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Biomedical subjects

E Ngugi

Publications and source records attributed to E Ngugi.

14 recordsLinked to original sources
PubMed2006

Anal and dry sex in commercial sex work, and relation to risk for sexually transmitted infections and HIV in Meru, Kenya.

OBJECTIVE: To examine the practices of anal intercourse and dry sex within a cohort of female sex workers (FSWs) in Kenya, focusing on the prevalence and perceived risk of the practices, demographic and behavioural correlates, and association with sexually transmitted infections (STI). METHODS: A survey was conducted among FSWs in Meru, Kenya, with 147 participants randomly sampled from an existing cohort of self identified FSWs. RESULTS: 40.8% of participants reported ever practising anal intercourse and 36.1% reported ever practising dry sex. Although the majority of women surveyed believed anal intercourse and dry sex to be high risk practices for HIV infection compared with vaginal sex, about one third of women reported never or rarely using condoms during anal intercourse, and about 20% never or rarely using condoms during dry sex. Reported consistent condom use was lower with both of these practices than with penile-vaginal intercourse. Anal intercourse was associated with experience of recent forced sexual intercourse, while dry sex was not. Anal intercourse was almost always initiated by clients, whereas dry sex was likely to be initiated by the women themselves. Sex workers reported charging higher fees for both practices than for vaginal intercourse. Both practices were associated with reported symptoms and diagnoses of STI. CONCLUSIONS: Both anal intercourse and dry sex were common in this sample, and although perceived as high risk practices, were not adequately protected with condom use. Education and other interventions regarding these high risk sexual behaviours need to be translated into safer practices, particularly consistent condom use, even in the face of financial vulnerability.

Adolescent↗
PubMed2004

Sexual patterning and condom use among a group of HIV vulnerable men in Thika, Kenya.

BACKGROUND/AIM: A composite sample of 37 peer educators and 215 members of self help groups of male informal sector workers in Thika, Kenya, targeting HIV/AIDS prevention, were interviewed about their sexual behaviour, using a customised template, as part of a broader survey on gender attitudes and peer pressure. METHOD: Details on each sexual partner reported by each man over a 12 month recall period included type of partner, months during which sexual relations took place, and condom use. RESULTS: The men reported 471 sexual partners over the recall period, with a range of 0-16 partners, and an average of just under two partners. 8% of men had had no sexual partner, half were monogamous, and 3% had multiple partners with whom they used condoms exclusively, leaving 39% at varying degrees of risk. Condom use increased significantly with reduced intimacy of partner. 16% of men reported having at least one liaison with a female sex worker and two thirds of such liaisons were exclusively protected by condom use. Younger, single men had significantly more partners, but were more likely to use condoms. Duration of membership in self help groups was strongly associated with exclusive use of condoms with casual or FSW partners. Recorded attitudes corresponded somewhat with practice, but the data showed large gaps between the two, and low levels of gender sensitivity. CONCLUSION: There is some evidence that group membership has resulted in increased condom use and partner reduction, but there are doubts as to the extent to which the "ABC" strategy can be successful in stemming the HIV/AIDS epidemic. It may be necessary for interventions to target contextual issues, particularly gender relations, if the approach is to be more successful.

Adult↗
PubMed2003

Decentralisation of tuberculosis treatment from the main hospitals to the peripheral health units and in the community within Machakos district, Kenya.

SETTING: A rural district, Machakos, in Kenya, facing decreasing national resources for health and an increasing tuberculosis (TB) caseload fuelled by the human immunodeficiency virus (HIV). OBJECTIVE: To evaluate the impact on district TB programme performance of decentralising TB treatment by providing ambulatory care in the hospital and peripheral health units and in the community. METHODS: A comparative study of district TB programme performance before and after the decentralisation of TB services at the end of 1997. To facilitate ambulatory care, ethambutol replaced streptomycin in the new treatment regimen. FINDINGS: The number of patients registered in the control period (1996) was 1141, of whom almost 100% were admitted during the intensive phase of TB treatment, and in the intervention period (1998 and 1999), it was 3244, of whom only 153 (4.7%) required admission in the intensive phase. Of 3244 TB patients (all forms) registered in the intervention period, the number (%) choosing the different options for directly observed treatment (DOT) supervision were: hospital clinic 1618 (49.9%), peripheral health unit 904 (27.9%), community volunteer 569 (17.5%) and hospitalisation 153 (4.7%). The options were found to be acceptable to patients, their families and health staff. The treatment outcomes among new sputum smear-positive pulmonary TB patients were similar in the intervention and control cohorts, with treatment success rates of 88% vs. 85% and death rates of 4% vs. 6%, respectively. Treatment completion was significantly higher among new sputum smear-negative and extra-pulmonary TB patients in the intervention than in the control cohort (79% vs. 48%, respectively). CONCLUSION: The decentralisation of the intensive phase of TB treatment resulted in maintenance of good TB programme performance, while Machakos hospital closed its TB wards. A separate paper describes the cost-effectiveness of this approach. The National Tuberculosis Control Programme plans to adopt this approach as national policy.

