Scanning and Transmission Electron Microscopic Study of Recovered Porcine Aortic Valved Conduits

Four explanted porcine aortic valved conduits were examined using scanning and transmission electron microscopy. Sources of obstruction such as neointima or peel and calcification were observed. In one sample the neointima was found to possess an unusually large expanse of squamous cells partially lining the luminal surface. This lining much resembled a normal endothelium, which is not an expected feature of neointima. Cells, presumably of host origin, were noted upon the leaflet surfaces. They did not seem as well organized as those found on the neointima. Calcification did not seem greatly advanced but was clearly apparent. Certain treatments proposed by others to curtail calcification are discussed and amended herein. SEM examination of three of these conduits provided good evidence of lining cells on only the inflow surface of the leaflet. The fourth conduit, however, showed cells on both inflow and outflow surfaces. These cells possessed certain characteristics of cells from leaflets of the other three conduits, but questions remain as to the precise identification of all of these lining cells. TEM examination provided cytological evidence of macrophage-like cells lining the inflow surface of a leaflet

Outbreak of Aeromonas hydrophila associated with the parasitic infection Ichthyophthirius multifiliis in pond of African catfish (Clarias gariepinus) fingerlings at Sebeta, Ethiopia

Outbreak of a disease was observed on African catfish (Clarias gariepinus) fingerlings manifested by white nodules all over the body and hemorrhage in the skin that occurred on June 20, 2011 in an earthen pond at Sebeta, Ethiopia. The outbreak was investigated by using a combination of methods that included clinical observations, gross and histopathology examination and bacterial isolation. On histopathological  examination co-infection of Aeromonas hydrophila with Ichthyophthirius multifiliis a holotrichous ciliate, was found to be the cause of the outbreak. In order to control the outbreak, the fish density was reduced and the fish were removed and treated with sodium chloride (3%) and moved to another properly disinfected pond that contains fresh and good quality water. The former pond was drained and left empty for two  weeks to dry and then lime was added over it before filling it with water. The sick fish got cured after three weeks and no new case was observed; which may be due to development of immunity or the intervention measures taken to control the problem. This intervention protocols need to be further investigated in a properly designed experiment as a possible control of co-infection of these two pathogens in catfish  fingerlings.Keywords: Aeromonas hydrophila, Co-infection, Ethiopia, Ichthyophthirius multifilii

Reducing Calf Mortality in Ethiopia

SIMPLE SUMMARY: Disease and death of young livestock cause financial and production difficulties to farmers around the world. High rates of disease and death occur in various production systems in Ethiopia, hampering livestock production, reducing incomes, and damaging livelihoods. Over the last 10 years, studies carried out in Ethiopia have reported death and disease incidence rates in young livestock as high as 31% and 67%, respectively. Diarrhea and respiratory infections are the two leading causes of disease and death in calves in all production systems. In this paper, we describe findings from the experience of the Young Stock Mortality Reduction Consortium. This unique group produced important information on the main causes of disease and death in Ethiopia and created activities for small-scale farmers to address these problems. We found that several diseases caused diarrhea and respiratory infections in young calves in Ethiopia. Improving farmer knowledge and behaviors with respect to basic livestock management led to considerable reductions in young livestock disease and death and has the potential to help improve livestock productivity and human livelihoods in Ethiopia. ABSTRACT: Morbidity and mortality of young stock present economic and production challenges to livestock producers globally. In Ethiopia, calf morbidity and mortality rates, particularly due to diarrhea and respiratory disease, are high, limiting production, incomes, and the ability of farmers to improve their livelihoods. In this paper, we present findings from the combined experience of the Young Stock Mortality Reduction Consortium, which conducted epidemiological and intervention testing in calves across three production systems. This innovative alliance identified Cryptosporidium parvum and E. Coli K99 as the most common causes of diarrhea in pastoral and peri-urban calves; Strongyloides spp. as the most common fecal parasite in mixed crop–livestock and peri-urban calves; and bovine adenovirus, parainfluenza virus-3, and bovine respiratory syncytial virus as the most common respiratory pathogens in peri-urban calves. Furthermore, by improving producer knowledge with respect to fundamental livestock husbandry, feeding, housing, and neonatal care practices, calf mortality risk across production systems was reduced by 31.4 to 71.4% compared to baseline (between 10.5 and 32.1%), whereas risk of diarrhea was reduced by 52.6–75.3% (baseline between 11.4 and 30.4%) and risk of respiratory disease was reduced by 23.6–80.8% (baseline between 3.3 and 16.3%). These findings have informed scaling strategies and can potentially contribute to improved livestock productivity and human livelihoods in Ethiopia

