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International audience; Live bird market surveillance for avian influenza viruses in Cambodia in 2015 has led to the detection of two 7:1 reassortant influenza A(H5N1) clade 2.3.2.1c viruses. These reassortant strains, designated A/duck/Cambodia/ Z564W35M1/2015 and A/chicken/Cambodia/Z850W49M1/2015, both contained a single gene (PB1 and matrix gene, respectively) from concurrently circulating A(H9N2) influenza viruses. All other viral genes from both isolates clustered with A(H5N1) clade 2.3.2.1 viruses. Continued and prolonged co-circulation of influenza A(H5N1) and A(H9N2) viruses in Cambodian live bird markets may present a risk for the emergence of novel influenza reassortant viruses with negative agricultural and/or public health implications.

International audience; Low pathogenic A(H9N2) subtype avian influenza viruses (AIVs) were originally detected in Cambodian poultry in 2013, and now circulate endemically. We sequenced and characterised 64 A(H9N2) AIVs detected in Cambodian poultry (chickens and ducks) from January 2015 to May 2016. All A(H9) viruses collected in 2015 and 2016 belonged to a new BJ/94like h9-4.2.5 sub-lineage that emerged in the region during or after 2013, and was distinct to previously detected Cambodian viruses. Overall, there was a reduction of genetic diversity of H9N2 since 2013, however two genotypes were detected in circulation, P and V, with extensive reassortment between the viruses. Phylogenetic analysis showed a close relationship between A(H9N2) AIVs detected in Cambodian and Vietnamese poultry, highlighting cross-border trade/movement of live, domestic poultry between the countries. Wild birds may also play a role in A(H9N2) transmission in the region. Some genes of the Cambodian isolates frequently clustered with zoonotic A(H7N9), A(H9N2) and A(H10N8) viruses, suggesting a common ecology. Molecular analysis showed 100% of viruses contained the hemagglutinin (HA) Q226L substitution, which favours mammalian receptor type binding. All viruses were susceptible to the neuraminidase inhibitor antivirals; however, 41% contained the matrix (M2) S31N substitution associated with resistance to adamantanes. Overall, Cambodian A(H9N2) viruses possessed factors known to increase zoonotic potential, and therefore their evolution should be continually monitored.

International audience; In Cambodia, highly pathogenic avian influenza A(H5N1) subtype viruses circulate endemically causing poultry outbreaks and zoonotic human cases. To investigate the genomic diversity and development of endemicity of the predominantly circulating clade 2.3.2.1c A (H5N1) viruses, we characterised 68 AIVs detected in poultry, the environment and from a single human A(H5N1) case from January 2014 to December 2016. Full genomes were generated for 42 A(H5N1) viruses. Phylogenetic analysis shows that five clade 2.3.2.1c genotypes, designated KH1 to KH5, were circulating in Cambodia during this period. The genotypes arose through multiple reassortment events with the neuraminidase (NA) and internal genes belonging to H5N1 clade 2.3.2.1a, clade 2.3.2.1b or A(H9N2) lineages. Phylogenies suggest that the Cambodian AIVs were derived from viruses circulating between Cambodian and Vietnamese poultry. Molecular analyses show that these viruses contained the hemagglutinin (HA) gene substitutions D94N, S133A, S155N, T156A, T188I and K189R known to increase binding to the human-type α2,6-linked sialic acid receptors. Two A (H5N1) viruses displayed the M2 gene S31N or A30T substitutions indicative of adamantane resistance, however, susceptibility testing towards neuraminidase inhibitors (oseltamivir, zanamivir, lananmivir and peramivir) of a subset of thirty clade 2.3.2.1c viruses showed susceptibility to all four drugs. This study shows that A(H5N1) viruses continue to reassort with other A(H5N1) and A(H9N2) viruses that are endemic in the region, highlighting the risk of introduction and emergence of novel A(H5N1) genotypes in Cambodia.

International audience; Longitudinal surveillance of 2 live bird markets in Cambodia revealed year-round, high co-circulation of H5, H7, and H9 influenza viruses. We detected influenza A viruses in 51.3% of ducks and 39.6% of chickens, and co-infections, mainly by H5 and H9 viruses, in 0.8% of ducks and 4.5% of chickens.

