin lymphoma in Gabon and its relation to HTLV-I.

A case-control study was performed in Libreville, Gabon, to determine whether a relationship can be established between the relatively high proportion of non-Hodgkin lymphoma (NHL) among all cancer cases and the high seroprevalence rate of HTLV-I observed, and to discover whether cases of adult T-leukemia/lymphoma (ATLL) related to HTLV-I exist in Gabon. From November 1987 to April 1989, a total of 32 patients with NHL were recruited; 6 were infants with Burkitt's lymphoma and 26 were adults with NHL. Each patient was matched with 2 asymptomatic controls for age, sex and ethnic group. HTLV-I serology was done by ELISA and Western blot. Comparison of the groups was done by chi-square analysis. None of the 6 infants with Burkitt's lymphoma and none of their controls had antibodies to HTLV-I. Of the 26 patients with NHL, 7 (26.9%) had HTLV-I antibodies. Among the 52 controls, the HTLV-I rate was 13.4% (n = 7). There was no difference between cases and controls (Fisher's exact test, p = 0.16). Among the 26 NHL, 4 cases fitted the criteria of ATLL and were HTLV-I-positive; 3 others who were positive for HTLV-I were a woman with lymphoblastic gastric NHL and 2 old men with an unclassified lymphoma. From the results of this limited series it is not possible to state that there is an association between NHL and HTLV-I infection. Nevertheless, cases of ATLL related to HTLV-I are reported from this area. Based on the HTLV-I seroprevalence rates reported in Gabon, the estimated incidence rate of ATL among seropositive people in Gabon appears much lower than in Japan. Different explanations can be proposed, but under-diagnosis of ATLL is probably one of the main factors.

Adolescent↗
PubMed1993

Use of a rapid test and an ELISA for HIV antibody screening of pooled serum samples in Lubumbashi, Zaire.

Pools with a size of 3 and 5 were prepared by mixing one HIV confirmed HIV-1 seropositive serum with either 2 or 4 HIV seronegative sera at the Regional HIV Laboratory in Lubumbashi, Zaire. These pools were assessed in a blind fashion by ELISA (Vironostika anti-HTLV-III microELISA system, Organon Technika). Similarly constituted pools of 3 samples were assayed by a rapid test with visual reading (HIVCHEK 1 + 2, Dupont de Nemours). With the HIVCHEK, pooling was achieved on the test device itself by dropping consecutively 3 different serum samples on the devices's membrane. After the last serum was soaked in, wash fluid and conjugate were added. Results of the pooling experiments were compared with testing sera individually. The ELISA results from pools and from individual tested samples matched completely if, and only if, the final dilution of individual samples in the reagent medium was the same as recommended by the manufacturer for testing of individual samples. With the HIVCHEK a sensitivity of 99-100% was obtained with pooled sera. Both approaches seemed sensitive enough to enable their use for screening of blood donors and patient management, but a prospective study to validate these preliminary results is necessary.

Democratic Republic of the Congo↗
PubMed1993

Clinical algorithms for the screening of women for gonococcal and chlamydial infection: evaluation of pregnant women and prostitutes in Zaire.

A substantial proportion of women with gonococcal and/or chlamydial infection are asymptomatic. Thus active case detection is problematical, particularly in developing countries, where facilities and materials for laboratory testing are limited. We assessed the diagnostic validity of the hierarchical clinical algorithms recommended by the World Health Organization as well as that of a nonhierarchical scoring system, using data for 1,160 pregnant women (a low-prevalence group) and 1,222 prostitutes (a high-prevalence group) in Kinshasa, Zaire. Neisseria gonorrhoeae and/or Chlamydia trachomatis was detected in 6.5% and 31.0% of pregnant women and prostitutes, respectively. No single variable that was both sensitive (> 60%) and specific (> 60%) was associated with infection. A simple hierarchical algorithm based only on reported symptoms had a sensitivity of 48.0% and 54.9% and a specificity of 75.2% and 52.2% for the screening of pregnant women and prostitutes, respectively. A second algorithm that included a speculum examination had a sensitivity of only 29.3% but a specificity of 85.3% in pregnant women. When a nonhierarchical scoring system was used, the sensitivity was 72.0% and 71.0% and the specificity was 73.5% and 55.8% for pregnant women and prostitutes, respectively. Scoring systems that incorporate risk markers as well as symptoms and signs may represent affordable alternative methods of screening for gonococcal and/or chlamydial infections among women in resource-poor settings.

