Prevalence of Under Nutrition and Its Effects on Response to Malaria Treatments Among Children Under Five Years at Ahero and Homa Bay Hospitals, Western Kenya

Nutritional status of a person with malaria infection is thought to contribute to host treatment outcome. Limited studies have investigated the association despite the widespread concern with nutrition in malaria endemic areas. We evaluated the impact of under nutrition on the treatment outcome by Artemether Lumefantrine and Clindamycin plus Quinine. Sample of 384 children aged below five years diagnosed with uncomplicated Plasmodium falciparum malaria, were randomized to receive Clindamycin plus quinine or Artemether-lumefantrine (AL) for treatment. The children were followed up for 28 days to monitor body weight and height, clinical and parasitological parameters of treatment response.Outcomes included parasite clearance at days 2 and 3 and risk of recurrent parasitemia after 28 days of follow-up. Prevalence of underweight was 6 % (n=23) and stunting was 12% (n=45). Body weight increased over the 28 day follow up period. The initial mean weight was 13.03kg while the mean weight on day 28 was 13.7kg.The proportion of children with stunting was comparable between the female and male children: 40% verse 60%, p=0.06. Generally, the prevalence of underweight was comparable between the treatment arms (p=0.08). Similarly, the prevalence of stunting was not significantly different between the treatment arms (p=0.34). Cure rate was high in the Artemether group (96.5%) compared to the Clindamycin group (44.2%). Children who were underweight were 0.69 times less likely to be cured compared to those who were not underweight, but this difference was not significantly different from that of children were had no underweight (p = 0.429). Treatment outcomes were known for 43 of the 45 (95.6%) children with stunting. Overall, stunted children were 1.15 times more likely to be cured compared with children who were not stunted, but this difference was not statistically significant (p=0.704). No association between under nutrition (underweight and stunting) and treatment outcome was observed.  Further research is suggested on the impact of under nutrition on response to malaria treatment using Artemether Lumefantrine alone on children less than five years. Ministry of health and other policy makers may formulate guidelines to improve management of children with malaria taking into consideration their nutritional status, and to integrate nutrition in malaria programmes

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

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

Sources of resistance to Pseudocercospora fijiensis, the cause of black Sigatoka in banana

Open Access Article; Published online: 24 May 2021Black Sigatoka, caused by Pseudocercospora fijiensis, is one of the most devastating diseases of banana. In commercial banana-growing systems, black Sigatoka is primarily managed by fungicides. This mode of disease management is not feasible for resource-limited smallholder farmers. Therefore, bananas resistant to P. fijiensis provide a practical solution for managing the disease, especially under smallholder farming systems. Most banana and plantain hybrids with resistance to P. fijiensis were developed using few sources of resistance, which include Calcutta 4 and Pisang Lilin. To broaden the pool of resistance sources to P. fijiensis, 95 banana accessions were evaluated under field conditions in Sendusu, Uganda. Eleven accessions were resistant to P. fijiensis. Black Sigatoka symptoms did not progress past Stage 2 (narrow brown streaks) in the diploid accessions Pahang (AA), Pisang KRA (AA), Malaccensis 0074 (AA), Long Tavoy (AA), M.A. Truncata (AA), Tani (BB), and Balbisiana (BB), a response similar to the resistant control Calcutta 4. These accessions are potential sources of P. fijiensis resistance and banana breeding programmes can use them to broaden the genetic base for resistance to P. fijiensis

The Essential Interactions in Oxides and Spectral Weight Transfer in Doped Manganites

We calculate the value of the Fr\"ohlich electron-phonon interaction in manganites, cuprates, and some other charge-transfer insulators and show that this interaction is much stronger than any relevant magnetic interaction. A polaron shift due to the Fr\"ohlich interaction, which is about 1 eV, suggests that carriers in those systems are small (bi)polarons at all temperatures and doping levels, in agreement with the oxygen isotope effect and other data. An opposite conclusion, recently suggested in the literature, is shown to be incorrect. The frequency and temperature dependence of the optical conductivity of ferromagnetic manganites is explained within the framework of the bipolaron theory.Comment: 6 pages, REVTeX 3.1 with 3 eps-figures. Journal versio

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.

Prevalence and characteristics of gastrointestinal infections in men who have sex with men diagnosed with rectal chlamydia infection in the UK: an 'unlinked anonymous' cross-sectional study.

INTRODUCTION: Gastrointestinal infections (GII) can cause serious ill health and morbidity. Although primarily transmitted through faecal contamination of food or water, transmission through sexual activity is well described, especially among men who have sex with men (MSM). METHODS: We investigated the prevalence of GIIs among a convenience sample of MSM who were consecutively diagnosed with rectal Chlamydia trachomatis (CT) at 12 UK genitourinary medicine clinics during 10 weeks in 2012. Residual rectal swabs were coded, anonymised and tested for Shigella, Campylobacter, Salmonella, shiga toxin-producing Escherichia coli and enteroaggregative E. coli (EAEC) using a real-time PCR. Results were linked to respective coded and anonymised clinical and demographic data. Associations were investigated using Fisher's exact tests. RESULTS: Of 444 specimens tested, overall GII prevalence was 8.6% (95% CI 6.3% to 11.6%): 1.8% (0.9% to 3.6%) tested positive for Shigella, 1.8% (0.9% to 3.6%) for Campylobacter and 5.2% (3.5% to 7.7%) for EAEC. No specimens tested positive for Salmonella or other diarrhoeagenic E. coli pathotypes. Among those with any GII, 14/30 were asymptomatic (2/7 with Shigella, 3/6 with Campylobacter and 9/17 with EAEC). Shigella prevalence was higher in MSM who were HIV-positive (4.7% (2.1% to 10.2%) vs 0.5%(0.1% to 3.2%) in HIV-negative MSM; p=0.01). CONCLUSIONS: In this small feasibility study, MSM with rectal CT appeared to be at appreciable risk of GII. Asymptomatic carriage may play a role in sexual transmission of GII

Randomly Evolving Idiotypic Networks: Structural Properties and Architecture

We consider a minimalistic dynamic model of the idiotypic network of B-lymphocytes. A network node represents a population of B-lymphocytes of the same specificity (idiotype), which is encoded by a bitstring. The links of the network connect nodes with complementary and nearly complementary bitstrings, allowing for a few mismatches. A node is occupied if a lymphocyte clone of the corresponding idiotype exists, otherwise it is empty. There is a continuous influx of new B-lymphocytes of random idiotype from the bone marrow. B-lymphocytes are stimulated by cross-linking their receptors with complementary structures. If there are too many complementary structures, steric hindrance prevents cross-linking. Stimulated cells proliferate and secrete antibodies of the same idiotype as their receptors, unstimulated lymphocytes die. Depending on few parameters, the autonomous system evolves randomly towards patterns of highly organized architecture, where the nodes can be classified into groups according to their statistical properties. We observe and describe analytically the building principles of these patterns, which allow to calculate number and size of the node groups and the number of links between them. The architecture of all patterns observed so far in simulations can be explained this way. A tool for real-time pattern identification is proposed.Comment: 19 pages, 15 figures, 4 table