The diagnosis of trypanosome infections: applications of novel technology for reducing disease risk

Reliable DNA based methodologies to determine prevalence of trypanosome species in domestic livestock have been available for over 10 years. Despite this, they are rarely used to generate baseline data for control operations for these diseases in the field. Rather, such operations tend to rely on data which can be generated using low technology methods such as direct observation of parasites by light microscopy. Here we show the pitfalls of relying on such low tech methodology which, although simple in its application, can provide inaccurate and inadequate data on which to base control methodologies. Our analysis of 61 cattle selected for trypanosome carrier status by either microscopy, low PCV or poor condition score, showed that 90% were infected with trypanosomes while 84% of the total were infected with T. brucei. Diagnosis by PCR on buffy coat preparations on Whatman® FTA® matrices was the most sensitive methodology relative to the gold standard, whereas microscopy was the least sensitive. (African Journal of Biotechnology: 2002 1(2): 39-45

Prevalence of endemic pig-associated zoonoses in Southeast Asia: A review of findings from the Lao people's Democratic Republic

The increasing intensification of pork production in southeast Asia necessitates an urgent requirement to better understand the dual impact of pig-associated zoonotic disease on both pig production and human health in the region. Sharing porous borders with five countries and representing many regional ethnicities and agricultural practices, the Lao People's Democratic Republic (Lao PDR) appears well placed to gauge the levels of pig-associated zoonoses circulating in the wider region. Despite this, little is known about the true impact of zoonotic pathogens such as leptospirosis, Trichinella, hepatitis E virus (HEV), Japanese encephalitis (JE), and Taenia solium on human health and livestock production in the country. A comprehensive review of the published prevalences of these five pig-associated zoonoses in Lao PDR has demonstrated that although suspicion remains high of their existence in pig reservoirs across the country, epidemiological data are scarce; only 31 epidemiological studies have been undertaken on these diseases in the past 25 years. A greater understanding of the zoonoses prevalence and subsequent risks associated with pork production in the southeast Asian region could help focus public health and food safety interventions at key points along the value chain, benefiting both livestock producers and the broader animal and human health systems in the region

The prevalence of brucellosis and bovine tuberculosis in ruminants in Sidi Kacem Province, Morocco

Bovine tuberculosis (BTB) and brucellosis are major endemic zoonoses in ruminants in Morocco that impact on both animal and human health. This study presents an assessment of the epidemiological and socioeconomic burden of bacterial zoonoses in Sidi Kacem Province in Northern Morocco from a cross-sectional survey of 125 cattle and/or small ruminantowning households. In total, 1082 sheep and goats were examined from 81 households. The single intradermal comparative cervical test to screen for bovine tuberculosis was undertaken on 1194 cattle from 123 households and all cattle were blood sampled. Cattle and small ruminant sera were tested for brucellosis using the standard Rose Bengal Test (sRBT) and the modified Rose Bengal Test (mRBT). Bacteriology was performed on 21 milk samples obtained from cattle that were seropositive for brucellosis for isolation and phenotyping of circulating Brucella strains. Individual and herd prevalence for BTB in cattle of 20.4% (95% CI 18%-23%) and 57.7% (95% CI 48%-66%), respectively, were observed in this study. The prevalence of brucellosis in cattle at individual and herd level was 1.9% (95% CI 1.2%-2.8%) and 9% (95% CI 4.5%-1.5%), respectively. Brucella pathogens were isolated from three cattle milk samples and were identified as B. abortus using Bruceladder (R) multiplex PCR and B. abortus biovar 1 by classical phenotyping. All small ruminants were seronegative to sRBT, two were positive to mRBT. A higher risk of BTB and brucellosis was observed in cattle in intensive livestock systems, in imported and crossed breeds and in animals from larger herds (>15). The three risk factors were usually present in the same herds, leading to higher transmission risk and persistence of both zoonoses. These results highlight the importance of implementing control strategies for both BTB and brucellosis to reduce productivity losses and the risk of transmission to humans. Prioritising control for BTB and brucellosis in intensive livestock production systems is essential for human and animal health