Ambulatory Care↗
PubMed2001

Human leucocyte antigen supertypes and immune susceptibility to HIV-1, implications for vaccine design.

T cell responses against HIV-1 have been identified in a number of exposed uninfected populations. We hypothesized that the ability to mount an effective T cell response is partly determined by the human leucocyte antigens (HLA) phenotype of the individual. We examined whether certain HLA supertypes were associated with differential HIV-1 susceptibility in sexually exposed adults and in the setting of mother to child HIV-1 transmission. By multivariate analysis, decreased HIV-1 infection risk was strongly associated with possession of a cluster of closely related class I HLA alleles (A2/6802 supertype) in sexually exposed adults (Hazard ratio=0.42, 95% confidence intervals (CI): 0.22-0.81, P=0.009) and perinatally exposed infants (Odds ratio=0.12, 95% CI: 0.03-0.54, P=0.006). The alleles in this HLA supertype are known in some cases, to present the same peptide epitopes (termed 'supertopes'), for T cell recognition. The identification of HIV-1 supertopes, which are associated with protection from HIV-1 infection, has important implications for the application of epitope-based HIV-l vaccines in a variety of racial groups.

AIDS Vaccines↗
PubMed2001

Evaluation of a low-dose nonoxynol-9 gel for the prevention of sexually transmitted diseases: a randomized clinical trial.

BACKGROUND: Low-dose nonoxynol-9 products have a potential advantage of reduced toxicity. However, little is known about their efficacy in reducing the incidence of sexually transmitted diseases (STDs). GOAL: To determine the effect that an intravaginal gel containing 52.5 mg of nonoxynol-9 has on the acquisition of STDs in a cohort of HIV-1-seronegative female sex workers in Mombasa, Kenya. STUDY DESIGN: A randomized double-blind placebo controlled trial was performed. RESULTS: In this study, 139 women were randomized to the nonoxynol-9 group and 139 to the placebo group. No significant differences were found between the two study groups in terms of safety outcomes and reported symptoms, except for a lower incidence of vaginal erythema in the nonoxynol-9 group. There was a significantly higher incidence of gonorrhea in the nonoxynol-9 group than in the placebo group. No significant differences were observed between the groups for acquisition of Candida, trichomonas, bacterial vaginosis, C trachomatis, syphilis, or HIV-1, although the statistical power to detect differences for some of these STDs was limited. CONCLUSIONS: In this randomized placebo-controlled trial of a low-dose nonoxynol-9 gel, a significantly higher incidence of gonorrhea was found in the nonoxynol-9 group, but no significant differences between the groups were found for Candida, trichomonas, bacterial vaginosis, C trachomatis, syphilis, or HIV-1.

Administration, Intravaginal↗
PubMed2000

Influence of HLA supertypes on susceptibility and resistance to human immunodeficiency virus type 1 infection.