Adult↗
PubMed1993

Antigen detection and immunological typing of Haemophilus ducreyi with a specific rabbit polyclonal serum.

A rabbit polyclonal serum was raised against the 29-kDa species-specific marker, as well as the 30- to 34-kDa immunotype-specific markers of Haemophilus ducreyi described elsewhere (E. Roggen, S. De Breucker, E. Van Dyck, and P. Piot, Infect. Immun. 60:590-595, 1992). These antigens were purified from a cocktail of H. ducreyi isolates by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The immune serum reacted in enzyme-linked immunosorbent assay (ELISA) preferentially with H. ducreyi, at a titer as high as 50,000. To make it specific to H. ducreyi, nonspecific antibodies were removed by adsorption on a mixture of Haemophilus spp., Escherichia coli, Candida albicans, and Corynebacterium spp. In the 29- to 34-kDa region of immunoblot profiles from H. ducreyi isolates (n = 450), the adsorbed serum revealed essentially the same antigens as did a pool of well-characterized human sera. Yet, eight different immunotypes were observed. With this rabbit polyclonal serum, an ELISA-based antigen detection test was developed. The adsorbed serum reacted specifically with all H. ducreyi isolates tested (n = 450), but not with other bacterial species (n = 15). This test was evaluated with a limited number of clinical specimens from African patients with culture-proven chancroid and no evidence for any other ulcerating etiology (n = 10) and a number of chancroid-negative control patients from Belgium (n = 20). Within this context, the test yielded a sensitivity and specificity of 100%.

Animals↗
PubMed1993

Effectiveness of norfloxacin and ofloxacin for treatment of gonorrhoea and decrease of in vitro susceptibility to quinolones over time in Rwanda.

OBJECTIVE: To study the effectiveness of single-dose norfloxacin and ofloxacin in the treatment of gonococcal urethritis in men, and to monitor in vitro antimicrobial susceptibility to these antibiotics over time. SETTING: Centre Médico-Social de Bilyogo, Kigali, Rwanda. The only clinic in Rwanda using quinolones for the treatment of gonorrhoea. METHODS: As part of a monitoring programme, men with gonococcal urethritis were evaluated after treatment with norfloxacin (800 mg) in 1986 and 1987, and after treatment with ofloxacin (400 mg) in 1989. RESULTS: Neisseria gonorrhoeae was eradicated from the urethra from 96.0% (189/197) and from 97.1% (166/171) men treated with norfloxacin and ofloxacin, respectively. Overall 38.2% of the pretreatment isolates produced penicillinase (PPNG isolates) and 20.4% (44/216) of the tested non-PPNG isolates were chromosomally resistant to penicillin (MIC > or = 2.0 mg/l). Resistance to tetracycline and thiamphenicol was common in both PPNG and non-PPNG and increased considerably in 1989. All isolates were susceptible to kanamycin, spectinomycin, ceftiaxone, norfloxacin, ofloxacin and ciprofloxacin. However, a higher number of isolates recovered in 1989 showed decreased susceptibility to the quinolones. Treatment failure occurred more often in subjects with isolates having MIC values > or = 0.06 mg/L of norfloxacin (p = 0.006). Seven out of 13 patients who did not respond to therapy had no signs nor symptoms of urethritis. CONCLUSION: Quinolone antibiotics are now indicated as a first line treatment of gonorrhoea in countries with a problem of antimicrobial multiresistance. However, antimicrobial susceptibility to the quinolones may decrease rapidly, and close monitoring of the in vitro susceptibility of N gonorrhoeae and the clinical effectiveness of the antibiotics is imperative.

Administration, Oral↗
PubMed1993

High prevalence of sexually transmitted diseases in a rural area in Mozambique.

