SF Weekly Letters

Swine influenza and Pig Cell Transplants

The sudden outbreak of the swine influenza just seems to have come out of the blue but it just seems too weird to be random. Two events that may be random but also seem connected involve Mexican pig cell transplants and the outbreak of the swine influenza in Mexico. Recently a Spanish language online newspaper called Paralelo 36.com published an article presenting a hypothesis that transplants of pig tissues and cells may have caused the Mexico Swine Influenza pandemic of 2009 . Eventhough there is no evidence to prove or disprove this link, it does raise some interesting questions. It is important to note that Mexico is the country where the most number of pig cell transplants have been performed both in clinical studies and also in a private clinic in Mexico City. Xenotransplantation is a new and exciting area of research where chemically or genetically modified tissues or cells from pigs (and other animals) are being transplanted into humans to cure disease. Pig cell transplants have been conducted in Mexico, Russia and New Zealand. What is troubling is that the patients who were administered these pig cell transplants were taking immunosuppressive medications which would make them immunologically vulnerable to viruses. There have been interesting reports from the Russian and Mexican trials where some of patients no longer needed insulin which is a remarkable finding. Many scientists have been debating the potential dangers of transmitting pig viruses to humans through pig cell transplants. It is interesting that pigs have been well known to carry many pathogens and this is may have been the practical reason why both Jewish and Islamic law have forbidden the eating of pork. At the same time, it is important to note that humans have raised pigs for millennia but there have been only two examples of viral pandemics related to pig viruses. The two major examples are the 1918 Spanish swine influenza and the 2009 Mexican Swine influenza (both H1N1 strains) that have led to pandemics. One unusual limited outbreak of H1N1 was reported at Fort Dix in 1976 where it infected about 200 soldiers. The outbreak led to the death of 2 soldiers but it never led to a pandemic .Studies have found that pigs can definitely infect humans with a variety of pathogens(bacteria or viruses, parasites) but in the majority of cases, these infections have sickened a few people and the spread of the infection has remained localized. Several studies have found that pigs can infect humans with the H1N1 virus. There is also evidence that pigs can infect humans with other types of viruses. A study conducted by one of the research teams involved in pig cell transplantation found no evidence of viral infections in patients who were injected with pig cells. It is important to mention that the presence of pig influenza viruses were not evaluated in that study. We are entering a brave new world and it is always better err on the side of caution . It might be best to put a temporary voluntary moratorium on pig cell transplants(eventhough no link may exist) until this swine influenza outbreak is under control rather than to take foolish risks that endanger all of mankind.
Patrick Movsessian
Citations for Verification of information by editors:Influenza and other Respiratory Viruses, September 2009, Clinical Infectious Diseases Jan 2006, JAMA, January 1991 ,Current Topics in Microbiology and Immunology,2003, Journal of Thoracic Cardiovascular Surgery, April 2001, ABC Science Online March 2006,Journal of Medical Virology Microbiology, September 2008.

www.paralelo36.com/la-gripe-porcina-y-los-xenotransplantes-inquietantes-hipotesis/ -
www.abc.net.au/science/.../InnovationRepublish_1587896.htm
www.newscientist.com/.../mg19826515.400-pig-cell-transplants-help-people-with-diabetes.html

www.medscape.com/viewarticle/408761_5

www.ctv.ca/servlet/ArticleNews/.../1084058627125_26/?hub

www.sciencedaily.com/releases/2002/08/020828063019.htm

http://www.cdc.gov/ncidod/eid/vol12no01/05-1007.htm

http://www.nhmrc.gov.au/media/media/rel02/xenofaq.htm

www.gene.ch/gentech/2002/Sep/msg00030.html

http://eprints.qut.edu.au/3449/1/3449.pdf