Detection of infectious bronchitis virus 793B, avian metapneumovirus, Mycoplasma gallisepticum and Mycoplasma synoviae in poultry in Ethiopia

A survey was conducted into respiratory infectious diseases of poultry on a chicken breeder farm run by the Ethiopian Institute of Agricultural Research (EIAR), located in Debre Zeit, Ethiopia. Oropharyngeal swabs were collected from 117 randomly selected birds, and blood was taken from a subset of 73 of these birds. A combination of serological and molecular methods was used for detection of pathogens. For the first time in Ethiopia, we report the detection of variant infectious bronchitis virus (793B genotype), avian metapneumovirus subtype B and Mycoplasma synoviae in poultry. Mycoplasma gallisepticum was also found to be present; however, infectious laryngotracheitis virus was not detected by PCR. Newcastle disease virus (NDV) was not detected by PCR, but variable levels of anti-NDV HI antibody titres shows possible exposure to virulent strains or poor vaccine take, or both. For the burgeoning-intensive industry in Ethiopia, this study highlights several circulating infectious respiratory pathogens that can impact on poultry welfare and productivity

Seroprevalence of Camel Brucellosis In Pastoral Areas of Afar, Somali and Oromia Regions, Ethiopia

A cross-sectional study was conducted in the pastoral areas of Afar, Somali and Oromia regions of Ethiopia between October 2008 and May 2009 to determine the antibody prevalence and to identify risk factors for brucellosis in camels (Camelus dromedorius). Sera were collected from 1100 camels and 86 herds. Rose Bengal plate test (RBPT) was used to screen all serum samples and positive samples were subjected to confirmation by complement fixation test (CFT). Twenty six of these (2.36%) tested positive using the Rose Bengal plate test and 21 (1.91%) tested positive by the complement fixation test. The true seroprevalence of camel brucellosis as adjusted to the RBPT and CFT sensitivities and specificities was 5.71%. The highest prevalence (3.16%) was reported in Afar however the difference was not significant (p>0.05) among regions. Age and sex were not found to be significant in the occurrence of brucellosis. Univariable logistic regression model showed that adult camels in the age group of 4-6years had significant impact on camel seropositivity to brucellosis (P<0.05, odds ratio (OR), 4.56; 95% confidence interval (CI), 1.38-15.04). Herd size recorded significant association with seropositivity of brucellosis (P<0.05, medium herds OR, 5.51; 95%CI, 1.80-16.91 and large herds OR, 1.85; 95%CI, 0.46-7.48). The authors recommend the implementation of well-organized disease control and prevention methods to mitigate the economic losses and public health hazard caused by the disease

Assessment of effectiveness of a foot-and-mouth disease vaccine in cattle in Ethiopia

This study was aimed at evaluating the field effectiveness of a trivalent foot and mouth disease (FMD) vaccine (containing serotypes O, A and SAT 2), produced and widely used in Ethiopia, in terms of preventing clinical infection and severe disease. A randomized controlled trial design was employed in the study in which the attack rate of clinical FMD infection in vaccinated cattle was compared with the attack rate in unvaccinated controls in cattle population of 16 villages in Gondar Zuria district, Northwest Ethiopia. The vaccine was administered as a single dose course in the face of an impending FMD outbreak and the trial groups were monitored for clinical infection until the end of the outbreak. The attack rate of clinical FMD in the vaccinated cattle (34%) was significantly lower than the attack rate in unvaccinated controls (49%) (p< 0.001). However, the effectiveness of the vaccine was only 31% (95%CI: 20 - 40%). The proportion of severely affected cattle in the vaccinated group (5.7%) was significantly lower than in the unvaccinated group (9.4%) (p< 0.001), resulting in 39% (95%CI: 18-55%) vaccine effectiveness against severe disease. The observed level of vaccine effectiveness was lower than the internationally recommended 70% expected percentage of protection for a standard potency 3PD50/dose FMD vaccine. Moreover, the level of effectiveness was insufficient to provide herd immunity to control the disease at the population level. Nevertheless, given the significant difference in the incidence of clinical disease between vaccinated and unvaccinated cattle, it might still be cost-effective to use the current vaccine to reduce production losses. Factors that cause low effectiveness of the vaccine need to be identified and addressed for effective control of the disease at population level

Sediment budget of Lake Tana and the role of lacustrine plains

status: publishe