An urban outbreak of leptospirosis in Mumbai,India

An outbreak of leptospirosis occurred during the rainy season in the city of Mumbai, India. Out of 169 suspected cases, 74 (43.7%) were determined serologically positive by microagglutination test (MAT) carried out with a battery of eight pathogenic serovars, while 78 (46.1%) were shown positive for IgM antibodies to leptospira by enzyme-linked immunosorbent assay. On the basis of MAT, serovar Copenhageni accounted for 66 (89.1%) out of the 74 cases admitted during the period of the outbreak. Myalgia, conjunctival suffusion, cough with hemoptysis, icterus, and oliguria were significantly more common in patients whose samples were determined positive by MAT. The presence of pulmonary signs and symptoms and renal failure were significantly associated with mortality in patients presumed to be suffering from leptospirosis.     

Cross-species surveillance of Leptospira in domestic and peri-domestic animals in Mahalla City, Gharbeya Governorate, Egypt

A survey of 179 animals (black rats, dogs, sheep, buffaloes, cattle, donkeys, weasels, and cats) for Leptospira infection was conducted in Mahalla City (Lower Egypt). Blood, urine, and kidney were collected and tested by culture, microscopic agglutination test (MAT), and/or polymerase chain reaction (PCR). Among rats, 26% were positive by PCR, including 7% that were also positive by culture for L. interrogans serovars Grippotyphosa, Pyrogenes, and Icterohaemorrhagiae. L. borpetersenii serovar Polonica was isolated for the first time in Egypt in three rats. MAT titers ≥ 1:800 were observed in 11% of rats and 12% of dogs. L. interrogans serovar Grippotyphosa was detected in one cat. Sheep and donkeys were negative for leptospirosis by all methods. Buffaloes and cattle were seropositive in 20% and 44% of animals, respectively. Data indicate that several pathogenic serovars are circulating in the animals, which may pose exposure risks and account for high rates of acute febrile illness.     

Clinical presentation of leptospirosis: a retrospective study of 201 patients in a metropolitan city of Brazil

IntroductionLeptospirosis is a zoonosis of worldwide importance. The disease is endemic in Brazil. This study was conducted to describe the clinical and laboratory presentation of leptospirosis in a metropolitan city of Brazil.MethodsThis is a retrospective study including 201 consecutive patients with leptospirosis admitted to tertiary hospitals in Fortaleza, Brazil, between 1985 and 2006. All patients had clinical and epidemiological data suggestive of leptospirosis, and positive laboratorial test for leptospirosis (microscopic agglutination test, MAT, higher than 1:800).ResultsA total of 201 patients were included, with mean age of 38.9 ± 15.7 years; 79.1% were male. The mean length from onset of symptoms to admission was 7 ± 3 days. The main clinical signs and symptoms at admission were fever (96.5%), jaundice (94.5%), myalgia (92.5%), headache (74.6%), vomiting (71.6%) and dehydration (63.5%). Hemorrhagic manifestations were present in 35.8%. Acute kidney injury was found in 87% of the patients. Platelet count was less than 100,000/mm³ in 74.3%. Hematuria was found in 42.9%. Death occurred in 31 cases (15.4%).ConclusionsLeptospirosis is a globally relevant disease with potential fatal outcome. Signs and symptoms suggestive of leptospirosis must be known by any physician in order to institute early adequate treatment to improve outcome. Early indication and daily hemodialysis seems to be beneficial in this group of patients.     

Introduction of a rapid dipstick assay for the detection of Leptospira-specific immunoglobulin m antibodies in the laboratory diagnosis of leptospirosis in a hospital in Makassar, Indonesia