OBJECTIVE: To assess the extent of the sexually transmitted diseases (STDs) problem in a rural area of Mozambique. METHODS: A cross sectional study among pregnant women and patients presenting with genital complaints. Laboratory confirmation was done for gonorrhoea, chlamydial infection, active syphilis, trichomoniasis and HIV infection. SETTING: A primary health care setting in Vilanculos, Inhambane province, Mozambique. RESULTS: Evidence of one or more of the above STDs was found in 51% of 201 pregnant women, 56% of 85 women and 62% of 77 men with genital complaints. Neisseria gonorrhoea or Chlamydia trachomatis were found in 16% of pregnant women, 23% of female patients and 28% of male patients; genital ulcer disease was present in 6%, 28% and 36%, of respectively pregnant women, female and male patients. The prevalence of active syphilis was about the same in the three groups of study subjects, that is 15%. HIV infection was found in 4% of the male patients; no HIV infection could be detected in the female groups. CONCLUSION: STDs were a major health problem in this rural area in Mozambique. Though HIV infection was still low, the high prevalence of STDs indicates that the potential is there for an explosive spread of the HIV/AIDS epidemic.

Adolescent↗
PubMed1993

Low and stable HIV seroprevalence in pregnant women in Shaba province, Zaire.

Sentinel serosurveillance for HIV infection has been carried out in Shaba province, Zaire, among consecutive pregnant women attending antenatal clinics from 1989 to 1991. There were four surveillance sites (three urban and one semiurban), at which a total of 13 surveillance studies were made of 4,205 women. Overall, 3.1% were HIV seropositive. There were no significant differences in HIV seroprevalence between surveillance sites, and HIV seroprevalence did not increase at any of the surveillance sites during the 2-year period of study. Since changes in the population studied did not occur between surveillance studies, it is believed that the observed stable trend reflects stable HIV seroprevalence rates in the general adult population of the surveillance sites. Collateral HIV seroprevalence data were available from 8,725 blood donors at 20 sites (six urban, 14 rural) in the province, who had an overall HIV seroprevalence of 4.6%. The higher HIV seroprevalence rate among blood donors was probably due to selection bias, since HIV seroprevalence rates in two blood banks, which relied nearly exclusively on replacement donors, were 2.7 and 2.8%, our best estimate for HIV seroprevalence in the three cities where blood banks exist and where no surveillance studies were carried out. The stable and relatively low HIV seroprevalence rates in Shaba province are in sharp contrast with the rapidly increasing and much higher rates in neighboring Zambia and other East African cities. Reasons for this discrepancy are unclear, and their eludication may yield critical information for HIV prevention programs.

Adult↗
PubMed1993

Blood transfusion as a major risk factor for HTLV-I infection among hospitalized children in Gabon (Equatorial Africa).

To study the risk factors for HTLV-I infection of African infants living in a high seroprevalence area, a survey was conducted among hospitalized children and their mothers in Franceville, southern Gabon. A total of 610 children (6 months to 14 years old) from 555 families and 434 mothers participated in the study. HTLV-I seroprevalence was 7.1% in the mothers and 2.8% in the children. No increase by age was observed in the children. Significantly more children with sickle cell anemia (11 of 57, or 19.2%) were infected than others (1%) (Fisher's exact test p < 0.001). Of the 13 seropositive infants (C+) whose mothers were tested, six (43%) had a seropositive mother (M+) [p < 0.001, prevalence ratio (PR) 10.12, 95% CI 3.40-30.35, attributable risk (AR) 0.55]. Risk factors for nonmaternally acquired HTLV-I infection were previous blood transfusion (Fisher's exact test p < 0.001, PR 15.74, CI 5.20-47.60, AR 0.71) and hospital admission. In a hospitalized pediatric population in Gabon mother-to-child transmission and blood transfusion (because of sickle cell disease) were equally implicated in HTLV-I infection. Control of HTLV-I infection in children in Africa requires prevention of both vertical and transfusion-associated transmission, which may be exceedingly difficult in developing countries.

Adolescent↗
PubMed1992

Virological and polymerase chain reaction studies of HIV-1/HIV-2 dual infection in Côte d'Ivoire.

Dual serological reactivity to the human immunodeficiency virus (HIV) types 1 and 2 is common in Côte d'Ivoire. To assess whether dual infection is the reason for dual seropositivity we sought HIV-1 and HIV-2 proviral DNA in primary uncultured peripheral blood mononuclear cells from selected seropositive patients in Côte d'Ivoire with the polymerase chain reaction (PCR). PCR on primary lymphocytes in 36 dually seropositive samples revealed the presence of both HIV-1 and HIV-2 proviral DNA in 12 cases and the presence of HIV-1 only in 24 cases. In 18 of these 36 samples a virus was isolated and identified by PCR. HIV-1 was isolated from the 9 specimens with only HIV-1 proviral DNA in the primary lymphocytes. Among dually PCR-positive samples, 2 viral isolates reacted with both HIV-1 and HIV-2 primers; and only HIV-2 (n = 1) or HIV-1 (n = 6) strains were isolated from the other samples. The findings show that surveys based on serology may overestimate the prevalence of mixed infections in areas where both HIV-1 and HIV-2 occur.

