Seroprevalence of leptospiral antibodies among market workers and food handlers in the central state of Malaysia

Objective:The high prevalence of leptospirosis in humans is of great public health concern, particularly in tropical and subtropical regions. This study aimed to determine the seroprevalence of leptospiral antibodies and distribution of serovars, and to assess the usefulness of enzyme-linked immunosorbent assay (ELISA) as a screening method for leptospiral antibodies in a high-risk healthy community. Methods: Cross-sectional study of 231 market workers and food handlers in wet markets and food premises from two localities in central Malaysia. Respondents' background information was obtained using a questionnaire. Serum samples were tested for leptospiral antibodies using ELISA and microscopic agglutination test (MAT). Results: Seroprevalence of leptospirosis among healthy workers was 46.3%. Detection of seropositivity was higher by MAT (46%) than ELISA (15%). We observed high seropositivity among local workers (49%), food handlers (49.5%), females (60.8%) and those aged 34 years and older (46.3%). Local strain LEP175 was the predominant serovar, followed by WHO strain Patoc. Conclusion: Overall seroprevalence among healthy food handlers and market workers was high in this study. The workplace places susceptible individuals at risk of leptospirosis

Seroprevalencija leptospiroze u različitih kategorija pasa u Bosni i Hercegovini

The increasing number of stray dogs and the lack of sufficient data on the prevalence of leptospirosis among dogs were the main reasons for conducting this research in different populations of dogs on the territory of Bosnia and Herzegovina. A total of 300 serum samples were tested from three different categories of dogs of various breeds from 12 cities. Twelve leptospiral serovars were used in the microscopic agglutination test (MAT). The presence of specific antibodies was confirmed for eight serovars. The proportion of seropositive dogs was 22.3% (67/300). The highest seropositivity (n = 38; 42.7%) was found for the serovar Pomona. The seropositivity rates found for the other serovars tested were as follow: Canicola (14.6%), Icterohaemorrhagiae (13.5%), Sejroe (12.4%), Autumnalis (12.4%), Grippotyphosa (2.2%), Bratislava (1.1%), and Australis (1.1%). The highest number of positive responses was obtained at the serum dilution of 1:100 (39.3%, n = 35). The highest number of positive reactions was identified in the category of ‘house dogs’ (29.3%, 29/99) followed by ‘stray dogs’ (21.6%, 24/111), while the lowest number of positive tests was recorded in the category of ‘guard/hunting dogs’ (15.6%, 14/90). Vaccination with tetravalent vaccines, including the serovars Icterohaemorrhagiae, Canicola, Pomona and Grippotyphosa could be an effective measure for the prevention of canine leptospirosis.Porast broja pasa lutalica i nepostojanje podataka o prevalenciji leptospiroze u različitih kategorija pasa na području Bosne i Hercegovine bili su glavni razlozi za provedbu ovog istraživanja. Analizirano je ukupno 300 uzoraka seruma iz tri kategorije pasa različitih pasmina iz 12 gradova. U mikroskopskom aglutinacijskom testu (MAT) upotrijebljeno je 12 serovarova leptospira, a za njih osam je potvrđena prisutnost specifičnih protutijela. Udio seropozitivnih pasa bio je 22,3 % (67 od 300). Najveća seropozitivnost (n = 38; 42,7 %) utvrđena je za serovar Pomona. Seropozitivnost za ostale serovarove bila je: Canicola (14,6 %), Icterohaemorrhagiae (13,5 %), Sejroe (12,4 %), Autumnalis (12,4 %), Grippotyphosa (2,2 %), Bratislava (1,1 %) i Australis (1,1 %). Najveći broj pozitivnih nalaza bio je kod razrjeđenja seruma 1 : 100 (39,3 %, n = 35). Najveći broj pozitivnih reakcija dokazan je u kućnih pasa (29,3 %, 29 od 99), a zatim u pasa lutalica (21,6 %, 24 od 111), dok je najmanji broj pozitivnih reakcija zabilježen u lovačkih i pasa čuvara (15,6 %, 14 od 90). Cijepljenje tetravalentnim cjepivima koja uključuju serovarove Icterohaemorrhagiae, Canicola, Pomona i Grippotyphosa mogla bi biti učinkovita mjera prevencije leptospiroze u pasa

Evaluation and comparison of native and recombinant LipL21 protein-based ELISAs for diagnosis of bovine leptospirosis

A 21-kDa leptospiral lipoprotein (LipL21) was evaluated for its diagnostic potential to detect bovine leptospirosis by ELISA. Both native LipL21 (nLipL21) and recombinant LipL21 (rLipL21) proteins were tested and compared regarding diagnostic efficiency, and no statistically significant difference was observed. The sensitivity of rLipL21 ELISA for 62 microscopic agglutination test (MAT) positive sera was 100% and the specificity with 378 MAT negative sera was 97.09%. Thus, rLipL21 protein-based ELISA could be used as an alternative to MAT for the diagnosis of bovine leptospirosis

