8 September 2006

 

Plague - Human cases in USA

In 2006, as of 25 August, a total of 13 cases of human plague have been reported from the United States [1]. This is the largest number of cases reported in a single year since 1994. The cases have occurred in four states; New Mexico (seven cases), Colorado (three), California (two) and Texas (one). Five patients developed primary septicaemic plague and the remaining eight developed bubonic plague. Two of the 13 patients died.

Plague is caused by the bacteria Yersinia pestis and is endemic in many countries within tropical and sub-tropical areas of the world, including northern and southern Africa, parts of North America, and central, south and south-east Asia. There are three forms of plague; bubonic, pneumonic and septicaemic. The natural reservoir for plague is wild rodents.

The disease is transmitted to humans most commonly through bites by infected fleas, but it can also be contracted from handling infected animals especially rodents, rabbits, and cats, and rarely through contact with patients who have pulmonary infection with plague. At least two of these human cases were infected after preparing infected wild rabbits for eating. Most cases in the U.S. occur in the domestic setting where it is suspected that free-roaming pets acquire and bring into the household infected rodent fleas.

Advice for travellers

Plague is low risk for the majority of travellers. However, persons residing or visiting plague endemic areas should avoid contact with rodents. Areas around the home or campsite should be cleared of rubbish to control rodent populations. Insect bite avoidance measures should be employed to discourage flea bites, and domestic animals should be regularly treated for fleas. Travellers who hunt rabbits should take precautions when handling the carcases such as by wearing gloves.

Reference

1. Centers for Disease Control and Prevention. Human plague - Four states, 2006. Morbidity and Mortality Wkly Rep. 2006; 55: September 1. Available online at http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5534a4.htm

Further information

NaTHNaC Plague information sheet:

http://www.NaTHNaC.org/travel/factsheets/plague1.htm