The prevalence and associated risk factors of Toxocara vitulorum infection in buffalo and cattle calves was studied in 3 provinces in central Cambodia. Fecal samples were collected from 517 calves between the age of 1-15 weeks and processed for nematode egg counts by a modified McMaster method. A total of 64 calves were found to excrete T. vitulorum eggs in their feces (12.4%; 95% exact CI: 9.7-15.5). The mean fecal egg count was 2,798 EPG (SD=16,351; range=0-224,400). A multivariable generalized linear mixed model showed higher odds of T. vitulorum infection for buffalo versus cattle, for animals aged 4-8 weeks versus younger and older ones, and for animals with strongyle infection. There was no association with fecal consistency. Farmers should be aware of the potential impact of T. vitulorum, and treat their calves at the age of 2-3 weeks with anthelmintics such as benzimidazoles or pyrantel.

Helminth infections are the cause of morbidity in Cambodian cattle but other factors such as nutritional deficiencies and concurrent diseases may enhance the effects of parasites. The present study aimed to investigate the impact of anthelmintic treatment, feed supplementation, or both on gastrointestinal strongyle (GIS) and trematode infections as well as on morbidity parameters in Cambodian village cattle. At the beginning of the dry season, cattle populations in six villages were randomly assigned to a group: (A) receiving anthelmintic treatment (ivermectin+clorsulon) at week 0; (P) feed pellet supplementation during week 0-13 or both (AP). On five visits (week 0-29), faecal and blood samples were obtained for parasitological examination and haematocrit determination, respectively. Body condition (BCS), hind quarter fouling (HQFS), diarrhoea (DS), and conjunctiva colour (FAMACHA©) were scored and heart girth circumference was determined. To investigate the impact of treatment over time (week 0-29), a mixed model was used with treatment, time, and their interaction as fixed effects, and animal and village as random factors. At baseline, the proportion of GIS positive animals was high (67.9%), whereas trematode infections were low (Paramphistomum: 8.8%; Fasciola: 2.6%). Very thin to emaciated cattle (BCS 1-2) were more prevalent (11.4%) and FAMACHA© scores of ≤3 or below (65.8%) less prevalent than in an earlier study in the region. A Time ⨯ Treatment interaction was present for faecal egg counts (FEC) of GIS, GIS prevalence (both p

The Highly Pathogenic Avian Influenza H5N1 (HPAI) virus is now considered endemic in several Asian countries. In Cambodia, the virus has been circulating in the poultry population since 2004, with a dramatic effect on farmers’ livelihoods and public health. In Thailand, surveillance and control are still important to prevent any new H5N1 incursion. Risk mapping can contribute effectively to disease surveillance and control systems, but is a very challenging task in the absence of reliable disease data. In this work, we used spatial multicriteria decision analysis (MCDA) to produce risk maps for HPAI H5N1 in poultry. We aimed to i) evaluate the performance of the MCDA approach to predict areas suitable for H5N1 based on a dataset from Thailand, comparing the predictive capacities of two sources of a priori knowledge (literature and experts), and ii) apply the best method to produce a risk map for H5N1 in poultry in Cambodia. Our results showed that the expert-based model had a very high predictive capacity in Thailand (AUC = 0.97). Applied in Cambodia, MCDA mapping made it possible to identify hotspots suitable for HPAI H5N1 in the Tonlé Sap watershed, around the cities of Battambang and Kampong Cham, and along the Vietnamese border.

