anti-Leptospira Antibodies Research Articles

Anti-Leptospira Antibodies in Buffaloes on Marajó Island

Leptospirosis is a zoonotic disease that has a cosmopolitan geographical distribution, reported in domestic and wild animals, which act as reservoirs and contribute to the spread of microorganisms in the environment. In Brazil, studies on the occurrence of leptospirosis in buffaloes in the Amazon Biome are scarce. The objective of this study was to determine the occurrences of antibodies against Leptospira spp., including serovar Hardjo (Bolivia), isolated from cattle in Brazil and not yet tested in buffaloes. A total of 387 blood serum samples of animals from nine municipalities on Marajó Island, State of Pará, northern Brazil, were obtained from a biological sample bank and analyzed using the microscopic agglutination test (MAT). Serology revealed 91.5% (387/354) of the animals tested positive for anti-Leptospira antibodies. The presence of various detected serovars may have been related to the local practice of combined rearing of different livestock species, as well as to the contact with wild animals and rodents from adjacent forest areas, all factors that likely facilitated the epidemiological chain of the disease in buffaloes. Among the serovars tested, the serovar Hardjo (Bolivia) was the most prevalent, which was present in 79.3% of the reactive buffaloes. It was important to carry out serological and bacteriological surveys in order to identify the serovars that occurred in the herds, with the objective of designing efficient strategies to control leptospirosis in the production of buffaloes.

Comparison of anti-Leptospira antibodies by microscopic agglutination test in ruminants and equines of Urmia, Iran.

Leptospirosis, a zoonotic disease, is characterized by fever, jaundice, abortion and hemo-globinuria. It is widespread and the determination of the dominant serotype in the animal species of each region accelerates the control and prevention program. 862 blood samples were prepared from ruminants and equines. Serum antibody of leptospira serovars were determined based on gender and age parameters. Sera were examined by microscopic agglutination test (MAT) with six live serotypes. The overall prevalence was 22.30%, with the highest (37.00%) and the lowest (6.60%) in Holsteins and mules, respectively. The overall male and female incidence were 12.20% and 9.86%, respectively, which was not different. The highest gender infection was in male Holsteins (19.20%) and the lowest were in male Simmentals and mules (1.72%). The highest dilution was 1:100 for pomona and the lowest was for canicola. All animals responded positively to grippotyphosa. The highest infection to one serovar was in Holsteins and the lowest for four serovars were in goats and Simmentals. Males less than 1.5 years old showed the highest infection. Age differences in leptospira infection except for sheep was significant. In conclusion, leptospira infection in ruminants was high compared to equines. Gender differences were not significant. The highest dilution was 1:100, with pomona in ruminants and grippotyphosa in all species. Leptospiral infection was increased with age and the differences among animals except for sheep were significant. Finally, regarding 22.30% infection rate, vaccination is necessary to Holsteins, and preventive measures for others. Health advices would be necessary for human safety.

Soroepidemiologia de leptospirose em equinos da região de Santarém, Pará

Abstract Leptospirosis is an endemic zoonotic disease that is distributed worldwide, which has the potential to have health and economic impacts. Leptospira spp. is spiral-shaped and capable of infecting mammals, including horses, which may result in asymptomatic or clinical forms. Therefore, the current study aimed to analyze the frequency of anti-Leptospira antibodies in serum samples from horses from Santarém, Pará, Brazil. For that purpose, 88 blood samples from horses without a history of leptospirosis vaccination were serologically evaluated through the microscopic agglutination technique (MAT) with a 13 serovars, belonging to ten different serogroups. There were 58 samples that were seropositive (65.90%), which included 28 samples seropositive for Pyrogenes (48.3%), 24 for Autumnalis (41.4%), 18 for Icterohaemorrhagiae (31.0%), and 16 for Grippotyphosa (27.6%). Even without clinical suspicion of leptospirosis or a history of vaccination, the horses showed different frequency of seropositivity. Considering the well-known impact of leptospirosis in human and animal health, our results are important to establish preventive measures to reduce the economic loss in equine production as well as a reduction in public health risk.

