Epidemiology of selected respiratory diseases and their impacts on smallholder pig production systems in Lira District, Uganda

Respiratory diseases contribute significant economic losses to the swine industry globally. In Uganda, no detailed studies on pig respiratory pathogens have been undertaken previously. This doctoral thesis aimed to fill knowledge gaps on epidemiology of important respiratory pathogens, gastro-intestinal (GIT) parasites and their economic impacts on smallholder pig production systems in Uganda. The studies were conducted in Lira district from October 2018 to September 2019. Four respiratory pathogens of economic importance in pigs including porcine reproductive and respiratory syndrome virus (PPRSv), porcine circovirus type 2 (PCV2), Mycoplasma hyopneumoniae (M. hyo) and Actinobacillus pleuropneumoniae (App) were studied. The first study was a desk systematic review on status and gaps of research on swine respiratory pathogens in Africa. This was followed by three cross-sectional studies: prevalence and risk factors for respiratory co-infections, a slaughter slab survey which correlated serology to 4 selected respiratory pathogens and pneumonia lesions and identify PRRSv genotypes. Tissue and blood samples were collected from pigs and used for genotypying PRRSv and to determine exposure to respiratory pathogens using ELISA assays, respectively. A mixed effects model was fitted to quantify economic losses due to exposure of pigs to respiratory pathogens and GIT parasites. Results highlighted major knowledge, information gaps on epidemiology, and economic impacts of the 4 studied pathogens reported in pigs in Africa. We found that there was dual circulation of both PRRSv PRRSv-1 and PRRSv-2 in Lira district with type 1 more predominant. A high prevalence and severity of pneumonia forms (17.4 – 74.2%) in slaughtered pigs was observed. The model showed that a grower pig in a given farm exposed to PRRSv and Ascaris spp infection had significantly lower average daily weight gain by 18.5 and 23.7 grams/pig/day respectively, compared to a similar unexposed pig. Monetary losses encountered by farmers due to PRRSv and Ascaris spp. infection amounted to USD 7.12 and USD 9.16 respectively, per pig during 200 days of fattening. In conclusion, these findings strengthened evidence of the role of housing, hygiene and biosecurity in reducing disease incidence in herds. The most important respiratory pathogens were PPRSv, App, Ascaris spp and risk factors were use of murram as floor type, poor hygiene, biosecurity practices, and concurrent GIT parasite infestations. Associations between serology and lung lesions suggests their potential role in lung disease precipitation. Farmers should pay close attention to proper housing, hygiene, biosecurity, wastes management and parasite control and limiting contacts with outside pigs. The findings from this study shall inform national policy in Uganda

Science and Technology: A Catalyst for Improving Human Health in Developing Countries

Science and technology have the potential to make major contributions to the development of medical devices that can help address the highest burdens of diseases in developing countries. This paper examined how science and technology could assist in speeding the development and dissemination of information on new health products that could address the largest health threats in developing countries. The paper investigated the traits needed by such production to have the desired impact. It also reviewed the extent to which some medical devices and processes possess those traits and discuss the potential of science and technology to develop healthproducts,reveal the constrains on product development and the mechanism in overcoming the new health products. Towards understanding the potential of science and technology to develop more new health products to addressing high-burden diseases, it was therefore recommended that there is need to consider the characteristics of diagnostics, drugs, vaccines and medical devices that could most effectively and efficiently address the critical continent health problems. Science and technology should focus on bio-technologies that could help improve health products that are affordable and appropriate to the circumstances of developing countries, using instrument to addressing the most pressing health needs and be appropriate to the health conditions that cause the largest burden of diseases in developing countries of the world

Economic losses associated with respiratory and helminth infections in domestic pigs in Lira district, Northern Uganda.

