Case of the Month

Agriculture Expert in India

A 35 year old agricultural expert from Israel was invited to participate in a farming project in India. Six days later, he returned to Israel, and the following morning developed fever, headache, vomiting and muscle pain. Two days later, he felt somewhat better, but symptoms returned the following week, with additional symptoms of cough, shortness of breath and rigors. On admission to hospital, the patient was obtunded, hypotensive and icteric, and a chest x-ray revealed bilateral pulmonary infiltrates. Blood tests demonstrated elevated bilirubin and creatinine levels. In view of his recent travel to India, a presumptive diagnosis of malaria was entertained, and a course of Mefloquine was initiated pending further laboratory tests.

The following morning, blood smears were negative for malaria. At this point, an alternative diagnosis of Dengue shock syndrome was considered.

Clinical data to this point were entered into GIDEON, as follows:

The GIDEON differential diagnosis was as follows:

Note that neither malaria nor dengue were listed. The reasons for this become evident by clicking on the "Why Not" button:

In other words, these two diseases were discounted on the basis of incompatible clinical findings and incubation period.

Based on the revised differential diagnosis list offered by GIDEON, a course of intravenous ceftriaxone was initiated, and the patient discharged well one week later. The diagnosis of Leptospirosis was confirmed through serologic testing.

The following GIDEON note detailing the status of Leptospirosis in India was appended to the hospital chart.

This was an actual case treated in 2005. Failure to establish the correct diagnosis might have been fatal, since standard malaria therapy is ineffective against leptospirosis unless doxycycline is included.