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Biomedical subjects

F A Plummer

Publications and source records attributed to F A Plummer.

At least 91 records · Page 5Linked to original sources
PubMed1995

Effect of human immunodeficiency virus on local immunity in children with diarrhoea.

The purpose of this study was to determine the relationship between intestinal mucosal immunity and diarrhoea. Stools were tested for total IgA by radial immunodiffusion, cultured for bacteria and examined for ova/cysts by microscopy. Peripheral blood was screened for HIV-1 antibody by ELISA, CD4 and CD8 enumerated by flow cytometry and phagocytic activity by C. albicans engulfment. A total of 271 children were enrolled with a mean age of 20.3 m (range 0.3-60.0 m). HIV exposed (born to HIV seropositive mothers) had more episodes of diarrhoea than HIV unexposed (born to HIV seronegative mothers) children in the first six months of life (26.0% versus 5.5%, p = 0.002). Exposed children had severe (16/44 versus 6/29, p = 0.02) and prolonged diarrhoea lasting more than nine days (11.0% versus 1.4%, p = 0.03) than unexposed. CD8 counts were significantly higher in exposed than unexposed children (1837.0 versus 1373.0 cells/mm3, p = p.01). Among children aged 15 months and over, HIV seropositive children had severe diarrhoea (4/6 versus 11/32, p<0.01), reduced phagocytic activity (phagocytic index 15.4 versus 28.9, p<0.01), total intestinal IgA (0.2 versus 0.7 mg/ml, p = 0.04) and CD4 counts (624.2 versus 1345.1 cells/mm3, p = 0.01) than seronegative. Reduction of CD4 was more significant in HIV seropositive children with severe diarrhoea (298.7 versus 1318.5 cells/mm3, p = 0.01). Isolation of enteric pathogens was independent of either maternal or child's HIV serostatus although E. coli was more frequent in children with low CD4 counts. These results highlight the importance of mucosal immunity in the intestinal infections. Exposure to HIV, reduced CD4 counts and IgA were associated with diarrhoea probably due to impaired intestinal mucosal immunity.

CD4 Lymphocyte Count↗
PubMed1994

Sexual behaviour in Kenya: implications for sexually transmitted disease transmission and control.

Sexual behaviour in Kenya in relation to STD transmission was investigated with a view to forming a basis for the more rational design of STD/HIV control interventions. Questionnaires were administered to a sample of 762 men and women attending eight health facilities in two urban centres. Equal numbers of STD patients (cases) and non-STD related clinic attenders (clinic controls) were selected, matched by gender and clinic. Another sample of 427 men and women was obtained from a random sampling of households in a slum area in Nairobi (community controls). Male STD patients who were unmarried, or married but living apart from their wives, reported a higher mean number of sex partners in the previous three months than did male clinic or community controls. Unmarried female STD patients reported a higher mean number of sex partners in the previous three months than did unmarried female clinic or community controls. Both male and female STD patients were more likely to report having been involved in commercial sex transactions in the previous three months than clinic or community controls. Considerable heterogeneity in sexual behaviour was apparent. In multivariate analysis, the most important predictor of STD acquisition for both men and women was the number of reported sex partners in the previous three months. In addition, for men only, marital status (unmarried, or married but living apart from their wives) and purchasing sex were significant predictors of being an STD patient. These data confirm the importance of commercial sex in STD transmission, and suggest that men play a bridging role between female sex workers and the general population of women.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Survey of knowledge, behaviour and attitudes relating to HIV infection and AIDS among Kenyan secondary school students.

To evaluate the knowledge, attitudes and sexual behaviour with respect to HIV and AIDS among Kenyan secondary school students, a questionnaire was issued to 3,018 students of mean age 16.3 years in 11 Kenyan schools. Questions of knowledge were answered correctly by an average of 77.1% of students. Areas where students' knowledge was less complete included the inability of mosquitoes to transmit the virus, the protective effect of condoms, the lack of protection from medications, the fatal and incurable nature of AIDS, and the fact that those infected with HIV may appear healthy. No prior sexual experience was reported by 71.3% of females and 25.2% of males. Multiple sexual partners were reported by 41.2% of males and 7.3% of females. Sixty per cent of students denied ever using condoms during sex and only 6.8% of those with multiple partners used them all the time. A prior sexually-transmitted disease was reported by 5.6% of students. Although a high level of knowledge regarding HIV and AIDS is evident among Kenyan students there is a sizable number who admit to extensive sexual experience, but who are not using condoms, thereby putting themselves at risk.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Sexual behavior and perceived risk of AIDS among men in Kenya attending a clinic for sexually transmitted diseases.

