Sexually transmitted infections in male clients of female sex workers in Benin: risk factors and reassessment of the leucocyte esterase dipstick for screening of urethral infections.

OBJECTIVES: (1) To assess risk factors for urethral infections with Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis among male clients of female sex workers (FSWs) in Benin; (2) to study the validity of LED testing of male urine samples compared to a highly sensitive gold standard (PCR) for the diagnosis of urethral infections with the organisms cited above. METHODS: Male clients of FSWs (n=404) were recruited on site at prostitution venues in Cotonou, Benin, between 28 May and 18 August 1998. A urine sample was obtained from each participant just before he visited the FSW, and tested immediately using a leucocyte esterase dipstick (LED) test. It was then tested for HIV using the Calypte EIA with western blot confirmation, and for C. trachomatis, N. gonorrhoeae, and T. vaginalis by PCR. After leaving the FSW's room, participants were interviewed about demographics, sexual behaviour, STI history and current symptoms and signs, and were examined for urethral discharge, genital ulcers, and inguinal lymphadenopathies. RESULTS: STI prevalences were: C. trachomatis, 2.7%; N. gonorrhoeae, 5.4%; either chlamydia or gonorrhoea 7.7%; T. vaginalis 2.7%; HIV, 8.4%. Lack of condom use with FSWs and a history of STI were independently associated with C. trachomatis and/or N. gonorrhoeae infection. Over 80% of these infections were in asymptomatic subjects. The overall sensitivity, specificity, positive and negative predictive values of the LED test for detection of either C. trachomatis or N. gonorrhoeae were 48.4%, 94.9%, 44.1%, and 95.7%, respectively. In symptomatic participants (n=22), all these parameters were 100% while they were 47.4%, 94.7%, 37.5%, and 96.4% in asymptomatic men (n=304). CONCLUSIONS: Since most STIs are asymptomatic in this population, case finding programmes for gonorrhoea and chlamydia could be useful. The performance characteristics of the LED test in this study suggest that it could be useful to detect asymptomatic infection by either C. trachomatis or N. gonorrhoeae in high risk men.

Prevalence of Chlamydia trachomatis and Neisseria gonorrhoeae among at-risk women, young sex workers, and street youth attending community organizations in Quebec City, Canada.

BACKGROUND: Despite a relatively recent decline in the global incidence of Chlamydia trachomatis and Neisseria gonorrhoeae it seems that some segments of the population such as street youth, sex workers, and individuals with social problems or delinquent behavior could be part of a core group for STDs. These persons may be reluctant to undergo STD diagnosis in traditional medical settings. GOALS: To determine the prevalence of C trachomatis and N gonorrhoeae infection using polymerase chain reaction on urine samples among subjects attending an anonymous HIV testing clinic and four community organizations in Quebec City, and to identify associated risk factors. STUDY DESIGN: A cross-sectional study of 626 street youth, sex workers, and women with social problems or delinquent behavior was conducted. RESULTS: The prevalences of N gonorrhoeae and C trachomatis were, respectively, 1.1% (95% CI, 0.5%--2.3%) and 5.8% (95% CI, 4.1%--7.9%). No significant difference was found between men and women, but the sexually transmitted disease (STD) prevalence was much higher in subjects younger than 20 years: 11.4% versus 3.6% (P < 0.01). In a logistic regression model, factors independently associated with STD infection were age younger than 20 years (OR, 2.6; P = 0.007), occasional sex partners (OR, 2.9; P = 0.007), and injection of drugs (OR, 2.8; P = 0.002) in the preceding 6 months. CONCLUSIONS: A moderate STD prevalence was found in the study population. The prevalence, however, can be considered high (>10%) among street youth and young sex workers. Providing community-based STD screening and treatment services appear to be an efficient method for reaching these high-risk groups.

Unexpected similarity of pulsed-field gel electrophoresis patterns of unrelated clinical isolates of Legionella pneumophila, serogroup 1.

