Assessing the impacts of in-feed probiotic on the growth performance and health condition of pangasius (Pangasianodon hypophthalmus) in a farm trial.

The effects of in-feed probiotics on growth performance, haematological parameters, gut microbial content, and morphological changes to pangasius fish were assessed. The trial had three phases, i.e., larvae to fry (20 days), fry to fingerlings (45 days), and grow-out phase from fingerlings to marketing (90 days). The stocking densities were 400 m-3, 200 m-3, and 12 m-3 for phases 1, 2, and 3, respectively. Phases 1 and 2 were conducted in hapas in the same pond, whereas phase 3 was performed in concrete tanks. The in-feed probiotic was administered at a rate of 0.2 g kg-1 of feed three times per day in phases 1 and 2 only. In phase 3, in-feed probiotics was not applied to any groups. The treated group exhibited higher growth performances (p < 0.05) than the control in all three phases of experiment. The survival % in phase 1 and 2 were found significantly (p < 0.05) higher in treatment groups. This indicates that pangasius nurserers would benefit from using probiotics as a safeguard to increase fry survival to a greater extent. Two haematological parameters including red blood cells (RBC) and white blood cells (WBC) levels were found significantly (p < 0.05) higher in treated groups in phase 2 and 3, while glucose and hemoglobin level were found significantly (p < 0.05) higher in the treated groups during phases 2 and 3, respectively. The gut microbiota content was relatively higher in the treated groups in phase 2 and 3. Histological findings indicate that the use of probiotics during the nursing phases of pangasius induced a positive change in the intestinal morphological structures. The positive impacts of probiotics on the phase 3 confirmed an immediate and long-term growth performance and health of pangasius.

Identifying hotspots for antibiotic resistance emergence and selection, and elucidating pathways to human exposure: Application of a systems-thinking approach to aquaculture systems.

Aquaculture systems are highly complex, dynamic and interconnected systems influenced by environmental, biological, cultural, socio-economic and human behavioural factors. Intensification of aquaculture production is likely to drive indiscriminate use of antibiotics to treat or prevent disease and increase productivity, often to compensate for management and husbandry deficiencies. Surveillance or monitoring of antibiotic usage (ABU) and antibiotic resistance (ABR) is often lacking or absent. Consequently, there are knowledge gaps for the risk of ABR emergence and human exposure to ABR in these systems and the wider environment. The aim of this study was to use a systems-thinking approach to map two aquaculture systems in Vietnam - striped catfish and white-leg shrimp - to identify hotspots for emergence and selection of resistance, and human exposure to antibiotics and antibiotic-resistant bacteria. System mapping was conducted by stakeholders at an interdisciplinary workshop in Hanoi, Vietnam during January 2018, and the maps generated were refined until consensus. Thereafter, literature was reviewed to complement and cross-reference information and to validate the final maps. The maps and component interactions with the environment revealed the grow-out phase, where juveniles are cultured to harvest size, to be a key hotspot for emergence of ABR in both systems due to direct and indirect ABU, exposure to water contaminated with antibiotics and antibiotic-resistant bacteria, and duration of this stage. The pathways for human exposure to antibiotics and ABR were characterised as: occupational (on-farm and at different handling points along the value chain), through consumption (bacterial contamination and residues) and by environmental routes. By using systems thinking and mapping by stakeholders to identify hotspots we demonstrate the applicability of an integrated, interdisciplinary approach to characterising ABU in aquaculture. This work provides a foundation to quantify risks at different points, understand interactions between components, and identify stakeholders who can lead and implement change.

A multifaceted risk model of brucellosis at the human-animal interface in Egypt.

Brucellosis is a highly contagious zoonosis affecting humans and a wide range of domesticated and wild animal species. An important element for effective disease containment is to improve knowledge, attitudes and practices (KAP) of afflicted communities. This study aimed to assess the KAP related to brucellosis at the human-animal interface in an endemic area of Egypt and to identify the risk factors for human infection. A matched case-control study was conducted at the central fever hospitals located in six governorates in northern Egypt. Face-to-face interviews with cases and controls were conducted using a structured questionnaire. In total, 40.7% of the participants owned farm animals in their households. The overall mean practice score regarding animal husbandry, processing and consumption of milk and dairy products were significantly lower among cases compared with controls (-12.7 ± 18.1 vs. 0.68 ± 14.2, respectively; p < .001). Perceived barriers for notification of animal infection/abortion were predominate among cases and positively correlated with participants' education. The predictors of having brucellosis infection were consumption of unpasteurized milk or raw dairy products and practicing animal husbandry. Applying protective measures against infection significantly reduced its risk. A model predicting risk factors for brucellosis among those who own animal showed that frequent abortions per animal increased the chance for brucellosis infection among human cases by 50-fold (95% CI: 8.8-276.9), whereas the use of protective measures in animal care reduced the odds (OR = 0.11 [95% CI: 0.03-0.45]). In conclusion, consumption of unprocessed dairy products was equally important as contact with infected/aborted animals as major risk factors for Brucella spp. infection among humans in Egypt. There is poor knowledge, negative attitudes and risky behaviours among villagers which can perpetuate the risk of brucellosis transmission at the human-animal interface. This supports the need for integrating health education into the national brucellosis control programme.

Update on the status of leptospirosis in New Zealand.

