Leptospira Canicola Infection: Report of 81 Cases and Review of the Literature

Publisher Website
Google Scholar
Abstract
Summary Thirty to forty new cases of leptospirosis appear annually in Israel. A third of these are canicola fever. The annual average of 10–12 cases of this disease is very high and represents a morbidity rate of 8 per million (calculated for 1949–1957). In other countries the rate is less than one per million. Most of the cases of canicola fever appeared in three geographical areas in which concentrations of infected pigs and jackals were found. It was earlier proved that in Israel jackals are the main reservoir of Leptospira canicola and are responsible for its transmission to pigs and cattle. Men are infected especially through contact with pigs. It seems that stricter control of sanitary conditions in pigsties is essential for reduction of morbidity. In this series 81 cases were collected over a period of eight and a half years (1952–1960). Of these, 67 were hospitalized and 14 treated ambulatorially. Fifty-nine of the hospitalized patients and all of the ambulatory patients satisfied the diagnostic criteria of a compatible clinical picture and serological confirmation. The eight others met the clinical and epidemiological criteria but lacked sufficient serological examination. There were 63 men and 18 women, the majority in the younger age group (16–45 years). Thirty-three cases had contact with pigs and only eight with dogs. In the other 40 cases the source of infection was not ascertained, but 80% were farmers from areas having concentrations of pigsties infected with porcine leptospirosis canicolaris. The clinical manifestations were sudden fever, muscular pains, headache and conjunctival injection. This picture, together with high sedimentation rate and urinary findings, was highly suggestive of the diagnosis even before serological confirmation could be obtained. Signs of upper respiratory infection were found in a quarter of the patients. Meningeal signs appeared in 31% and in an additional 12% the central nervous system was involved. In all patients renal lesions appeared, usually mild and reversible. Only one patient died in acute renal failure. Mild jaundice was found in 21%. The level of blood bilirubin was usually lower than 3 mg%. Sometimes pathological liver function tests were found in non-icteric patients. Seven cases showed ECG changes, such as arrhythmias, T′ changes or patterns of myocardial damage, which were reversible in six. Iridocyclitis occurred in only one case. Leucocytosis with shift to the left appeared in 31% and shift to the left alone in 32% of the cases. Blood sedimentation rate was significantly increased in 88% of the cases. In 79% urinary findings were already positive in the first week of disease. Blood urea was elevated in nearly half of the patients and was more than 11 mg% in 13% of them. The course of the disease was usually short and benign, the one fatal case giving a mortality rate of 1.5%. The results of treatment with various antibiotics led to the impression that Terramycin is the drug of choice. It shortens the febrile period and accelerates the disappearance of urinary findings.