Phenotypic and genotypic methods identify subtypes of Legionella pneumophila, serogroup 1, and match patient and environmental isolates from suspected sources. The strength of this association is limited by the lack of information regarding the frequency and distribution of isolates belonging to various subtypes. In this study, 62 clinical isolates of L. pneumophila, serogroup 1, were subtyped by using pulsed-field gel electrophoresis (PFGE), to determine the distribution and degree of diversity of PFGE patterns among monoclonal antibody (MAb) subtypes. Unexpectedly, 8 of 21 MAb Philadelphia 1 isolates had a common PFGE pattern, and, among 12 MAb OLDA isolates, only 2 PFGE patterns were seen. Our hypothesis was that PFGE patterns were distributed randomly; however, statistical analysis showed that the distribution of subtypes was not random (Fisher's exact test 0.13; P>.05). In light of these results, researchers who do epidemiological investigations should use caution when interpreting the significance of matching PFGE patterns of L. pneumophila, serogroup 1.

Diagnostic performance of the Roche AMPLICOR PCR in detecting Neisseria gonorrhoeae in genitourinary specimens from female sex workers in Cotonou, Benin.

The objective of this study was to evaluate the diagnostic performance of the Roche multiplex AMPLICOR Chlamydia trachomatis/Neisseria gonorrhoeae PCR test for the detection of Neisseria gonorrhoeae infection in female urine specimens and wet and dry endocervical swabs. Endocervical swabs and urine specimens were collected from 342 female sex workers from Cotonou, Benin, and were tested using the AMPLICOR C. trachomatis/N. gonorrhoeae test (Roche Diagnostic Systems, Inc., Branchburg, N.J.) with internal control detection. Endocervical swabs were also cultured on Thayer-Martin medium. A series of alternate standards that included a combination of all the tests but not the test being evaluated was used to assess the performance of the test with each type of specimen. The sensitivity, specificity, and positive and negative predictive values for the urine were 53.8, 98.9, 93.5, and 87.5%, respectively. Corresponding figures for the wet swab were 91.5, 100, 100, and 97.4%, respectively. Those for the dry swab were 96.3, 96.2, 88.5, and 98.8%, respectively. Based on this study, the AMPLICOR PCR assay showed a low sensitivity for detection of N. gonorrhoeae infection in urine specimens, whereas the test was found to be highly sensitive and specific with endocervical specimens.

Prevalence of Chlamydia trachomatis, Neisseria gonorrhoeae, and HIV infection among drug users attending an STD/HIV prevention and needle-exchange program in Quebec City, Canada.

OBJECTIVES: To determine the prevalence of Chlamydia trachomatis, Neisseria gonorrhoeae, and human immunodeficiency virus (HIV) infection among injection and noninjection drug users in Quebec City and to identify associated risk factors. STUDY DESIGN: Cross-sectional study of 738 drug users attending a sexually transmitted disease/HIV prevention and needle-exchange program in Quebec City, Canada. RESULTS: The prevalences of N. gonorrhoeae and C. trachomatis were, respectively, 0.4% (95% CI: 0.08%-1.2%) and 3.4% (95% Cl: 2.2%-5.0%). Through multivariate analysis, risk factors associated with sexually transmitted diseases were: among women, being aged between 20 and 24 years and having unprotected sex with commercial partners; in noninjection drug users; cocaine use and first intercourse before 13 years of age; in male noninjection drug users, having regular sexual partners in the previous 6 months. No case of HIV was found in participants who have never injected drugs, but the prevalence was 5.5% (6/110) among the exinjectors and 10.1% (35/347) in current injectors. CONCLUSION: Moderate sexually transmitted disease and HIV prevalences were found, although a high proportion of drug users reported risky behaviors. Needle-exchange program sites may offer a good opportunity to provide sexually transmitted disease/HIV prevention and medical services to drug users.

Passive immunity against measles during the first 8 months of life of infants born to vaccinated mothers or to mothers who sustained measles.

Neutralizing antibody titers of 47 infants whose mothers sustained measles (measles group) and 70 whose mothers were vaccinated (vaccine group) were compared at birth, 4 and 8 months of age. All children had antibodies at birth and 88% at 4 months. At 8 months, 49% had antibodies in the measles group and 15% in the vaccine group (P < 0.001). The geometric mean titers were significantly lower in the vaccine group than in the measles group and the difference corresponded to the antibody loss occurring in only 1.5 months of life. This small difference may reflect past exposure to wild virus of many vaccinated mothers.