The neglected zoonoses-the case for integrated control and advocacy

AbstractThe neglected zoonotic diseases (NZDs) have been all but eradicated in wealthier countries, but remain major causes of ill-health and mortality across Africa, Asia, and Latin America. This neglect is, in part, a consequence of under-reporting, resulting in an underestimation of their global burden that downgrades their relevance to policy-makers and funding agencies. Increasing awareness about the causes of NZDs and how they can be prevented could reduce the incidence of many endemic zoonoses. Addressing NZDs by targeting the animal reservoir can deliver a double benefit, as enhanced animal health means a reduced risk of infection for humans, as well as improved livelihoods through increased animal productivity. Advocacy for NZD control is increasing, but with it comes a growing awareness that NZD control demands activities both in the short term and over a long period of time. Moreover, despite the promise of cheap, effective vaccines or other control tools, these endemic diseases will not be sustainably controlled in the near future without long-term financial commitment, particularly as disease incidence decreases and other health priorities take hold. NZD intervention costs can seem high when compared with the public health benefits alone, but these costs are easily outweighed when a full cross-sector analysis is carried out and monetary/non-monetary benefits—particularly regarding the livestock sector—are taken into account. Public–private partnerships have recently provided advocacy for human disease control, and could prove equally effective in addressing endemic zoonoses through harnessing social impact investments. Evidence of the disease burdens imposed on communities by the NZDs and demonstration of the cost-effectiveness of integrated control can strengthen the case for a One Health approach to endemic zoonotic disease control

The rickettsia-like organisms of Glossina spp

Available from British Library Document Supply Centre- DSC:DX184314 / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo

Programmed cell death in procyclic Trypanosoma brucei rhodesiense is associated with differential expression of mRNAs

Procyclic Trypanosoma brucei rhodesiense have a cell death mechanism which can be activated by an external signal, the lectin ConA, in vitro. ConA has been shown to cause profound changes in cellular morphology and induce fragmentation of nuclear DNA in T.b. rhodesiense which are characteristic of apoptosis, a form of programmed cell death (PCD) in other eukaryotic cells. RNA analysis of trypanosomes induced to undergo PCD revealed that RNA remains intact up to 48 h into the process, a time when nuclear DNA fragmentation has already started. Using the randomly amplified differentially expressed sequences polymerase chain reaction method, ConA-induced cell death in T.b rhodesiense is shown to be associated with differential expression of mRNAs, including up regulation of mRNAs late in the death process. The results demonstrate that trypanosomes actively participate in their own destruction through a PCD process and confirm that cell death in trypanosomes is associated with de novo gene expression

Sleeping sickness rediscovered

This paper is a review of the meeting "Sleeping Sickness Rediscovered". The meeting focussed on human sleeping sickness, which, despite improvements in diagnosis and control has returned with a vengeance across central Africa. Topics of discussion include control activities; control tools; research; and drugs and vaccines. The paper also summarises the WHO/TDR/CTD round table which was a special session of the meeting

An experimental and modelling study of water vapour adsorption on SBA-15

Bovine trypanosomiasis caused by pathogenic trypanosomes, and cyclically transmitted by tsetse flies, is considered to be a major disease constraint to livestock production in sub-Saharan Africa, preventing full use of the land to feed the rapidly increasing human population. Privatisation of veterinary services in Africa has led to a situation where drug administration is in the hands of farmers or extension workers, who are unskilled in differential diagnosis and lack knowledge on appropriate drug user. This indiscriminate use of trypanocides is undesirable because it is uneconomical to treat uninfected animals, and misuse and overuse of trypanocides may be associated with the Development of drug resistance*' and occasionally with toxicity5. The objective of this study was to obtain data from cattle owners on their current knowledge, attitude and practices concerning on-farm disease diagnosis and treatment, and their perceptions of the importance and control of trypanosomiasis and other endemic diseases in Busia and Kwale Districts of Kenya