25 August 2010

Increase in trichinellosis in Argentina

The Ministry of Health of Argentina have reported an increase in cases of trichinellosis in 2010 [1]. As of 16 July, there have been 173 presumptive or confirmed cases compared with 34 cases for the same period in 2009. Cases have been reported from seven provinces: La Pampa (51), Buenos Aires (44), Mendoza (36), Santa Fé (24), San Luis (11), Córdoba (6) and Neuquén (1) [1]. Media sources have also reported cases in the province of Entre Ríos [2].

The Bureau of Health in Mendoza has updated case numbers as of 18 August for the province of Mendoza, with 219 reported cases and 13 persons hospitalised [3].

Preliminary investigations have identified pork sausage as the likely cause of transmission. Possible sources for contaminated pork are farms with improper sanitation, illegal slaughter houses and home–farmed pigs [1-3].

The National Service for Food Safety and Quality (SENASA) is inspecting farms and slaughter houses for infected pigs, and improving standards for food hygiene [4]. Information about the symptoms of trichinella infection and guidance on food preparation has also been issued.

Trichinellosis

Trichinellosis is a parasitic disease caused by an intestinal worm, Trichinella spp. It is transmitted to humans following the consumption of undercooked or raw meat products containing Trichinella larvae. Larvae invade the intestine, mature to adult worms and reproduce, making more larvae that migrate via the bloodstream to invade the muscles and other organs. T. spiralis is responsible for most human infections and has worldwide distribution in many species of carnivorous animals. Domestically raised pigs are the most frequently implicated animal host, although wild game such as bear and boar, have been associated with case clusters [5].

Illness ranges from a sub-clinical infection to fulminating, fatal disease depending upon the number of larvae ingested. The incubation period is from one to three weeks. Intestinal invasion by larvae with maturation to adult worms can be accompanied by diarrhoea, abdominal pain and vomiting. Once larvae are produced and begin to migrate into muscle, symptoms include the sudden onset of muscle soreness and pain together with fever. Periorbital and facial swelling, conjunctivitis, myalgia, rash and eosinophilia can be seen. In severe cases with central nervous system invasion, altered consciousness and coma can ensue.

Treatment is effective and should be commenced early, and is usually begun on the basis of a clinical diagnosis. Treatment consists of an anthelmintic, usually mebendazole or albendazole, in conjunction with corticosteroids.  

Advice for travellers

Trichinellosis can be prevented by ensuring that all meat products have been thoroughly cooked, particularly meats that are from wild animals or domestically raised pigs. No undercooked or raw meat products should be eaten.

Physicians who evaluate returned travellers from these areas of Argentina with suspected trichinellosis should be alert to the possible diagnosis and can seek appropriate guidance on management from the local infectious disease or tropical medicine unit.

References

1. Ministerio de Salud de la Nación. Boletín de Vigilancia. 20 August 2010. [Accessed  25 August 2010]. [In Spanish] Available at:

http://www.msal.gov.ar/htm/site/pdf/epidemiologia/boletin-semanal/BoletinSemanalVigilanciaSE33-20-08-2010.xls

2. Proyecto Salud. Cinco provincias en alerta por casos de triquinosis. 15 August 2010. [Accessed 25 August 2010]. [In Spanish] Available at: http://www.proyecto-salud.com.ar/shop/detallenot.asp?notid=6209

3. Ministerio de Salud. Salud informa sobre nuevos brotes de triquinosis. Prensa, Gobierno de Mendoza. 18 August 2010. [Accessed 25 August 2010]. [In Spanish] Available at:

http://www.prensa.mendoza.gov.ar/index.php?option=com_cont

ent&view=article&id=1592:salud-informa-sobre-nuevos-brotes-de-triquinosis&catid=50:salud&Itemid=65

4. Servicio Nacional de Sanidad y Calidad Agroalimentaria. El Senasa envió a faena sanitaria 20 cerdos en Río Negro. 17 August 2010. [Accessed 25 August 2010]. [In Spanish] Available at:

http://www.senasa.gov.ar/contenido.php?to=n&in=1392&io=13621

5. McIntyre L, Pollock SL, Fyfe M, et al. Trichinellosis from consumption of wild game meat. CMAJ 176:449-51, 2007. Available at: http://www.cmaj.ca/cgi/reprint/176/4/449

Links

U.S Centers for Disease Control and Prevention (CDC)