Control of invasive Liriomyza leafminer species and compliance with food safety standards by small scale snow pea farmers in Kenya

The Kenyan horticultural industry faces a new challenge following invasion by the quarantine Liriomyza leafminer species Liriomyza huidobrensis, Liriomyza sativae and Liriomyza trifolii which have recently become pests of economic importance. Controlling Liriomyza leafminers poses serious difficulties due to their biology and quarantine status. This paper examines farmers’ awareness of the pests and difficulties faced in controlling them. (1) A questionnaire survey showed that snow pea farmers in Kenya rely mainly on pesticides for control of invasive Liriomyza leafminers; (2) Sixty five percent of respondents perceived pesticides to be ineffective; (3) As a result, 74% of respondents increased the frequency of pesticide applications, 61% increased dose rates and 58% used broad-spectrum insecticides to avert damage by the pests; (4) Snow pea farmers who signed contracts with exporters and whose production practices were monitored for compliance with Good Agricultural Practices (GlobalGAP) used fewer control strategies; (5) These findings imply that the pest status of Liriomyza leafminers is likely to increase and snow pea production will significantly decrease in Central areas of Kenya unless an integrated leafminer management strategy is developed and farmers educated on methods of identifying them in their early stages of attack and use appropriate chemicals and application methods.     

Correlation of quantified contrast-enhanced power Doppler ultrasonography with immunofluorescent analysis of microvessel density in spontaneous canine tumours

Conventionally, tumour vascularity is assessed invasively by immunofluorescent analysis. Quantified contrast-enhanced power Doppler ultrasound has been used to measure tumour angiogenesis non-invasively in humans and experimental animals. The purpose of this study was to correlate quantified contrast-enhanced power Doppler ultrasound with immunofluorescent results in 45 spontaneous canine tumours. With power Doppler, mean vascularity was high in squamous cell carcinomas, moderate in malignant oral melanomas and low in sarcomas. There was high mean vascularity in squamous cell carcinomas and low mean vascularity in sarcomas and malignant oral melanomas. Although Doppler parameters correlated moderately with microvascular density for all tumours (P=0.004, r=0.4), they did not correlate within histology groups. These analyses show that vascularity differs among canine tumour histology groups. However, dependent on the method used, measurement of tumour vascularity can provide different biological information.     

Seroprevalence of antibodies to Borrelia burgdorferi in a population of horses in central Texas.

Four hundred sixty-nine serum samples were obtained from horses admitted to the internal medicine service of the Texas Veterinary Medical Center between Jan 1 and Dec 31, 1990. Serum samples were tested by ELISA for antibody to Borrelia burgdorferi. Of these 469 samples, 1 (0.2%) was repeatedly seropositive for the organism by ELISA. Confirmatory testing by protein immunoblot was negative. The observed seroprevalence was 0%; the upper bound of the 95% confidence interval was 0.6%. These findings indicate the evidence of infection with B burgdorferi is presently uncommon in horses in central Texas.     

Development of a diagnostic PCR assay based on novel DNA sequences for the detection of Mycoplasma suis (Eperythrozoon suis) in porcine blood

An efficient method of control of porcine eperythrozoonosis (PE) caused by Mycoplasma suis is eradication of infection by detection and removal of infected carrier animals. At present, only a few tests are available for the diagnosis of these latent M. suis infections in pigs. The objective of this study was to develop a PCR assay based on novel DNA sequences for the identification of M. suis-infected pigs. A 1.8 kb EcoRI DNA fragment of the M. suis genome was isolated from the blood of pigs experimentally infected with M. suis. Specificity of the DNA fragment was confirmed by DNA sequence analysis and PCR using primers directed against sequences contained in the 1.8 kb fragment. PCR products of 782 bp in size were amplified only from M. suis particles prepared from the blood of experimentally infected pigs but not from any controls, comprising blood from gnotobiotic piglets and a panel of bacteria including other porcine mycoplasmas. PCR results were confirmed by dot blot hybridisation. The applicability of the PCR assay to diagnose M. suis infections in pigs was evaluated by investigating blood samples from 10 symptomatic pigs with clinical signs typical of porcine eperythrozoonosis and blood samples from 10 healthy pigs. The M. suis-specific PCR product was amplified from all samples taken at episodes of acute disease as well as from samples taken during the latent stage of infection, thus demonstrating the suitability of the PCR assay for detecting latent infected carrier animals.     