An easy, rapid and robust dipstick assay for detection of leptospira-specific immunoglobulin M (IgM) antibodies was evaluated on 403 patients admitted for hospitalization because of fever. The clinical symptoms and signs of 35 patients were consistent with leptospirosis. The final diagnosis for the remaining patients was as follows: 136 with typhoid fever, 82 with hepatitis, 74 with malaria, 48 with infections of the respiratory tract, and 20 with fever of unknown origin. The clinical diagnosis of leptospirosis was confirmed for 24 (68.6%) patients by the combined results of the microscopic agglutination test (MAT), the reference test for leptospirosis, and of IgM ELISA, a standard laboratory test for the serodiagnosis of leptospirosis. In addition, serum specimens from 8 (2.2%) patients with a final clinical diagnosis other than leptospirosis were found to be positive in MAT and/or IgM ELISA. Compared with the results of MAT and IgM ELISA a sensitivity of 91.6% and specificity of 93.6% was calculated for the dipstick assay. Most of the serum samples from the laboratory confirmed patients gave a moderate to strong staining intensity of the antigen band of the dipstick and were easy to read. The results demonstrate that the dipstick assay is convenient to use and allows the rapid and accurate confirmation of patients with clinical suspicion of leptospirosis in areas where the disease is endemic.     

Epitope mapping of monoclonal antibodies specific to serovar of Leptospira, using phage display technique

Random heptapeptide library displayed by bacteriophage T7 was used to characterize epitopes of five monoclonal antibodies that were specific to L. australis, L. bangkok, and L. bratislava. Phages selected by biopanning were cloned by plaque isolation, and the binding specificity of individual clones was confirmed by enzyme-linked immunosorbent assay, before being further amplified and checked for phage peptide sequence using PCR and DNA sequencing. Almost all of the peptide epitopes were continuous or linear. Interestingly, in phages reacting with the monoclonal antibody (MAb) clones F11, F20, 2C3D4, and 8C6C4A12, the deduced amino acid sequence of the displayed peptides corresponded to a segment of hypothetical protein of the Leptospira genome (L. interrogans serovar Lai and Copenhageni). Considering the deduced amino acid sequences of phages reacting with the MAb clones F11, F20, 2C3D4, and 8C6C4A12, the consensus motif -SKSSRC-, -TLINIF-, -SSKSYR- and -CTPKKSGRC- appeared respectively. No similarity was observed among phage reacting with the MAb clone F21. The results demonstrate that T7 phage display technique has potential for epitope mapping of leptospiral MAbs, and for rapid analysis of the interactions between phage display peptides with the MAb. The finding of a phage peptide that binds to MAb with protective activity can be further tested as a candidate for leptospirosis vaccine in the future.     

Human leptospirosis in Denmark 1970-1996: an epidemiological and clinical study

Epidemiological and clinical aspects of 118 laboratory confirmed cases of human leptospirosis in Denmark from 1970 to 1996 were reviewed. Icterohaemorrhagiae (72%) and sejroe (20%) were the most frequent serovars. The incidence of leptospirosis was 0.09/100,000 inhabitants/y. 93% of the patients were 18-64 y old, 90% were men and 72% of the cases occurred from July to November. Occupational exposure was present in 63% (74/118) of the cases (41% fish farmers, 28%, farmers). Eight percent of the patients had travelled abroad, 7% had been exposed to sewers and 4%, had been exposed through recreational activities (fishing). Initial symptoms were generally non-specific. Weil's disease developed in 63%, of the patients, more often in patients infected with the serovar icterohaemorrhagiae (73%) compared to patients infected with serovars sejroe or saxkoebing (25%). The fatality rate was 7%, all due to icterohaemorrhagiae. Though a rare disease in Denmark, leptospirosis should be considered in certain risk groups as a possible diagnosis in patients with acute febrile illness.     

Retrospective serosurvey of leptospirosis among patients with acute febrile illness and hepatitis in Egypt

The epidemiologic status of leptospirosis in Egypt has not been well defined because of difficulties in disease diagnosis. A retrospective study was conducted to detect leptospiral antibodies among undiagnosed acute febrile illness (AFI) and hepatitis cases. Approximately 16% of both AFI (141/886) and acute hepatitis (63/392) cases showed seroreactivity to Leptospira IgM by ELISA and microscopic agglutination test (MAT). Canicola, Djasiman, Grippotyphosa, Pyrogenes, Icterohemorrhagiae, and Pomona were the most commonly reactive serovars among patients with AFI. Djasiman, Grippotyphosa and Icterohemorrhagiae were the most reactive among patients with acute hepatitis. This study represents the first systematic report of Leptospira associated with patients with AFI and hepatitis in Egypt. Physicians need to have increased awareness about the importance of leptospirosis in the differential diagnosis of AFI and acute hepatitis in Egypt. In addition, laboratory capacity should be developed at fever hospitals to diagnose leptospirosis.     

