6320 research outputs found
Sort by
Phylogeny of Leishmania species based on the heat-shock protein 70 gene
No full textThe 70kDa heat-shock protein (HSP70) is conserved across prokaryotes and eukaryotes, and the protein as well as its encoding gene have been applied in phylogenetic studies of different parasites. In spite of the frequent use of New World Leishmania species identification on the basis of restriction fragment length polymorphisms (RFLP) in the hsp70 gene, it was never sequenced extensively for studying evolutionary relationships. To fill this void we determined the nucleotide sequence of an 1380bp fragment of the coding region commonly used in RFLP analysis, from 43 isolates and strains of different geographic origins. Combination with previously determined sequences amounted to a phylogenetic analysis including 52 hsp70 sequences representing 17 species commonly causing leishmaniasis both in the New and Old World. The genus Leishmania formed a monophyletic group with three distinct subgenera L. (Leishmania), L. (Viannia), and L. (Sauroleishmania). The obtained phylogeny supports the following eight species: L. (L.) donovani, L. (L.) major, L. (L.) tropica, L. (L.) mexicana, L. (V.) lainsoni, L. (V.) naiffi, L. (V.) guyanensis and L. (V.) braziliensis, in some of which subspecies can be recognized: L. (L.) donovani infantum, L. (V.) guyanensis panamensis, and L. (V.) braziliensis peruviana. The currently recognized L. (L.) aethiopica, L. (L.) garnhami, and L. (L.) amazonensis did not form monophyletic clusters. These findings are discussed in relation to results from other genes and proteins, which have to be integrated in order to build a genetically supported taxonomy for the entire genus
Serological and parasitological survey of dourine in the Arsi-Bale highlands of Ethiopia
No full textThis study was conducted from August 2005 to January 2007 to determine prevalence and distribution of dourine in horses and to investigate the occurrence of clinical and carrier cases in donkeys and mules in the Arsi-Bale highlands. Study methodology was based on questionnaire, serological, clinical and parasitological survey. The questionnaire indicated that dourine is a major health problem of equines in the Arsi-Bale highlands. Though dourine is commonly observed throughout the year, it has a seasonal character and occurs mostly during the breeding season from June to late September. Serological screening of 646 horses showed a seroprevalence of 184 (28%), 161 (25%) and 125 (19%) for card agglutination test for trypanosomosis, LATEX and enzyme-linked immunosorbent assay, respectively. Risk factors were parity number, previous history of abortion and body condition score. No trypanosomes could be detected by Giemsa staining or by haematocrit centrifugation technique. Ten puppies inoculated with blood samples, genital washes and oedematous fluids remained parasitologically negative. Different characteristic signs of dourine were observed. During the genital stage, mares showed vaginal oedema, discharge and presence of depigmented scars over the external genitalia. In stallions, oedema of the scrotum and prepuce, prepucial and urethral discharge, and ulceration of the genital mucosae mainly of the penile were observed. In both sexes, lameness in one or both legs, partial dragging and stiffness of the hind legs and incoordination were the dominant signs observed as nervous form of the disease
The influence of the Gilgel-Gibe hydroelectric dam in Ethiopia on caregivers' knowledge, perceptions and health-seeking behaviour towards childhood malaria
No full textBACKGROUND: Malaria remains the most important public health problem in tropical and subtropical areas. Mothers' or caregivers' ability to recognize childhood malaria-related morbidity is crucial as knowledge, attitudes and health seeking behavior of caregivers towards childhood malaria could influence response to signs of the disease. METHODS: A total of 1,003 caregivers in 'at-risk' villages in close proximity to the Gilgel-Gibe hydroelectric dam in south-western Ethiopia, and 953 caregivers in 'control' villages further away from the dam were surveyed using structured questionnaires to assess their knowledge, perceptions and health seeking behaviour about childhood malaria. RESULTS: Malaria (busa) was ranked as the most serious health problem. Caregivers perceived childhood malaria as a preventable ('at-risk' 96%, 'control' 86%) and treatable ('at-risk' 98% and 'control' 96%) disease. Most caregivers correctly associated the typical clinical manifestations with malaria attacks. The use of insecticide-treated nets (ITNs) was mentioned as a personal protective measure, whereas the role of indoor residual spraying (IRS) in malaria prevention and control was under-recognized. Most of the caregivers would prefer to seek treatment in health-care services in the event of malaria and reported the use of recommended anti-malarials. CONCLUSION: Health education to improve knowledge, perceptions and health-seeking behaviour related to malaria is equally important for caregivers in 'at risk' villages and caregivers in 'control' villages as minimal differences seen between both groups. Concluding, there may be a need of more than one generation after the introduction of the dam before differences can be noticed. Secondly, differences in prevalence between 'control' and 'at-risk' villages may not be sufficient to influence knowledge and behaviour
