| 171. |
- Ochieng, Phillis E. E., et al.
(author)
-
Maximizing Laboratory Production of Aflatoxins and Fumonisins for Use in Experimental Animal Feeds
- 2022
-
In: Microorganisms. - : MDPI. - 2076-2607. ; 10:12
-
Journal article (peer-reviewed)abstract
- Warm and humid climatic conditions coupled with poor agricultural practices in sub-Saharan Africa favor the contamination of food and feed by Aspergillus flavus and Fusarium verticillioides fungi, which subsequently may produce aflatoxins (AFs) and fumonisins (FBs), respectively. The growth of fungi and the production of mycotoxins are influenced by physical (temperature, pH, water activity, light and aeration), nutritional, and biological factors. This study aimed at optimizing the conditions for the laboratory production of large quantities of AFs and FBs for use in the animal experiments. A. flavus and F. verticillioides strains, previously isolated from maize in Kenya, were used. Levels of AFB1 and total FBs (FB1, FB2, and FB3) in different growth substrates were screened using ELISA methods. Maize kernels inoculated with three different strains of A. flavus simultaneously and incubated at 29 degrees C for 21 days had the highest AFB1 level of 12,550 +/- 3397 mu g/kg of substrate. The highest level of total FBs (386,533 +/- 153,302 mu g/kg of substrate) was detected in cracked maize inoculated with three different strains of F. verticillioides and incubated for 21 days at temperatures of 22-25 degrees C in a growth chamber fitted with yellow light. These two methods are recommended for the mass production of AFB1 and FBs for animal feeding trials.
|
|
| 172. |
- Ochieng, Phillis Emelda, et al.
(author)
-
Effects of Aflatoxins and Fumonisins, Alone or in Combination, on Performance, Health, and Safety of Food Products of Broiler Chickens, and Mitigation Efficacy of Bentonite and Fumonisin Esterase
- 2023
-
In: Journal of Agricultural and Food Chemistry. - : American Chemical Society (ACS). - 0021-8561 .- 1520-5118. ; 71:36, s. 13462-13473
-
Journal article (peer-reviewed)abstract
- The current study evaluated the effects of feeding diets contaminated with aflatoxin B1 (AFB1), fumonisins (FBs), or both on the performance and health of broiler chickens and the safety of their food products as well as the efficacy of bentonite and fumonisin esterase to mitigate the effects of these mycotoxins under conditions representative for sub-Saharan Africa (SSA). Four hundred one-day-old Cobb 500 broiler chickens were randomly assigned to 20 treatments with either a control diet, a diet with moderate AFB1 (60 mu g/kg feed) or high AFB1 (220 mu g/kg feed), or FBs (17,430 mu g FB1+FB2/kg feed), alone or in combination, a diet containing AFB1 (either 60 or 220 mu g/kg) and/or FBs (17,430 mu g FB1+FB2/kg) and bentonite or fumonisin esterase or both, or a diet with bentonite or fumonisin esterase only. The experimental diets were given to the birds from day 1 to day 35 of age, and the effects of the different treatments on production performance were assessed by feed intake (FI), body weight gain (BWG), and feed conversion ratio (FCR). Possible health effects were evaluated through blood biochemistry, organ weights, mortality, liver gross pathological changes, and vaccine response. Residues of aflatoxins (AFB1, B2, G1, G2, M1 and M2) were determined in plasma, muscle, and liver tissues using validated UHPLC-MS/MS methods. The results obtained indicated that broiler chickens fed high AFB1 alone had poor FCR when compared to a diet with both high AFB1 and FBs (p = 0.0063). Serum total protein and albumin from birds fed FBs only or in combination with moderate or high AFB1 or detoxifiers increased when compared to the control (p < 0.05). Liver gross pathological changes were more pronounced in birds fed contaminated diets when compared to birds fed the control or diets supplemented with mycotoxin detoxifiers. The relative weight of the heart was significantly higher in birds fed high AFB1 and FBs when compared to the control or high AFB1 only diets (p < 0.05), indicating interactions between the mycotoxins. Inclusion of bentonite in AFB1-contaminated diets offered a protective effect on the change in weights of the liver, heart and spleen (p < 0.05). Residues of AFB1 were detected above the limit of quantification (max: 0.12 +/- 0.03 mu g/kg) in liver samples only, from birds fed a diet with high AFB1 only or with FBs or the detoxifiers. Supplementing bentonite into these AFB1-contaminated diets reduced the levels of the liver AFB1 residues by up to 50%. Bentonite or fumonisin esterase, alone, did not affect the performance and health of broiler chickens. Thus, at the doses tested, both detoxifiers were safe and efficient for use as valid means of counteracting the negative effects of AFB1 and FBs as well as transfer of AFB1 to food products (liver) of broiler chickens.
|
|
| 173. |
- Ochieng, Phillis E., et al.