A quantitative PCR (TaqMan) assay for pathogenic Leptospira spp

Background  

Leptospirosis is an emerging infectious disease. The differential diagnosis of leptospirosis is difficult due to the varied and often "flu like" symptoms which may result in a missed or delayed diagnosis. There are over 230 known serovars in the genus Leptospira. Confirmatory serological diagnosis of leptospirosis is usually made using the microscopic agglutination test (MAT) which relies on the use of live cultures as the source of antigen, often performed using a panel of antigens representative of local serovars. Other techniques, such as the enzyme linked immunosorbent assay (ELISA) and slide agglutination test (SAT), can detect different classes of antibody but may be subject to false positive reactions and require confirmation of these results by the MAT.     

Field evaluation of a one-step dipstick assay for the diagnosis of human leptospirosis in the Seychelles

OBJECTIVE AND METHOD: To compare the response of a dipstick assay (DSA) detecting Leptospira-specific immunoglobulin M (IgM) antibodies with that of an enzyme-linked immunosorbent assay (ELISA), an indirect haemagglutination assay (IHA), the microagglutination test (MAT) and a polymerase chain reaction assay (PCR) in patients with leptospirosis confirmed by MAT alone or by MAT and/or PCR (MAT/PCR). RESULT: In 75 patients with acute leptospirosis diagnosed by MAT (respectively, 90 patients diagnosed by MAT/PCR), the response in paired early and convalescent sera was positive in 78.9% (67.9%) by DSA, 76.0% (67.8%) by ELISA, 58.7% (55.6%) by IHA, 44.0% (53.3%) by PCR, and 100% (90.0%) by MAT. In early serum only, the response in patients diagnosed by MAT (respectively by MAT/PCR) was positive in 36.0% (38.9%) by DSA, 36.0% (37.8%) by ELISA, 14.7% (18.9%) by IHA, 39.2% (48.3%) by PCR, and 53.3% (58.9%) by MAT titre > or =1:100. DSA detected the main serogroups implicated in human leptospirosis in Seychelles and demonstrated sensitivity comparable to ELISA. In 124 single sera from control subjects without overt disease, the response was positive in 4.8% by DSA, 3.2% by ELISA, 3.2% by IHA, 13.8% by PCR, 37.9% by MAT titre > or =1:100, and 2.4% by MAT titre > or =1:800, giving evidence of the frequency of both past and current subclinical infection in Seychelles and that DSA was less sensitive than MAT to detect moderate levels of leptospiral antibodies. CONCLUSION: DSA is a simple and reproducible assay well adapted to field conditions and could usefully contribute to the evaluation of leptospirosis in areas devoid of serological laboratory facilities.     

Evaluation of two enzyme-linked immunosorbent assay methods for detection of immunoglobulin M antibodies in acute leptospirosis

Leptospirosis is a common zoonosis of worldwide distribution. Diagnosis of leptospirosis is usually accomplished by serology, but the microscopic agglutination test (MAT) generally requires paired sera for detection of seroconversion and is considered too complex for routine use. A number of rapid assays have been developed in recent years. In the present study, 2 immunoglobulin (Ig) M enzyme-linked immunosorbent assay (ELISA) methods were evaluated for the early diagnosis of acute leptospirosis in Barbados. A total of 103 patients admitted to the Queen Elizabeth Hospital for diagnosis of suspected leptospirosis were investigated. A case of leptospirosis was confirmed by a 4-fold rise in titer between 2 sera tested by MAT, an initial titer of > or = 800 in the MAT, or by isolation of leptospires from blood or urine. A total of 48 cases of leptospirosis were confirmed. In 33 cases, both commercial assays were positive in the first sample, taken at admission, a mean of 6.7 days after onset of symptoms, whereas seroconversion was detected in a further 9 cases. Both assays were negative in 5 cases, and the remaining case gave discordant results in the 2 assays. False-positive IgM results were detected in 4 patients without leptospirosis. The sensitivity of the 2 assays was 89.6 and 97.5%, respectively, and specificities were 92.7 and 96.4%, respectively. The positive predictive values were 87.8 and 95.5%, and the negative predictive values were 90.7 and 89.5%, respectively. Either of these assays can be used for early diagnosis of leptospirosis, particularly in laboratories that cannot perform more specialized leptospiral serology.     

