Systematic review of brucellosis in the Middle East: disease frequency in ruminants and humans and risk factors for human infection

This paper considers the problem of finding global states incoming to a specified global state in a Boolean network, which may be useful for pre-processing of finding a sequence of control actions for a Boolean network and for identifying the basin of attraction for a given attractor, We show that this problem is NP-hard in general along with related theoretical results, On the other hand, we present algorithms that are much faster than the naive exhaustive search-based algorithm. ©2007 IEEE.link_to_subscribed_fulltex

Knowledge, Attitudes, and Practices Associated with Brucellosis in Livestock Owners in Jordan

We evaluated livestock owners' knowledge, attitudes, and practices regarding brucellosis in Jordan. A questionnaire was administered and biological samples were examined to verify the serological status of animals. Seroprevalence estimates indicated that 18.1% (95% CI: 11–25.3) of cattle herds and 34.3% (95% CI: 28.4–40.4) of small ruminant flocks were seropositive. The results showed that 100% of the interviewed livestock keepers were aware of brucellosis: 87% indicated a high risk of infection if unpasteurized milk is consumed and 75% indicated a high risk if unpasteurized dairy products are consumed. Awareness of the risk of infection through direct contact with fetal membranes or via physical contact with infected livestock is considerably lower, 19% and 13%, respectively. These knowledge gaps manifest in a high frequency of high-risk practices such as assisting in animal parturition (62%), disposing aborted fetuses without protective gloves (71.2%) or masks (65%), and not boiling milk before preparation of dairy products (60%). When brucellosis is suspected, basic hygiene practices are often disregarded and suspect animals are freely traded. Public health education should be enhanced as the disease is likely to remain endemic in the ruminant reservoir as long as a suitable compensation program is not established and trust on available vaccines is regained

Prevalence of Giardia Assemblages Among Equines in Jordan

A cross-sectional study was carried out on 400 equine holding (326 horses and 74 donkeys) samples to determine the prevalence of Giardia assemblages A, B, and E in Jordan. Identifying the Giardia assemblages was carried out using enzyme-linked immunosorbent assay (ELISA) as a screening test and PCR-RFLP targeting β-giardin loci. In addition, polymerase chain reaction targeting triose phosphate isomerase gene specific for assemblages A and B were used as confirmatory. Thirty-four samples tested positive by ELISA for Giardia with an apparent prevalence of 8.5%. The PCR-RFLP test confirmed Giardia assemblages in 30 of the 34 ELISA-positive samples giving a true prevalence of 7.7% (95% confidence interval: 4.8–10.1). Of the 30 positive animals/holdings, 18, 4, and 8 had assemblages A, B, and E. Assemblage A was significantly (P < .05) more prevalent when compared to assemblages B and E. The total infection rates of Giardia, assemblages B and E were significantly (P < .05, chi-square) higher in donkeys 14.8%, 2.7%, and 5.5% compared to horses 5.8%, 0.6%, and 1.2%, respectively. Analysis of risk factors revealed that only season was significantly associated with the different Giardia assemblages. Autumn (odds ratio [OR] = 0.09) was associated with Giardia infection regardless of the assemblage type as reducing factor. The odds of infection of assemblages A and E increased in winter (OR = 6.8) and spring (OR = 4.5), respectively. Giardia assemblages A, B, and E infect both horses and donkeys in Jordan with potential impact on human and animal health, and the odds of infections is significantly associated with season

A systematic review of sub-microscopic Plasmodium vivax infection.

