Leptospirosis and dengue coinfection: Report of three cases with review of literature


Leptospirosis is a zoonosis having a worldwide prevalence and has recently emerged as a major public health problem, especially in tropical and subtropical regions. Likewise, dengue is one of the major endemic health problems in the Indian subcontinent. It is a mosquito-borne arboviral infection causing considerable morbidity and mortality. Epidemiologically, mixed infections of dengue and leptospirosis are possible because similar environmental conditions are needed for the transmission of both these infections. Still, their coinfection is rarely reported in medical literature. Here, we report three such cases of dengue and leptospirosis coinfection, encountered in clinical practice during the monsoon season at Kolkata, West Bengal, India.

Keywords: Coinfection, dengue, leptospirosis

How to cite this article:
Pan K, Roy U, Kumar S, Panwar A. Leptospirosis and dengue coinfection: Report of three cases with review of literature. Ann Trop Med Public Health 2016;9:119-21


How to cite this URL:
Pan K, Roy U, Kumar S, Panwar A. Leptospirosis and dengue coinfection: Report of three cases with review of literature. Ann Trop Med Public Health [serial online] 2016 [cited 2020 Aug 6];9:119-21. Available from: https://www.atmph.org/text.asp?2016/9/2/119/177380

[TAG:2]Introduction [/TAG:2]

Leptospirosis is a zoonosis with a worldwide distribution, especially in tropical and subtropical regions. It is caused by spirochete belonging to genus Leptospira interrogans. It presents with varied clinical manifestations ranging from self-limiting acute febrile illness to fatal Weil’s disease. The disease was considered inconsequential of late, but it has emerged as an important public health problem. [1] Dengue is one of the major endemic mosquito-borne arboviral infections in India causing substantial morbidity and mortality. It may present as self-limiting febrile illness to fatal dengue hemorrhagic fever or dengue shock syndrome. Mixed infection of dengue and leptospirosis may be abundantly present as similar environmental condition is responsible for the spread of both but in literature mixed infections are sparsely reported. Here, we report three cases of mixed infection with dengue fever (DF) and leptospirosis in Kolkata, West Bengal, India, India in the monsoon season.

Case Report

Case 1

A 20-year-old male patient presented with high-grade intermittent rise of temperature for 10 days with chill and rigor for the initial 2 days. Fever was associated with nausea, vomiting, and myalgia. On the 6th day of the onset of fever patient noticed erythematous rash mainly on the face and the trunk. The patient noticed yellow discoloration of skin from the 7th day of the fever. On examination, higher functions were normal, vitals were stable but anemia, jaundice, pedal edema, right cervical lymphadenopathy, conjunctival suffusion, and neck rigidity were present. Systemic examination was normal except for the just palpable spleen. Provisional diagnosis of enteric fever was considered along with consideration of DF, leptospirosis, and malaria as important differentials. Complete blood count showed hemoglobin (Hb) as 7.4 g/dL, total leukocyte count (TLC) as 11,800 cells/mm 3 [Neutrophils (N) −53, Lymphocytes (L) −37, Monocytes (M) −8, Eosinophils (E) −2], and platelet count as 180,000/mm 3 . Liver function test (LFT) revealed conjugated hyperbilirubinemia (Total bilirubin 5.8 mg/dL, conjugated bilirubin 4.2 mg/dL) with elevated levels of alkaline phosphatase (ALP), aspartate transaminase (AST), and alanine transaminase (ALT) with normal albumin globulin ratio. Computerized tomography (CT) scan of the brain was normal. Cerebrospinal fluid (CSF) study showed glucose −2 mg/dL, protein −54 mg/dL, cell count −10/mm 3 (L 75%, N 25%). Peripheral blood smear (PBS) for malarial parasite was negative and there was no growth on blood and urine culture. Viral markers for human immunodeficiency virus (HIV), hepatitis A, hepatitis B, hepatitis C, and hepatitis E were negative. Immunoglobulin M (IgM) typhoid was negative. Dengue IgM antibody capture enzyme-linked immunosorbent assay (MAC-ELISA) and IgM leptospira were positive, whereas dengue immunoglobulin G (IgG) ELISA was negative.

Case 2

A 43-year-old obese male patient presented with high-grade continuous fever with chill and rigor for 10 days, followed by yellow discoloration of the skin. The patient also complained of noncolicky pain in the right upper quadrant of the abdomen. There was no history of rash during this period. On general examination anemia and jaundice were found to be present. The right upper quadrant was tender with an enlarged liver. Provisional diagnosis of liver abscess was considered along with possibilities of malaria, acute cholecystitis, leptospirosis, viral hepatitis, and dengue as important differentials. Routine laboratory investigations showed Hb −5.5 g/dL, TLC −14,000/dL (N −80%, L −14%, M −3%, E −3%), platelet −60,000/dL. LFT showed total bilirubin −2.6 mg/dL (direct 1.9 mg/dL), ALT −104 U/L, AST −127 U/L, ALP −625 U/L. Serum urea level was 60 mg/dL and creatinine was 1.3 mg/dL. Urine routine examination showed the presence of albumin in urine. The malaria parasite was not found on PBS. Ultrasonography (USG) of the abdomen showed the presence of fatty liver. Viral markers for HIV, hepatitis A, hepatitis B, hepatitis C, and hepatitis E were negative. Dengue MAC-ELISA and IgM leptospira were positive, whereas dengue IgG ELISA was negative.

