Bruce Gummow

Validation of the FAMACHA© eye colour chart using sensitivity/specificity analysis on two South African sheep farms

A validation study of the FAMACHA(©) system for clinical evaluation of anaemia due to Haemonchus contortus was conducted on two commercial sheep farms in the summer rainfall region of South Africa. In this region, the Haemonchus season lasts from October to April. On Farm 1 the system was tested over a period of five successive years in consecutive sets of young stud Merino replacement rams and ewes examined at intervals of 3-5 weeks over each Haemonchus season, under routine farming conditions. When FAMACHA(©) scores of 3, 4, and 5 and haematocrit values of ≤ 22%, ≤ 19%, and ≤ 15% were separately considered to be anaemic, sensitivity on Farm 1 ranged from a maximum of 83% for a haematocrit cut-off of ≤ 15%, to 40% for a haematocrit cut-off of ≤ 22%. Sensitivity increased to 93% when FAMACHA(©) scores of 2, 3, 4, and 5 were considered anaemic at a cut-off value of ≤ 19%, but the positive predictive value decreased to 0.43, indicating that many non-anaemic animals would be treated. The analysis indicated a high level of classification bias on Farm 1, with the animals consistently being classified one FAMACHA(©) category lower (i.e. less anaemic) than reality. On Farm 2 the test was conducted over two successive years in yearling rams evaluated at weekly to fortnightly intervals during each worm season. Every ram judged to be in FAMACHA(©) category 4 or 5 was bled for haematocrit determination, and it was only dewormed with effective anthelmintics if the haematocrit was 15% or lower. When FAMACHA(©) scores of 3, 4, and 5 and haematocrit values of ≤ 22% and ≤ 19% were separately considered to be anaemic on Farm 2, sensitivity ranged from 64% for a haematocrit cut-off of ≤ 22%, to 80% for a cut-off of ≤ 19%. For identical haematocrit cut-off values and proportions of the sampled flock considered to be diseased as for Farm 1, sensitivity was always higher for Farm 2. On the other hand, further analysis of the data indicated that the magnitude of the error on Farm 1 was very consistent on average over the entire trial period. The results of this study indicate that (i) persons introduced to the system should not only be trained, but also be evaluated for accuracy of application; (ii) the sensitivity of the FAMACHA(©) diagnostic system should ideally be evaluated at shorter intervals to avoid production losses due to failure to detect anaemic animals which may be at risk of death; (iii) that calibration of the FAMACHA(©) scoring is essential per individual evaluator, and (iv) that animals should be examined at weekly intervals during periods of the highest worm challenge.

A questionnaire-based evaluation of the veterinary cordon fence separating wildlife and livestock along the boundary of the Kruger National Park, South Africa

Veterinary cordon fences are used in Southern Africa to separate wildlife from domestic animals in order to prevent transmission of infectious diseases. Such fences are a control method recognized by the World Organization for Animal Health (OIE) for establishing disease-free zones in beef exporting countries. However, few studies have evaluated the ecological impact of these physical barriers or their effectiveness at a multispecies level. We examined the permeability of one such barrier, along 357 km of the western and southern boundary of the Kruger National Park (KNP) during 2007. Information was gathered using a semi-structured questionnaire implemented among 32 teams of fence maintenance workers. Data were analyzed to identify (a) the main causes of fence damage, (b) the seasonality, location and duration of fence repairs, (c) high permeability areas for elephant (Loxodonta africana), kudu (Tragelaphus strepsiceros), impala (Aepyceros melampus), buffalo (Syncerus caffer) and warthog (Phacochoerus africanus), and (d) the influence of fence electrification, rivers and elephant damage on the frequency of observation of wildlife species outside the KNP estimated during the year. Human and elephant damage were the most common reasons for fence repairs. Elephant and buffalo were the most and least common large mammal species reported observed outside the KNP (1076 and 162 reports/year), respectively. Cattle incursions into the KNP were also reported in 44% of the fence sections. Electrification of the fence was an important factor explaining differences in estimated wildlife species observations outside the KNP during the year. Correlations between estimations of observed species suggested that fence gaps created by elephants might be used by the other wildlife species. Estimated annual counts of kudu, impala and buffalo, but not warthog, were found to correlate with elephant observations. Negative binomial regression models were developed to explore the relationships between observed estimations of different wildlife species outside the KNP the fence, electrification of fence sections and the presence of watercourses, suggesting that kudu, impala and buffalo could use elephant induced fence damage to leave the KNP. The questionnaire was able to evaluate fence integrity and identify sections where integrity was sub-optimal for separating wildlife from domestic livestock species. If combined with more quantitative methods and applied on a routine basis, it could provide an efficient and cost-effective method for monitoring the effectiveness of physical barriers to contain wildlife within protected areas such as is the case with veterinary cordon fences in Southern Africa.

