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Pig health issues: Overview of Latin America

New diseases and persistent ones restrain progress in the field of animal health in Latin America. Reasons for this are numerous – lack of animal health legislation based on international standards, insufficient education and knowledge updates for veterinarians and poor diagnosis capacity. Even so, meat production continues to rise, even in countries where disease pressure is still high.

Circovirus, teschovirus, paramyxovirus, Classical Swine Fever (CSF), gastro-enteritis. These are some of the persistent diseases in Latin America. While some affect animal production, others cause huge losses to the business and to human health. Dr Jésus Hernandez, coordinator of the Ibero-american network of swine production and researcher at the Mexican Centre for Food Research and Development (CIAD), says, “61% of the diseases that affect humans originate from animals.”
 
The situation is getting worse. In the last decades, over 75% of the emerging diseases affecting humans were related to pathogens that had already affected animals at an earlier stage. He says, “This fact results from a larger animal and human population density in certain areas, and also from the international trade, which moves both people and animal products, thus favouring the creation of a ‘perfect microbe waterfall.”
 
Backyard production plays a pivotal role in transmitting diseases, Hernan-dez says, “We know that this kind of production represents a very important source of income and food for the lower classes – however, it is also a source of zoonotic infections. The problem gets worse with the types of feed given to the animals and with the poor management of their excrements, which generates a negative image for the activity, helping to spread wrong concepts, as it happens in e.g. some regions of Mexico and Peru.”
 
Sanitary development
The road of sanitary development is long and winding. Hernandez points out that corruption in official veterinarian organisations is often a common factor in Latin American countries. In addition, contributing to this scenario are the lack of knowledge recycling by veterinarian professionals and limited financial investments in animal health. Hernandez says, “I believe advancing in sanitary management depends on the implantation of programmes for eradicating diseases and their continuity, as well as mutual support among countries, especially from the ones with technical and human qualification. Besides, it is necessary that the local legislation follows international standards.”
 
He adds, “Pig health and food safety of animal products must be a priority to producers, to the meat processing industry, to veterinarians, and also to the health authorities.”
To comprehend sanitary issues affecting Latin America, Hernandez divides the diseases in three types: the ones that affect swine production at farm level, the ones that affect national and international trade and the ones that could also have an impact on human health (zoonotic diseases).
 
Diseases at farm level
Hernandez explains that the diseases that affect production are the ones that directly affect a farm’s production. However, their impact varies depending on the region where they occur. Currently there are 18 diseases listed under this category.
 
Paramyxovirusis one of them, described uniquely in the central region of Mexico. “Impact of this virus varies between regions, due to the association with another infectious agent. The presence of specific disease antibodies is reported in the north western region and there are suspicions in the south east side of the country.”
 
Another disease widely spread in Latin American countries is porcine circovirus (PCV2). The disease is notified in virtually all producing countries in South America, like Brazil, Argentina, Chile and Uruguay. The same thing has happened in Mexico, in North America. Only Ecuador did not report cases.Regarding occurrences, the most complicated are happening in Haiti and for the specialists the one that is bringing more concern is teschovirus, diagnosed in February 2009. Hernandez states, “Besides having a high mortality rate, between 40% and 50%, surviving pigs present neurological problems. The situation is aggravated because poverty is leading the population to consume the sick animals and there is the risk of virus dissemination to other regions.”
 
Diseases affecting commerce
The second category includes diseases affecting trade relationships, and are subject to obligatory notification to the Organization for Animal Health (OIE).
 
For Classical Swine Fever (CSF), even an Intercontinental Program has been set up that aims to eradicate the disease by 2020. Despite this programme, not all countries seem to be worried. Peru, a country that reported cases in 2010, does not have a programme to combat the disease; neither has Ecuador. In those countries where programmes have been applied, CSF proved to be a very persistent disease, with reoccurrences in the last two years. Outbreaks occurred in northern regions of Brazil in 2009; last year also Guatemala and Nicaragua were affected.
 
Porcine Reproductive and Respiratory Syndrome (PRRS) has been eradicated in Chile, but was reported in Mexico, Costa Rica, Dominican Republic, Colombia, Venezuela and Bolivia.Regarding transmittable gastro-enteritis, this one seems to be close to its end. Since 2005 there have been no reports from Latin American countries. Just in Mexico its presence was noticed, without clinic manifestation.
 
A lot still needs to be done when it comes to dealing with cisticercosis. Statistics from OIE reveal that Peru registered 8,559 outbreaks in 2009. Even large producing countries, such as Argentina, Brazil and Chile, diagnosed the disease in the last five years. Ecuador, the Dominican Republic and Guatemala also reported the disease.Aujeszky’s Disease is (unsurprisingly) diagnosed in countries that do not have eradication programmes (Cuba, Venezuela, Colombia, Peru and Bolivia).
 
However, even countries having control programmes had some cases in the last years, as it is the case with Argentina. Brazil has reported cases in 2005 and in the past year. In Mexico, even counting with eradication programmes, the country reported over 2,700 occurrences in some specific regions since 2005.Another disease that caused losses for the activity is the Nipah Virus. According to WHO, this virus can cause serious diseases in pigs, and can also be transmitted from humans to animals as well as between humans. Fruit bats are a natural host of the virus, which was recognised in 1999 during an outbreak between pig producers in Malaysia. Since then, there were over 12 outbreaks, all in south Asia. For a while, Latin America could feel relieved, because until 2009 there was not a single case in swine or humans. There is no vaccine.
Another positive mention can be given to African Swine Fever as it is now more than six years ago since the disease was last reported in Latin America. It is important, however, to be vigilant for new diseases.
 
Zoonotic diseases
Influenza H1N1 2009 is one of the most recent examples of how sanitary issues can affect the commerce, because it alarmed the society, there was a reduction of pork consumption, and it also impacted human health. “The so-named swine flu widely affected the pork trade. In Mexico, tourism was also deeply affected, hotel reservations decreased 70% and several restaurants were closed due to the reduced consumption of pork”, recalls Hernandez. The disease was diagnosed in pigs in Mexico and Argentina; in Chile, it occurred in turkeys.
 
Among the main zoonotic diseases, cisticercosis can be mentioned, just as trichinellosis, salmonellosis, E.coliand swine brucellosis. Official reports mention trichinellosis in Chile and Argentina, registering 15 outbreaks per year. Swine brucellosis has not been reported by any Latin American country in the last two years.
 
In conclusion, when observing the amount of diseases found in Latin America, it is easy to conclude that the development of meat production may be severely hampered.
 
Nevertheless, even with all those diseases, meat production has grown tremendously in most Latin American countries between 2001 and 2008 – Brazil (12.5%), Mexico (8.8%), Chile (41.9%), Argentina (14.1%) and Ecuador (34.3%).
 
 

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Luciana Martins

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