A case of leptospirosis caused by Leptospira borgpetersenii serovar sejroe infected in Bali Island, Indonesia

We report a patient with leptospirosis caused by Leptospira borgpetersenii serovar Sejroe infection on Bali Island, Indonesia. This 33-year-old Japanese man had stayed at a resort hotel on the island from July 8 to July 13 2004. At the hotel, he swam in the pool, walked barefoot, and lied down in the grass. He developed a high fever and headache 7 days after completing his trip, and was admitted to our hospital on July 23. On admission he showed conjunctival suffusion and complained of myalgias. Laboratory findings included granulocytosis and elevated CRP. Plasmodium spp. were not found in blood smears, and no pathogenic bacteria were isolated from blood or fecal cultures. We diagnosed the patient as leptospirosis upon detection of slender coiled organisms with characteristic morphology by darkfield examination of blood sample. Minocycline 100 mg i.v.b.i.d. showed excellent efficacy. A microscopic agglutination test (MAT) during the convalescent stage demonstrated a significant increase in antibodies against L. borgpetersenii serovar Sejroe, confirming the diagnosis of leptospirosis. Despite occurrence of a pandemic of leptospirosis in certain Southeast Asian countries including Indonesia, information concerning pandemic disease is limited. In addition serovars of "imported" cases representing infection in pandemic areas differ widely from those in domestic cases. Adequate laboratory support therefore is crucial for accurate diagnosis of leptospirosis.     

Leptospirosis in northern India: a clinical and serological study

A total of 400 serum samples collected from patients, clinically suspected of leptospirosis, were evaluated for antibodies by LEPTO dipstick and microscopic agglutination test (MAT). Twenty of these patients (5%) had serological evidence of leptospirosis. Leptospira interrogans serovars Autumnalis and Icterohaemorrhagiae, Canicola and Javanica were serogroups recorded serologically. Fever and jaundice were the most common clinical presentations. Male preponderance was seen in the leptospirosis cases. Outdoor activities, agricultural activities, contact with animals were significantly associated with seropositivity for Leptospira. This study highlights that leptospirosis is a significant health problem in northern India, though grossly under reported due to the absence of routine laboratory diagnostic facilities for this disease.     

Two simple immunoassays using endemic leptospiral antigens for serodiagnosis of human leptospirosis

Two simple enzyme immunoassays, a conventional microplate and dot-ELISA, were developed to detect specific IgM antibodies using pool sonicated antigen prepared from three of the most reactive serovars of Leptospira associated with disease in Thailand. Both assays were evaluated and compared with the standard microscopic agglutination test (MAT) performed with 343 serum samples. A battery of 16 pathogenic serovars of L. interrogans were used as antigens in the MAT assay. The result of MAT at serum titers > or = 1:400 showed three pathogenic serovars of leptospira, Bratislava (71.88%), Sejroe (63.54%) and Pyrogenes (36.46%), were among the most commonly reacted serovars and they were selected for preparation of pool sonicated antigen for both IgM ELISA tests. The microplate IgM-ELISA, performed with sera at 1:80 dilution using the cutoff OD of 0.60, demonstrated sensitivity, specificity and efficiency of 87.50, 97.57, and 94.75%, respectively. The same values for IgM dot-ELISA performed with sera at 1:160 dilution were 98.96, 93.93, and 95.33%, respectively. Both ELISA methods showed results with statistically significant differences from MAT (p < 0.05). The agreement rate of IgM dot-ELISA compared with microplate IgM-ELISA was 0.85 by Kappa analysis. Both assays offered relatively high negative predictive values (95.26-99.57%), thus making the assays ideally suited for rapid screening. Future applications of the IgM dot-ELISA as a test kit would be suitable for use at the peripheral level as a rapid screening test for human leptospirosis.     

