Predicting environmental factors influencing crop raiding by African elephants (Loxodonta africana) in the Luangwa Valley, eastern Zambia

Elephant crop raiding is pervasive and widespread in elephant-agriculture landscapes. Due to rare investigations on underlying African elephant (Loxodonta africana) crop raiding processes and patterns, neither reliable predictive models nor empirical evidence on elephant crop raiding parameters are available or adequate to support intervening decisions by susceptible farmers and other stakeholders. By developing predictive models of binary logistic regression and employing questionnaire surveys, we examined the environmental factors influencing occurrence of crop raiding by interrogating effectiveness of counter-measures implemented by local farmers in Luangwa Valley, eastern Zambia. Farm sizes, vegetation types in peripherals of crop fields and types of counter-measures used by local farmers to restrain marauding elephants were the most important elephant crop raiding predictors. Smaller crop fields (.4782.00 } 342.00 m2) were more vulnerable than larger ones. Most crop fields (75.88%, n=236) surrounded by Brachystegia and Acacia dominated vegetation communities were damaged, largely due to high tree fruiting which were elephant attractants. Solar powered electric fences were more effective than other counter-measures. Though traditional methods were prevalent, they were less effective than other counter-measures. It was posited that additional capacity development of local farmers was required particularly, in participatory integrative land use practices to minimize elephant crop raiding.Key words: Predictive models, elephant crop raiding, conservation, Luangwa Valley, Zambia

Stakeholder narratives on trypanosomiasis, their effect on policy and the scope for One Health

Background This paper explores the framings of trypanosomiasis, a widespread and potentially fatal zoonotic disease transmitted by tsetse flies (Glossina species) affecting both humans and livestock. This is a country case study focusing on the political economy of knowledge in Zambia. It is a pertinent time to examine this issue as human population growth and other factors have led to migration into tsetse-inhabited areas with little historical influence from livestock. Disease transmission in new human-wildlife interfaces such as these is a greater risk, and opinions on the best way to manage this are deeply divided. Methods A qualitative case study method was used to examine the narratives on trypanosomiasis in the Zambian policy context through a series of key informant interviews. Interviewees included key actors from international organisations, research organisations and local activists from a variety of perspectives acknowledging the need to explore the relationships between the human, animal and environmental sectors. Principal Findings Diverse framings are held by key actors looking from, variously, the perspectives of wildlife and environmental protection, agricultural development, poverty alleviation, and veterinary and public health. From these viewpoints, four narratives about trypanosomiasis policy were identified, focused around four different beliefs: that trypanosomiasis is protecting the environment, is causing poverty, is not a major problem, and finally, that it is a Zambian rather than international issue to contend with. Within these narratives there are also conflicting views on the best control methods to use and different reasoning behind the pathways of response. These are based on apparently incompatible priorities of people, land, animals, the economy and the environment. The extent to which a One Health approach has been embraced and the potential usefulness of this as a way of reconciling the aims of these framings and narratives is considered throughout the paper. Conclusions/Significance While there has historically been a lack of One Health working in this context, the complex, interacting factors that impact the disease show the need for cross-sector, interdisciplinary decision making to stop rival narratives leading to competing actions. Additional recommendations include implementing: surveillance to assess under-reporting of disease and consequential under-estimation of disease risk; evidence-based decision making; increased and structurally managed funding across countries; and focus on interactions between disease drivers, disease incidence at the community level, and poverty and equity impacts

Evaluation of bleach-sedimentation for sterilising and concentrating Mycobacterium tuberculosis in sputum specimens

RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are.Abstract Background Bleach-sedimentation may improve microscopy for diagnosing tuberculosis by sterilising sputum and concentrating Mycobacterium tuberculosis. We studied gravity bleach-sedimentation effects on safety, sensitivity, speed and reliability of smear-microscopy. Methods This blinded, controlled study used sputum specimens (n = 72) from tuberculosis patients. Bleach concentrations and exposure times required to sterilise sputum (n = 31) were determined. In the light of these results, the performance of 5 gravity bleach-sedimentation techniques that sterilise sputum specimens (n = 16) were compared. The best-performing of these bleach-sedimentation techniques involved adding 1 volume of 5% bleach to 1 volume of sputum, shaking for 10-minutes, diluting in 8 volumes distilled water and sedimenting overnight before microscopy. This technique was further evaluated by comparing numbers of visible acid-fast bacilli, slide-reading speed and reliability for triplicate smears before versus after bleach-sedimentation of sputum specimens (n = 25). Triplicate smears were made to increase precision and were stained using the Ziehl-Neelsen method. Results M. tuberculosis in sputum was successfully sterilised by adding equal volumes of 15% bleach for 1-minute, 6% for 5-minutes or 3% for 20-minutes. Bleach-sedimentation significantly decreased the number of acid-fast bacilli visualised compared with conventional smears (geometric mean of acid-fast bacilli per 100 microscopy fields 166, 95%CI 68-406, versus 346, 95%CI 139-862, respectively; p = 0.02). Bleach-sedimentation diluted paucibacillary specimens less than specimens with higher concentrations of visible acid-fast bacilli (p = 0.02). Smears made from bleach-sedimented sputum were read more rapidly than conventional smears (9.6 versus 11.2 minutes, respectively, p = 0.03). Counting conventional acid-fast bacilli had high reliability (inter-observer agreement, r = 0.991) that was significantly reduced (p = 0.03) by bleach-sedimentation (to r = 0.707) because occasional strongly positive bleach-sedimented smears were misread as negative. Conclusions Gravity bleach-sedimentation improved laboratory safety by sterilising sputum but decreased the concentration of acid-fast bacilli visible on microscopy, especially for sputum specimens containing high concentrations of M. tuberculosis. Bleach-sedimentation allowed examination of more of each specimen in the time available but decreased the inter-observer reliability with which slides were read. Thus bleach-sedimentation effects vary depending upon specimen characteristics and whether microscopy was done for a specified time, or until a specified number of microscopy fields had been read. These findings provide an explanation for the contradictory results of previous studies.Peer Reviewe

Conservation and ecology of African Raptors

Africa supports breeding populations of over 20% of all raptor species globally and over 20 regular Palearctic migratory raptors. Here, we discuss the importance of Africa in terms of the diversity of both resident and migrant species, the ecosystem services they provide, and the threats they face. We examine the state of knowledge of African raptors, including monitoring to determine trends, and describe ongoing research. African raptors provide important ecosystem services, by bringing in tourism revenues, functioning as bio-indicator species, and controlling the spread of pathogens and pest species. Many species are under pressure from growing human populations and associated habitat loss, persecution, and pollution. Most are declining, with some exceptions, some catastrophically so, such as vultures. Of 66 African species, 26% are currently on the IUCN Red List. For many species, there is a need for their conservation status to be re-evaluated, but rigorous monitoring for most of Africa is generally lacking. A systematic literature review showed considerable variation in the number of studies per species, 36% of 67 species having been relatively “well-studied” (12 or more studies), but 64% with less than 10 studies. There has been a general and consistent increase in the numbers of studies on African raptors, the majority from Southern Africa (n = 466, 62%). We found most studies focused on feeding ecology (n= 247) and distribution and abundance, with the least number of studies on behaviour and movement ecology. We list some ongoing studies and conclude that developing future leadership in research and conservation will be critical for successful raptor conservation in Africa