University of Nairobi

About: University of Nairobi is a education organization based out in Nairobi, Nairobi, Kenya. It is known for research contribution in the topics: Population & Health care. The organization has 6702 authors who have published 10777 publications receiving 231294 citations. The organization is also known as: UoN & IAU-020319.

Sexual behaviour of heterosexual men and women receiving antiretroviral pre-exposure prophylaxis for HIV prevention: a longitudinal analysis

Abstract: Summary Background Scarce data are available to assess sexual behaviour of individuals using antiretroviral pre-exposure prophylaxis for HIV prevention. Increased sexual risk taking by individuals using effective HIV prevention strategies, like pre-exposure prophylaxis, could offset the benefits of HIV prevention. We studied whether the use of pre-exposure prophylaxis in HIV-uninfected men and women in HIV-serodiscordant couples was associated with increased sexual risk behaviour. Methods We undertook a longitudinal analysis of data from the Partners PrEP Study, a double-blind, randomised, placebo-controlled trial of daily oral pre-exposure prophylaxis among HIV-uninfected partners of heterosexual HIV-serodiscordant couples (n=3163, ≥18 years of age). Efficacy for HIV prevention was publicly reported in July 2011, and participants continued monthly follow-up thereafter. We used regression analyses to compare the frequency of sex—unprotected by a condom—during the 12 months after compared with the 12 months before July 2011, to assess whether knowledge of pre-exposure prophylaxis efficacy for HIV prevention caused increased sexual risk behaviour. Results We analysed 56 132 person-months from 3024 HIV-uninfected individuals (64% male). The average frequency of unprotected sex with the HIV-infected study partner was 59 per 100 person-months before unmasking versus 53 after unmasking; we recorded no immediate change (p=0·66) or change over time (p=0·25) after July, 2011. We identified a significant increase in unprotected sex with outside partners after July, 2011, but the effect was small (average of 6·8 unprotected sex acts per year vs 6·2 acts in a predicted counterfactual scenario had patients remained masked, p=0·04). Compared with before July, 2011, we noted no significant increase in incident sexually transmitted infections or pregnancy after July, 2011. Interpretation Pre-exposure prophylaxis, provided as part of a comprehensive prevention package, might not result in substantial changes in risk-taking sexual behaviour by heterosexual couples. Funding The Bill & Melinda Gates Foundation and the US National Institute of Mental Health.

Effects of Selected Corporate Governance Characteristics on Firm Performance: Empirical Evidence from Kenya

Abstract: This paper examines the interrelations among ownership, board and manager characteristics and firm performance in a sample of 54 firms listed at the Nairobi Stock Exchange (NSE). These governance characteristics, designed to minimize agency problems between principals and agents are operationalized in terms of ownership concentration, ownership identity, board effectiveness and managerial discretion. The typical ownership identities at the NSE are government, foreign, institutional, manager and diverse ownership forms. Firm performance is measured using Return on Assets (ROA), Return on Equity (ROE) and Dividend Yield (DY). Using PPMC, Logistic Regression and Stepwise Regression, the paper presents evidence of significant positive relationship between foreign, insider, institutional and diverse ownership forms, and firm performance. However, the relationship between ownership concentration and government, and firm performance was significantly negative. The role of boards was found to be of very little value, mainly due to lack of adherence to board member selection criteria. The results also show significant positive relationship between managerial discretion and performance. Collectively, these results are consistent with pertinent literature with regard to the implications of government, foreign, manager (insider) and institutional ownership forms, but significantly differ concerning the effects of ownership concentration and diverse ownership on firm performance. Keywords : Ownership Structure; Agency Theory; Ownership Concentration; Ownership Identity; Managerial Discretion; Firm Performance. JEL Classifications: G32; L25

Earth-eating and reinfection with intestinal helminths among pregnant and lactating women in western Kenya.

Abstract: We conducted a longitudinal study among 827 pregnant women in Nyanza Province, western Kenya, to determine the effect of earth-eating on geohelminth reinfection after treatment. The women were recruited at a gestational age of 14-24 weeks (median: 17) and followed up to 6 months postpartum. The median age was 23 (range: 14-47) years, the median parity 2 (range: 0-11). After deworming with mebendazole (500 mg, single dose) of those found infected at 32 weeks gestation, 700 women were uninfected with Ascaris lumbricoides, 670 with Trichuris trichiura and 479 with hookworm. At delivery, 11.2%, 4.6% and 3.8% of these women were reinfected with hookworm, T. trichiura and A. lumbricoides respectively. The reinfection rate for hookworm was 14.8%, for T. trichiura 6.65, and for A. lumbricoides 5.2% at 3 months postpartum, and 16.0, 5.9 and 9.4% at 6 months postpartum. There was a significant difference in hookworm intensity at delivery between geophagous and non-geophagous women (P=0.03). Women who ate termite mound earth were more often and more intensely infected with hookworm at delivery than those eating other types of earth (P=0.07 and P=0.02 respectively). There were significant differences in the prevalence of A. lumbricoides between geophagous and non-geophagous women at 3 (P=0.001) and at 6 months postpartum (P=0.001). Women who ate termite mound earth had a higher prevalence of A. lumbricoides, compared with those eating other kinds of earth, at delivery (P=0.02), 3 months postpartum (P=0.001) and at 6 months postpartum (P=0.001). The intensity of infections with T. trichiura at 6 months postpartum was significantly different between geophagous and non-geophagous women (P=0.005). Our study shows that geophagy is associated with A. lumbricoides reinfection among pregnant and lactating women and that intensities built up more rapidly among geophagous women. Geophagy might be associated with reinfection with hookworm and T. trichiura, although these results were less unequivocal. These findings call for increased emphasis, in antenatal care, on the potential risks of earth-eating, and for deworming of women after delivery.

The different epidemiologic subtypes of Burkitt lymphoma share a homogenous micro RNA profile distinct from diffuse large B-cell lymphoma.

Abstract: Sporadic Burkitt lymphoma (sBL) can be delineated from diffuse large B-cell lymphoma (DLBCL) by a very homogeneous mRNA expression signature. However, it remained unclear whether all three BL variants-sBL, endemic BL (eBL) and human immunodeficiency virus-associated BL (HIV-BL)-represent a uniform biological entity despite their differences in geographical occurrence, association with immunodeficiency and/or incidence of Epstein-Barr virus (EBV) infection. To address this issue, we generated micro RNA (miRNA) profiles from 18 eBL, 31 sBL and 15 HIV-BL cases. In addition, we analyzed the miRNA expression of 86 DLBCL to determine whether miRNA profiles recapitulate the molecular differences between BL and DLBCL evidenced by mRNA profiling. A signature of 38 miRNAs containing MYC regulated and nuclear factor-kB pathway-associated miRNAs was obtained that differentiated BL from DLBCL. The miRNA profiles of sBL and eBL displayed only six differentially expressed miRNAs, whereas HIV and EBV infection had no impact on the miRNA profile of BL. In conclusion, miRNA profiling confirms that BL and DLBCL represent distinct lymphoma categories and demonstrates that the three BL variants are representatives of the same biological entity with only marginal miRNA expression differences between eBL and sBL.