Leptospirosis presenting as acute encephalitis syndrome (AES) in Assam,India

ObjectiveTo establish leptospirosis as a new aetiology of the patients presenting acute encephalitis syndrome (AES).MethodsJapanese encephalitis, West Nile, Dengue and Chikungunya negative samples were tested by IgM capture ELISA for leptospira specific IgM. For further confirmation, the IgM positive samples were subjected to Microscopic agglutination test (MAT). The clinical details and laboratory findings of the positive patients were recorded.ResultsWe report 8 cases of leptospirosis presenting as AES, proven on IgM capture ELISA and confirmed by MAT. Fever (100%) and altered sensorium (62.5%) were two most common symptoms. Low haemoglobin (7.5 ± 2.8) g/dL, elevated blood urea (79.16 ± 46.43) mg/dL, serum creatinine (1.5 ±1.2) mg/dL, SGOT (66.5 ± 14.84) U/L and SGPT (70.5 ± 4.9) U/L were observed in positive patients.ConclusionsThis is the maiden study reporting leptospirosis as a new aetiology of the patients presenting AES. Establishing aetiology is very important for a successful therapy at least in treatable conditions like leptospirosis.     

Comparison of serology and isolates for the identification of infecting leptospiral serogroups in Hawaii, 1979-1998

Laboratory confirmation of leptospirosis is usually accomplished serologically, without isolates, using the microscopic agglutination test (MAT). However, optimal performance of the MAT is dependent on the knowledge of enzootic serogroups and serovars so that an appropriate MAT antigen testing battery can be established. Infecting leptospiral serogroups can be identified serologically without isolates, using the MAT, or by serogrouping of isolates, but little information is available regarding the correlation between these methods. The identification of infecting serogroups for 53 culture-confirmed leptospirosis cases, diagnosed in Hawaii between 1979 and 1998, using serology and culture isolates were compared. The overall agreement between the two methods was good (kappa = 0.71, 95% CI: 0.56, 0.86). However, the agreement varied between serogroups from 0 to 100%. In establishing the prevalence of serogroups, results obtained via MAT serology (in the absence of serogrouped isolates) should be considered presumptive rather than definitive.     