Evaluation of a screening algorithm for the diagnosis of genital infections with Neisseria gonorrhoeae and Chlamydia trachomatis among female sexworkers in Bénin.

BACKGROUND AND OBJECTIVES: In developing countries, simple and cheap procedures for the diagnosis of sexually transmitted diseases (STDs) are urgently needed, especially for screening purposes in high risk groups. GOALS: To evaluate the sensitivity and specificity of a screening algorithm for STDs among 364 female sex workers in Bénin, in comparison with reference laboratory tests. STUDY DESIGN: The algorithm relied on the following criteria, which were evaluated in sequence: the presence of endocervical mucopus on visual inspection of the cervix, a positive swab test, or a microscopic examination of vaginal fluid showing more than 10 polymorphonuclear cells per field. The algorithm diagnosed an infection if any one of these criteria was fulfilled. True infectious status was determined by the combined results of culture for Neisseria gonorrhoeae, enzyme immunoassay for Chlamydia trachomatis, and polymerase chain reaction assays for both infections. RESULTS: Gonococcal or chlamydial infection was diagnosed in 39.8% of the study population according to the reference tests. The algorithm had a sensitivity of 57.9% and a specificity of 61.2%. In the presence of Candida sp or Trichomonas vaginalis, specificity decreased to 39.1%, but sensitivity increased to 67.5%. CONCLUSIONS: These results underscore the limitations of simple, nonlaboratory diagnostic tools for screening STDs in high-risk groups in developing countries. Further research is needed to increase the validity--especially the sensitivity--of these algorithms.

Measles, mumps, and rubella antibodies in children 5-6 years after immunization: effect of vaccine type and age at vaccination.

The levels of antibody against measles, mumps, and rubella were determined at 5-6 years postimmunization in 468 children vaccinated with two different trivalent vaccines. The proportions of children without detectable antibody levels were 12 and 3.6% for measles (p < 0.001), 14.9 and 7% for mumps (p = 0.006), and 3.3 and 3.1% for rubella (p = 0.88), respectively, in MMR II and Trivirix recipients. A higher proportion of those vaccinated at younger ages had undetectable or low levels of measles antibody. These data indicate that a large proportion of children vaccinated under routine conditions do not have detectable measles and mumps antibody.

Randomised comparison of amoxycillin and erythromycin in treatment of genital chlamydial infection in pregnancy.

Erythromycin, the standard treatment for chlamydial infection in pregnant women, commonly causes side-effects, which limits its efficacy. In a randomised, double-blind study, we compared amoxycillin with erythromycin in this setting. 210 pregnant women with Chlamydia trachomatis infection were randomly assigned 7 days' treatment with amoxycillin (500 mg three times daily) or erythromycin (500 mg four times daily). Control cultures were obtained 21 days after treatment, during late pregnancy, and from the infant within a week of birth. Treatment was judged a failure if any post-treatment culture was positive or if the patient had to stop therapy because of severe side-effects. 11 women (5.2%) were lost to follow-up. 1 (of 100) amoxycillin-treated women had to stop treatment because of severe side-effects compared with 12 (of 99) erythromycin-treated women (p = 0.002). 1 woman in the amoxycillin group had a positive culture at the third-trimester examination. No positive post-treatment culture was found in the erythromycin group. Severe gastrointestinal side-effects were more common in women who received erythromycin (31 vs 6%, p < 0.001). The overall failure rate was therefore 2% in the amoxycillin group and 12% in the erythromycin group (p = 0.005). These results suggest that amoxycillin is an acceptable alternative to erythromycin for C trachomatis infection in pregnant women.

Sentinel hospital surveillance of HIV infection in Quebec. Quebec Sentinel Hospital HIV-Seroprevalence Study Group.