Evaluation of the enzyme-linked immunosorbent: assay (elisa) test for the detection of leptospiral antibodies in bovine sera, 1979

The Micro-Enzyme-Linked Immunosorbent Assay (ELISA) test was evaluated as a presumptive test for the diagnosis of bovine lepto�spirosis. Disposable flat bottom Micro-ELISA plates were utilized as antigen carriers and test vehicles. The antigen was prepared from a soluble alcohol extract of serovars, hardjo, Hardjoprajitno and ill ini, 3055 and stored at -70 C until ready for use in the test. Serology on each bovine serum sample was performed by using the Microscopic Agglutination Test (MA), the Indirect Hemagglutination Test (IHA), and the Enzyme-Linked Immunosorbent Assay (ELISA) Test. The comparison of the ELISA test with the MA and IHA was done with coded sera, randomized as to order of testing and stored at -20 C. A total of 142 different bovine serum samples was tested for the presence of 1eptospiral antibodies, using antigens serovar hardjo (a pathogen) and serovar ill ini (a saprophyte). Reproducibility was checked by duplicating 83 serum samples and triplicating 58 serum samples, resulting in a final total of 482 bovine serum samples being tested. All sera were tested by MA, IHA, and ELISA tests before being decoded for comparison of results. The total agreement of hardjo sera for both positive and negative sera was 48% among all 3 test procedures, whereas the total agreement of ill ini sera for both positive and negative sera was 92% among all 3 test procedures. The test was safer to perform since there was no need to use live antigens in the test; the test did not require pretreatment of sera; the test was read visually, and the test was a simple and rapid procedure. The sensitivity and specificity appear to have been low; however, in order to obtain further definitive results regarding the specificity, sensitivity, and the role of the ELISA test in the detection of 1eptospiral antibodies in bovine sera, other investigations will be needed in the future

Proteinuria in early detection of human leptospirosis

Background: Leptospirosis is an infectious disease caused by spirochetes bacteria Leptospira spp. and is reported from all over the world. As the clinical signs and symptoms of Leptospirosis often are nonspecific and the disease is early mistaken for other major infectious febrile illness, laboratory test to confirm the clinical diagnosis thus is essential for optimal treatment and patient management.Methods: Serum and urine samples were collected from patients clinically suspected cases of Leptospirosis. Preparations of urine concentrate by precipitation and centrifugation.Results: It was interesting to note that immunoglobulins are present in the urine protein concentrate of patients with Leptospirosis on the day of admission in the hospital, with urine albumin reports either positive or negative. By ELISA test it was noted that antibodies present in urine and serum were of both IgM and IgG class against the Leptospiral antigens from three pathogenic serovars and one non-pathogenicserovars. In the immunospot test which was done and compared with standard ELISA test for serum antibodies using same antigen showed that antibodies present in urine protein concentrate, which was collected on the day of admission when patients come with suspecting symptoms of Leptospirosis.Conclusions: Proteinuria is the most frequent abnormality noted in all patients at some stage of illness. This is the first report on the presence of immunoglobulins in urine samples, which were found to be of IgM and IgG classes. These findings are of significant diagnostic potential as a simple immune-spot test can be done for detecting anti-leptospiral antibodies in urine samples of suspected cases. The present attempt was aimed at developing an immunospot test, a simple and rapid diagnostic test to detect Leptospirosis using urine samples of clinically suspected patients of the infection at the earliest. It was found to be in good correlation with standard ELISA method which is being used to detect serum antibodies in Leptospira infected patients using the same antigen

Asymptomatic Renal Colonization of Humans in the Peruvian Amazon by Leptospira

Leptospirosis is a bacterial disease commonly transmitted from animals to humans. The more than 200 types of spiral-shaped bacteria (spirochetes) in the genus Leptospira are classified as pathogenic, intermediately pathogenic, or saprophytic (meaning not causing infection in any mammal) based on their ability to cause disease and on genetic information. Unique among the spirochetes that infect humans, Leptospira live both in the environment (in surface waters and moist soils), and in mammals, where they cause chronic infection by colonizing kidney tubules. Infected animals are the source of human infection, but humans have not been systematically studied as chronic Leptospira carriers. In our study, we found that more than 5% of people (in fact, only women) in a rural Amazonian village, without clinical evidence of infection by Leptospira, were chronically colonized by the bacteria. Chronic infection was not associated with a detectable immune response against the spirochete. Pathogenic and intermediately pathogenic Leptospira caused asymptomatic, chronic kidney infections. Future work is needed to determine whether such chronic infection can lead to human-to-human transmission of leptospirosis, and whether subtle measures of kidney disease are associated with asymptomatic, long-term leptospiral infection

Seroprevalencija leptospiroze među zatočenim azijskim slonovima u Kerali, Indija - kratko priopćenje