Leptospirosis is a zoonotic disease that poses public health and ecological threats worldwide. In New Zealand (NZ), incidence of the disease is relatively high compared to other developed countries. The aim of this review was to describe the epidemiological status, ecological risk of leptospirosis and prevention in NZ. Disease notification data for leptospirosis in humans in NZ from 2010 to 2015 were collected from the Institute of Environmental Science and Research database. These data were supported by a literature review of epidemiological studies in human and animal populations. During this six-year period, exotic serovars of Leptospira interrogans sv Australis and Leptospira kirschneri sv Grippotyphosa were identified in patients who had travelled abroad to Samoa (Pacific Ocean) and Thailand, respectively. Most cases of leptospirosis were recorded in New Zealanders of European ethnicity, followed by Maori people. Males had a nine-fold increased risk compared to females mostly due to occupation. The risk of leptospirosis increased gradually with the age, with a peak in the 40 to 49-year-old age group, after which it decreased. Workers in meat-processing and farming industries appeared at highest-risk of occupational exposure compared with other risky occupations such as hunters, veterinarians, technicians, stock truck drivers and lake workers. Other cases were also attributed to outdoor exposures or travelling overseas. Highest disease notification rates occurred in the West Coast region of the South Island (average annual incidence 9.7 per 100,000 people), followed by Whanganui region (8.2 per 100,000) and Hawke's Bay region (8 per 100,000) in the North Island. Vaccines currently available for animals are specific for cattle, sheep, deer and dogs and do protect against all serovars present in NZ. The development and use of molecular diagnostics is crucial for specific identification of Leptospira isolates and informing deployment of efficient vaccines.

Brucella spp. infection in large ruminants in an endemic area of Egypt: cross-sectional study investigating seroprevalence, risk factors and livestock owner's knowledge, attitudes and practices (KAPs).

BACKGROUND: Brucellosis is regarded as one of the major zoonotic infections worldwide. It was first reported in Egypt in 1939 and is now endemic, the predominate species of Brucella in cattle and buffalo in Egypt is B. melitensis. The aim of the study was to estimate seroprevalence of Brucella spp. in cattle and buffalo reared in households in an Egyptian village, identify risk factors for animals testing seropositive and to assess the knowledge, attitudes and practices (KAPs) of livestock owners with regards to brucellosis. METHODS: A cross-sectional study was carried out in a village in Menufiya Governorate of Egypt. In June and July 2009, 107 households were selected using systematic sample and all lactating cattle and buffalo present in the household were sampled and tested for antibodies against Brucella spp. In addition, a questionnaire collecting information on potential risk factors for Brucella spp. infection in cattle and buffalo was administered to the household member responsible for rearing the livestock. Between December 2009 and February 2010 households were revisited and a second questionnaire regarding KAPs associated with brucellosis was administered. RESULTS: True individual and household seroprevalence were estimated to be 11.0% (95% CI: 3.06% to 18.4%) and 15.5% (95% CI: 6.61% to 24.7%), respectively. Cattle and buffalo kept in a household with sheep and goats had 6.32 (95% CI: 1.44 to 27.9) times the odds of testing seropositive for Brucella spp., compared to cattle and buffalo that were not. Most participants in the study stated that livestock owners assist in the parturition of ruminants without wearing gloves and that some farmers sell animals which they suspect are Brucella infected to butchers or at market. Many participants made their livestock's milk into cheese and other dairy products without pasteurising it. CONCLUSIONS: Brucellosis was endemic at high levels, in the current study. Although livestock owners had good general knowledge of brucellosis, they still appeared to participate in high-risk behaviours, which may contribute to the high seroprevalence in the area. Veterinarians, public health authorities and other community leaders need to collaborate to control the disease in animals and to manage the risk of human exposure.

Brucella infection in fresh water fish: Evidence for natural infection of Nile catfish, Clarias gariepinus, with Brucella melitensis.

Brucellosis is endemic among ruminants in the Nile Delta region of Egypt, where recent reports suggest that the incidence of human infection is increasing. In this region the practice of throwing animal waste into Nile canals is common. As a result, water can be contaminated with potential zoonotic pathogens such as B. melitensis that could infect fish. This study aimed at isolating and characterizing B. melitensis from Nile catfish. Serum samples from 120 catfish captured from Nile canals and 120 farmed catfish were tested for the presence of antibodies against Brucella spp. by using the Rose Bengal Test (RBT) and the Rivanol test (Riv T). Skin swabs from all fish and samples from internal organs (liver, kidney and spleen) from all serologically positive fish were cultured to identify B. melitensis biovar 3 isolates. Polymerase Chain Reaction (PCR) was used to confirm the results. 9.2% and 8.3% of serum samples from Nile catfish were positive by RBT and Riv T, respectively. None of the samples from farmed catfish were seropositive. B. melitensis biovar 3 was isolated from 5.8%, 4.2%, 5.8% and 13.3% of liver, kidney and spleen samples and skin swabs, respectively. To our knowledge this is the first report of isolation of B. melitensis biovar 3 from fresh water fish. Our results suggest that Nile catfish are naturally infected with B. melitensis biovar 3 and this may play a role in the epidemiology of brucellosis. The public should be aware of the consequences of disposing of animal waste into the canals and public health authorities should consider the potential role of catfish as a source of infection.