OBJECTIVE: To measure the HIV seroprevalence rate in a surrogate sample of the general population in the province of Quebec, using a network of sentinel hospitals. DESIGN: Anonymous unlinked sentinel surveillance study. SETTING: Outpatient surgery units in 19 acute care hospitals throughout Quebec. PARTICIPANTS: All patients attending the outpatient surgery units from November 1990 to October 1992. A total of 61,547 plasma samples were obtained from leftover blood samples collected for cell counts. Fifty samples were excluded because of an insufficient amount of plasma and one because of an indeterminate result. INTERVENTION: HIV antibody testing with enzyme-linked immunosorbent assay; positive results confirmed with radioimmunoprecipitation assay. OUTCOME MEASURES: HIV antibody status, sex, year of birth and area of residence. RESULTS: The crude seroprevalence rate among the subjects aged 15 years or more was 0.4 per 1000 population (95% confidence interval [CI] 0.2 to 0.7) among the women and 3.6 per 1000 population (95% CI 2.8 to 4.4) among the men (p < 0.001). The rate after adjustment for age, sex and geographic distribution of the study population was 2.3 per 1000 population (95% CI 1.9 to 2.7). The seroprevalence rate among the male patients in the City of Montreal was much higher than the rates elsewhere in the province. It increased progressively during each of the four 6-month intervals of the study: 8.1, 8.7, 13.9 and 18.3 per 1000 respectively (chi 2 linear trend = 4.76; p = 0.029). No similar trends were observed outside Montreal for the male patients. There were too few seropositive female patients to draw any solid conclusion. CONCLUSIONS: Despite the possible drawbacks of a nonrandomized sampling scheme, this study suggests that in the male population the HIV seroprevalence rate is increasing in Montreal and is stable in all other areas of the province. The continued surveillance of HIV infection through anonymous unlinked studies is useful to monitor trends.

Comparison of single-dose cefotetan and multidose cefoxitin as intravenous prophylaxis in elective, open biliary tract surgery: a multicentre, double-blind, randomized study.

OBJECTIVE: To compare the safety, tolerance and prophylactic effectiveness of a single 2-g dose of cefotetan with a standard prophylactic regimen of cefoxitin in reducing the incidence of postoperative infections after elective, open biliary tract surgery. DESIGN: Multicentre, double-blind, randomized comparative study with a 4-week follow-up. SETTING: Five Canadian university centres. PARTICIPANTS: One hundred and eleven patients scheduled to undergo elective, open biliary tract surgery. INTERVENTIONS: The patients were randomly assigned to receive either cefotetan or cefoxitin in a ratio of 2:1; 76 patients received cefotetan and 35 received cefoxitin. MAIN OUTCOME MEASURES: Wound infection as defined by the Centers for Disease Control and Prevention and by clinical evaluation, adverse events and laboratory parameters. RESULTS: Two incisional wound infections were reported by patients in the cefotetan group, for an overall infection rate of 1.8% (2 of 111). No significant differences were found in the failure rate or in any other indicator of efficacy. The incidence of adverse events for cefotetan (12.6%) was not statistically different from that for cefoxitin (10.4%), and none of the 16 adverse events in the cefotetan group and 5 in the cefoxitin group was serious or severe. Only one event (rash) was possibly related to the study drugs. Several hematologic and biochemical parameters were found to be normal preoperatively and abnormal postoperatively, but no relation was found between these variations and the study drugs. These changes were mainly attributable to the operation. CONCLUSION: Cefotetan was found to be effective and comparable to cefoxitin, both in safety and in reducing the incidence of infection after elective, open biliary tract surgery.

Strategy for screening pregnant women for chlamydial infection in a low-prevalence area.

OBJECTIVE: To assess the prevalence and risk factors for chlamydial infection in pregnant women in the Quebec City area and to propose strategies for a screening program. METHODS: From January 1990 to July 1991, pregnant women from six centers were cultured for Chlamydia trachomatis. One hundred thirty-six with positive results and 536 with negative results were included in a case-control study on risk factors for this infection. RESULTS: The prevalence of C trachomatis was 1.9% (136 of 7305). In a logistic regression analysis, young age (P < .0001, test for trend), nulliparity (odds ratio [OR] 3.3; P < .00001), and a new sexual partner in the last year (OR 3.3; P = .0012) were independently associated with infection. With screening restricted to pregnant women under age 25 or those with at least one risk factor, 81.7% of women positive for C trachomatis would have been detected, whereas only 40.6% of all women would have been cultured. CONCLUSION: In a low-prevalence area for chlamydial infection in pregnant women, pre-screening criteria could optimize the use of specific diagnostic tests.