Risk assessment as an indicator for the distribution of BSE in the world

For a long time, BSE was considered a problem of the UK exclusively. Even after the detection of BSE cases in countries outside the UK, the risk of having BSE was categorically denied by many other countries. Only after the introduction of active surveillance did several "BSE free" countries detect BSE in their country. However, before the detection of the first cases in several of these countries, a risk assessment (GBR) conducted by the Scientific Steering Committee of the EU showed that a risk could be present. There remain many countries with an unknown BSE risk. In order to minimise import risks from these countries, further risk assessment is needed to evaluate the real BSE distribution worldwide.     

Review on the epidemiology and dynamics of BSE epidemics

The paper describes how the comprehensive surveillance of bovine spongiform encephalopathy (BSE) and studies carried out on these data has enhanced our knowledge of the epidemiology of BSE. Around 7, 000 BSE cases were detected through the screening of about 50 million cattle with rapid tests in Europe. It confirmed that the clinical surveillance had a poor capacity to detect cases, and also showed the discrepancy of this passive surveillance efficiency between regions and production types (dairy/beef). Other risk factors for BSE were being in a dairy herd (three times more than beef), having a young age at first calving (for dairy cattle), being autumn-born (dairy and beef), and being in a herd with a very high milk yield. These findings focus the risk on the feeding regimen of calves/heifers. Several epidemiological studies across countries suggest that the feedborne source related to meat and bone meal (MBM) is the only substantiated route of infection - even after the feed ban -, while it is not possible to exclude maternal transmission or milk replacers as a source of some infections. In most European countries, the average age of the cases is increasing over time and the prevalence decreasing, which reflects the effectiveness of control measures. Consistent results on the trend of the epidemic were obtained using back-calculation modelling, the R(0) approach and Age-Period-Cohort models. Furthermore, active surveillance also resulted in the finding of atypical cases. These are distinct from previously found BSE and classified in two different forms based on biochemical characteristics; their prevalence is very low (36 cases up to 1st September 2007), affected animals were old and some of them displayed clinical signs. The origin and possibility of natural transmission is unknown.     

First report of Enterocytozoon bieneusi infection on a pig farm in the Czech Republic

Enterocytozoon bieneusi infects humans and animals and can cause life-threatening diarrhea in immunocompromised people. The routes of transmission and its zoonotic potential are not fully understood. Pigs have been frequently reported to have E. bieneusi; therefore, we surveyed farm-raised pigs in the Czech Republic to determine its presence and genetic diversity. Spores were detected by microscopy in the faeces of 65 out of 79 examined animals (82%). A species-specific polymerase chain reaction (PCR) identified E. bieneusi in 94% of samples. Genotyping based on the ITS regions of the SSU rRNA gene identified that most pigs were infected with the species-specific genotype F, while two animals had the zoonotic genotype D and two had genotype Peru 9. This is the first report of E. bieneusi in swine in the Czech Republic, and demonstrated that most infections were with pig-specific genotypes. Nonetheless, swine may still play a role in the transmission of E. bieneusi to humans.     

Quantification of the effect of various patient and image factors on ultrasonographic detection of select canine abdominal organs.

We assessed factors that affected ultrasonographic visualization of the pylorus, duodenal papilla, pancreas, adrenal glands, and jejunal and medial iliac lymph nodes in the dog. An abdominal ultrasonographic examination was performed on 100 canine patients, equally divided between two facilities. The pylorus was visible in 64% of the dogs, the major duodenal papilla in 42%, the left pancreatic lobe in 56%, the body of the pancreas in 60%, the right pancreatic lobe in 87%, the left adrenal gland in 91%, the right adrenal gland in 86%, the medial iliac lymph nodes in 54%, and the jejunal lymph nodes in 51%. The parameters that negatively influenced the visibility of these organs were the presence of air or food in the gastrointestinal tract (pancreas, duodenal papilla), age (lymph nodes), and body weight (pancreas, duodenal papilla). The parameters that positively influenced their visibility were the presence of air or food in the gastrointestinal tract (lymph nodes), body weight (lymph nodes), body condition score (right adrenal gland), and inherent image quality (left pancreatic lobe). There was a significant difference between the two institutes for the visualization of the pylorus, pancreas, and lymph nodes, which was probably related to different body positions used for scanning in each institution.