(author)
-
Mycotoxins in Poultry Feed and Feed Ingredients from Sub-Saharan Africa and Their Impact on the Production of Broiler and Layer Chickens : A Review
- 2021
-
In: Toxins. - : MDPI. - 2072-6651. ; 13:9
-
Research review (peer-reviewed)abstract
- The poultry industry in sub-Saharan Africa (SSA) is faced with feed insecurity, associated with high cost of feeds, and feed safety, associated with locally produced feeds often contaminated with mycotoxins. Mycotoxins, including aflatoxins (AFs), fumonisins (FBs), trichothecenes, and zearalenone (ZEN), are common contaminants of poultry feeds and feed ingredients from SSA. These mycotoxins cause deleterious effects on the health and productivity of chickens and can also be present in poultry food products, thereby posing a health hazard to human consumers of these products. This review summarizes studies of major mycotoxins in poultry feeds, feed ingredients, and poultry food products from SSA as well as aflatoxicosis outbreaks. Additionally reviewed are the worldwide regulation of mycotoxins in poultry feeds, the impact of major mycotoxins in the production of chickens, and the postharvest use of mycotoxin detoxifiers. In most studies, AFs are most commonly quantified, and levels above the European Union regulatory limits of 20 mu g/kg are reported. Trichothecenes, FBs, ZEN, and OTA are also reported but are less frequently analyzed. Co-occurrences of mycotoxins, especially AFs and FBs, are reported in some studies. The effects of AFs on chickens' health and productivity, carryover to their products, as well as use of mycotoxin binders are reported in few studies conducted in SSA. More research should therefore be conducted in SSA to evaluate occurrences, toxicological effects, and mitigation strategies to prevent the toxic effects of mycotoxins.
|
|
| 174. |
- Paixão, Maria Margarida, et al.
(author)
-
Effect of Education on Improving Knowledge and Behavior for Arboviral Diseases : A Systematic Review and Meta-Analysis
- 2019
-
In: American Journal of Tropical Medicine and Hygiene. - : The American Society of Tropical Medicine and Hygiene. - 0002-9637 .- 1476-1645. ; 101:2, s. 441-447
-
Journal article (peer-reviewed)abstract
- Arboviral diseases are responsible for a high burden of disease in humans, and a significant part of disease risk reduction efforts relies on vector control methods. The elimination of potential breeding sites for the mosquito vectors and a higher level of literacy by the populations at risk could present a sustainable and environmentally friendly solution. This review aims to assess the efficacy of educational interventions for arboviral diseases on knowledge and self-reported behavior. A systematic literature search was performed using Cochrane, EMBASE, Global Health, and PubMed. References of articles retrieved were searched manually for further studies. Critical appraisal of the selected articles was performed using the Effective Public Health Practice Project tool, and studies with a control group were further assessed through the Cochrane's risk of bias tool. A summary narrative of the results and a meta-analysis was conducted. Fourteen studies fulfilling the inclusion criteria were analyzed. Overall, there was an increase in knowledge and in self-reported adoption of protective measures. No effect was found using solely printed material. A meta-analysis was performed separately for the two outcomes measured, which produced a mean standardized difference of 1.86 (95% CI: 1.33-2.39) in knowledge scores compared with the control groups. Regarding the self-reported protective behavior, the results show a summary value of odds ratio of 5.23 (95% CI: 3.09-7.36). Most of the educational interventions had a positive impact on knowledge and self-reported adoption of protective measures. More research producing stronger evidence and evaluating long-term impact is needed.
|
|
| 175. |
- Pham-Thanh, Long, et al.
(author)
-
Dogs as Sentinels for Flavivirus Exposure in Urban, Peri-Urban and Rural Hanoi, Vietnam
- 2021
-
In: Viruses. - : MDPI. - 1999-4915. ; 13:3
-
Journal article (peer-reviewed)abstract
- Diseases caused by flaviviruses, including dengue fever and Japanese encephalitis, are major health problems in Vietnam. This cross-sectional study explored the feasibility of domestic dogs as sentinels to better understand risks of mosquito-borne diseases in Hanoi city. A total of 475 dogs serum samples from 221 households in six districts of Hanoi were analyzed by a competitive enzyme-linked immunosorbent assay (cELISA) for antibodies to the pr-E protein of West Nile virus and other flaviviruses due to cross-reactivity. The overall flavivirus seroprevalence in the dog population was 70.7% (95% CI = 66.4-74.8%). At the animal level, significant associations between seropositive dogs and district location, age, breed and keeping practice were determined. At the household level, the major risk factors were rural and peri-urban locations, presence of pigs, coil burning and households without mosquito-borne disease experience (p < 0.05). Mosquito control by using larvicides or electric traps could lower seropositivity, but other measures did not contribute to significant risk mitigation of flavivirus exposure in dogs. These results will support better control of mosquito-borne diseases in Hanoi, and they indicate that dogs can be used as sentinels for flavivirus exposure.
|
|
| 176. |
- Pham-Thanh, Long, et al.
