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Abstract

  1. Top of page
  2. Abstract
  3. Case Report
  4. Discussion
  5. Acknowledgments
  6. Declaration of Interests
  7. References

We present the case of two Australian tourists aged 25 and 26  years who, after immersion in a canal in Venice, developed severe leptospirosis. After a 1-week history of fever, headache, myalgia, and vomiting they developed jaundice and renal failure. Complete remission was achieved by antibiotic therapy and hemodialysis.

Leptospirosis is a zoonotic disease, globally distributed, caused by bacteria of the genus Leptospira. Although transmission may occur in rural and urban areas worldwide and the disease has been traditionally considered an occupational hazard among professionals in contact with urine of infected animals, nowadays most cases of travel-related leptospirosis occur in an epidemic setting among groups participating in water sports or contact with water surface.[1] Leptospirosis is now considered an emerging disease in travelers.

Case Report

  1. Top of page
  2. Abstract
  3. Case Report
  4. Discussion
  5. Acknowledgments
  6. Declaration of Interests
  7. References

On July 1, 2011, two Australian male tourists aged 25 and 26 years were admitted to the emergency department of the Careggi Hospital, Florence, Italy, reporting a 1-week history of fever with sudden onset of headache, myalgia, nausea, vomiting, and diarrhea. They had no significant past medical or surgical history and they had recently traveled from Venice to Florence. At the time of admission they showed similar clinical signs and symptoms, mainly jaundice, conjunctival hyperemia, and muscle tenderness. Routine hematological and biochemical profiles were similar (Table 1). In both cases laboratory findings evidenced acute renal failure and hepatic impairment. Vital signs were normal. On auscultation, the heart sounds had no abnormalities and air entry was equal on both lungs with occasional scattered wheezing. Results of neurological examination were normal. Electrocardiogram, abdominal ultrasound, and X-ray of the chest revealed no abnormalities. Asked about recent exposure to animals, mud, or potentially contaminated freshwater sources, the young tourists mentioned they had settled at a campsite near Venice 2 weeks earlier; because of the heat, they had both immersed their feet in the waters of a Venice canal close to Rialto Bridge. One of them had also swum in it for less than a minute without any protection for the conjunctiva. No skin lesions or trauma were observed at the time of possible infection, nor any swallowing of the canal water. The common history of exposure to possible contaminated water, along with hepatic and renal impairment, suggested the diagnosis of leptospirosis. However, blood and urine specimens were collected for culture and polymerase chain reaction (PCR) was also evaluated. Serum samples were tested by the microscopic agglutination test (MAT). Intravenous ceftriaxone (2 g every 24 h) was empirically administered.[2] Adequate fluids and a diuretic infusion were also started. Both patients required daily hemodialysis for 5 days as a result of the severe renal injury. Blood and urine cultures had no growth. The PCR result was positive for leptospiral DNA in the urine of both patients. First collected serum sample results (approximately the tenth day of disease) were positive by MAT in both subjects with titers to serovars icterohaemorrhagiae of 1 : 1,600 and serovars copenhageni of 1 : 200 (serogroup icterohaemorrhagiae). Serovars icterohaemorrhagiae and copenhageni are commonly associated with rats as reservoir hosts.[3] Ten days later, the titer of 1 : 1,600 was confirmed in the first subject, while that of 1 : 200 of the other attained 1 : 3,200 (Table 1). The clinical picture progressively improved, restoring normal function of liver and kidney, and they were discharged after 2 weeks.

Table 1. Laboratory results at the admission and on discharge of two subjects with severe leptospirosis acquired immerging legs in a canal of Venice, Italy
 Reference rangesSubject 1 (25 y)Subject 2 (26 y)
AdmissionDischargeAdmissionDischarge
Laboratory results     
Erythrocytes (×1012/L)4.20–5.404.573.364.773.31
White blood cell count (×109/L)4.00–10.0010.310.819.36.00
Neutrophil granulocytes (% of white blood cell)37.0–75.082618364
Platelets (×109/L)140–4408443540345
Aspartate transaminase (IU/L)5–40733315279
Alanine transaminase (IU/L)5–408489132154
Gamma-glutamyl transferase (IU/L)10–4012890171100
Alkaline phosphatase (IU/L)55–13097120159112
Serum creatinine (mg/dL)0.44–0.909.420.829.870.70
Creatine kinase (IU/L)20–16089921227928
Blood urea nitrogen (mg/dL)0.10–0.502.710.463.420.27
Total bilirubin (mg/dL)0.30–1.0022.232.1418.364.17
Prothrombin rate (INR)0.8–1.21.11.01.31.0
Erythrocite sedimentation rate (mm/h)2–1564355547
C-reactive protein (mg/L)<9.097<9102<9
Procalcitonin (ng/mL)<0.510.61/12.11/
Mirobiological results     
MAT titer 1 : 1,6001 : 3,2001 : 2001 : 1,600
PCR on blood Negative/Negative/
PCR on urine Positive/Positive/
Blood culture Negative/Negative/
Urine culture Negative/Negative/