Case 3

A 16-year-old female was admitted with high-grade continuous fever with chill and rigor for 17 days, generalized rash for 10 days, and facial puffiness for 7 days. On the 7 th day of fever, nonpruritic rash appeared initially on the trunk and gradually spread over extremities. This was associated with the appearance of jaundice. Following this, facial swelling appeared with normal urine output. On presentation, the patient was drowsy. General physical examination was significant for anemia, jaundice, cervical lymphadenopathy on both sides, and bilateral pitting edema of lower limbs along with facial puffiness. Abdominal examination revealed hepatosplenomegaly, ascites, and diffuse tenderness over the abdomen. On respiratory system examination, dull percussion note was present below the 5th intercostal space on both sides with diminished vesicular breath sound. Further, neck rigidity was present and the Brudziρski sign was positive. Differential diagnoses considered were malaria, enteric fever, leptospirosis, meningoencephalitis. Complete hemogram showed Hb −7.0 mg/dL, TLC −18,600 (N −82, L −14, M −1, E −3), and platelet count was 365,000/dL. LFT showed total bilirubin to be 4 mg/dL (conjugated 2.5 mg/dL), ALP −466 U/L, AST −65 U/L, ALT −35 U/L, albumin −3.1 and globulin −4.1 g/dL. The serum electrolytes level was within normal limit but serum urea was 54 mg/dL and creatinine was 1.9 mg/dL. No growth was present on blood and urine culture. Chest X-ray showed the presence of bilateral pleural effusion. USG of the abdomen showed hepatosplenomegaly, ascites, and increased echogenicity of both kidneys. CT scan of the brain was normal and cerebrospinal fluid study showed glucose −54 g/dL, protein −35 g/dL, ADA −4.6 U/L, and cell count −5/dL (lymphocyte 70%, neutrophil 30%). Gram stain, fungal stain, and AFB stain didn’t show the presence of any organism. Viral markers for HIV, hepatitis A, hepatitis B, hepatitis C, and hepatitis E were negative. Pleural fluid study was exudative in nature. Dengue MAC-ELISA and IgM leptospira were positive, whereas dengue IgG ELISA was negative.


Dengue infection is caused by four antigenically distinct dengue virus serotypes (DEN 1-4). It is a disease of tropical and subtropical zones, transmitted by the bite of the Aedes mosquito. Dengue transmission occurs throughout the year in endemic regions but increased transmission is observed during the rainy season. Leptospires are finely coiled, motile slow growing obligate anaerobes. Man is infected through the exposure to animal’s urine. Farmers and sewer workers are at an increased risk for infection. Additional risk factors are overcrowding, poor sanitation, rainfall, and exposure to contaminated water. Increased rainfall and floods may lead to the emergence of more than one disease. This was observed during a dengue outbreak in Mumbai in 2002 where comparable number of screened febrile children had leptospirosis. [2] A study from Bangladesh, whose climatic conditions are similar to India, had also shown significant number of patients suffering from leptospirosis during the dengue outbreak. [3] However, patients concomitantly having both dengue and leptospirosis are rarely reported. We report three such cases of coinfection. All of the three cases occurred in the rainy season during the recent outbreak of DF in Kolkata, West Bengal, India.

Clinical presentation of DF and leptospirosis are considerably overlapping, leading to misdiagnosis or underdiagnosis in cases of mixed infection. In acute stage of infection, both may present as acute febrile illness with chill, myalgia, headache, backache, abdominal pain, and anorexia. Conjunctival suffusion (case 1) would be a sign that favors leptospirosis while a skin rash (case 1 and 3) would be indicative of DF. Lymphadenopathy (case 1 and 3), leukopenia is more frequent in DF and hepatomegaly (case 2 and 3) is common in leptospirosis but thrombocytopenia may be present in both cases from the very beginning. Meningeal (case 1 and 3) and hepatorenal (case 1-3) manifestations are more pronounced in leptospirosis but may also be present in DF. [4] It is generally recommended to use Polymerase chain reaction (PCR) or NS1 antigen detection in patients with suspected DF with onset of fever being less than 5 days’ duration, and MAC-ELISA in patients with fever for more than 5 days. The IgG ELISA is used for the detection of a past dengue infection. MAC-ELISA was positive in all the three cases. IgM-ELISA is preferably used for diagnosis of leptospirosis; although definitive test includes isolation of organism and microscopic agglutination test. [5]

DF is treated symptomatically, whereas moderate to severe leptospirosis is treated with intravenous penicillin G. Ceftriaxone is equally effective as penicillin G and has an advantage of extended-spectrum coverage. [6] All patients were treated with ceftriaxone and they responded well.


The possibility of dengue-leptospirosis coinfection should be kept in mind, particularly in endemic regions where the environmental condition is conducive for the spread of both the organisms.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.



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Source of Support: None, Conflict of Interest: None


DOI: 10.4103/1755-6783.177380

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