Challenges posed by new and re-emerging infectious diseases in livestock production, wildlife and humans

Abstract In todays world, emerging and re-emerging diseases have a significant impact on global economies and public health, and with bioterrorism a constant threat this has become a very topical subject in recent years. Bernard Vallat, director general of the OIE, made the statement, “As a result of globalisation and climate change we are currently facing an unprecedented worldwide impact of emerging and re-emerging animal diseases and zoonoses”. He is not alone in this thinking, but are we facing an unprecedented impact of diseases and are globalisation and climate change the main driving forces? This paper examines some historical disease outbreaks and the factors that played a role in their emergence and compares these with recent emerging diseases. In doing so it highlights certain challenges that face livestock producers and decision makers today as they grapple with emerging diseases. One of the driving forces for the emergence of diseases is translocation of people and their livestock and this has often been coupled with invading armies or peoples, political unrest and a concurrent environment of socio-economic upheaval. Contact between wild animals, domestic animals and people is another driving force involving the interaction between naïve population groups that induces the emergence of new diseases. Pandemics are not new to human society and nor are many of the driving forces that caused them to occur in the past; what has changed is our increased knowledge and awareness of disease dynamics, allowing identification of challenges for the future and ways of addressing these. Modern farming practices often serve to amplify emerging infectious diseases and modern trade and transport mechanisms and routes have served to sometimes accelerate the spread of disease. How can we reduce the risks and should we only be worried about emerging infectious diseases or are emerging non-communicable diseases just as important in our modern society? This paper serves to explain some of the reasons for the emergence of diseases and to try and answer some of the pressing questions that confront livestock producers today.

Contacts between domestic livestock and wildlife at the Kruger National Park Interface of the Republic of South Africa

One of the most important transboundary animal diseases (TADs) in the southern African region is foot-and-mouth disease (FMD). In this region, a pathway for spread of FMD virus is contacts between cattle and certain species of wildlife. The objective of this study was to evaluate contacts between cattle and wildlife in the Kruger National Park (KNP) and the adjacent Limpopo province for the time periods October 2006 to March 2007 and April to September 2007. In this study, 87 livestock owners and 57 KNP field rangers were interviewed. Fifteen (17%) livestock owners reported contacts between wildlife and cattle. More livestock owners reported observing contacts between cattle and all wildlife species during October-March than April-September (p=0.012). However, no difference was found between these periods for contacts between cattle and individual wildlife species. A total of 18 (32%) field rangers reported contacts between cattle and wildlife. The most common species-specific contacts were between cattle and buffalo (63/year), cattle and impala (17/year) and cattle and lion (10/year). There were no significant differences in rangers reporting observed contacts between cattle and wildlife during October-March versus April-September or between rangers reporting observed contacts outside versus within the KNP. Overall, there was no evidence of higher contact rates between cattle and wildlife in the study area during October-March compared to April-September. Contact data collected in this study can be used to better understand the transmission of FMD virus in this region.

Vanadium: Environmental Pollution and Health Effects

Vanadium has gone from being a rare and obscure metal to become one of strategic military importance and a pillar of modern technology. As scientific and technological developments expand its horizon, vanadium is clearly poised to have a potentially significant environmental impact within the twenty-first century. This article briefly outlines the history of vanadium, where it is currently found in the world and the environment around us, and its uses in modern society. Information is provided on the clinical signs and other health effects of vanadium poisoning in vertebrate animals, including man, and toxic levels and acceptable dietary levels for some common domestic species and man are discussed. A brief mention of the biochemistry behind the symptoms and possible treatments is also given. Some information is provided on reported baseline levels of vanadium in common tissues and which tissues are best for monitoring vanadium in the environment. This is discussed together with other potential biomarker systems.