Discussion

  1. Top of page
  2. Abstract
  3. Case Report
  4. Discussion
  5. Acknowledgments
  6. Declaration of Interests
  7. References

The severe form of leptospirosis observed in the two young Australian tourists is attributable to an imprudent and forbidden behavior. Interdiction to immersion and bathing in the canals of Venice is clearly indicated. Beside imprudence, peculiar water conditions of the small canal chosen by the tourists for the immersion may have played a crucial role. Although flooding occurs regularly in Venice and the locals are exposed to frequent contact with flood waters, no other cases of leptospirosis were notified in the city of Venice during the whole of 2011 (Vittorio Selle, personal communication). The water composition of the Venice lagoon is a mix of fresh and salt water and is considered salty enough to inhibit the survival of leptospires excreted with the urine of infected rats. In fact, leptospires die rapidly in salt waters. The two young tourists probably contracted leptospirosis through exposure to heavily contaminated and not enough salty stagnant water. Another possible source of exposure to leptospires could have been camping and the associated exposure to soil and contaminated water. However, this hypothesis was not supported by any obtainable information. Neither heavy rainfall nor flooding had been documented in the days preceding the time of exposure, nor was exposure to wet soil recorded. No other case was reported in the camp. Furthermore, microbiological screening by culture method conducted by the local department of hygiene on the camp water samples gave negative results (Vittorio Selle, personal communication). However, because of the relatively low sensitivity of the environmental investigation, even when it is conducted through the screening of numerous samples and using highly diagnostic methods such as in vivo testing and PCR, failure to find leptospires does not necessarily mean their absence.[1] Leptospirosis is today a relatively infrequent disease in Italy, mostly ascribed to serovars icterohaemorrhagiae, poi, copenhageni, and bratislava, and associated with an overall fatality rate of 23%.[4]

Leptospirosis is a zoonotic disease caused by bacteria of the genus Leptospira that affects humans as well as other mammals, birds, amphibians, and reptiles.[5] Transmission to humans occurs through direct contact with blood, tissues, organs, or urine of infected animals, or through indirect contact, when injured mucosa or healthy skin is exposed to contaminated fresh water.[3] Furthermore, swallowing river or swamp water and being submerged in any contaminated water, are common sources of infection reported in literature during outbreaks of leptospirosis.[1, 6] The clinical manifestations of human leptospirosis are diverse, ranging from mild, flu-like illness to a severe disease form known as Weil's syndrome. Severe disease is characterized by jaundice, acute renal and hepatic failure, pulmonary distress, and hemorrhage, which can lead to death. Early detection and initiation of supportive and antibiotic treatment are then essential in case of severe illness.[3] Leptospirosis has a broad geographical distribution, occurring in both rural and urban areas of tropical, subtropical, and temperate regions. Tropical countries carry the major burden of the disease, by virtue of the favorable conditions for its transmission, with half a million cases reported yearly and a mortality rate ranging from 5% to 10%. Several cases of leptospirosis are reported in literature in the returning traveler population.[7, 8] Most of those cases have been associated with outdoor activities in rural areas in tropical destinations, like ecotourism, swimming, camping, and kayaking. The cases we presented here differ from those because they were acquired by travelers to a major city in Europe and illustrate the increasing importance of urban leptospirosis in developed as well as developing countries.[9]

Leptospirosis has a wide variety of clinical presentations, and a high index of clinical suspicion is essential for early diagnosis particularly in areas with very low incidence of leptospirosis, such as Venice: a poor outcome or even death in these patients could have occurred if the diagnosis was delayed. Diagnosis was suggested by the combination of a clinical pattern characteristic of Weil's disease and the history of exposure to possible contaminated water, and then laboratory confirmed by serology and PCR.

In conclusion, leptospirosis should be considered in febrile travelers whatever was the at-risk exposure even if there is no history of high-risk exposure, such as fresh water bathing, fishing, canoeing, or rafting.[10]

Acknowledgments

  1. Top of page
  2. Abstract
  3. Case Report
  4. Discussion
  5. Acknowledgments
  6. Declaration of Interests
  7. References

We are grateful to Rocco Sciarrone and Vittorio Selle of the Public Health Unit, Venice, Italy; Enzo Raise of the Infectious and Tropical Diseases Unit, Ospedale SS. Giovanni e Paolo, Venice, Italy; and Maria Grazia Santini and Simonetta Baretti of the Public Health Unit, Florence, Italy for the support in obtaining epidemiological information; Fabiola Mancini of the Istituto Superiore di Sanità, Department of Infectious, Parasitic and Immune-mediated Diseases, Rome, Italy for the molecular analysis on blood and urine samples; Lorenzo Ciceroni for helpful comments on the manuscript.

Declaration of Interests

  1. Top of page
  2. Abstract
  3. Case Report
  4. Discussion
  5. Acknowledgments
  6. Declaration of Interests
  7. References

The authors state they have no conflicts of interest to declare.

References

  1. Top of page
  2. Abstract
  3. Case Report
  4. Discussion
  5. Acknowledgments
  6. Declaration of Interests
  7. References