International audience; Surveillance for avian influenza viruses (AIVs) in poultry and environmental samples was conducted in four live-bird markets in Cambodia from January through November 2013. Through real-time RT-PCR testing, AIVs were detected in 45% of 1048 samples collected throughout the year. Detection rates ranged from 32% and 18% in duck and chicken swabs, respectively, to 75% in carcass wash water samples. Influenza A/H5N1 virus was detected in 79% of samples positive for influenza A virus and 35% of all samples collected. Sequence analysis of full-length haemagglutinin (HA) and neuraminidase (NA) genes from A/H5N1 viruses, and full-genome analysis of six representative isolates, revealed that the clade 1.1.2 reassortant virus associated with Cambodian human cases during 2013 was the only A/H5N1 virus detected during the year. However, multiplex reverse transcriptase-polymerase chain reaction (RT-PCR) analysis of HA and NA genes revealed co-circulation of at least nine low pathogenic AIVs from HA1, HA2, HA3, HA4, HA6, HA7, HA9, HA10 and HA11 subtypes. Four repeated serological surveys were conducted throughout the year in a cohort of 125 poultry workers. Serological testing found an overall prevalence of 4.5% and 1.8% for antibodies to A/H5N1 and A/H9N2, respectively. Seroconversion rates of 3.7 and 0.9 cases per 1000 person-months participation were detected for A/H5N1 and A/H9N2, respectively. Peak AIV circulation was associated with the Lunar New Year festival. Knowledge of periods of increased circulation of avian influenza in markets should inform intervention measures such as market cleaning and closures to reduce risk of human infections and emergence of novel AIVs.

We performed a two-source capture-recapture analysis for estimating the true number of villages that experienced clinical cases of foot-and-mouth disease (FMD) in 2009 in Svay Rieng province, Cambodia, and assessing the completeness of the official case-reporting procedure. As a first source, we used the 2009 official dataset made up of the 15 FMDinfected villages that were reported to the provincial authorities, and enlarged this list by assuming that all the villages located at less than 4 km from one of these villages also experienced clinical cases in 2009. In addition, we created a retrospective detection protocol using participatory tools cross-checked against a serological survey that detected 13 infected villages. The capture-recapture analysis of these two detection sources led us to the conclusion that 315 (CI95% 117-514) villages experienced clinical cases of foot-and-mouth disease in Svay Rieng province in 2009, corresponding to a village-level annual prevalence rate of 0.46 (CI95% 0.17-0.74). The official reporting rate to provincial authorities could therefore be evaluated at 0.05 (CI95% 0.03-0.13). An analysis of the sensitivity of the estimation of the number of cases to the radius used for enlargement of Source 1 was performed, indicating its low influence. This study clearly highlights the highly enzootic situation of Cambodia regarding foot-and-mouth disease and the substantial underreporting of clinically affected villages to veterinary authorities. We propose explanations for this low notification rate, stress the importance of accurate reporting procedures and, finally, discuss the potential of capture-recapture techniques as a tool for the quantitative evaluation of animal disease surveillance systems. (Resume d'auteur)

Background: This study was conducted from 2006 to 2010 and investigated the seroprevalence of influenza A viruses in Cambodian pigs, including human H1N1, H3N2, 2009 pandemic H1N1 (A(H1N1)pdm09), and highly pathogenic avian H5N1 influenza A viruses. Methods: A total of 1147 sera obtained from pigs in Cambodia were tested by haemagglutination inhibition (HI) assays for antibody to human influenza A viruses along with both HI and microneutralization (MN) tests to assess immunological responses to H5N1 virus. The results were compared by year, age, and province. Results: Antibodies against a human influenza A virus were detected in 14·9% of samples. A(H1N1)pdm09 virus were dominant over the study period (23·1%), followed by those to human H1N1 (17·3%) and H3N2 subtypes (9·9%). No pigs were serologically positive for avian H5 influenza viruses. The seroprevalence of human H1N1 and H3N2 influenza viruses peaked in 2008, while that of A(H1N1)pdm09 reached a peak in 2010. No significant differences in seroprevalence to human influenza subtypes were observed in different age groups. Conclusions: Cambodian pigs were exposed to human strains of influenza A viruses either prior to or during this study. The implications of these high prevalence rates imply human-to-swine influenza virus transmission in Cambodia. Although pigs are mostly raised in small non-commercial farms, our preliminary results provide evidence of sustained human influenza virus circulation in pig populations in Cambodia.

