The genomic landscape of swine influenza A viruses in Southeast Asia.

Swine are a primary source for the emergence of pandemic influenza A viruses. The intensification of swine production, along with global trade, has amplified the transmission and zoonotic risk of swine influenza A virus (swIAV). Effective surveillance is essential to uncover emerging virus strains; however gaps remain in our understanding of the swIAV genomic landscape in Southeast Asia. More than 4,000 nasal swabs were collected from pigs in Cambodia, yielding 72 IAV-positive samples by RT-qPCR and 45 genomic sequences. We unmasked the cocirculation of multiple lineages of genetically diverse swIAV of pandemic concern. Genomic analyses revealed a novel European avian-like H1N2 swIAV reassortant variant with North American triple reassortant internal genes, that emerged approximately seven years before its first detection in pigs in 2021. Using phylogeographic reconstruction, we identified south central China as the dominant source of swine viruses disseminated to other regions in China and Southeast Asia. We also identified nine distinct swIAV lineages in Cambodia, which diverged from their closest ancestors between two and 15 B.P., indicating significant undetected diversity in the region, including reverse zoonoses of human H1N1/2009 pandemic and H3N2 viruses. A similar period of cryptic circulation of swIAVs occurred in the decades before the H1N1/2009 pandemic. The hidden diversity of swIAV observed here further emphasizes the complex underlying evolutionary processes present in this region, reinforcing the importance of genomic surveillance at the human-swine interface for early warning of disease emergence to avoid future pandemics.

Effectiveness and implementation challenges of a livestock asset transfer intervention for smallholders in community-protected areas in Cambodia.

BACKGROUND: Limited opportunities to generate income in community-protected areas (CPAs) often lead to the illegal harvesting of wildlife and natural resources, undermining the aim of protected areas. Sustained livestock production can be an alternative income source. OBJECTIVES: To understand the effectiveness and feasibility of livestock production in CPAs. METHODS: We conducted a livestock asset transfer intervention in 25 CPAs across three agroecological zones in Cambodia. We monitored livestock mortality, consumption and sales of livestock over 2 years. Participant observations and structured questionnaires were conducted to elicit information about constraints for livestock production perceived by the participants. A total of 756 households were recruited and 320, 184 and 252 households received chicken, pigs and cattle, respectively. All participants received technical training in livestock production and biosecurity management practices. RESULTS: After the intervention, the number of chickens, pigs and cattle increased on average by 5.9 (range: 0.3-26.3), 0.5 (-1 to 2.7) and 0.12 (0-0.35) per 1 input animal, respectively. The extent of increase was significantly different between zones only for chickens (Kruskal-Wallis test p = 0.004). The number of chickens and pigs sold per household was significantly different among zones. We observed that training was ineffective to alter livestock management practices in some CPAs, which partially explains their suboptimal performance of livestock production. CONCLUSIONS: Understanding contextual factors required for successful livestock production in CPAs is crucial for improving livelihoods and preventing biodiversity loss in Cambodia.

Social contact patterns relevant for infectious disease transmission in Cambodia.

Social mixing patterns are key determinants of infectious disease transmission. Mathematical models parameterised with empirical data from contact pattern surveys have played an important role in understanding epidemic dynamics and informing control strategies, including for SARS-CoV-2. However, there is a paucity of data on social mixing patterns in many settings. We conducted a community-based survey in Cambodia in 2012 to characterise mixing patterns and generate setting-specific contact matrices according to age and urban/rural populations. Data were collected using a diary-based approach from 2016 participants, selected by stratified random sampling. Contact patterns were highly age-assortative, with clear intergenerational mixing between household members. Both home and school were high-intensity contact settings, with 27.7% of contacts occurring at home with non-household members. Social mixing patterns differed between rural and urban residents; rural participants tended to have more intergenerational mixing, and a higher number of contacts outside of home, work or school. Participants had low spatial mobility, with 88% of contacts occurring within 1 km of the participants' homes. These data broaden the evidence-base on social mixing patterns in low and middle-income countries and Southeast Asia, and highlight within-country heterogeneities which may be important to consider when modelling the dynamics of pathogens transmitted via close contact.

Understanding networks in rural Cambodian farming communities and how they influence antibiotic use: A mixed methods study.