(author)
-
Livestock Development in Hanoi City, Vietnam-Challenges and Policies
- 2020
-
In: Frontiers in Veterinary Science. - : FRONTIERS MEDIA SA. - 2297-1769. ; 7
-
Journal article (peer-reviewed)abstract
- The rapid urban growth of Hanoi city requires a livestock production system that ensures both food security and the livelihoods of dwellers. This paper reviews the existing policies for livestock production of Hanoi city and the changes in livestock population between 2014 and 2018 and identifies major challenges for livestock development of the city. While a remarkable increase of the livestock population in recent years is evident, the dominance of small-scale farms, the presence of animal diseases, the slow progress of transiting farms out of urban areas, as well as the lack of analysis of climate change and gender impacts are major challenges that could affect the livestock development of Hanoi.
|
|
| 177. |
- Pham-Thanh, Long, 1975-
(author)
-
The influence of urban livestock-keeping on the epidemiology of mosquito-borne zoonotic flaviviruses in Hanoi city of Vietnam
- 2022
-
Doctoral thesis (other academic/artistic)abstract
- In rapid urbanizing cities, the high density of livestock populations in close vicinity to humans, and high mosquito vector abundance have provided suitable conditions for transmission of mosquito-borne zoonotic flaviviruses, that cause several million cases of human disease annually. This thesis explores the urban livestock-keeping in Hanoi and its potential influence on the epidemiology of flavivirus infections. Four major components were investigated: livestock development of the city, knowledge and practices of local people on mosquito-borne diseases (MBDs), mosquito vector abundance, and risk factors for flavivirus exposure in animals.The analyses of the livestock development policy, animal data and key informant interviews showed that the livestock production system of Hanoi had increased in line with the governmental policy during 2014 to 2018. However, some major challenges were identified such as the high proportion of small-scale livestock farms, animal diseases, and a slow progress of translocation of livestock farms out of the urban areas.A cross-sectional study was conducted in 513 households in six districts of Hanoi (two urban, two peripheral, and two peri-urban). Knowledge and practices were evaluated; mosquitoes and larvae inside and outside the houses were collected and identified; blood samples of pigs and dogs were tested by a West Nile virus competitive enzyme-linked immunosorbent assay (cELISA), a kit that allowed for detection of antibodies against several flaviviruses of different animal species. JEV-specific antibodies were confirmed by plaque reduction neutralization test (PRNT). Logistic regression models using seropositivity of households as the outcome were built to identify significant risk factors.A low level of knowledge and preventive practices against zoonotic MBDs in community was indicated in the study. Among 12,861 adult mosquitoes and 2,427 larvae collected, Culex mosquitoes were the most abundant (93.01%), followed by Anopheles (3.82%), Mansonia (1.21%), Armigeres (1.18%) and Aedes mosquitoes (0.78%). In contrast, Aedes genus larvae were prominent at 87.02%, followed by Culex spp. (12.2%). There was a positive association between pig-keeping and Culex mosquitoes (p<0.001). In total, 475 dogs and 636 pigs were tested by a cELISA. The overall flavivirus seroprevalences in dogs and pigs were 70.7% and 88.5%, respectively. The PRNT results for a subset of 50 dog sera (34 positive, 6 doubtful and 10 negative samples by cELISA), and 50 pig sera (26 positive, 6 doubtful and 18 negative samples by cELISA) showed a lower proportion of JEV-specific antibodies (28 positives for dog samples, and 13 positives for pig samples). In conclusion, this thesis shows associations between livestock-keeping and risks of mosquito-borne zoonotic flavivirus infections to humans in Hanoi.
|
|
| 178. |
- Pham-Thanh, Long, et al.