Although Cambodia, a Southeast Asian country, is suspected to be highly endemic for Japanese encephalitis virus (JEV), there are no nationally representative data on JEV transmission. Most of the existing data on human disease comes from few sentinel hospitals, and there have been no previous studies or surveillance for JEV transmission among pigs--the amplifying hosts in the natural cycle of JEV transmission. In preparation to develop a nationwide vaccination policy, data are required to show transmission of JEV in all the geographical regions of Cambodia. Analysis of JEV transmission among pigs will provide additional data on geographical scope and intensity of JEV transmission in Cambodia and will help to inform human vaccination policies in Cambodia. In this study, 505 sera obtained from swine bred in familial settings from 8 different provinces in Cambodia were tested by hemagglutination inhibition (HI) and ELISA tests to assess the presence of an immunological response to a JEV infection. Three hundred and thirty two sera (65.7%) were tested positives by HI assay and 321 (63.5%) by ELISA. Our results indicate that pigs particularly older than 6 months (95.2%) were highly infected with JEV in the 8 provinces. The high prevalence of HI antibodies and the high HI titer (>160 in 65.2% of cases and ≥ 1280 in 24.6% of cases) found in this age group suggest the important role of pigs in the transmission cycle of JEV in nature as they become probably rapidly infected and repeatedly re-exposed to the virus. Since the current pig rearing practices (within the backyard of home) are the same all over Cambodia, the results suggest that the human disease is also likely to be highly prevalent in the other provinces and warrant comprehensive policies for human vaccination and strengthened surveillance for acute meningo-encephalitis.

Movement of poultry through markets is potentially important in the circulation and spread of highly pathogenic avian influenza. However little is understood about poultry market chains in Cambodia. We conducted a cross-sectional survey of 715 rural villagers, 123 rural, peri-urban and urban market sellers and 139 middlemen from six provinces and Phnom Penh, to evaluate live poultry movement and trading practices. Direct trade links with Thailand and Vietnam were identified via middlemen and market sellers. Most poultry movement occurs via middlemen into Phnom Penh making live bird wet markets in Phnom Penh a potential hub for the spread of H5N1 and ideal for surveillance and control.

To understand transmission of avian influenza A (H5N1) virus, we conducted a retrospective survey of poultry deaths and a seroepidemiologic investigation in a Cambodian village where a 28-year-old man was infected with H5N1 virus in March 2005. Poultry surveys were conducted within a 1-km radius of the patient's household. Forty-two household flocks were considered likely to have been infected from January through March 2005 because >60% of the flock died, case-fatality ratio was 100%, and both young and mature birds died within 1 to 2 days. Two sick chickens from a property adjacent to the patient's house tested positive for H5N1 on reverse transcription–PCR. Villagers were asked about poultry exposures in the past year and tested for H5N1 antibodies. Despite frequent, direct contact with poultry suspected of having H5N1 virus infection, none of 351 participants from 93 households had neutralizing antibodies to H5N1. H5N1 virus transmission from poultry to humans remains low in this setting.

Human infections with influenza A(H5N1) virus in Cambodia increased sharply during 2013. Molecular characterization of viruses detected in clinical specimens from human cases revealed the presence of mutations associated with the alteration of receptor-binding specificity (K189R, Q222L) and respiratory droplet transmission in ferrets (N220K with Q222L). Discovery of quasispecies at position 222 (Q/L), in addition to the absence of the mutations in poultry/environmental samples, suggested that the mutations occurred during human infection and did not transmit further.

The prevalence and associated risk factors of Toxocara vitulorum infection in buffalo and cattle calves was studied in 3 provinces in central Cambodia. Fecal samples were collected from 517 calves between the age of 1-15 weeks and processed for nematode egg counts by a modified McMaster method. A total of 64 calves were found to excrete T. vitulorum eggs in their feces (12.4%; 95% exact CI: 9.7-15.5). The mean fecal egg count was 2,798 EPG (SD=16,351; range=0-224,400). A multivariable generalized linear mixed model showed higher odds of T. vitulorum infection for buffalo versus cattle, for animals aged 4-8 weeks versus younger and older ones, and for animals with strongyle infection. There was no association with fecal consistency. Farmers should be aware of the potential impact of T. vitulorum , and treat their calves at the age of 2-3 weeks with anthelmintics such as benzimidazoles or pyrantel.

