Antibiotic susceptibility of organisms causing urinary tract infection in patients presenting at Kenyatta National Hospital, Nairobi

Background: Changes in susceptibility patterns of bacterial pathogens isolated from urinary tract   infections emphasize the need for regional surveillance to generate information that can be used in  management of patients. Knowledge on the current status of antimicrobial resistance in uropathogens,  and the prevalence of expanding spectrum beta-lactamases (ESBLs) in the isolates will guide policy  formulations and encourage prudent use of antimicrobials.Objectives: To identify bacterial pathogens causing UTI and determine the association between the pathogens isolated from patients attending KNH. Determine antimicrobial susceptibility patterns of the UTI pathogens and the prevalence of ESBL in the isolated pathogens.Design: Laboratory-based study.Setting: Department of Medical Microbiology University of Nairobi and Kenyatta National Hospital   microbiology laboratory, Nairobi, Kenya.Subjects: Nine hundred and forty eight patients presenting directly to the Kenyatta National Hospital’s diagnostic laboratory. Patients were only classified as in-patients if at the time of specimen collection  they were being admitted to one of KNH wards.Results: Out of the 948 urine samples processed, 189 in-patients and 37 out-patients samples had  significant bacterial growth. The uropathogens identified from inpatient specimens were Escherichia coli (56), Klebsiellapneumoniae (33), Enterococcus spp. (34) and Entrobacter (16) making up 30%, 18%,  18% and 9% respectively. ESBL isolates were found to be resistant to the locally administered   antibiotics; Augmentin (37%), Levofloxacin (37%), Cefoperazone (37%), Ampicillin (39%), Doxycyline (41%), Gentamicin (30%) and Nalidixic Acid (38%).Conclusion: The increased prevalence of multidrug resistant ESBL pathogens poses challenges for  healthcare providers at KNH and signifies the need for new approach to treat UTI. It would be prudent for laboratories to include specialised tests for detection of ESBL producing pathogens from isolates obtained from in-patients. Further studies on the mechanisms and pathways utilised by these bacteria to cause UTI will highlight other avenues in patient management

Pregnancy rates among female participants in phase 1 and phase 2A AIDS vaccine clinical trials in Kenya

Background: Female participants in AIDS candidate vaccine clinical trials must agree to use effective contraception to be enrolled into the studies, and for a specified period after vaccination, since the candidate vaccines’ effects on the embryo or foetus are unknown.Objectives: To review data on female participants’ pregnancy rates from phase I and IIA AIDS vaccine clinical trials conducted at the Kenya AIDS Vaccine Initiative (KAVI) and to discuss the challenges of contraception among female participants.Design: Descriptive observational retrospective study.Setting: KAVI clinical trial site, Kenyatta National Hospital and University of Nairobi, Kenya.Subjects: Thirty nine female participants were enrolled into these trials. They received family planning counselling and were offered a choice of different contraceptive methods, as per the protocols. All contraception methods chosen by the participants were offered at the study site at no cost to the participant.Results: Four women conceived during the study period when pregnancies were to be avoided. All four had opted for sexual abstinence as a contraceptive method, but reported having been coerced by their partners to have unprotected sexual intercourse.Conclusion: Abstinence is clearly not a reliable contraceptive option for women in developing-country settings. Effective female-controlled contraceptives, administered at the clinical trial site, may empower female participants to better control their fertility, leading to more complete clinical trial data

Geographic and ecologic heterogeneity in elimination thresholds for the major vector-borne helminthic disease, lymphatic filariasis

<p>Abstract</p> <p>Background</p> <p>Large-scale intervention programmes to control or eliminate several infectious diseases are currently underway worldwide. However, a major unresolved question remains: what are reasonable stopping points for these programmes? Recent theoretical work has highlighted how the ecological complexity and heterogeneity inherent in the transmission dynamics of macroparasites can result in elimination thresholds that vary between local communities. Here, we examine the empirical evidence for this hypothesis and its implications for the global elimination of the major macroparasitic disease, lymphatic filariasis, by applying a novel Bayesian computer simulation procedure to fit a dynamic model of the transmission of this parasitic disease to field data from nine villages with different ecological and geographical characteristics. Baseline lymphatic filariasis microfilarial age-prevalence data from three geographically distinct endemic regions, across which the major vector populations implicated in parasite transmission also differed, were used to fit and calibrate the relevant vector-specific filariasis transmission models. Ensembles of parasite elimination thresholds, generated using the Bayesian fitting procedure, were then examined in order to evaluate site-specific heterogeneity in the values of these thresholds and investigate the ecological factors that may underlie such variability</p> <p>Results</p> <p>We show that parameters of density-dependent functions relating to immunity, parasite establishment, as well as parasite aggregation, varied significantly between the nine different settings, contributing to locally varying filarial elimination thresholds. Parasite elimination thresholds predicted for the settings in which the mosquito vector is anopheline were, however, found to be higher than those in which the mosquito is culicine, substantiating our previous theoretical findings. The results also indicate that the probability that the parasite will be eliminated following six rounds of Mass Drug Administration with diethylcarbamazine and albendazole decreases markedly but non-linearly as the annual biting rate and parasite reproduction number increases.</p> <p>Conclusions</p> <p>This paper shows that specific ecological conditions in a community can lead to significant local differences in population dynamics and, consequently, elimination threshold estimates for lymphatic filariasis. These findings, and the difficulty of measuring the key local parameters (infection aggregation and acquired immunity) governing differences in transmission thresholds between communities, mean that it is necessary for us to rethink the utility of the current anticipatory approaches for achieving the elimination of filariasis both locally and globally.</p