Distribution of Leptospira Serogroups in Cattle Herds and Dogs in France

A retrospective study was conducted to identify and describe the distribution pattern of Leptospira serogroups in domestic animals in France. The population consisted of cattle herds and dogs with clinically suspected leptospirosis that were tested at the “Laboratoire des Leptospires” between 2008 and 2011. The laboratory database was queried for records of cattle and dogs in which seroreactivity in Leptospira microagglutination tests was consistent with a recent or current infection, excluding vaccine serogroups in dogs. A total of 394 cattle herds and 232 dogs were diagnosed with clinical leptospirosis, and the results suggested infection by the Leptospira serogroup Australis in 43% and 63%, respectively; by the Leptospira serogroup Grippotyphosa in 17% and 9%, respectively; and by the Leptospira serogroup Sejroe in 33% and 6%, respectively. This inventory of infecting Leptospira serogroups revealed that current vaccines in France are not fully capable of preventing the clinical form of the disease.Leptospirosis is a zoonotic bacterial disease that infects humans and domestic and wild mammals worldwide. This disease is important globally because of its worldwide distribution and its potentially fatal effects in humans. In Western Europe, France is one of the most affected countries, with a reported incidence of 0.37/100,000 inhabitants in 2011 (230 cases).¹The pathogenic agents of leptospirosis are bacteria from the genus Leptospira, specifically Leptospira interrogans sensu lato. Approximately 250 pathogenic serovars are now recognized and gathered into 24 antigenically related serogroups.² Although Leptospira can be maintained in wet environments for weeks, the main source of the bacteria is a wide range of domestic and wild mammals carrying specific Leptospira serogroups. Rodents are the predominant maintenance hosts of the bacteria, whereas infected dogs and cattle are less prevalent as hosts but may pose an important public health risk. Indeed, infectious urine excreted by infected domestic mammals³ and its potential contact with human mucosa could lead to Leptospira transmission. In addition, leptospirosis induces significant economic losses caused by reproductive disorders in cattle herds. Vaccines against certain Leptospira serovars are available for humans, dogs, and cattle, but the range of Leptospira serogroups is much broader compared with the range that vaccination protects against. Additionally, there is no cross-immunity between Leptospira serogroups.The vaccines available before 2012 for domestic animals in France only targeted dogs and included the serovars icterohaemorrhagiae and canicola. The canine vaccine has been augmented with the serovar grippotyphosa (Versican)^®, and a bovine vaccine that includes the serovar hardjo is now available. Previous studies have questioned the reliability of these vaccines and have reported that certain uncommon serogroups are increasingly found to be the cause of clinical leptospirosis in the United States⁴ and Europe.⁵ Therefore, understanding the distribution of currently circulating serogroups is critical for prophylactic purposes and vaccine design. This study provides an overview of Leptospira serogroups in France that are currently circulating in dogs and cattle herds showing signs suggestive of leptospirosis.From January 2008 to December 2011, veterinarians from across the country obtained samples from cattle and dogs showing clinical signs consistent with leptospirosis. Leptospirosis diagnosis was performed at the Laboratoire des Leptospires (Marcy L''Etoile, France) using a microagglutination test (MAT) as the reference test. The MAT was performed using a panel of antigens representing both ubiquitous serovars and locally prevalent serovars, with log2 dilution series between 1:40 and 1:5120 in dogs and between 1:50 and 1:6400 in cattle. The following Leptospira serogroups, with related serovars in parentheses, were tested in both species: Icterohemorrhagiae (icterohemorrhagiae, copenhageni), Australis (munchen, australis, Bratislava), Autumnalis (autumnalis, bim), Bataviae (bataviae), Grippotyphosa (grippotyphosa, vanderhoedoni), and Sejroe (sejroe, saxkoebing, hardjo, wolffi). Four additional Leptospira serogroups, Canicola (canicola), Panama (manama, mangus), Pomona (pomona, mozdok), and Pyrogenes (pyrogenes), were only tested in dogs.For cattle, no consensus is reported on the titer cut-off required to define an infected individual. Previously, the MAT showed a sensitivity and a specificity of 95% and 90%, respectively, at a cut-off ≥ 1:50 compared with microbiological cultures.⁶ From this, occurrences of cattle leptospirosis at the herd level were determined by identifying signs suggestive of leptospirosis, such as reproductive disorders and the presence of at least one cow with MAT titers ≥ 1:400. The cut-off was arbitrarily defined to increase the previously mentioned specificity. The predominant serogroup was then defined based on the maximum titer directed against one serogroup.⁷ Cross-reactivity between serogroups frequently occurs in MAT⁸ and results from a lack of specificity, especially from predominant non-specific immunoglobulin M (IgM) antibodies at the onset of infection.⁹ In these cases, MAT results involve maximum titers directed against two or more serogroups, thus preventing determination of the infecting serogroup. The MAT results including maximum titers directed against two serogroups are still informative by indicating one or the other as potentially circulating. In contrast, consideration of more than two possible circulating serogroups is speculative and uninformative. Therefore, among MAT results including maximum titers directed against two or more serogroups only the ones with two serogroups (“mix” results) were considered in this study.Most dogs monitored by veterinarians are vaccinated, which results in the development of seroreactivity directed against the icterohaemorrhagiae, copenhageni, and canicola serovars (called vaccine serovars). As previously described, in the current study, occurrences of canine leptospirosis were defined by signs suggestive of leptospirosis, such as acute renal failure or liver failure and at least one MAT titer of ≥ 1:640 against non-vaccine serovars.