Evidencia serológica y molecular de especies patógenas de Leptospira en rastros de bovinos del estado de Veracruz, México

Cattle raising is the most important livestock activity in Mexico, highlighting the fact that the Country is eight place worldwide in the production of bovine meat. However, cattle can be affected by leptospirosis (a bacterial disease caused by 17 species of spirochetes of the genus Leptospira), which cause reproductive problems that translate into great economic losses. Additionally, these zoonotic agents can cause a rapidly evolving febrile condition in humans, which can be solved after the first week of symptoms or could progress to develop a severe late-phase manifestations. Despite the great impact of these agents on the economy and Public Health, epidemiological surveillance against the infectious disease that cause is not present in municipal slaughterhouses (MS). Therefore, the aim of this study was to identify, using serological and molecular methods, the circulating Leptospira species in three MS in Veracruz State. The frequency of anti-Leptospira antibodies was 67.5%. Additionally, five sequences were recovered that were 99% similar to L. interrogans. This work represents the first national effort for the evaluation of MS as sentinel units, that allow establishing the diversity of species of the genus Leptospira that circulate in cattle and establishing intervention measures for workers risk mitigation, who come into contact with the fluids and organs of infected animals.

Epidemiological Study of Pathogenic Leptospira in Raccoons (Procyon lotor) in a Suburb of Tokyo, Japan.

Leptospirosis is a zoonosis that affects humans and animals worldwide. Raccoons (Procyon lotor), adopted in urban environments, may act as potential reservoirs of Leptospira. We investigated the prevalence of pathogenic Leptospira in the kidney and urine samples of raccoons living in Tokyo, as well as anti-leptospiral antibodies in their serum, and aimed to examine the factors that expose raccoons to Leptospira. Polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA) were used to detect leptospiral DNA and anti-leptospiral antibodies, respectively. Thirty-six of 156 raccoons (23.1%) were positive by PCR, and 16 of 165 raccoons (9.7%) were positive by ELISA. The prevalence and seroprevalence rates differed depending on the raccoon dispersal period. We used univariable logistic regression to estimate the environmental factors associated with pathogenic Leptospira and anti-leptospiral antibodies in raccoons. Significant differences were observed in the PCR results for the seasons (spring−summer) (p = 0.01), average monthly temperature (p < 0.01), and average monthly rainfall (p < 0.01). No significant difference was seen in the ELISA results, but raccoons in larger urban areas tended to have higher seroprevalence rates (p = 0.06). We identified a pattern of leptospiral spread in raccoon dispersal and environmental factors that expose raccoons to Leptospira.

Leptospira spp. Prevalence in Cats from Southern Italy with Evaluation of Risk Factors for Exposure and Clinical Findings in Infected Cats.

Leptospirosis is a worldwide zoonotic disease, but feline leptospirosis is rarely reported. This study aimed at investigating Leptospira spp. prevalence in cats from southern Italy, evaluating risk factors, clinical findings and laboratory data associated with infection. The serum of 112 cats was investigated by microscopic agglutination test (MAT), detecting anti-Leptospira antibodies against 14 pathogenic serovars. Blood and urine samples were tested by a real-time polymerase chain reaction targeting the lipL32 gene of pathogenic Leptospira. Antibodies against serovars Poi, Bratislava, Arborea, Ballum, Pomona and Lora were detected in 15.3% (17/111) of cats (titers range: 20–320). Leptospira spp. DNA was found in 3% (4/109) of blood and 9% (10/111) of urine samples. The spring season was the only risk factor for urinary Leptospira DNA shedding. Laboratory abnormalities significantly associated and/or correlated with Leptospira spp. positivity were anemia, monocytosis, neutrophilia, eosinopenia, increased alanine aminotransferase activity, hypoalbuminemia and hyperglobulinemia. In the investigated areas, cats are frequently infected by Leptospira spp. and can represent an additional reservoir or sentinel for a risk of infection. Moreover, some laboratory changes could be compatible with a pathogenic effect of Leptospira spp. in the feline host.

