563 research outputs found
Participation and its determinants in East Cost Fever immunization by smallscale cattle keepers in Mazabuka district of Zambia
Currently 1.4 million cattle are at risk of East Coast Fever out of approximately 3 million in Zambia. A cross sectional study was carried out in Mazabuka district of Zambia from July to September 2015, to assess participation and factors affecting cattle farmers participation in ECFimmunisation by the infection and treatment method. The study involved 224 randomly selected small scale cattle farmers from three veterinary camps in Mazabuka who participated in the second round of 2015 immunisation campaign. Semi-structured questionnaire was administeredto consented farmers to seek information about demographic and socio-economic characteristics, knowledge and experience in cattle rearing, herd characteristics, management and perceived benefits, costs and challenges of ECF immunisation. Data on immunisation statistics, schedules, coverage, adequacy, vaccine delivery, successes and challenges were collected from the district veterinary office and the Central Veterinary Research Institute covering the period between the years 2008 to 2014. Descriptive statistics such as frequencies and proportions were computed toestablish immunization coverage, participation trend and socio-demographic parameters of cattle farmers. Fischer exact test was used to assess associations between variables at 5% significance level. Logistic regression was run using R software to assess influence of different factors onwillingness of farmers to participate in immunization campaign. Majority of participants were males (94%), had secondary education (49.1%), more than five year experience of keeping cattle (89.3%) and depended on sources other than cattle for their livelihood (47.3%). From 2008 to2014 vaccination coverage was on average 65% of the target per annum and 97% of the participants appreciated reduction in cattle mortality post immunisation. Willingness to participate in immunisation campaign was influenced by education level (secondary education: OR=27, 95% CI: 2.29-352.71), satisfaction with immunisation service (OR=5.14, 95% CI: 1.04- 24.64) and experience of post-immunisation mortality reduction (OR=7.33, 95% CI: 1.26-44.00). Improvement in service delivery quality and monitoring of post immunisation outcome can lead to increased participation of farmers in immunisation campaigns.
Key words: East Coast Fever, immunisation, Infection and Treatment Method, Theileriosis, Tick Borne Diseases, Mazabuk
Planar electromagnetic bandgap structures based on polar curves and mapping functions
A type of electromagnetic bandgap structure is described
that is easily parameterized and can produce a range of
square and spiral geometries. Individual electromagnetic bandgap
(EBG) geometries are defined on a cell-by-cell basis in terms of
their convolution factor , which defines the extent to which the elements
are interleaved and controls the coupling slot length between
adjacent elements. Polar equations are used to define the slot locus
which also incorporate a transformation which ensures the slot extends
into the corners of the square unit cell and hence extends the
maximum slot length achievable. The electromagnetic properties
of the so-called polar EBG are evaluated by means of numerical
simulation and measurements and dispersion diagrams are presented.
Finally, the performance is compared with other similar
miniaturized EBG cell geometries. It is shown that the polar EBG
has better angular stability than the equivalent square patch design
and is comparable in terms of performance to other low frequency
EBG elements. At the same time it retains the ability to fine tune
the response by adjusting
Silencing of three Amblyomma americanum (L.) insulin-like growth factor binding protein-related proteins prevents ticks from feeding to repletion
Identifying malaria vector breeding habitats with remote sensing data and terrain-based landscape indices in Zambia
<p>Abstract</p> <p>Background</p> <p>Malaria, caused by the parasite <it>Plasmodium falciparum</it>, is a significant source of morbidity and mortality in southern Zambia. In the Mapanza Chiefdom, where transmission is seasonal, <it>Anopheles arabiensis </it>is the dominant malaria vector. The ability to predict larval habitats can help focus control measures.</p> <p>Methods</p> <p>A survey was conducted in March-April 2007, at the end of the rainy season, to identify and map locations of water pooling and the occurrence anopheline larval habitats; this was repeated in October 2007 at the end of the dry season and in March-April 2008 during the next rainy season. Logistic regression and generalized linear mixed modeling were applied to assess the predictive value of terrain-based landscape indices along with LandSat imagery to identify aquatic habitats and, especially, those with anopheline mosquito larvae.</p> <p>Results</p> <p>Approximately two hundred aquatic habitat sites were identified with 69 percent positive for anopheline mosquitoes. Nine species of anopheline mosquitoes were identified, of which, 19% were <it>An. arabiensis</it>. Terrain-based landscape indices combined with LandSat predicted sites with water, sites with anopheline mosquitoes and sites specifically with <it>An. arabiensis</it>. These models were especially successful at ruling out potential locations, but had limited ability in predicting which anopheline species inhabited aquatic sites. Terrain indices derived from 90 meter Shuttle Radar Topography Mission (SRTM) digital elevation data (DEM) were better at predicting water drainage patterns and characterizing the landscape than those derived from 30 m Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) DEM.</p> <p>Conclusions</p> <p>The low number of aquatic habitats available and the ability to locate the limited number of aquatic habitat locations for surveillance, especially those containing anopheline larvae, suggest that larval control maybe a cost-effective control measure in the fight against malaria in Zambia and other regions with seasonal transmission. This work shows that, in areas of seasonal malaria transmission, incorporating terrain-based landscape models to the planning stages of vector control allows for the exclusion of significant portions of landscape that would be unsuitable for water to accumulate and for mosquito larvae occupation. With increasing free availability of satellite imagery such as SRTM and LandSat, the development of satellite imagery-based prediction models is becoming more accessible to vector management coordinators.</p
Women's Perceptions and Misperceptions of Male Circumcision: A Mixed Methods Study in Zambia.
