Dilution effect and identity effect by wildlife in the persistence and recurrence of bovine tuberculosis.

Current theories on disease-diversity relationships predict a strong influence of host richness on disease transmission. In addition, identity effect, caused by the occurrence of particular species, can also modify disease risk. We tested the richness effect and the identity effects of mammal species on bovine tuberculosis (bTB), based on the regional bTB outbreak data in cattle from 2005-2010 in Africa. Besides, we also tested which other factors were associated with the regional bTB persistence and recurrence in cattle. Our results suggested a dilution effect, where higher mammal species richness (MSR) was associated with reduced probabilities of bTB persistence and recurrence in interaction with cattle density. African buffalo had a positive effect on bTB recurrence and a positive interaction effect with cattle density on bTB persistence, indicating an additive positive identity effect of buffalo. The presence of greater kudu had no effect on bTB recurrence or bTB persistence. Climatic variables only act as risk factors for bTB persistence. In summary, our study identified both a dilution effect and identity effect of wildlife and showed that bTB persistence and recurrence were correlated with different sets of risk factors. These results are relevant for more effective control strategies and better targeted surveillance measures in bTB.

Notification of animal and human diseases: the global legal basis.

The successful control of a disease, and a possible epidemic, depends on rapid access to complete information on the disease situation. To ensure a timely response, diseases must be immediately notified in a transparent manner. The rapid exchange of information about animal diseases, including zoonoses, was the key objective in the establishment of the World Organisation for Animal Health (OIE) in 1924. For diseases concerning humans, a set of new rules dealing with the quick reporting of infectious diseases--the International Health Regulations--was adopted by Members of the World Health Organization (OMS) in 2005. The article explains these two systems of notification, which make information accessible to the public and allow decision-makers to better manage the risks related to the diseases concerned.

The OIE World Animal Health Information System: the role of OIE Reference Laboratories and Collaborating Centres in disease reporting.

One of the main objectives of the World Organisation for Animal Health (OIE) is to ensure transparency in and knowledge of the world animal health situation. To achieve this objective, the OIE relies on its network of Member Countries, which is complemented by the activities of 221 Reference Laboratories (RLs) and Collaborating Centres. The RL mandate states that, in the case of positive results for diseases notifiable to the OIE, the laboratory should inform the OIE Delegate of the Member Country from which the samples originated and send a copy of the information to OIE Headquarters. However, since 2006 the OIE has received a lower than expected number of notifications from RLs, which implies eitherthat the majority of samples are sent to national laboratories or that some RLs are not fully complying with their mandate. The OIE sent a questionnaire to RLs in preparation for the Second Global Conference of OIE Reference Laboratories and Collaborating Centres (Paris, France, 21-23 June 2010). Two main factors emerged: the need for RLs to clarify their role and responsibilities in disease reporting and the need for an awareness campaign to sensitise national Veterinary Services to the importance of conducting more surveillance (and consequently of submitting samples to RLs) for all OIE-listed diseases. Reference laboratories indicated two main reasons for not sharing more data on positive samples with the OIE: i) a perceived contradiction between their mandate as OIE RLs and the standards of the International Organization for Standardization (ISO) dealing with confidentiality; and ii) certain Member Countries or stakeholders asking RLs not to share positive results with the OIE, for political or economic reasons. The OIE has put forward proposals to help RLs resolve these problems in future. The use of ISO standards must be clarified and there must be improved communication between the OIE and its RLs. A lack of transparency about a significant disease event can jeopardise the biosecurity of several countries, an entire region or even the whole world. The reference status of a non-transparent RL could be questioned.

WAHIS and the role of the OIE's reference laboratories and collaborating centres.

In May 2004, OIE Member Countries adopted a resolution on the implementation of a new notification procedure. This new notification procedure led to the creation of a new World Animal Health Information System, which came into force in January 2005. In April 2006, the OIE launched a secure web application called the World Animal Health Information System (WAHIS), an online notification system for Member Countries. For countries with fully functional internet connections, this new system has replaced the use of paper report forms. It constitutes a major achievement in the worldwide use of information technology and modem communication techniques and their applications, enabling Member Countries to notify the OIE of disease and epidemiological information in accordance with the requirements laid down in Chapter 1.1.2. of the Terrestrial Animal Health Code and Chapter 1.2.1. of the Aquatic Animal Health Code. As well as being an online notification system, WAHIS is also a two-way communication system. It goes without saying that a good flow of information is essential if the system is to function optimally. WAHIS thus serves to disseminate information to OIE Member Countries in addition to such information being publicly disseminated via distribution lists and the World animal Health Information Database (WAHID) interface. It can also be used to ask a country to provide explanations or clarifications on the data it has submitted.

International monitoring and surveillance of animal diseases using official and unofficial sources.

The need for quality and timely animal disease information, including data on zoonoses, has become more crucial than ever, not only for animal health stakeholders but also for the general public worldwide. Since its creation in 1924, the World organisation for animal health (OIE: Office International des EEpizooties) has played an active role in sharing disease information among countries and in the prevention and control of animal and zoonotic disease spread. Recently, the OIE established a single list of animal diseases with new criteria for inclusion in this list. The overriding criterion for a disease to be listed is its potential for international spread. Other criteria include its zoonotic potential or its capacity for significant spread within naive populations. Special attention is paid to the detection and listing of emerging infectious animal diseases. Member countries are obliged to submit immediate notifications and follow-up reports if infections of the listed diseases or exceptional epidemiological events occur within their country. Early warning of emerging and re-emerging animal diseases is essential for prompt precautionary measures to be taken, at national and international levels, to protect both animal and human health. At times, a proactive approach is required to ensure greater transparency. For the past few years the OIE has been examining different sources of unofficial information on disease outbreaks. These are analysed and if necessary, verified. One of the external sources of information used by the OIE to improve transparency is ProMED-mail, an internet-based reporting system that derives its data from a comprehensive range of official and unofficial sources, the media and on-site observers. Free of political constraint and staffed by professionals to ensure credibility, it is able to post very rapid preliminary and unofficial reports and summaries.