Surveillance of animal diseases in developing countries faces many constraints. Innovative tools and methods to enhance surveillance in remote and neglected areas should be defined, assessed and applied in close connection with local farmers, national stakeholders and international agencies. The authors performed a narrative synthesis of their own publications about surveillance in Madagascar and Cambodia. They analysed the data in light of their fieldwork experiences in the two countries' very challenging environments. The burden of animal and zoonotic diseases (e.g. avian influenza, African swine fever, Newcastle disease, Rift Valley fever) is huge in both countries which are among the poorest in the world. Being poor countries implies a lack of human and financial means to ensure effective surveillance of emerging and endemic diseases. Several recent projects have shown that new approaches can be proposed and tested in the field. Several advanced participatory approaches are promising and could be part of an innovative method for improving the dialogue among different actors in a surveillance system. Thus, participatory modelling, developed for natural resources management involving local stakeholders, could be applied to health management, including surveillance. Data transmission could benefit from the large mobile-phone coverage in these countries. Ecological studies and advances in the field of livestock surveillance should guide methods for enhancing wildlife monitoring and surveillance. Under the umbrella of the One Health paradigm, and in the framework of a risk-based surveillance concept, a combination of participatory methods and modern technologies could help to overcome the constraints present in low-income countries. These unconventional approaches should be merged in order to optimise surveillance of emerging and endemic diseases in challenging environments.

International audience; In Cambodia, most poultry are raised in backyard flocks with a low level of biosecurity, which increases the risk of spread of infectious diseases. The aim of this study was to evaluate the effectiveness of a practical biosecurity intervention based on affordable basic measures. A cluster randomised trial was conducted in 18 villages in Cambodia from November 2009 to February 2011. Generalised estimating equations were used to test the association between the intervention and mortality rates in flocks of chickens and ducks. Mortality rates in chicken flocks in intervention villages (mean 6.3%, range 3.5-13.8%, per month) were significantly higher than in control villages (mean 4.5%, range 2.0-9.7%, per month; P

To determine potential risk for bird-to-human transmission during influenza A virus (H5N1) outbreaks among backyard poultry in rural Cambodia, we collected environmental specimens. Viral RNA was detected in 27 (35%) of 77 specimens of mud, pond water, water plants, and soil swabs. Our results underscore the need for regular disinfection of poultry areas.

The economic and social impacts of foot-and-mouth disease (FMD) for livestock owners of developed countries have been extensively documented over the past few years. In developing countries such as Cambodia, this evaluation is often lacking due to the scarcity of accurate data. In the present study, we used a range of participatory tools to infer farmers' knowledge and perception, and the relative incidence of FMD from January 2009 to June 2010 in fifty-one villages of Svay Rieng province, Cambodia. In addition, the detection of non-structural protein at village level was used to cross-validate the results from the participatory epidemiology (PE) study. A quantitative assessment using Bayesian modeling was carried out to assess the ability of PE to retrospectively determine the FMD-infected status of a village in Cambodia. Our study shows that even if FMD is ranked second in the list of priority diseases, livestock owners did not see any benefit in reporting it since the disease entailed low direct losses. The average clinical incidence rates at individual level for cattle-buffaloes and pigs in infected villages were assessed by proportional piling at 18% and 11%, respectively for the year 2009. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of PE study were estimated at 87%, 30%, 51% and 74%, respectively. This approach seems to largely overestimate the presence of the disease but proves useful in evaluating the impact of FMD at household level and in understanding the reasons for not reporting it. This information may be important in establishing well-adapted disease prevention and control strategies in Cambodia.

Prevalence and seasonal variations of helminth infections and their association with morbidity parameters were studied in traditionally reared Cambodian cattle. Four villages in two provinces of West Cambodia were visited on monthly intervals over a period of 11 months, during which 2391 animals were faecal and blood sampled for parasitological and haematological examinations. The body condition score (BCS), faecal consistency (diarrhoea score, DS), colour of the ocular conjunctivae (FAMACHA©) and packed cell volume were determined for each individual animal. The overall proportion of samples that was positive for gastrointestinal nematodes was 52%, 44% and 37% in calves (from 1 to 6 months), young animals (6 to 24 months) and adults (over 24 months), respectively, while geometric mean faecal egg counts (FECs) for each of these age categories were 125, 66 and 15 eggs per gram, respectively. Six genera of strongyles were found in the faecal cultures, i.e. in descending order of occurrence, Cooperia, Oesophagostomum, Haemonchus, Trichostrongylus, Mecistocirrus and Bunostomum. The prevalences of Fasciola and Paramphistomum, estimated by coprological examination, varied between 5–20% and 45–95%, respectively. Logistic mixed models were used to investigate associations of morbidity markers with the presence of parasite infection. A low BCS was associated with gastrointestinal nematode and liver fluke infections, and soft faecal consistency with Paramphistomum infections. However, other factors such as nutritional deficiencies and intercurrent diseases are likely to enhance the effects of parasites and should therefore be considered when using these morbidity parameters as indicators of parasitism.

