An assessment of the risk of foreign animal disease introduction into the United States of America through garbage from Alaskan cruise ships.

The United States Department of Agriculture, Animal and Plant Health Inspection Service (USDA-APHIS) has been exploring methods of quantitative risk assessment to support decision-making, provide risk management options and identify research needs. With current changes in world trade, regulatory decisions must have a scientific basis which is transparent, consistent, documentable and defensible. These quantitative risk assessment methods are described in an accompanying paper in this issue. In the present article, the authors provide an illustration by presenting an application of these methods. Prior to proposing changes in regulations, USDA officials requested an assessment of the risk of introduction of foreign animal disease to the United States of America through garbage from Alaskan cruise ships. The risk assessment team used a combination of quantitative and qualitative methods to evaluate this question. Quantitative risk assessment methods were used to estimate the amount of materials of foreign origin being sent to Alaskan landfills. This application of quantitative risk assessment illustrates the flexibility of the methods in addressing specific questions. By applying these methods, specific areas were identified where more scientific information and research were needed. Even with limited information, the risk assessment provided APHIS management with a scientific basis for a regulatory decision.

Recommendations of the International Roundtable Workshop on Bovine Spongiform Encephalopathy.

Recommendations of the working party were summarized as follows: Determine the status in all countries of their national cattle herds with respect to BSE. Attempt to develop a test to recognize BSE-infected animals before they become clinically ill. Establish procedures to prevent spread of BSE agent into the cattle populations, especially by eliminating feeds containing rendered ruminant proteins. Review the rendering processes, identify the sources and destinations of rendered products, and suggest appropriate changes if needed. Especially needed are standardized rendering procedures in regard to use of organic solvents, temperature, and duration of heat treatment. Review import and export regulations to reduce the risk of spreading BSE and to maximize opportunities for safe trading in cattle and cattle products. The scrapie-free certification program of the USDA was supported, and similar programs might be considered by other countries. If BSE/scrapie is diagnosed in a given country, determine baseline incidence of CJD in those countries and consider contributing to an international registry. The WHO should address the problems of BSE, formulate policy, participate in and coordinate research, and provide training opportunities for veterinary and human health care workers from eastern European countries and developing nations. Government and private agencies should consider increasing support for research on transmissibility and pathogenesis of CJD, BSE, CWD, scrapie, and transmissible mink encephalopathy. Prepare and publish a critical neuropathologic review of all spongiform encephalopathies, naturally and experimentally transmitted, defining the characteristics of each disease in the various species known to be susceptible. Consider producing guidelines for the biological and pharmaceutical industries with regard to sourcing, collecting, and processing bovine and ovine materials.(ABSTRACT TRUNCATED AT 250 WORDS)

Metastasis of Rous sarcoma tumors in chickens is influenced by the major histocompatibility (B) complex and sex.

Six-week-old second generation progeny from the cross of inbred Lines 6(1) and 15(1), segregating into three major histocompatibility (B) complex groups (B2/B2, B2/B5, and B5/B5), were inoculated subcutaneously in the wingweb with one of three pseudotypes of Rous sarcoma virus. Chickens that died during a 10-week period after inoculation were necropsied and scrutinized for gross metastasis and histological sections of at least one lesion per affected organ examined for Rous sarcoma-transformed cells. By definition, a metastatic tumor was one located in an organ or tissue other than the primary inoculation site and having the histological appearance of a Rous sarcoma. Sarcomas developed in 1144 chickens, 390 of which died with tumor. For B2/B2, compared to B5/B5 hosts, mortality was 8 vs. 93%, median days to death were 45 vs. 31, and metastatic frequency was significantly lower, 32 vs. 58%. Disseminated lesions were significantly less frequent in females than males and grew preferentially in the heart and pericardial sac. Because the frequency of metastasis was significantly lower in B2/B2 than in B5/B5 chickens, a gene(s) within, or closely linked to, the B complex sharply retards the spread of Rous sarcoma virus-induced tumors.