The economic impact of pig-associated parasitic zoonosis in Northern Lao PDR.

The parasitic zoonoses human cysticercosis (Taenia solium), taeniasis (other Taenia species) and trichinellosis (Trichinella species) are endemic in the Lao People's Democratic Republic (Lao PDR). This study was designed to quantify the economic burden pig-associated zoonotic disease pose in Lao PDR. In particular, the analysis included estimation of the losses in the pork industry as well as losses due to human illness and lost productivity. A Markov-probability based decision-tree model was chosen to form the basis of the calculations to estimate the economic and public health impacts of taeniasis, trichinellosis and cysticercosis. Two different decision trees were run simultaneously on the model's human cohort. A third decision tree simulated the potential impacts on pig production. The human capital method was used to estimate productivity loss. The results found varied significantly depending on the rate of hospitalisation due to neurocysticerosis. This study is the first systematic estimate of the economic impact of pig-associated zoonotic diseases in Lao PDR that demonstrates the significance of the diseases in that country.

Towards a standardised surveillance for Trichinella in the European Union.

Each year, more than 167 million pigs in the European Union (EU) are tested for Trichinella spp. under the current meat hygiene regulations. This imposes large economic costs on countries, yet the vast majority of these pigs test negative and the public health risk in many countries is therefore considered very low. This work reviewed the current Trichinella status across the EU as well as the national level of monitoring and reporting. It also reviewed which animal species were affected by Trichinella and in which species it should be surveyed. This information was used to design a cost-effective surveillance programme that enables a standardised monitoring approach within the EU. The proposed surveillance programme relies on identifying sub-populations of animals with a distinct risk. Low-risk pigs are finisher pigs that originate from so-called controlled housing. All other pigs are considered high-risk pigs. Controlled housing is identified by the application of a specific list of management and husbandry practices. We suggest that member states (MS) be categorised into three classes based on the confidence that Trichinella can be considered absent, in the specified sub-population of pigs above a specified design prevalence which we set to 1 per million pigs. A simple and transparent method is proposed to estimate this confidence, based on the sensitivity of the surveillance system, taking into account the sensitivity of testing and the design prevalence. The probability of detecting a positive case, if present, must be high (>95 or >99%) to ensure that there is a low or negligible risk of transmission to humans through the food chain. In MS where the probability of a positive pig is demonstrated to be negligible, testing of fattening pigs from a sub-population consisting of pigs from controlled housing can be considered unnecessary. Furthermore, reduced testing of finishers from the sub-population consisting of pigs from non-controlled housing might even be considered, if conducted in conjunction with a proportionate sampling scheme and a risk-based wildlife surveillance programme where applicable. The proposed surveillance programme specifies the required number of samples to be taken and found negative, in a MS. A MS with no data or positive findings will initially be allocated to class 1, in which all pigs should be tested. When a MS is able to demonstrate a 95% or 99% confidence that Trichinella is absent, the MS will be allocated to class 2 or 3, in which the testing requirement is lower than in class 1.

Clinical, haematological, biochemical and economic impacts of Trichinella spiralis infection in pigs.

The purpose of this work was to assess the clinical, haematological and biochemical responses of pigs experimentally inoculated with Trichinella spiralis. Groups of three pigs were inoculated per os with 100, 500 and 5000 T. spiralis muscle larvae, two pigs were used as control. Clinical evaluation of disease in pigs included daily examination, rectal temperature measurements and cardiac and respiration rates. Haematological studies included: hematocrit (%), hemoglobin (g/dl), and white cell, neutrophil, lymphocyte and eosinophil counts. Blood biochemistry included: bun (mg/dl), creatinine (mg/dl), AST (UI/l), ALT (UI/l), CPK (UI/l) and ALP (UI/l). No significant differences were observed in rectal temperature and in cardiac and respiration rates between inoculated animals and the control group (p> or =0.05). Significant differences were detected (p< or =0.05) in the values of % hemoglobin, and eosinophils, as well as in the values of CK, ALP, AST and ALT. The variations observed in some cases were related to the number of T. spiralis larvae inoculated and varied with the number of days post-infection. Inoculated pigs showed significant differences (p< or =0.05) in weight gain when compared with uninoculated controls. This study has clinical, haematological, and enzyme alterations in Trichinella infected pigs provides a better understanding of acute and chronic trichinellosis in pigs.