A review of domestic animal diseases within the Pacific Islands region

The Pacific Island countries and territories (PICTs) are reported to be free of the most serious infectious livestock diseases which are prevalent in other parts of the globe, such as Highly Pathogenic Avian Influenza, Foot and Mouth Disease or Rabies. Yet there is a lack of scientifically based evidence to confirm this animal health status. This paper reviews what has been published on diseases of domestic animals in the Pacific Islands region with a particular focus on data from the last 20 years (1992-2012). Relevant published papers were identified by a computerized literature search of two electronic databases (PubMed and Web of Knowledge). The latest reports on the animal health situation submitted by the PICTs to the World Organisation for Animal Health (OIE) were accessed on the World Animal Health Information Database (WAHID) interface and included in this review. Additionally, paper searches of resources were undertaken at the library of the Secretariat of the Pacific Community (SPC) in Fiji to retrieve any relevant grey literature for this review. The study eligibility criteria included qualitative or quantitative information on any disease (bacterial, viral, parasitic and other health disorders) affecting domestic terrestrial animals (mammals, reptiles, birds and bees) in any of the 22 PICTs members of the SPC. A total of 158 eligible references were retrieved of which only 77 (48.7%) were published since 1992 and analysed in more details. One hundred and one diseases and pathogens were reported on for bee, bird, carabao, cat, cattle, crocodile, deer, dog, donkey, goat, horse, pig, pigeon, poultry and sheep in the Oceania region and in 17 PICTs in particular. The paper gives information about known animal diseases, their reported prevalence and diseases not reported within the Pacific Islands region. The study found retrieved literature on animal diseases in PICTs was scarce and no longer up to date. There is a need to improve the published knowledge on the current animal disease status in the region.

Diseases of livestock in the Pacific Islands region : setting priorities for food animal biosecurity

Most Pacific Island countries and territories (PICTs) have developing economies and face a critical shortage of veterinarians with limited financial resources allocated to their animal disease surveillance programmes. Thus, animal health authorities have to set priorities for better focusing their scarce resources. The main objective of this study was to identify animal diseases perceived to be of importance by decision makers within selected PICTs, at the regional and national levels, to ensure better targeting of animal health resources. A second objective was to investigate whether the targeted surveillance programmes resulting from this rationalized approach would also benefit the local communities engaged in livestock production. A multi-criteria prioritization process was developed, involving local experts, to score and rank 132 animal diseases based on their priority at the regional and national levels for four PICTs: Fiji, Papua New Guinea, Solomon Islands, and Vanuatu, which form part of a regional Food Animal Biosecurity Network. In parallel interviews with farmers and field animal health and production workers were conducted to assess their perception of animal diseases. The list of the top-twenty ranked diseases for the Pacific Islands region shows a mix of endemic zoonotic diseases (such as leptospirosis ranked first; brucellosis third; tuberculosis sixth; and endoparasites and ectoparasites, respectively eleventh and thirteenth) with exotic diseases (such as HPAI ranked second, FMD fifth, and rabies ninth). There were different disease ranking lists for each of the four targeted PICTs, confirming different strategies of disease prevention and control may be required for each country, rather than a regional approach. Interviewed animal health and production workers were unfamiliar with most of the prioritized diseases and a majority acknowledged that they would not be able to recognize clinical signs if outbreaks were to occur in their area. Leptospirosis, which is endemic and identified as the top priority disease at the regional level, was never mentioned by any interviewed farmer. Farmers did not name any emerging infectious diseases as priorities. Instead, they identified endemic diseases (parasites, flu, coccidiosis, and scabies) as the most important. While animal disease priorities appear to differ widely between the targeted regions and countries, it also varies significantly between experts and farmers. Better targeted surveillance programmes may thus result in more rational and transparent allocation of resources, and thus enhanced food security, but may not directly match the needs of the local communities.