BACKGROUND: An accurate estimate of Plasmodium vivax prevalence is essential for the successful implementation of malaria control and elimination programmes. Prevalence estimates both inform control strategies and are used in their evaluation. Light microscopy is the main method for detecting Plasmodium parasitaemia in the peripheral blood, but compared to molecular diagnostics, such as polymerase chain reaction (PCR), has limited sensitivity. METHODS: A systematic review and meta-analysis was conducted to assess the effect of detection method on the prevalence of P. vivax and to quantify the extent to which P. vivax infections are undetected by microscopy. Embase, Medline and the Cochrane Database were searched for studies reporting prevalence by PCR and by microscopy and that contained all of the following key words: vivax, PCR, and malaria. Prevalence estimates and study meta-data were extracted systematically from each publication. Combined microscopy:PCR prevalence ratios were estimated by random effects meta-analysis. Sensitivity and specificity of microscopy were calculated using PCR as the gold standard. RESULTS: Of 874 studies reviewed, 40 met the criteria for inclusion contributing 54 prevalence pairs. The prevalence of P. vivax infection measured by PCR was consistently higher than the prevalence measured by microscopy with sub-patent parasitaemia. The mean prevalence of infection detected by microscopy was 67 % (95 % CI 59-73 %) lower than the prevalence detected by PCR. The detection of sub-patent parasitaemia did not vary according to the microscopy method (thick or, thick and thin smears), the PCR prevalence (as a measure of the true P. vivax prevalence), the type of blood used or DNA extraction method. CONCLUSIONS: Quantifying P. vivax parasitaemia by PCR rather than microscopy consistently increased prevalence estimates by a factor of 2.3. Whilst the sensitivity of microscopy can be improved by better methods, molecular methods have potential to be scaled up to improve the detection of P. vivax transmission reservoirs

Taenia multiceps coenurosis in Tanzania: a major and under-recognised livestock disease problem in pastoral communities

A neurological syndrome of small ruminants, known locally as ‘ormilo’, has been reported among pastoralist livestock keepers in Tanzania. This study was carried out in four affected pastoral communities to determine the prevalence and associated risk factors, characterise the clinical signs and investigate the aetiology of the syndrome. Questionnaires were administered at all households (n=480) within four study villages. Overall, 94 per cent of households reported at least one case in the previous 12 months. By village, the individual-level 12-month period prevalence ranged from 11 per cent to 34 per cent, equivalent to about 10,000 small ruminants across the four villages. Thirty-eight households were randomly selected for further investigation. Proprioceptive deficits and weakness were the most commonly observed clinical signs in affected animals. Brain and spinal cord cysts consistent with Taenia multiceps infection were detected in 32 (82 per cent) of 39 affected animals selected for postmortem examination. Feeding small ruminant brains to dogs was identified as an important risk factor for the syndrome, even in households that did not own dogs. This study confirms cerebral coenurosis as a major cause of small ruminant neurological disease in northern Tanzania and highlights the urgent need for further investigation to quantify the disease burden and to identify and implement control measures

Experimental Toxocara cati Infection in Gerbils and Rats

Mongolian gerbils and Wistar rats were inoculated orally with 240 and 2,500 Toxocara cati embryonated eggs, respectively, to evaluate the larval recovery in different tissues and organs, such as the liver, lungs, heart, kidney, and skeletal muscles after 5, 30, 49, 70, and 92 days post-infection (PI). Larval recovery rates were 1.7-30.0% in Mongolian gerbils on days 5-92 PI and 0.2-3.8% in rats on the same days. These results indicate that Mongolian gerbils and Wistar rats are suitable experimental paratenic hosts for the study of neurological toxocariasis as well as visceral toxocariasis

Expression plasticity of Phlebotomus papatasi salivary gland genes in distinct ecotopes through the sand fly season

<p>Abstract</p> <p>Background</p> <p>Sand fly saliva can drive the outcome of <it>Leishmania </it>infection in animal models, and salivary components have been postulated as vaccine candidates against leishmaniasis. In the sand fly <it>Phlebotomus papatasi</it>, natural sugar-sources modulate the activity of proteins involved in meal digestion, and possibly influence vectorial capacity. However, only a handful of studies have assessed the variability of salivary components in sand flies, focusing on the effects of environmental factors in natural habitats. In order to better understand such interactions, we compared the expression profiles of nine <it>P. papatasi </it>salivary gland genes of specimens inhabiting different ecological habitats in Egypt and Jordan and throughout the sand fly season in each habitat.</p> <p>Results</p> <p>The majority of investigated genes were up-regulated in specimens from Swaymeh late in the season, when the availability of sugar sources is reduced due to water deprivation. On the other hand, these genes were not up-regulated in specimens collected from Aswan, an irrigated area less susceptible to drought effects.</p> <p>Conclusion</p> <p>Expression plasticity of genes involved with vectorial capacity in disease vectors may play an important epidemiological role in the establishment of diseases in natural habitats.</p