Seroprevalence of Leptospirosis in Suspected High-Risk Sudanese Patients; A Pilot Exploratory Study

The extent of leptospirosis is unknown in Sudan, and it might be mistaken for other more common febrile infectious diseases. Leptospirosis might also be associated with renal diseases that are common in Sudan. We intended to explore the existence of human leptospirosis in suspected high-risk patients in Khartoum, Sudan, via sero-screening random febrile patients and those undergoing renal dialysis. This pilot exploratory study was conducted over six months, from April to September 2013. Four hospitals were selected conveniently following a non-random sampling approach. One hundred nineteen febrile patients (with or without definitive diagnosis) and patients under renal dialysis were included, and their serum specimens and clinical and demographic data were collected. Sera were screened qualitatively for the existence of anti-leptospiral IgM antibodies using a rapid lateral flow immune-sorbent assay. Ethical clearance and official permissions were obtained. Of the 119 patients, 57 (47.9%) had end-stage renal disease. They were under dialysis at Renal Dialysis Unit in Asbab Charity Hospital in Bahri, 47 (39.5%) were febrile with unknown origin attending the Tropical Medicine Hospital in Omdurman, and 15 (12.6%) were febrile and were diagnosed as having malaria or typhoid and attended Yastabshiron Medical Centre and Bashauer Teaching Hospital. The prevalence of anti-leptospiral IgM antibodies among all 119 screened patients was 7%. The prevalence among the 57 with the end-stage renal disease was 9%, and among the 47 with a fever of unknown origin was 6%. The prevalence among the 15 with a fever of known origin (diagnosed as malaria or typhoid) was 0%. Almost all positive patients had recurring episodes of fever, were in close contact with livestock, were farmers, and had an untreated natural source for drinking water. Human leptospirosis does exist in this targeted population. It is probably a common febrile condition and can be easily considered one of the major causes of chronic kidney disease affecting people in Sudan. A national sero-screening for leptospirosis among those living in high-risk geographical areas and those at occupational risk is highly recommended.

Analysis of 1840 Equine Intraocular Fluid Samples for the Presence of Anti-Leptospira Antibodies and Leptospiral DNA and the Correlation to Ophthalmologic Findings in Terms of Equine Recurrent Uveitis (ERU)-A Retrospective Study.

Simple SummaryIn horses, the chronic intraocular leptospiral infection has been shown to cause equine recurrent uveitis (ERU). This inflammatory ophthalmic disease recurs for years and usually leads to blindness. Only recently it was found that biofilm formation of the leptospires in the vitreous cavity leads to uveitis recurrences and prevents effective elimination of the infection by antibiotics or by the immune system. The most effective treatment is vitrectomy (lavage of the vitreous cavity), which mechanically removes the biofilm infection. This surgery has been performed in horses for more than 30 years, and thousands of intraocular specimens have been analyzed for antibodies directed against leptospires and by PCR for leptospiral DNA. For the present study, medical records were retrospectively analyzed. Complete medical and laboratory records were available for 1800 intraocular specimens from horses treated from 2002 to 2017 (1387 specimens from ERU-eyes, 237 specimens from eyes affected with another type of uveitis, and 216 specimens from healthy eyes). In 83% of intraocular samples from ERU eyes, antibodies were detectable, and especially the detection of immunoglobulin A (IgA) seems to play an important role. In 72% of the intraocular specimens, leptospiral DNA was detectable by PCR. No antibodies were detectable in the samples from eyes with another type of uveitis or in the samples from healthy eyes. A PCR was positive in only one sample from a healthy eye. These results with a very high number of intraocular specimens demonstrate the great importance of an intraocular leptospiral infection for ERU. It can be concluded that for a reliable diagnosis of intraocular leptospiral infection or to reliably exclude an infection, multiple tests should be applied.In the equine clinic of the LMU in Munich, therapeutic vitrectomies have been routinely performed in horses for three decades. The vitreous samples obtained during vitrectomies were usually tested for anti-Leptospira antibodies and for more than 20 years also by PCR for leptospiral DNA. If the indication for surgery was ophthalmologically inconclusive, an aqueous humor was collected preoperatively and examined for evidence of leptospiral infection. In this study, medical records from 2002 to 2017 were analyzed. Records for 1387 eyes affected by equine recurrent uveitis (ERU) and 237 eyes affected by another type of uveitis met the inclusion criteria. A total of 216 samples from healthy eyes were used as controls. In 83% of intraocular samples from ERU eyes, antibody titers of 1:100 or higher were detectable by microscopic agglutination test (MAT). Similarly, 83% of intraocular samples had anti-Leptospira antibodies detected by ELISA. In 72% of the intraocular specimens, leptospiral DNA was detectable by PCR. No antibodies were detectable in the samples from eyes with another type of uveitis or in the samples from healthy eyes. A PCR was positive in only one sample from a healthy eye. These results with a very high number of intraocular specimens demonstrate the great importance of an intraocular leptospiral infection for ERU. It can be concluded that for a reliable diagnosis of intraocular leptospiral infection or to reliably exclude an infection multiple tests should be applied.