Leptospirosis is an infectious disease of zoonotic significance, caused by distinct members of the genus Leptospira, with a broad spectrum of hosts, including domestic and wild animals. The present paper reports the seroprevalence of leptospirosis among captive Asian elephants in Kerala. Whole blood samples were collected from fifty, apparently healthy captive elephants from different districts of Kerala state. The serum was separated from the whole blood and subjected to the Microscopic Agglutination Test (MAT) for detection of antibodies to different serovars of Leptospira. The test was carried out using actively grown cultures of twelve common leptospiral serovars. Out of the total of fifty serum samples screened by MAT, 19 samples (38 per cent) showed a positive reaction with antibody titres in a 1:200 dilution. The prevalent serovars were Pomona, Icterohaemorrhagiae, Hebdomadis, Grippotyphosa and Canicola, and the highest prevalence was noticed for the serovar Pomona. The positive results indicated the presence of infection or the previous exposure of captive elephants to leptospiral antigens. The high rate of prevalence of leptospiral antibodies in captive elephants warrants the monitoring of these animals for clinical disease and adopting the necessary control strategies for preventing this re-emerging zoonotic disease.Leptospiroza je zarazna bolest od zoonotske važnosti uzrokovana različitim pripadnicima roda Leptospira, koja ima velik raspon domaćina, uključujući domaće i divlje životinje. U ovom je radu prikazana seroprevalencija leptospiroze među zatočenim azisjkim slonovima u Kerali u Indiji. Uzorci pune krvi prikupljeni su od naizgled zdravih pedeset zatočenih slonova iz različitih okruga Kerale. Serum je odvojen od pune krvi i podvrgnut mikroskopskom testu aglutinacije (MAT) radi otkrivanja protutijela na različite serovarove leptospira. Test je proveden uz upotrebu aktivno uzgojenih 12 učestalijih serovarova leptospira. Od ukupno pedeset uzoraka seruma analiziranih MAT-om 19 uzoraka (38 %) pokazalo je pozitivnu reakciju s titrom protutijela pri razrjeđenju 1:200. Najučestaliji su serovarovi bili Pomona, Icerohaemorrhagiae, Hebdomadis, Grippotyphosa i Canicola, s najvećom uočenom prevalencijom za serovar Pomona. Pozitivni rezultati upućuju na prisutnost infekcije ili prethodnu izloženost zatočenih slonova antigenima leptospira. Veća stopa prevalencije na protutijela leptospira u zatočenih slonova upozorava na potrebu za praćenjem ovih životinja s obzirom na kliničku bolest te usvajanje potrebnih strategija kontrole radi prevencije ove reemergentne zoonoze

Protein Profile And Antigenicity Of Representative Leptospiral Serovars Reported In Malaysia And Experimental Leptospira Interrogans Infection In Dogs

Wide distribution of leptospires in the world has caused tremendous economic losses in agricultural sector due to decrease in animal production, quality of animal products and increased cost of treatments and also one of the public health concerns as this zoonosis has caused fatalities in human beings. In the study, immunoprobing experiments with rabbit antisera against serovars canicola, icterohaemorrhagiae, hardjobovis, pomona and australis, band with molecular weight 137.6 kDa is unique in serovar canicola 35 kDa in icterohaemorrhagiae, 10.5 kDa and 71.4 kDa in hardjobovis, 48.1 kDa in pomona while 20.9 kDa and 25.0kDa in australis. These distinct bands could have explained the selectiveness of different serovars on the target hosts, organs or perhaps tissues. In the experiment, Leptospira interrogans serovar canicola caused interstitial nephritis while serovar icterohaemorrhagiae caused liver damage in local stray dogs. Two dimensional SDS-Polyacrylamide Gel Electrophoresis (SDS-PAGE) on both serovars canicola and icterohaemorrhagiae have revealed differences in the protein distributions. Three different protein spots sharing the same molecular weights at 42.1kDa, 126kDa and 136 kDa while at 60.9kDa, 65.2kDa and 89.6kDa, two proteins spots sharing the same molecular weight were detected in serovar canicola. Serovar icterohaemorrhagiae on the other hand has three protein spots at 31kDa, 36kDa and 45kDa while 5 protein spots at 32 kDa were detected. Antibody titres peaked between 6 to 11 post inoculation day (P.I.D) with the highest titre at 1:1,600 in dogs infected with Leptospira canicola through intravenous route (Group 1). While dogs infected with serovar icterohaemorrhagiae through intravenous route had peak antibody titre between 9 to 11 (Group 2) P.I.D, with the highest titre at 1:1,600. Dogs infected with serovar icterohaemorrhagiae through oculonasal route (Group 3), the peak titre of antibody production was much delayed, at between 19 to 23 P.I.D but with much higher than the two previous tests (Group 1 and Group 2) at the highest titre reached was 1:3,200. The study also shows that dogs once infected with leptospiral serovar, especially through oculonasal route, would shed the organism in its urine for a long period of time up till the end of study (nine months). This reflects the oculonasal route to be the actual route which dogs are most likely to be infected by leptospires in natural environment