[Estimation of trichinosis-induced economic damage].

The paper presents calculations and estimations of the economic damage caused by cases of trichinosis in the North Caucasus before and after economic reforms. Before ruble denomination, the economic damage from a case ofsubclinical, mild, moderate, severe, and very severe (and fatal) trichinosis was 246.9, 374.6, 621.6, 882.1, and 63,000 rbl., respectively. After the country's economic transition to market relations, it was 10,688, 12,935, 24,885, 37,596, and 139,592 rbl., respectively, as shown by the 2003 data. Before and after economic reforms, the mean cost of a case of trichinosis was 1,342 and 21,526 rbl., respectively. According to the author's estimates, the damage caused by cases of trichinosis to the economy of the North Caucasus in the period of 1990 to 2004 was over 50 million rbl. Only did the 2001 large-scale outbreak of invasion in the Krymsky District, Krasnodar Territory, cause damage at 7 million rbl.

Historical perspectives and current global challenges of Trichinella and trichinellosis.

Trichinella spiralis and related species of Trichinella have had a long history of causing human disease, and as a foodborne pathogen have had a major impact on international commerce of pork and other meat animal species which are known to transmit the parasite. Our knowledge of Trichinella has increased substantially over the past few years particularly in the areas of phylogeny, host diversity, epidemiology and control. In this paper, we provide a brief overview of our understanding of Trichinella from its discovery to present time. Past and current challenges of the control of Trichinella and trichinellosis are summarized. As editors of this special issue of Veterinary Parasitology, we introduce a series of invited review articles prepared by experts from around the world, summarizing recent knowledge in Trichinella and trichinellosis.

Economic losses resulting from food-borne parasitic zoonoses.

Economic losses resulting from food-borne parasitic zoonoses are difficult to assess. Estimating the global economic impact of these diseases is handicapped by inadequate information on the prevalence and public health importance of parasitic zoonoses for most countries. However, the economic losses caused by certain zoonoses has been estimated for some regions and in these instances the costs are significant. In Mexico, for example, porcine cysticercosis is responsible for a loss of more than one-half of the national investment in swine production and for more than US$17 million annually in hospitalization and treatment costs for humans with neurocysticercosis. For all of Latin America, porcine cysticercosis accounts for an economic loss of US$164 million. In Africa, losses of one to two billion dollars per year due to bovine cysticercosis have been reported. Human toxoplasmosis in the United States is estimated to be an annual economic/public health burden of more than US$400 million. The implication from these examples and other are discussed. A set of recommendations is presented for obtaining the necessary information needed to permit assigning to food-borne parasitic zoonoses their appropriate priority within each country's complex economic and public health problems.

[Evaluation of the medical and social cost of 2 trichinosis outbreaks in France in 1985]. / Evaluation du coût médical et social de deux épidémies de trichinose survenues en France en 1985.

Two outbreaks of trichinosis occurred in France in 1985 and 1,073 cases were identified. These outbreaks were related to the consumption of parasitized horse meat. The medical and social cost of these outbreaks have been estimated with a sample of 92 patients. The average medical cost was 1,200 FF by outpatient and 17,300 FF by hospitalized patient. For the 1,073 cases, the total cost of these 2 outbreaks is estimated to have been between 7 and 11 millions FF. Of this sum, the hospitalization fees exceeded 51% and the social cost was 36% (loss of productivity). Since October 1985, a decree of the French Ministry of Agriculture has imposed a parasitologic test on all horse carcasses slaughtered in France or imported. This examination costs under 5 FF (under $1) per carcass. This study shows that the systematic examination for trichinosis of horse meat carcasses should be continued and that more sensitive screening methods should be developed.