A door-to-door prevalence study of feline immunodeficiency virus in an Australian suburb

A door-to-door survey was conducted within the limits of the suburb of Douglas in northern Queensland, Australia, to determine the prevalence of feline immunodeficiency virus (FIV) infection in the overall population of domestic cats. Previous FIV prevalence studies have relied on convenience sampling strategies, leaving out an important group of pet cats that do not receive regular veterinary attention. Saliva was selected for testing because collection was non-invasive and was likely to achieve a high rate of participation. Ninety-six cats were surveyed and tested for salivary antibodies against FIV and with real-time polymerase chain reaction (PCR). PCR was considered to be the gold standard and a cat was considered to be FIV-positive if sequencing results on a PCR product of appropriate size matched previously published FIV genome sequences available in GenBank. Results showed 10/96 cats to be infected with FIV subtype A, indicating a prevalence of 10.4% (95% confidence interval: 4.4–16.4) in the area studied. High risk associations were established with the roaming lifestyle of the cat (P <0.002), presence of abscesses (P <0.03) and occurrence of bite wounds (P <0.10). This is the first known cross-sectional study of a population of urban northern Australian cats living in an affluent suburb and presenting saliva as a potential non-invasive sample for large-scale epidemiological surveys on FIV.

A questionnaire survey of poultry layer farmers in Khartoum State, Sudan, to study their antimicrobial awareness and usage patterns

An initial census of layer farms in Khartoum State, Sudan, was carried out in late 2007 and early 2008 and found that there were 252 layer farms with a total population of 2 221 800 birds. This paper reports the findings of the census. Based on this information, a structured questionnaire survey of 92 farms was then conducted in the state in April 2008 to collect data on antibiotic usage, demographic data and public health awareness. Ninety-eight per cent of participating farms comprised open-sided houses. It was found that 49% of the farms surveyed were on antibiotic treatment when the survey was conducted, whilst 59% of the farms had used antibiotics within the last 3 months. The study found that farmers and producers had a lack of knowledge about antimicrobial residues, their withdrawal periods and the risk posed by the consumption of these residues. The study also concluded that traditional farming systems in Sudan relied heavily on antimicrobial medication to control disease and almost half of the farms surveyed were treating their flocks with antimicrobials. In addition to this, there was a lack of disease control programmes which probably resulted in a massive use of antibiotics to control endemic diseases. This was further compounded by the absence of governmental supervision and control on the use of drugs.

Understanding pig and poultry trade networks and farming practices within the Pacific Islands as a basis for surveillance

&NA; Pacific Island countries have large pig and poultry populations. Yet little is known about patterns of contact between animals and how this influences disease spread in these islands. The objectives of this study were to examine farmer practices and the movements of pig and poultry within the Pacific Islands using questionnaires and social network analysis (SNA) tools to understand disease spread in the region. Questionnaire‐based surveys were conducted in Fiji, Papua New Guinea (PNG), Solomon Islands and Vanuatu with interviews of 310 pig farmers and 491 poultry farmers. Pacific Island farmers were found to have few animals (median = 7 pigs/farm, IQR 4–12), (median = 50 chicken/farm, IQR 23–52), (median = 10 ducks/farm, IQR 4–25), (median = 12 Muscovy ducks/farm, IQR 7–28) and a diversified number of species. A large proportion of farmers (44.6–61.3%) do not implement any preventive or control measures, yet the majority (80.6–88%) did not experience any animal diseases over the past 12 months. Most farmers never ask for veterinary care, never engage in laboratory testing and do not report when their animals show clinical signs. Many pig farmers (31.8%) trade within their communities only and sell (24.5%) directly to consumers which reduces the risk of diseases spreading. Our results show an association between farmers that report having had disease on their farm in the past 12 months and movements of animals on and off their farms. The capitals of the studied provinces in PNG, Vanuatu and Solomon Islands were identified as the most connected nodes of both pig and poultry trade, while Fiji networks appeared much less connected. Our study found that farmer practices increased the risk of disease spread, but this was currently limited by trading practices. The SNA results serve as a basis for more targeted disease surveillance and better use of available resources for disease prevention and control.