Biomarkers↗
PubMed1992

Human T-cell lymphotropic virus type 1 infection and tropical spastic paraparesis in Belgian expatriates.

A case of HTLV-1 associated tropical spastic paraparesis is described in a Belgian nun who had been working as a midwife in Central Africa. Occupational exposure was the only risk factor identified. Among 2,482 Belgian expatriates in tropical countries, 92% of whom had resided in sub-Saharan Africa for an average of 15.5 years, only one Belgian-born man was found seropositive for HTLV-1. He was married to an African woman and living in Central Africa for 23 years. The risk of HTLV-1 infection is low in Belgian expatriates and on its own does not support generalised anti-HTLV screening in autochthonous Belgian blood donors.

Belgium↗
PubMed1992

Accuracy of two enzyme immunoassays and cell culture in the detection of Chlamydia trachomatis in low and high risk populations in Senegal.

Two enzyme immunoassays (EIAs), Chlamydiazyme (CZ; Abbott Laboratories) and Pathfinder (PF; Kallestadt), were compared with a cell culture technique in the detection of cervical Chlamydia trachomatis infection in 670 women in urban settings in Senegal (377 pregnant women and 293 prostitutes). Positive CZ and positive PF specimens were tested a second time using a monoclonal antibody blocking technique. True positive specimens were defined as those positive on culture or positive on EIA with confirmation of the result after blocking. Using this definition, the prevalence of genital chlamydial infection was 14.6% and 14.3% in pregnant women and prostitutes respectively. An important difference between the two populations was that the pregnant women were younger than the prostitutes, which might explain the fact that the prevalence of infection among the pregnant women was as high as that among the prostitutes, although the age-adjusted prevalence was higher among prostitutes than among pregnant women. The chlamydial detection rates of cell culture, CZ and PF were 62% (26/42), 69% (29/42) and 86% (36/42) respectively in prostitutes and 76% (42/55), 40% (22/55) and 53% (29/55) respectively in pregnant women. Agreement between the tests was 89%, 85% and 88% for culture/CZ, culture/PF and CZ/PF respectively. However, when data were adjusted for chance agreement, kappa coefficients were 0.40 for culture/CZ, 0.34 for culture/PF and 0.48 for CZ/PF. These results indicate that the accuracy of the EIAs and cell culture may vary greatly in different populations: both EIAs showed a distinctly higher detection rate than culture in prostitutes and a significantly lower detection rate in pregnant women.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Alternative confirmatory strategy for anti-HIV antibody detection.

Enzyme immuno assays for simultaneous screening of antibodies to HIV-1 and HIV-2 (EIA HIV-1 + HIV-2) have recently been developed. Confirming all reactive EIA HIV-1/2 screening results by Western blot (WB) for HIV-1 and HIV-2 antibodies is expensive. Six different EIA HIV-1/2 screening assays and one supplemental Line immuno assay (INNO-LIA HIV-1/HIV-2 Ab (LIA)) for confirmation of reactive EIA HIV-1/2 screening assay results were carried out on a panel of 400 sera of which 13% were HIV-1- and 2.5% were HIV-2-positive. The LIA was used as the 'gold standard'. Retrospectively, the results of the six EIA HIV-1/2 were evaluated in pairs (A and B), applying B to those sera reactive in A. A+B+ results were reported as positive. A+B- were either interpreted as negative or the LIA result of A+B- was accepted as the final result. At least seven of the EIA HIV-1/2 pairs gave rise to no false-positive or -negative results. This strategy was 5 times faster and resulted in a budget on average 50% lower than that of the conventional strategy. Further investigation of these alternative confirmatory strategies, in which the proposed algorithms are applied in sequential use of the different screening assays, are needed under field conditions in developing countries.

Costs and Cost Analysis↗