Temporary expatriation is related to HIV-1 infection in rural Senegal.

OBJECTIVES: To assess temporary expatriation as a risk factor for HIV infection in a rural area of Senegal and to examine the transmission of HIV from expatriates to their families. DESIGN: Cross-sectional study in identified expatriates and in a representative cluster sample of the general population from the same geographical area in northern Senegal. METHODS: In 1989, a survey (including questionnaire and serological tests for HIV-1 and HIV-2) was conducted in all expatriates currently living in 11 villages in northern Senegal and spouses of all expatriates (present or not) from this area ('expatriate' group, n = 258). In parallel, a cluster sample of 600 adults was drawn from eight villages of the same area, of whom 414 were selected as the control group since they and their spouses had not travelled outside Senegal in the last 10 years. RESULTS: In the 'expatriate' group, sera from 39 subjects were confirmed as HIV-positive by Western blot [17 out of 63 men (27.0%) and 22 out of 195 women (11.3%)]. Of these subjects, 33 were infected by HIV-1, four by HIV-2 and two had a dual HIV-1/2 profile. In contrast, only two subjects (one man and one woman) from the control group were infected by HIV-2 and none by HIV-1. In men, HIV-1 seroprevalence was associated with age < 40 years [odds ratio (OR), 7.4; P = 0.03] and previous sexually transmitted disease (STD) symptoms (OR, 13.5; P = 0.03), whereas the risk factors in women were age < 25 years (OR, 3.7; P = 0.04), being a widow (OR, 30.4; P < 0.01) and presence of sexual activity over the last 2 years (OR, 21.3; P < 0.01). CONCLUSIONS: Penetration of HIV-1 infection in a country where HIV-2 is endemic shows that the HIV-1 epidemic is currently spreading to rural West Africa. Migrant workers appear to play a major role in this epidemic.

In-vitro activity of RP 59500, a new synergic antibacterial agent, against Legionella spp.

The in-vitro activity of RP 59500, a new semisynthetic injectable streptogramin, was compared with that of erythromycin, rifampicin and ciprofloxacin against 189 Legionella spp. Rifampicin was the most active agent tested. RP 59500 was found to be more active than erythromycin against most strains, but less active than ciprofloxacin. Legionella pneumophila serogroups 1, 3, 4, 5 and 6 were more susceptible to RP 59500 than were L. pneumophila serogroups 2, 7, and 8. Legionella micdadei was the least susceptible species to RP 59500 and erythromycin. RP 59500 was similar in activity against isolates obtained from both patients and environmental sources. This activity was generally better than that of erythromycin.

Comparison of culture methods and an immunofluorescence assay for the detection of Legionella pneumophila in domestic hot water devices.

The objective of this study was to compare an indirect immunofluorescence assay with culture methods for the identification of Legionella pneumophila serogroups 1 to 6 in hot water samples taken from domestic environments. Hot water samples were obtained from the water heater, the shower heads, and the most frequently used faucet of 211 private houses. Concentrated water samples were inoculated on buffered charcoal yeast extract agar (BCYE) and on a semi-selective culture medium (GPV). Colonies with a morphology similar to that of Legionellaceae were subcultured on BCYE and on blood agar plates; those that grew on the former but not the latter were further characterized and identified by direct immunofluorescence techniques. The concentrated samples were also smeared on multiple-well microscope slides and tested by indirect immunofluorescence with monoclonal antibodies against L. pneumophila, serogroups 1 to 6. Of the houses studied, 30% were found to contain culturable L. pneumophila in at least one water sample, whereas 63% were positive by indirect immunofluorescence. The sensitivity of this assay compared with culture varied from 16.7-21.1%, and its specificity was between 76.7% and 88.3% depending on the sample source (water heater, shower heads, or faucet). In the 38 houses with at least one positive sample found by both immunofluorescence and culture, total or partial agreement between serogroups identified by both techniques was only 34%. The results obtained in this study strongly suggest that indirect immunofluorescence is not an adequate alternative for the identification of L. pneumophila in hot water systems.