(author)
-
Zoonotic Flavivirus Exposure in Peri-Urban and Suburban Pig-Keeping in Hanoi, Vietnam, and the Knowledge and Preventive Practices of Pig Farmers
- 2022
-
In: Tropical Medicine and Infectious Disease. - : MDPI. - 2414-6366. ; 7:5
-
Journal article (peer-reviewed)abstract
- Mosquito-borne diseases (MBDs), including those caused by flaviviruses, remain human health problems for developing and urbanizing economies. This cross-sectional study examined risks of flavivirus exposure through a survey regarding knowledge and practices of pig farmers, and serological analysis of pigs in peri-urban and suburban Hanoi city. A total of 636 pig sera from 179 pig farms in 4 districts, namely, Chuong My, Dan Phuong, Ha Dong, and Bac Tu Liem, were analyzed by a competitive ELISA designed for flavivirus antibody detection. The results indicated a low level of awareness about MBDs among pig farmers, and a high seroprevalence in pigs at 88.5% (95%CI = 85.8-90.9%). Moreover, common practices of pig owners to prevent mosquitoes at home and farm did not show a significant reduction in flavivirus exposure in pigs. At animal level, significant associations between seropositive pigs and the farms with more than 60 pigs, and the district location were found. Farm-level multivariable analysis did not identify significant risk factors for flavivirus exposure. The study suggests that improving awareness of pig owners about MBDs in Hanoi city may be warranted to reduce the risk for MBD flavivirus infections in both humans and pigs.
|
|
| 179. |
- Pratim Deka, Ram, et al.
(author)
-
Estimates of the Economic Cost Caused by Five Major Reproductive Problems in Dairy Animals in Assam and Bihar, India
- 2021
-
In: Animals. - 2076-2615. ; 11
-
Journal article (peer-reviewed)abstract
- Reproductive problems in dairy animals reduce fertility, prevent conception, create problems in the delivery of healthy calves, lead to postpartum complications, increase inter-calving periods, reduce milk yield, and lower overall lifetime productivity. This study aimed at understanding the incidence of reproductive problems and the cost caused by these. The study covered 954 dairy animals in Bihar and 1348 dairy animals in Assam that were selected using a multi-stage random sampling method. The costs were calculated as the sum of income losses and expenditures incurred. The major cost incurred resulted from extended calving intervals (46.1% of the total cost), followed by loss through salvage selling (38.1%), expenditure for treatment of repeat breeders (5.9%), loss of milk production (5.3%) and expenditure for extra inseminations (2.0%). About one fifth of the selected reproductive problems were left untreated. The estimated cost of reproductive problems was Indian Rupees (INR) 2424.9 (USD 36.1) per dairy animal per year (of the total dairy animal population) which represented approximately 4.1% of the mean value loss of dairy animals (INR 58,966/USD 877) per year. Reproductive problems were significantly (p < 0.001) higher among improved (exotic breed or cross-bred) dairy animals than indigenous (native breed or nondescript indigenous) dairy animals. The study suggests that with the increase of improved dairy animal population, the loss may further increase. The study concludes that any economic estimation of reproduction problems based on aetiology without confirmatory diagnoses could be highly misleading because of the complex nature of the problems.
|
|
| 180. |
- Pratim Deka, Ram, et al.
(author)
-
Knowledge and practices of dairy farmers relating to brucellosis in urban, peri-urban and rural areas of Assam and Bihar, India
- 2020
-
In: Infection Ecology & Epidemiology. - : Informa UK Limited. - 2000-8686. ; 10
-
Journal article (peer-reviewed)abstract
- Background: Brucellosis is one of the most common zoonotic diseases in the world. This study aimed at assessing farmers’ knowledge about brucellosis as well as practices relevant to transmission of brucellosis and their associated determinants. Results: Few farmers knew about brucellosis (3.4%, n = 18) and its zoonotic importance (0.8%, n = 4). Knowledge about brucellosis was higher for farmers with a larger herd size (p < 0.001) and fully using a stall-fed system (p < 0.001). Training on dairy cattle management (p < 0.001), training on animal disease (p < 0.01), consultation with veterinarians (p < 0.001) and farms being in urban areas (p < 0.01) were also significantly positively associated with knowledge about brucellosis. No significant association was observed between farmers’ knowledge about brucellosis and state, family size, education, age or gender of the farmers. Farmers knowledge about brucellosis was significantly associated with certain practices that include use of disinfectant while cleaning farms (p < 0.05), animal movement (p < 0.01), introduction of new animals (p < 0.05) and raw milk consumption (p < 0.05). The study did not find any association between knowledge about brucellosis and method of disposal of aborted materials, personal hygiene and quarantine practices. Conclusion: More interaction with veterinarians and training on animal management may be an important tool for generating awareness among the farming community for reducing transmission of the disease.
|
|