Biosecurity and preventive animal health services in Cambodian smallholder backyard farming systems are often limited, leading to an over-reliance on antibiotics. However, data on factors influencing antibiotic use in these settings are lacking. We conducted a study in two rural Cambodian farming communities to investigate how social and contextual influences affect both human and animal antibiotic use behaviours. Data were collected in three phases: a baseline household census to enumerate village residents, a social network survey to understand village-level social ties, and in-depth interviews to elicit information about the influence of social ties on their decision-making processes. Primary outcome measures included knowledge, attitudes and practices surrounding antibiotic use, and awareness of issues relating to antibiotic resistance. Participants commonly accessed antibiotics or learned animal antibiotic use practices through village-level informal sources such as pharmacies or animal health workers. While most participants reported not using antibiotics for animal growth promotion or illness prevention, misconceptions surrounding both antibiotic effectiveness and resistance were common. Social networks capturing informal, work-related and health-related social ties showed that familial connections and geographic proximity were of primary importance for information sharing. Using exponential random graph models, we demonstrated that familial ties, and closer geographic and geodesic distance, were associated with similarity in overall antibiotic knowledge and attitudes. The informal private sector plays a major role in provision of antibiotics and antibiotic-related information in backyard farming communities, but such information is maintained within close social groups. This demonstrates the importance of engaging village-level informal sources in the provision of antibiotic-related information for both human and animal health, as well as in potential interventions to encourage appropriate antibiotic behaviours in lower-resourced settings.

Production Performance and Nutrient Conversion Efficiency of Field Cricket (Gryllus bimaculatus) in Mass-Rearing Conditions.

Currently, there is an increased interest in mass producing edible insects, e.g., field crickets (Gryllus bimaculatus), due to their market value and sustainable development. The current study aimed to measure the production performance of field crickets and to quantify the major nutrient deposition rate using a new approach for a nutrient conversion efficiency calculation for the field crickets under mass-rearing conditions. The field crickets were reared under mass-rearing conditions in the rearing crates and fed with a commercial cricket feed. Measurements for daily feed offered, final body weight, and dead cricket quantity were carried out during the feeding trial period. There were three production rounds with the same procedure for farmed cricket management. The samples of diet, adult crickets, and dead crickets were collected and then analyzed for chemical analysis of macronutrients. The production performance and nutrient conversion efficiency were calculated and then compared with applicable earlier reports for both field and house (Acheta domesticus) crickets. The production performance for the studied field crickets under mass-rearing conditions had final a body weight, an average daily gain (ADG), a feed conversion ratio (FCR), and a survival rate of 0.95 g, 23.20 mg/day, 2.94 and 88.51%, respectively. The field crickets had nutrient conversion efficiency for dry matter (DM), ash, crude protein (CP), crude fat (EE), crude fiber (CF), and nitrogen-free extract (NFE) of 13.26, 8.03, 28.95, 88.94, 34.87, and 1.85, respectively, with an adjusted nutrient conversion efficiency of 14.85, 8.99, 32.37, 99.17, 38.95, and 2.10, respectively. Thus, the production of field crickets could be performed under mass-rearing conditions, and the nutrient conversion efficiency for both adjusted and non-adjusted values could be measured.

Response in digestibility, growth performance, and carcass quality of local Kandol pigs to incremental levels of fermented banana stems.

Fermentation of banana stems is a novel method for increasing the digestibility of fibrous porcine rations in the tropics; however, optimal feeding rates have not been determined. An experiment was carried out to determine the response of digestibility, growth performance, and carcass quality in local Kandol pigs to incremental levels of FBS in rations. A total of 20 castrated male pigs were randomly allocated to five diets, containing 0, 400, 500, 600, and 700 g FBS of the ration. Daily feed on offer was provided as 4% of the body weight on a dry matter basis and offered three times per day. As result, the inclusion level of FBS was positively correlated with NR (p < 0.001, r = 0.68). The linear regression equation was y = 0.002x + 2.4276 (R2 = 0.63). Furthermore, it was also correlated with ADG (p < 0.05, r = 0.46) and with FCR (p < 0.05, r = - 0.45). The regression equation was y = 0.0634x + 174.2 (R2 = 0.43) and y = - 0.0009x + 4.6521 (R2 = 0.62) for ADG and FCR, respectively. The correlation between inclusion level of FBS and large intestine weight was also observed (p < 0.05, r = - 0.61). The R2 value was 63. However, there was no any correlation between the inclusion level of FBS and the percentages of hanging carcass, dressing carcass, pH, color score, marbling score of the meat, and WHC (p > 0.05). The economic benefit of using FBS to improve pig diets will depend on the availability of banana stems and the labor and processing costs.