This study sought to quantify direct economic losses due to respiratory and gastrointestinal (GI) helminth infections in domestic pigs in Uganda. In a longitudinal study design with repeated measures, farm visits were made at 2 month intervals from October 2018 to September 2019. Weaner and grower pigs (n = 288) aged 2-6  months from 94 farms were sampled. The pigs were monitored for growth and screened for exposure to four important respiratory pathogens: porcine circovirus type 2 (PCV2), porcine reproductive and respiratory syndrome virus (PRRSv), Mycoplasma hyopneumoniae (M. hyo), Actinobacillus pleuropneumoniae (App) using ELISA tests. Farm management practices were recorded and used to generate management level scores. Treatment expenses incurred were recorded throughout the study. A mixed effects model was fitted to quantify effects of respiratory and helminth infections on average daily weight gains (ADGs), with farm and pig as random effects. Analysis of variance (ANOVA) was used to determine differences in mean treatment costs by farm management standard. Financial losses were estimated from average carcass dressing percentage, ADG reductions during fattening (200  days). Results showed a grower pig in a given farm exposed to PRRSv and Ascaris spp. had significantly lower ADG by 17.10 gr/day and 16.80 grams/day respectively, compared to a similar unexposed pig (p < 0.05). Mean treatment costs per pig declined significantly with increase in management standard scores (MSS), from USD 1.13 per pig in MSS 1 (poor management) farms to USD 0.95 for MSS 3 (better management) farms (p < 0.05). We show that monetary losses due to PRRSv and Ascaris spp. infection amounted to USD 6.6 ± 2.7 and 6.50 ± 3.2 (Mean ± SEM) per pig, respectively during 200 days of fattening. This study strengthens evidence that improving management practices to reduce infections mitigates economic losses. To guide interventions, further studies are required to unravel the full extent of indirect economic losses

The status of sow welfare in selected districts of Uganda

Objective The pig sector in Uganda is among the fastest growing livestock sectors and is characterized by low productivity from limited resources and veterinary support. As the welfare status of pigs in the system is unknown a cross-sectional welfare assessment was carried out in four districts in central Uganda (Masaka, Mukono, Mpigi and Wakiso) to identify issues requiring action. Materials and methods Data were collected from 270 pig farms. Data on animal-based indicators (body condition and physical injuries) and resource-based indicators (housing and water supply) were obtained from physical assessments of pigs and farm facilities. Management data (morbidity and mortality) and demographic details were collected from farmer interview. We present sow results as they are the highest value animal of the herd, both raising piglets and requiring resource investment. Results Across all farms, sow mortality was 2.5%. Animal-based indicators identified 9% of sows with diarrhea, 7.6% with lameness and 92% dry or lactating were found to be ‘skinny’ (body condition score≤2). All of these are indicative of underperforming sows that may be at risk of low litter indices and shorter productive lives. Sow behaviour was restricted in 19% of cases, and while 93% of sows had access to continuous water, only 48.8% received clean water, which creates a risk of disease spread. Of reported health issues, 20% farms reported sows experiencing stillbirths, 15% ill thrift, 12.5% respiratory issues and 10.8% gastrointestinal issues. Conclusion These welfare issues indicates that a proportion of sows were in pain, discomfort and potentially hungry, which in turn negatively impact on owner livelihoods from wasted resources and opportunities. Future interventions focusing on herd health should focus on diseases and poor nutrition. Interventions that provide access to clean water and optimum living space that give sows the ability to move more freely are also required

Progression-Free Survival as a Surrogate for Overall Survival in Advanced/Recurrent Gastric Cancer Trials: A Meta-Analysis

The traditional endpoint for assessing efficacy of chemotherapies for advanced/recurrent gastric cancer is overall survival (OS), but OS requires prolonged follow-up. We investigated whether progression-free survival (PFS) is a valid surrogate for OS. Using individual patient data from the GASTRIC meta-analysis, surrogacy of PFS was assessed through the correlation between the endpoints and through the correlation between the treatment effects on the endpoints. External validation of the prediction based on PFS was also evaluated. Individual data from 4069 patients in 20 randomized trials were analyzed. The rank correlation coefficient between PFS and OS was 0.853 (95% confidence interval [CI] = 0.852 to 0.854). The R 2 between treatment effects on PFS and on OS was 0.61 (95% CI = 0.04 to 1.00). Treatment effects on PFS and on OS were only moderately correlated, and we could not confirm the validity of PFS as a surrogate endpoint for OS in advanced/recurrent gastric cance