Women's perceptions of male circumcision (MC) have implications for behavioral risk compensation, demand, and the impact of MC programs on women's health. This mixed methods study combines data from the first two rounds of a longitudinal study (n = 934) and in-depth interviews with a subsample of respondents (n = 45) between rounds. Most women correctly reported that MC reduces men's risk of HIV (64% R1, 82% R2). However, 30% of women at R1, and significantly more (41%) at R2, incorrectly believed MC is fully protective for men against HIV. Women also greatly overestimated the protection MC offers against STIs. The proportion of women who believed MC reduces a woman's HIV risk if she has sex with a man who is circumcised increased significantly (50% to 70%). Qualitative data elaborate women's misperception regarding MC. Programs should address women's informational needs and continue to emphasize that condoms remain critical, regardless of male partner's circumcision status
HIV clinical stage progression of patients at 241 outpatient clinics in Democratic Republic of Congo: Disparities by gender, TB status and rurality
Background: HIV clinical care programs are increasingly cognizant of the importance of customizing services according to patients’ clinical stage progression (WHO\u27s four-tiered staging) and other risk assessments. Understanding factors associated with Persons Living with HIV (PLHIV) patients’ progression through the treatment cascade and clinical stages is essential for programs to provide patient-centered, evidence-based services. Methods and materials: To analyze patient characteristics associated with disease progression stages for PLHIV on antiretroviral therapy (ART), this quantitative study used data, from January 2014–June 2019, from 49,460 PLHIV on ART from 241 HIV/AIDS outpatient clinics in 23 health zones in Haut-Katanga and Kinshasa provinces, Democratic Republic of Congo. To assess bivariate and multivariate associations, we performed Chi-square and multinomial logistic regression. Results: Among PLHIV receiving ART, 4.4% were at stage 4, and 30.7% at stage 3. Those at the less severe stages 2 and 1 constituted 22.9% and 41.9%. After controlling for covariates, patients with no TB were significantly more likely than those with TB (p\u3c = .05) to be at stage 1, rather than 3 or 4 (adjusted odds ratio or AOR, 5.73; confidence interval or CI, 4.98–6.59). Other characteristics significantly associated with higher odds of being at stage 1 included being female (AOR, 1.35; CI, 1.29–1.42), and shorter duration on ART (vs. \u3e 40.37 months); for ART duration less than 3.23 months the AOR was 2.47, for 3.23–14.52 months duration the AOR was 2.60, and for 14.53–40.37 months duration the AOR was 1.77 (quartile cut points used). Compared to patients in urban health zones, those in rural (AOR, 0.32) and semi-rural health zones (AOR, 0.79) were less likely to be at stage 1. Conclusion: Significant and substantial variation in HIV clinical progression stage by geographic location and demographic characteristics existed, indicative of the need for targeted efforts to improve the effectiveness of HIV care. Patients with TB coinfection compared to those without coinfection had a much greater risk of being at stage 3 or 4, implying a need for customized approaches and clinical regimens for this high-risk population
Impact of Xpert MTB/RIF rollout on management of tuberculosis in a South African community
Background. The Xpert MTB/RIF test shortens the time to microbiological confirmation of pulmonary tuberculosis (TB) under research conditions.Objective. To evaluate the field impact of Xpert MTB/RIF rollout on TB diagnostic yield and time to treatment in a South African (SA) community.Methods. We compared TB investigation outcomes for 6-month calendar periods before and after Xpert MTB/RIF rollout in a semi-rural area of SA. The proportion of adult patients who tested positive by sputum smear microscopy, liquid culture or Xpert MTB/RIF and the proportion of positive sputum smear, liquid culture or Xpert MTB/RIF tests were compared. Secondary outcomes included time to laboratory diagnosis and treatment initiation. Data were collected from the National Health Laboratory Service database and from the Western Cape Provincial Department of Health TB register.Results. Regional rollout of Xpert MTB/RIF testing occurred in 2013. Of the 15 629 patients investigated in the post-rollout period, 7.9% tested positive on GeneXpert, compared with 6.4% of the 10 741 investigated in the pre-rollout period who tested positive by sputum smear microscopy (p<0.001). Median laboratory processing time was <1 day for Xpert MTB/RIF (interquartile range (IQR) 0 - 1) compared with 1 day (IQR 0 - 16) for sputum smear microscopy (p=0.001). The median time to TB treatment initiation was 4 days (IQR 2 - 8) after rollout compared with 5 days (IQR 2 - 14) before (p=0.001).Conclusions. Patients investigated for suspected pulmonary TB were more likely to be diagnosed after rollout of Xpert MTB/RIF testing, although the benefit to diagnostic yield was modest, and Xpert MTB/RIF testing was associated with a marginal improvement in time to treatment initiation
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