¹⁰ The predominant serogroup was defined similar to that in cattle. However, the MAT results for which vaccine serogroup titers were equal to non-vaccine titers were analyzed separately, to minimize the impact of vaccination on the results.To assess potential variation in the serogroup spread, mainland France was divided into six areas: North, Northwest, Northeast, Central, Southwest, and Southeast. The determination of the location of the different animals tested for the serogroups was based on the owner''s address.The MAT results of 394 cattle herds (570 cattle) suspected of having leptospirosis were used to determine the distribution of serogroups circulating in France. These MAT titer results ranged from 1:400 to 1:6400, with a median of 1:800. The predominant serogroups were Australis, Sejroe, and Grippotyphosa, regardless of the titer cut-off (Figure 1), and a similar serogroup ranking was observed in the six defined regions (Figure 2). In total, 29 herds were found to contain cows with MAT results suggesting different predominant serogroups. The combinations of Australis and Sejroe (N = 16) and of Sejroe and Grippotyphosa (N = 7) within a herd were predominant.Open in a separate windowFigure 1.The distribution of Leptospira serogroups among 394 cattle herds and 232 dogs with suspected clinical leptospirosis (excluding microagglutination test (MAT) results indicating high icterohaemorrhagiae, copenhageni, and canicola titers in dogs). The bar plots show the distribution of the serogroups among 570 cows and 232 dogs, considering the maximum MAT titer. Australis (AUS), Autumnalis (AUT), Bataviae (BAT), Grippotyphosa (GRI), Icterohaemorrhagiae (IH), Panama (PAN), Pomona (POM), Pyrogenes (PYR), and Sejroe (SJ), results including maximum titers directed against two serogroups (MIX).Open in a separate windowFigure 2.The spatial distribution of the infecting serogroups in 394 cattle herds and 229 dogs in six areas in mainland France: North, Northwest, Northeast, Central, Southwest, and Southeast. Three dogs were not considered because of missing location data, and one dog from Corse was excluded.The MAT results of 232 dogs were included in the distribution. The MAT titer results ranged between 1:640 and 1:5120, with a median of 1:2580. According to the bar plots, the predominant serogroups were Australis and Grippotyphosa, regardless of the titer cut-off. In particular, Australis was predominant in all six regions, whereas Grippotyphosa was only recorded in the four regions of western France (North, Northwest, Central, and Southwest).In all, 66 dogs with equal maximum titers directed against vaccine serogroups and one non-vaccine serogroup were additionally considered. The distribution of the non-vaccine serogroups was Australis (75%), Pyrogenes (14%), Grippotyphosa (5%), Sejroe (5%), and Panama (< 2%).This study examined the distribution of infecting serogroups involved in clinical bovine and canine leptospirosis. The serogroups Australis and Grippotyphosa were consistently predominant in the two species, and the results in dogs were consistent with the findings of a previous study in Germany.⁵ Considering the sensitivity (Se) estimates related to the cut-off defined in dogs (Se = 22–67%),¹⁰ the occurrence of leptospirosis may have been underestimated in this species. Nevertheless, the specificity (Sp) estimates in cattle (Sp ≥ 90%) and dogs (Sp = 69–100%) and the high median titers associated with signs suggestive of leptospirosis supported a diagnosis of current or recent Leptospira infection. As previously reported, the MAT correctly predicted the infecting serogroup in 46–86% of cases^7,11; the presumptive serogroup data appears to provide a broad overview of the serogroups commonly present in a population. Specifically, the majority of results (> 60% in cattle and > 72% in dogs) suggesting Australis and Grippotyphosa infections and the consistency of the distribution, regardless of the cut-offs used for the two species, provided substantial evidence for Australis and Grippotyphosa predominance in bovine and canine leptospirosis. These results also suggested that dogs and cattle could be exposed to the same sources of infection and/or the same infection pressure.The spatial distribution of the predominant serogroups in cattle appeared homogeneous in all six regions, whereas in dogs, the distribution of Grippotyphosa was heterogeneous. This finding suggested that in contrast to cattle, the exposure of dogs to certain serogroups varied within mainland France.The results of this study indicated that Sejroe was responsible for 30% of cases of bovine clinical leptospirosis. This finding suggested that the available bovine vaccine targeting this serogroup is capable of preventing one-third of the clinical cases. Nevertheless, additional serogroups, such as Australis and, to a lesser extent, Grippotyphosa, should be included to eliminate most Leptospira-related diseases in cattle. For dogs, it would be important to include Australis antigens in a canine vaccine to aid in preventing infection with the serogroup responsible for most clinical cases of leptospirosis in dogs in France.This inventory of infecting Leptospira serogroups circulating in cattle and dogs should be considered when designing future vaccines to improve leptospirosis prevention. As part of a “one health” approach, this could lead to reduce human cases exposed to potentially infected domestic animals.     