The sexual transmission of human immunodeficiency virus type 1 (HIV-1) continues at an alarming rate in sub-Saharan Africa despite the fact that awareness of AIDS is high. One explanation for this alarming rate may be that individuals do not believe that they are personally at risk for AIDS and are not sufficiently motivated to make changes in their behavior. We conducted a cross-sectional study of men with genital ulcer disease to assess their sexual behavior and their perceived risk of AIDS. We studied 787 men between the ages of 17 and 54 years who presented to a referral clinic for sexually transmitted diseases (STDs) in Nairobi, Kenya. Of these 787 men, 188 (24%) were infected with HIV-1. Awareness of AIDS was essentially universal in this population; however, only 64 men (8%) thought that they were personally at risk of developing AIDS. A logistic regression analysis found that men who believed they were personally at risk knew someone with AIDS (odds ratio [OR], 8.9; 95% confidence interval [CI], 4.0-19.7), received information about AIDS from television or video (OR, 3.0; 95% CI, 1.7-5.5), or had previously had an STD (OR, 2.2; 95% CI, 1.2-4.1). Except for a modest increase in condom use, there was no significant difference in sexual behavior between the group who considered themselves to be at risk for AIDS and the group who did not consider themselves to be at risk. The results of this study challenge the current strategies on HIV/AIDS education and prevention for urban men in Kenya.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Human immunodeficiency virus type 1 seroconversion in women with genital ulcers.

Genital ulcers are implicated as a risk factor enhancing susceptibility to human immunodeficiency virus type 1 (HIV-1) infection. A prospective study to determine the incidence of and risk factors associated with acquisition of HIV-1 in women with genital ulcers was done. HIV-1-seronegative women with genital ulcers attending a clinic for sexually transmitted diseases in Nairobi were followed to HIV-1 seroconversion over a 6-month period. Of 81 women, 10 seroconverted to HIV-1. The crude 6-month incidence of HIV-1 infection was 12%. Risk factors associated with seroconversion included cervical ectopy (rate ratio [RR], 4.9; 95% confidence interval [CI], 1.5-15.6) and pelvic inflammatory disease (RR, 6.3; 95% CI, 1.9-20.4). Thus, cervical ectopy and pelvic inflammatory disease may increase susceptibility to HIV-1 in women with genital ulcers.

Adolescent↗
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

Human immunodeficiency virus type 1 IgA antibody in breast milk and serum.

Breast-feeding plays a potentially significant role in mother to child transmission of human immunodeficiency virus type 1 (HIV-1). The additional transmission risk attributable to breast-feeding and the factors that enhance or inhibit transmission are presently unknown. One mechanism by which breast milk might inhibit HIV-1 transmission is the presence of specific antibodies directed against HIV-1 in breast milk of seropositive mothers. In this study serum and breast milk samples from women in Nairobi, Kenya, were tested to determine the prevalence of HIV-1 IgA antibodies. A Western blot test developed in our laboratory was used to detect anti-HIV-1 immunoglobulin A in serum and anti-HIV-1 secretory IgA (sIgA) in breast milk. Ninety-four percent of 63 HIV-1 seropositive women had anti-HIV-1 IgA in serum and 59% had anti-HIV-1 sIgA in their breast milk. No significant associations with maternal characteristics or serum anti-HIV-1 IgA or IgG banding patterns and the presence of anti-HIV-1 sIgA in breast milk were found. No protective effect of anti-HIV-1 sIgA was seen regarding mother to child transmission; however, further studies are necessary to determine the effect of these antibodies in maternal sera or in breast milk on the efficacy of HIV-1 transmission.

AIDS Serodiagnosis↗
PubMed1994

Leukocyte esterase urine strips for the screening of men with urethritis--use in developing countries.

BACKGROUND AND OBJECTIVES: The leukocyte esterase (LE) strip is a useful tool for the screening of men with urethritis. In developing countries, where laboratory facilities are limited, and sexually transmitted diseases endemic, simple and inexpensive diagnostic tests which perform well, would be of great value. METHODS: Men presenting with urethritis to a referral clinic for sexually transmitted diseases in Nairobi, Kenya participated in this cohort analytical study. First-void urine was collected for LE dipstick testing as part of the diagnostic work-up. The results of the dipstick measurement were compared with the laboratory detection of Chlamydia trachomatis and Neisseria gonorrhoeae. RESULTS: Of 200 men with symptoms of urethritis, 33 (17%) had a pathogen detected from the urethra or the urine. Chlamydia was detected in urine by PCR in 22 (11%), and gonorrhoea was cultured from the urethra in 11 (6%). Esterase activity (trace or greater) had a sensitivity of 76%, a specificity of 80%, a positive predictive value of 42% and a negative predictive value of 94% for the presence of chlamydia or gonorrhoea. CONCLUSIONS: The use of the LE dipstick for the screening of men with symptomatic urethritis can improve diagnostic accuracy and reduce the amount of empiric antimicrobial therapy. The low detection rate of chlamydia in these men with a clinical diagnosis of nongonococcal urethritis needs further study.

Adult↗
PubMed1994

Antibodies to opacity proteins (Opa) correlate with a reduced risk of gonococcal salpingitis.

