Health Law

Salmonella paratyphi b

By Drew Falkenstein

Today, the Hawaii Department of Health announced a Salmonella paratyphi b outbreak linked to ahi tuna.  Interestingly, the ten illnesses in Hawaii appear to be linked to 13 other illnesses nationally, and possibly even linked to an outbreak of illnesses linked to the same product two years ago.  (We reported on this phase of the outbreak in February 2008).  Was it a frozen product that was held at the manufacturer or distributor's facilities for two years, and finally released now?  Or is there a persistent source of the paratyphi b strain at the manufacturer's facilities?

The paratyphi b strain of salmonella is different from those that we see most frequently in foodpoisoning outbreaks.  There are well over 2,000 individual strains of salmonella, but not all of them cause typhoid fever.  Paratyphi b, however, does cause typhoid fever. 

Typhoid fever is the most serious form of enteric fever, with humans being the sole reservoir of the bacteria. Based on a recent survey, the global number of typhoid cases in 2000 exceeded 21,000,000, with more than 200,000 deaths [1]. Enteric fever, that is typhoid and paratyphoid fevers, is the common name for infections caused by Salmonella enterica serotypes typhi and paratyphi. Of the three types of S. paratyphi (A, B, and C), B is the most common.

http://casesjournal.com/content/1/1/403.  Salmonella typhi and paratyphi are also more likely than other salmonella serotypes to cause enteric fever, as well as the chronic carrier state.

Typhoid fever, or enteric fever, differs from the typical salmonella gastrointestinal illness in that typhoid fever does not always cause severe gastrointestinal symptoms. 

The syndrome of enteric fever is characterized by prolonged sustained fever, relative bradycardia, hepatosplenomegaly, rose spots, and leucopenia and neutropenia [3]. After an incubation period of 5 to 21 days (generally 7 to 14 days), fever and malaise develop, often associated with cough. A small proportion of patients may have diarrhea during the incubation period. The fever tends to rise in stepwise fashion over the first few days to a week and then becomes sustained, usually at 39.4 to 40°C (103 to 104°F) or higher. After 2 weeks of illness, the severe complications of intestinal hemorrhage or perforation may be observed. The illness usually resolves by the end of the fourth week in an untreated patient. Relapse may occur in untreated as well as treated patients, but the illness is milder than the original episode. Rarely, some of the following complications may occur: pancreatitis, cholecystitis, infective endocarditis, pneumonia, hepatic or splenic abscess, orchitis, or focal infection at virtually any site [6].

Full post as published by Food Poison Blog on April 22, 2010 (boomark / email).