Evaluation of counterimmunoelectrophoresis with antigens of icterohaemorrhagiae and patoc serovars in the serodiagnosis of human leptospirosis]

Counterimmunoelectrophoresis (CIE) was applied on paired sera from 135 patients with leptospirosis and on 69 sera from a control group. The sera from patients were subdivided in 4 groups according to the results obtained by the Microscopic Agglutination Test (MAT). The first samples sera from 58 patients were non reagent by MAT. Six monthly samples of sera were taken from 7 patients to follow-up and to determine the level of agglutinin and precipitin antibodies present using MAT and CIE. Serovars icterohaemorrhagiae and patoc were used as antigens. Three types of antigens were compared, 1) Triton-X-100 extracted; 2) heat extracted and 3) a pool of them. The CIE using icterohaemorrhagiae derived antigens types agreed with MAT in 92.64, 92.64 and 94.11% of the leptospirosis sera. The patoc antigens types reacted with the control group in 7.24, 86.95 and 84.05% of the samples, and consequently were eliminated from the present study. The icterohaemorrhagiae CIE reaction become positive earlier than MAT negative sera, and reverted to negative earlier in the follow-up samples from the patients. The CIE was sensitive and specific, gave rapid results and was easy to perform.     

Human leptospirosis in eastern Croatia, 1969-2003: epidemiological, clinical, and serological features

This survey presents epidemiological, serological and clinical features of 270 patients (85% males, 18% children) treated for leptospirosis from 1969 to 2003 at the Clinic for Infective Diseases, University Hospital Osijek, Osijek, eastern Croatia. 75% of the admissions were between July and October. The route of transmission was mostly by indirect contact with domestic animals, less frequently by direct contact with urine or tissue of infected animals. Clinical presentation included signs and symptoms with expected and common frequency, with the exception of jaundice (62%) and aseptic meningitis (60%), which occurred with higher incidence than previously reported. Acute renal failure ensued in 53% of patients, 7% of whom required haemodialysis. No deaths were observed. Therapy consisted of antimicrobials (penicillin and doxycycline) and symptomatic measures. Diagnosis was confirmed by microscopic agglutination test (MAT). There were in total 18 serological types of Leptospira detected, and types L. sejroe, L.pomona, L. australis and L. icterohaemorrhagiae prevailed. During the last 10 y some new types were observed. Leptospirosis was not rare in the region of eastern Croatia, and its course could be life-threatening if not recognized and adequately treated.     

Leptospirosis in northeastern Thailand: hypotension and complications

During an outbreak of leptospirosis in northeastern Thailand, 148 patients with serologically diagnosed leptospirosis were seen in Loei Hospital. The clinical features were consistent with those described for the classic manifestation of the disease. However, hypotension was a common finding: noted in 94 patients (64%) upon admission or early in the course of the disease. Of these hypotensive patients, 64 (68%) had impaired renal function: 30 patients (32%) had prerenal azotemia and 34 (36%) were in renal failure. Pulmonary complications, including pulmonary edema, hemorrhage, ARDS, and interstitial pneumonitis, occurred in 22% of patients and were often associated with renal failure. A clear association existed between hypotension and renal failure and pulmonary complications. The overall mortality rate was 3.4%. The causes of death were pulmonary complications, renal failure, and sepsis. The death rate among patients with complications was 11.6%. Blood exchange, in addition to conventional treatment, was beneficial in severe leptospirosis with complications and hyperbilirubinemia.     

聚合酶链反应检测致病性钩端螺旋体DNA的研究

以黄疸出血型ＲＧＡ菌株对所有致病性钩端螺旋体特异的ＤＮＡ克隆片段序列为基础合成聚合酶链反应引物Ｇ１Ｇ２。用该对引物扩增各群型致病性钩端螺旋体微量ＤＮＡ，均获阳性结果，对非致病性钩端螺旋体和其他细菌不扩增。纯化的钩端螺旋体ＤＮＡ５ｐｇ经聚合酶链反应后，琼脂糖凝胶电泳可以目测。用地高辛配基标记的特异性探针可检测到５ｆｇ即相当于１条钩端螺旋体ＤＮＡ量的扩增产物。将该对引物扩增早期钩体病患者血清标本，阳性率为８２％，显著高于ＭＡＴ和ｄｏｔ－ＥＬＩＳＡ阳性率。由此表明，ＰＣＲ技术是灵敏、特异、快速的钩端螺旋体病早期诊断方法，还可用于流行病学调查。