Background Since 2004, 21 highly pathogenic avian influenza H5N1 outbreaks in domestic poultry and eight human cases have been confirmed in Cambodia. As a result, a large number of avian influenza education campaigns have been ongoing in provinces in which H5N1outbreaks have occurred in humans and/or domestic poultry. Methodology/Principal Findings Data were collected from 1,252 adults >15 years old living in two southern provinces in Cambodia where H5N1 has been confirmed in domestic poultry and human populations using two cross-sectional surveys conducted in January 2006 and in November/December 2007. Poultry handling behaviors, poultry mortality occurrence and self-reported notification of suspect H5N1 poultry cases to animal health officials in these two surveys were evaluated. Our results demonstrate that although some at risk practices have declined since the first study, risky contact with poultry is still frequent. Improved rates of reporting poultry mortality were observed overall, but reporting to trained village animal health workers decreased by approximately 50%. Conclusions/Significance Although some improvements in human behavior have occurred, there are still areas—particularly with respect to the handling of poultry among children and the proper treatment of poultry and the surrounding household environment—that need to be addressed in public health campaigns. Though there were some differences in the sampling methods of the 2006 and 2007 surveys, our results illustrate the potential to induce considerable, potentially very relevant, behavioral changes over a short period of time.

BACKGROUND: We conducted investigations in 2 villages in Cambodia where outbreaks of influenza H5N1 occurred among humans and poultry to determine the frequency of and risk factors for H5N1 virus transmission. METHODS: During May 2006, approximately 7 weeks after outbreaks of influenza H5N1 among poultry occurred, villagers living near households of 2 patients with influenza H5N1 were interviewed about potential H5N1 exposures and had blood samples obtained for H5N1 serological testing by microneutralization assay. A seropositive result was defined as an influenza H5N1 neutralizing antibody titer of 1:80, with confirmation by Western blot assay. A case-control study was conducted to identify risk factors for influenza H5N1 virus infection. Control subjects, who had seronegative results of tests, were matched with H5N1-seropositive persons by village residence, households with an influenza H5N1-infected poultry flock, sex, and age. RESULTS: Seven (1.0%) of 674 villagers tested seropositive for influenza H5N1 antibodies and did not report severe illness; 6 (85.7%) were male. The 7 H5N1-seropositive persons, all of whom were aged

Wet markets are common in many parts of the world and may promote the emergence, spread and maintenance of livestock pathogens, including zoonoses. A survey was conducted in order to assess the potential of Vietnamese and Cambodian live bird markets (LBMs) to sustain circulation of highly pathogenic avian influenza virus subtype H5N1 (HPAIV H5N1). Thirty Vietnamese and 8 Cambodian LBMs were visited, and structured interviews were conducted with the market managers and 561 Vietnamese and 84 Cambodian traders. Multivariate and cluster analysis were used to construct a typology of traders based on their poultry management practices. As a result of those practices and large poultry surplus (unsold poultry reoffered for sale the following day), some poultry traders were shown to promote conditions favorable for perpetuating HPAIV H5N1 in LBMs. More than 80% of these traders operated in LBMs located in the most densely populated areas, Ha Noi and Phnom Penh. The profiles of sellers operating at a given LBM could be reliably predicted using basic information about the location and type of market. Consequently, LBMs with the largest combination of risk factors for becoming virus reservoirs could be easily identified, potentially allowing control strategies to be appropriately targeted. These findings are of particular relevance to resource-scarce settings with extensively developed LBM systems, commonly found in South-East Asia.