Acute salpingitis complicating cervical gonococcal infection is a significant cause of infertility. Relatively little data are available concerning the pathophysiologic mechanisms of this disease. A cohort of 243 prostitutes residing in Nairobi were followed between March 1985 and April 1988. Gonococcal cultures were performed at each visit, and acute salpingitis was diagnosed clinically. Serum at enrollment was tested by immunoblot for antibody to gonococcal outer membrane proteins. 8.6% (146/1689) of gonococcal infections were complicated by salpingitis. Increased risk of salpingitis was associated with younger age, shorter duration of prostitution, HIV infection, number of gonococcal infections, and episodes of nongonococcal salpingitis. Rmp antibody increased the risk of salpingitis. Antibody to Opa decreased the risk of salpingitis. By logistic regression analysis, antibody to Opa was independently associated with decreased risk of gonococcal salpingitis (adjusted odds ratio [OR], 0.35; 95% confidence interval [95%CI], 0.17-0.76); HIV infection (adjusted OR, 3.5; 95% CI, 0.96-12.8) and episodes of nongonococcal salpingitis (adjusted OR, 3.4; 95% CI, 1.8-6.4) were independently associated with an increased risk of salpingitis. Antibody to Opa appears to protect against ascending gonococcal infection, perhaps by interfering with Opa mediated adherence and endocytosis. The demonstration of natural immunity that protects against upper genital tract infection in women suggests that a vaccine to prevent gonococcal salpingitis is possible.

Adult↗
PubMed1994

Health care-seeking behavior related to the transmission of sexually transmitted diseases in Kenya.

OBJECTIVES: The purpose of this study was to identify health-care seeking and related behaviors relevant to controlling sexually transmitted diseases in Kenya. METHODS: A total of 380 patients with sexually transmitted diseases (n = 189 men and 191 women) at eight public clinics were questioned about their health-care seeking and sexual behaviors. RESULTS: Women waited longer than men to attend study clinics and were more likely to continue to have sex while symptomatic. A large proportion of patients had sought treatment previously in both the public and private sectors without relief of symptoms, resulting in delays in presenting to study clinics. For women, being married and giving a recent history of selling sex were both independently associated with continuing to have sex while symptomatic. CONCLUSIONS: Reducing the transmission of sexually transmitted diseases in Kenya will require improved access, particularly for women, to effective health services, preferably at the point of first contact with the health system. It is also critical to encourage people to reduce sexual activity while symptomatic, seek treatment promptly, and increase condom use.

Female↗
PubMed1993

Fleroxacin in the treatment of chancroid: an open study in men seropositive or seronegative for the human immunodeficiency virus type 1.

Fleroxacin was prescribed to treat both HIV-negative and HIV-positive men with proven chancroid in an open study. HIV-negative men were treated with a single 400-mg dose of fleroxacin, and HIV-positive men were treated with 400 mg daily for 5 days. Three of the 58 evaluable HIV-negative men were clinical and microbiologic failures, and two of the 22 evaluable HIV-positive men had persisting infection with Haemophilus ducreyi. Both regimens were well tolerated. Fleroxacin is an acceptable alternative to existing treatment regimens for chancroid in men.

Administration, Oral↗
PubMed1993

Ceftriaxone no longer predictably cures chancroid in Kenya.

Ceftriaxone in a dose of 250 mg given intramuscularly is currently recommended for the treatment of chancroid. Among 133 men in Nairobi, Kenya, with culture-proven chancroid, who were treated with ceftriaxone, treatment failed in 35%. Poor outcome was associated with human immunodeficiency virus type 1 seropositivity. Thus, treatment recommendations for chancroid should be reevaluated.

Adult↗
PubMed1993

Human immunodeficiency virus infection among high-risk seronegative prostitutes in Nairobi.

To determine the frequency and duration of antibody-negative human immunodeficiency virus (HIV) infection among heterosexually exposed African women, 56 HIV-seronegative female prostitutes in Nairobi were studied. Polymerase chain reaction (PCR) was used to detect HIV DNA in peripheral blood at enrollment, and women were followed prospectively with serologic testing to determine HIV seroincidence. Six women (11%) were infected with HIV by PCR criteria at enrollment. Seroconversion occurred in 5 of these subjects within 1-12 months, while the sixth remained seronegative when last evaluated at 5 months. The cumulative annual seroconversion rate in the entire cohort was 38%. Using maximum likelihood analysis, the mean interval between HIV infection and seroconversion was estimated to be between 3 and 4 months, similar to that described for homosexual men and blood product recipients in the United States. Prolonged HIV infection in the absence of antibodies appears to be uncommon in this setting.

Adult↗
PubMed1993

Antibody to Rmp (outer membrane protein 3) increases susceptibility to gonococcal infection.

The severe adverse effects of gonococcal infection on human fertility suggests that Neisseria gonorrhoeae would exert powerful selection for the development of a protective immune response in humans. N. gonorrhoeae is an obligate human pathogen and must persist in humans to survive. Since it is an ecologically successful organism, it must have evolved strategies to evade any human immune response it elicits. In a longitudinal study among 243 women working as prostitutes and experiencing frequent gonococcal infection, younger women, women with HIV infection, and women with antibody to the gonococcal outer membrane protein 3 (Rmp) were at increased risk of infection (adjusted odds ratio 3.4, CI95% 1.1-10.4, P < 0.05). Rmp is highly conserved in N. gonorrhoeae and the blocking of mucosal defences may be one of its functions. As similar proteins occur in many gram negative mucosal pathogens, the enhancing effect of such proteins may be a general strategy whereby bacteria evade human immune responses.

Adult↗