Evaluation of variables in immunofluorescence procedures for the detection of antibodies against human herpesvirus 6 (HHV-6).

Ten human sera were used to study different parameters, namely, methods of smear preparation and fixation, and age of infected HSB-2 cells in order to optimize indirect immunofluorescence assay (IFA) and anticomplement immunofluorescence (ACIF) procedures to measure antibody levels against HHV-6. Results showed a greater sensitivity of rapid smear drying and methanol fixation over conventional acetone smear preparation. Cells harvested 6 days after infection and fixed with methanol exhibited a sharper and more intense fluorescence. IFA titers were higher than those obtained with ACIF, although the latter procedure enabled the distinction between three fluorescent sites. Reactivity pattern of individual sera against infected cells was variable and indicated that the human immune response to HHV-6 is directed against different antigens. An easier interpretation and a better definition of the fluorescence of HSB-2 cell line infected with HHV-6 strain Dv is obtained with the following conditions: cells should be harvested at 5-8 days after infection (at the giant cell stage of infection), cell smears have to be dried quickly before fixation with methanol at -20 degrees C, and finally, they should be stained by IFA.

Factors contributing to the contamination of hospital water distribution systems by legionellae.

To identify factors associated with the contamination of hospital water distribution systems by legionellae, 84 Quebec hospitals provided 3284 hot water specimens from 839 different sites. Concentrated samples were seeded on buffered charcoal yeast extract agar and a semi-selective medium. At least one water sample was contaminated by legionellae in 57 hospitals (67.9%). In 22 hospitals (26.2%), greater than 30% of samples were contaminated by these bacteria. In 9 (12.2%) of 74 hospitals, distilled water was colonized. The presence of at least one positive sample was found to be associated with localization and number of hospital beds (P = .02 for both). Heavy contamination was associated with large volume hot water tanks (P = .01), low water temperature at faucet (P = .03), and old water heaters (P = .06). Conditions required for the occurrence of nosocomial legionellosis may be present in numerous hospitals.

Seroprevalence of antibodies against human herpesvirus 6 in the Quebec City area.

Seroprevalence of antibodies against human herpesvirus 6 was determined in a sample of 303 randomly selected individuals from the Quebec City area. The influence of different variables on antibody litres was also evaluated. Human herpesvirus 6 was grown in the HSB-2 cell line, and antibody litres were measured by indirect immunofluorescence. Serum samples were collected from 177 females and 126 males ranging in age from two months to 88 years. Ninety-nine per cent (300 of 303) of this population had an antibody titre of at least 1:10, whereas 75% had a titre of at least 1:80. Women had a higher geometric mean litre than men (P=0.06). This difference between sexes varied according to age and became statistically significant in subjects older than 20 years of age (P=0.04). It was found that this difference was attributable to higher antibody litres in women in the 15 to 40 year age group who had previously had children.

Risk factors for contamination of domestic hot water systems by legionellae.

To assess risk factors associated with the contamination of the domestic environment by legionellae, 211 houses in the Quebec City area were randomly selected and water samples were collected from the hot water tank, the shower heads, and the most frequently used faucet. After centrifugation, concentrated samples were seeded in triplicate on BCYE and GPV media. Data on the characteristics of the hot water system and plumbing in the house and on the personal habits of the occupants were collected for each house. Among these 211 houses, hot water was provided by either an oil or gas heater in 33 and by an electric heater in 178. Legionellae were isolated from none of the samples from houses with oil or gas heaters and from 39% (69 of 178) of those with electric water heaters (P less than 0.0001). This association remained highly significant after control for water temperature and other variables in a stratified analysis. In the 178 houses with an electric heater, 12% of the faucets, 15% of the shower heads, and 37% of the water heaters were contaminated. Legionella pneumophila serogroups 2 and 4 were the most frequently isolated strains. Logistic regression showed that factors associated with electric water heater contamination were (i) location of the house in older districts of the city (P less than 0.0001), (ii) old age of the water heater (P = 0.003), and (iii) low water temperature (P = 0.05). Contamination of the water heater was the only factor significantly associated with the contamination of peripheral outlets (P less than 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)