Background Zoonotic diseases are disproportionately affecting poor societies in low-income countries and pose a growing threat to public health and global food security. Rural Cambodian households may face an increased likelihood of exposure to zoonotic diseases as people there live in close association with livestock. The objectives of the study was to identify practices known to influence zoonosis transmission in rural Cambodian households and relate the practices to agro-ecological region, socio-economic position, demographics, livestock management and zoonosis awareness. Methods The study was conducted in three different agro-ecological regions of Cambodia; 10 villages each in the central lowlands, north-west wetlands and on the south coast, where information was obtained in questionnaires administered to 300 households, and 30 village heads and animal health workers. Results Descriptive analysis revealed a gender difference in responsibility for livestock and that the main purpose of raising livestock was for sale. Few respondents (6%) perceived a likelihood of disease transmission in their village between livestock, humans and wildlife, despite household practices related to zoonosis transmission being common. More than one-forth of households practised behaviours such as culling sick animals for consumption, eating animals found dead and allowing animals to enter sleeping and food preparation areas. Associations between household practices and possible explanatory factors were analysed with multivariable models using generalised estimation equations to account for clustering of practices within villages. Factors found to influence household practices were agro-ecological region, socio-economic position, number of people in the household, livestock species reared and awareness of zoonoses. Conclusions Cambodia has experienced numerous fatal human cases of zoonotic influenza and extensive influenza information campaigns have been run, yet only a few of the households surveyed here reported the threat of zoonosis to be a concern in their village. Zoonosis awareness was positively related to hand washing behaviour, but other practices associated with an increased or decreased likelihood of exposure to zoonotic pathogens were unaffected by awareness. The findings indicate a knowledge-to-action gap among rural farmers and highlight the necessity for reconstructed interventions in zoonotic disease control. Electronic supplementary material The online version of this article (doi:10.1186/s12889-015-1811-5) contains supplementary material, which is available to authorized users.

Background Taeniasis/cysticercosis, caused by the pork tapeworm Taenia solium, represents an important public health and economic burden in endemic countries. However, there is a paucity of data on infection among pigs in many parts of Southeast Asia, particularly Cambodia. We aimed to estimate seroprevalence of porcine cysticercosis, and investigate husbandary practices and knowledge of the disease among livestock workers, across different pig sector units in south-central Cambodia. Methods A cross sectional survey was conducted among pig smallholders, commercial farms, slaughterhouses and traders/middlemen from south-central Cambodia, selected through multistage sampling in proportion to local pig populations sizes. Questionnaires were administered to 163 pig workers to obtain data pig production, trading and slaughtering practices. Sera from 620 pigs were tested for Taenia antigens using a commercial ELISA-based test. Associations between seroprevalence and pig husbandry practices were assessed using generalised linear mixed models, adjusting for random-effects at herd-level. Results Of 620 pigs sampled, 29 (4.7%) tested positive for Taenia antigens. Seropositivity was associated with type of pig sector unit (P = 0.008), with the highest seroprevalence among pigs sampled from traders/middlemen (16.7%; 95% CI: 4.4%–37.8%), smallholders (7.6%; 95% CI: 3.8%–14.1%) and slaughterhouses (4.1%; 95% CI: 2.0%–7.5%), while none of the pigs sampled from small/medium or large commercial farms tested positive. Although the vast majority of pigs were penned, practices that might facilitate human-to-pig transmission, such as use of household waste and surface water sources to feed pigs, were prevalent among smallholders. However these were not found to be significantly associated with infection. Of 163 interviewed pig workers, 115 (70.5%) were aware of porcine cysticercosis, and 78 (47.8%) also knew it could affect humans. Twenty-six (16.0%) reported having noticed lesions typical of cysticercosis in their pigs. Conclusions Despite most pigs being kept confined in pens rather than raised in free-roaming systems, porcine cysticercosis appears to be endemic in south-central Cambodia and is associated with smallholder production. Further investigation is needed to identify which Taenia species are causing infections among pigs, and how seroprevalence and zoonotic risk may vary across the country, to understand the risks to public health and assess where interventions might be needed.