Certain human leukocyte antigens, by presenting conserved immunogenic epitopes for T cell recognition, may, in part, account for the observed differences in human immunodeficiency virus type 1 (HIV-1) susceptibility. To determine whether HLA polymorphism influences HIV-1 susceptibility, a longitudinal cohort of highly HIV-1-exposed female sex workers based in Nairobi, Kenya, was prospectively analyzed. Decreased HIV-1 infection risk was strongly associated with possession of a cluster of closely related HLA alleles (A2/6802 supertype; incidence rate ratio [IRR], 0.45; 95% confidence interval [CI], 0.27-0.72; P=.0003). The alleles in this supertype are known in some cases to present the same peptide epitopes for T cell recognition. In addition, resistance to HIV-1 infection was independently associated with HLA DRB1*01 (IRR, 0.22; 95% CI, 0.06-0.60; P=.0003), which suggests that anti-HIV-1 class II restricted CD4 effector mechanisms may play an important role in protecting against viral challenge. These data provide further evidence that resistance to HIV-1 infection in this cohort of sex workers is immunologically mediated.

Acquired Immunodeficiency Syndrome↗
PubMed1998

Cytotoxic T cell responses to multiple conserved HIV epitopes in HIV-resistant prostitutes in Nairobi.

Many people who remain persistently seronegative despite frequent HIV exposure have HIV-specific immune responses. The study of these may provide information about mechanisms of natural protective immunity to HIV-1. We describe the specificity of cytotoxic T lymphocyte responses to HIV in seronegative prostitutes in Nairobi who are apparently resistant to HIV infection. These women have had frequent exposure to a range of African HIV-1 variants, primarily clades A, C, and D, for up to 12 yr without becoming infected. Nearly half of them have CTL directed towards epitopes previously defined for B clade virus, which are largely conserved in the A and D clade sequences. Stronger responses are frequently elicited using the A or D clade version of an epitope to stimulate CTL, suggesting that they were originally primed by exposure to these virus strains. CTL responses have been defined to novel epitopes presented by HLA class I molecules associated with resistance to infection in the cohort, HLA-A*6802 and HLA-B18. Estimates using a modified interferon-gamma Elispot assay indicate a circulating frequency of CTL to individual epitopes of between 1:3,200 and 1:50,000. Thus, HIV-specific immune responses-particularly cross-clade CTL activity- may be responsible for protection against persistent HIV infection in these African women.

Amino Acid Sequence↗
PubMed1995

International aspects of the AIDS/HIV epidemic.

This review provides the reader with pertinent information on the epidemiology, prevention, and new technologies of the ongoing HIV pandemic. These aspects are key to international policy discussions surrounding the public health response to the international spread of HIV. Our understanding of the impact of AIDS on other diseases is evolving, as is our insight into the demographic and economic effects of the epidemic on the global community. Observations on the success of certain prevention strategies allow rational allocation of resources in newly affected epidemic areas. Information on the origin and nature of HIV transmission exemplifies the phenomenon of global emerging infections. As world populations are brought closer together through transportation, communication, trade, and commerce, insight into emerging infections of epidemic potential becomes increasingly important to the practitioner of public health. Although important, legal and social aspects of the epidemic will not be emphasized here. The epidemics of HIV/AIDS in the United States and Europe are not reviewed here. The global pandemic has recently been described in an overview in this publication to which the reader is also referred.

AIDS Vaccines↗
PubMed1991

The Nairobi STD program. An international partnership.

Since 1980, Canadian, Belgian, and American scientists have been working together with colleagues in Kenya to understand the epidemiology and biology of sexually transmitted diseases (STDs) in Africa. The rapid spread of human immunodeficiency virus has dramatically increased the importance of this information. Interventions to slow the spread of all STDs and to reduce their consequences are now our major priority. However, this will require continuing research, ongoing training of scientists, epidemiologists, and technologists, and increasing financial support from industrialized societies.

Developing Countries↗
PubMed1989

Isolation of human immunodeficiency virus from genital ulcers in Nairobi prostitutes.

Recent epidemiologic studies have implicated genital/anorectal ulcer disease as an important cofactor for acquisition and transmission of human immunodeficiency virus (HIV) during sexual intercourse. To better understand the mechanism for the association between genital ulcers and HIV, exudates from 62 genital ulcers of 56 HIV-seropositive prostitutes in Nairobi (Kenya) were cultured for HIV. Twenty-six ulcer cultures could not be evaluated for the presence of HIV because of bacterial or fungal contamination. HIV was isolated from 4 (11%) of the 36 remaining uncontaminated ulcer cultures (2 introital, 1 vaginal, and 1 cervical) from 4 separate women. HIV was isolated from the cervical os from only 2 of the 4 women. HIV p24 antigen was detected in exudate from 1 of the 4 culture-positive ulcers and 0 of 32 culture-negative ulcers. Genital ulcers in seropositive patients should be regarded as potential sources of HIV, which could be important in transmission of HIV during intercourse. Public health measures aimed at controlling sexually transmitted genital ulcer diseases should be an integral part of acquired immunodeficiency syndrome (AIDS) prevention programs.

