Evaluation of a measles vaccine campaign by oral-fluid surveys in a rural Kenyan district: interpretation of antibody prevalence data using mixture models

We evaluated the effectiveness of a measles vaccine campaign in rural Kenya, based on oral-fluid surveys and mixture-modelling analysis. Specimens were collected from 886 children aged 9 months to 14 years pre-campaign and from a comparison sample of 598 children aged 6 months post-campaign. Quantitative measles-specific antibody data were obtained by commercial kit. The estimated proportions of measles-specific antibody negative in children aged 0–4, 5–9 and 10–14 years were 51%, 42% and 27%, respectively, pre- campaign and 18%, 14% and 6%, respectively, post-campaign. We estimate a reduction in the proportion susceptible of 65–78%, with ~85% of the population recorded to have received vaccine. The proportion of ‘weak’ positive individuals rose from 35% pre-campaign to 54% post-campaign. Our results confirm the effectiveness of the campaign in reducing susceptibility to measles and demonstrate the potential of oral-fluid studies to monitor the impact of measles vaccination campaigns

An Empirical Investigation of Exchange Rate Determination in Kenya: Does Current Account Imbalance Play a Role?

Abstract The paper investigates exchange rate determination in Kenya using vector error correction model approach to uncover the long run relationships. The empirical results show that current account balance has a role to play in the determination of the exchange rate. A rise, which denotes an improvement in the current account balance, is associated with an appreciation of the exchange rate. Additionally, higher domestic interest rates relative to foreign interest rates, as well as a rise in foreign price have an appreciating effect on the exchange rate while domestic price increase is associated with depreciation of the domestic currency. The results further show that although there are feedback effects between the exchange rate and the domestic price level, the feedback effect from exchange rate to the * The views expressed in this paper are those of the authors and do not necessarily represent those of the Institution they are affiliated to

Excited Random Walk in One Dimension

We study the excited random walk, in which a walk that is at a site that contains cookies eats one cookie and then hops to the right with probability p and to the left with probability q=1-p. If the walk hops onto an empty site, there is no bias. For the 1-excited walk on the half-line (one cookie initially at each site), the probability of first returning to the starting point at time t scales as t^{-(2-p)}. Although the average return time to the origin is infinite for all p, the walk eats, on average, only a finite number of cookies until this first return when p<1/2. For the infinite line, the probability distribution for the 1-excited walk has an unusual anomaly at the origin. The positions of the leftmost and rightmost uneaten cookies can be accurately estimated by probabilistic arguments and their corresponding distributions have power-law singularities near the origin. The 2-excited walk on the infinite line exhibits peculiar features in the regime p>3/4, where the walk is transient, including a mean displacement that grows as t^{nu}, with nu>1/2 dependent on p, and a breakdown of scaling for the probability distribution of the walk.Comment: 14 pages, 13 figures, 2-column revtex4 format, for submission to J. Phys.

Localization in Strongly Chaotic Systems

We show that, in the semiclassical limit and whenever the elements of the Hamiltonian matrix are random enough, the eigenvectors of strongly chaotic time-independent systems in ordered bases can on average be exponentially localized across the energy shell and decay faster than exponentially outside the energy shell. Typically however, matrix elements are strongly correlated leading to deviations from such behavior.Comment: RevTeX, 5 pages + 3 postscript figures, submitted to Phys. Rev. Let

Do clinicians adhere to practice guidelines? A descriptive study at a referral hospital in Kenya

Background: Clinical guidelines when implemented correctly have shown to improve disease outcomes. This study describes utilization of Kenya National guidelines in managing ante partum haemorrhage (APH) in 3rd trimester.Objective: To describe adherence to clinical guideline in management of antepartum haemorrhage at Garissa Provincial General Hospital Design: Crossectional mixed methods studySetting: Garissa Provincial General HospitalSubjects: Medical records of patients managed for APH between 2002 and 2012 and Key Informant Interviews (KIIs) of Health workers.Results: 36.1% of the cases assessed were managed with strict adherence to guidelines. 90% of health care workers had high levels of awareness of the existence of guidelines and sited utilization challenges attributed to resource inadequacies.Conclusion: Clinicians are skilled on APH guidelines, but adherence levels are still low. Therefore, continuous appraisal of clinical practices, availing equipment, facilities and supplies to reinforce adherence is recommended