Adult↗
PubMedDate not supplied

Human immunodeficiency virus, human papillomavirus, and cervical intraepithelial neoplasia in Nairobi prostitutes.

To evaluate the impact of human immunodeficiency virus (HIV) on human papillomavirus (HPV) and cervical intraepithelial neoplasia (CIN), a study was conducted of 147 HIV-seropositive and 51 HIV-seronegative prostitutes in Nairobi, Kenya. Among the women infected with HIV, 10 (7%) had signs or symptoms of significant HIV-related disease, and the remaining 93% were asymptomatic. The prevalence of cervical HPV DNA was 37% among HIV-seropositive women and 24% in HIV-seronegative women (odds ratio [OR] 1.7, 95% confidence intervals [CI] 0.8, 3.6, after adjusting for potential confounding factors). Genital warts, cervical HPV DNA, and cytologic findings consistent with CIN were all significantly associated with younger age and fewer years of prostitution, but were unrelated or weakly related to number of sexual partners per week or frequency of condom use. In a subset of 63 women with evaluable Papanicolaou smears, CIN was found in 50% of the women with HPV but only in 8% of those without HPV (adjusted OR 7.2, 95% CI 1.6, 32.1, P = 0.006). However, CIN was unrelated to HIV seropositivity (prevalence of 26% among HIV-seropositive women and 24% in HIV-seronegative women). Among women with cervical HPV DNA, HIV infection was not associated with an increased prevalence of CIN (47% prevalence among women with HIV versus 57% prevalence among women without HIV). Thus, in this population of HIV-seropositive women, most of whom had CDC Stage II or III infection, there was no demonstration of an adverse impact of HIV on CIN.

Adult↗
PubMedDate not supplied

Efficacy of nonoxynol 9 contraceptive sponge use in preventing heterosexual acquisition of HIV in Nairobi prostitutes.

OBJECTIVE: To determine the efficacy of the nonoxynol 9 contraceptive sponge in preventing sexual acquisition of the human immunodeficiency virus (HIV). DESIGN: Prospective, randomized placebo-controlled trial. SETTING: Research clinic for prostitutes in Nairobi, Kenya. PATIENTS AND INTERVENTIONS: One hundred thirty-eight HIV-seronegative women were enrolled, of whom 74 were assigned to nonoxynol 9 sponge use and 64 to placebo use. These two groups did not significantly differ with respect to demographic characteristics, sexual practices, or prevalence of genital infections at enrollment, except for a lower number of sex partners per week and a higher initial prevalence of genital ulcers among women assigned to nonoxynol 9 sponge use. Among the 116 women who returned for follow-up, the mean durations of follow-up were 14 and 17 months for the two groups, respectively. MAIN OUTCOME MEASURE: HIV seroconversion. RESULTS: Nonoxynol 9 sponge use was associated with an increased frequency of genital ulcers (relative risk [RR], 3.3; P less than .0001) and vulvitis (RR, 3.3; P less than .0001) and a reduced risk of gonococcal cervicitis (RR, 0.4; P less than .0001). Twenty-seven (45%) of 60 women in the nonoxynol 9 sponge group and 20 (36%) of 56 women in the placebo group developed HIV antibodies. The hazard ratio for the association between nonoxynol 9 sponge use and HIV seroconversion was 1.7 (95% confidence interval [CI], 0.9 to 3.0). Using multivariate analysis to control for the presence of genital ulcers at enrollment, the adjusted hazard ratio for the association between nonoxynol 9 sponge use and seroconversion was 1.6 (95% CI, 0.8 to 2.8). CONCLUSIONS: Genital ulcers and vulvitis occurred with increased frequency in nonoxynol 9 sponge users. We were unable to demonstrate that nonoxynol 9 sponge use was effective in reducing the risk of HIV infection among highly exposed women.

Adult↗