Leptospirosis among Dengue-Negative Febrile Patients in Selangor, Malaysia.

In recent years, the number of leptospirosis cases, including the number of deaths, has exponentially increased in Malaysia. From June 2016 to February 2018, blood samples of 321 febrile patients with the presumptive diagnosis of dengue-like illness were examined for possible exposure to Leptospira. Two hundred fifty-five blood samples were tested as negative for dengue. Seminested polymerase chain reaction (PCR) and IgM ELISA for leptospirosis were performed. From the samples, an overall prevalence for leptospirosis based on PCR of 4.7% (12/255) was obtained. Eighteen percent (46/255) were positive for anti-Leptospira IgM antibodies. The genome sequences of six of 12 Leptospira PCR-positive samples showed > 97.0% similarity to Leptospira interrogans. One patient's sample consisted of Leptospira and chikungunya virus, suggesting a coinfection. Findings from the study suggest that leptospirosis is prevalent among dengue-negative febrile patients in Malaysia.

Seroprevalence of pathogenic Leptospira spp. in domestic dogs from southern Chile and risk factors associated with different environments

Leptospirosis is a neglected and severe zoonotic bacterial disease that affects canine populations worldwide, and it is present in animals from different settings, such as urban and rural environments. Therefore, a cross-sectional study was conducted on owned domestic dogs from urban and rural origins in southern Chile. The study aimed: 1) to estimate the true prevalence of pathogenic Leptospira in dogs from urban and rural environments in southern Chile, 2) to determine the serovars circulating in an endemic area of Chile, 3) to assess potential risk factors associated with seropositivity in dogs from urban and rural environments. Blood samples from 706 canines were collected, and the serum was tested with Micro-Agglutination-Test (MAT), using a panel of 13 serovars. A Bayesian approach was applied to estimate True prevalence (TP). In addition, dog owners answered a questionnaire that had prompts regarding dog characteristics and potential risk factors. The effect of these factors on the risk of being infected was analysed using a logistic regression model. The TP for urban dogs was 9.4% and 9.1% for rural animals. However, seroprevalence was higher in dogs with different individual, lifestyle, and habitat characteristics regarding their origin. For example, in urban animals, those living in places with rodents roaming near houses and dogs with rodent hunting habits had decreased risk for the seropositivity in MAT. On the other hand, in rural dogs, those of a recognized breed, with contact with cattle and sheep, living with more than one cat at home and living in places close to natural water sources have more risk to seropositivity in MAT. The presence of anti-Leptospira antibodies is widespread in pet dogs in urban and rural environments in southern Chile, and individual, lifestyle and habitat characteristics of the animals, according to the origin, are associated with the seropositivity in MAT. Therefore, the adoption of preventive measures is urgent, in addition to increase the awareness either in public health institutions, practitioners and companion animals’ owners, considering the zoonotic potential of Leptospira infection and the close contact between people and their pets.

Prevalência e fatores associados ao risco da presença de aglutininas anti-Leptospira spp em bovinos de agricultores familiares da bacia leiteira do município de Ji-Paraná - RO, Brasil

ABSTRACT Leptospirosis affects several animal species, including man. This study aimed to evaluate the prevalence of Leptospira spp. and to identify factors associated with the risk of Leptospira spp. in dairy cattle in the municipality of Ji-Paraná, RO, Brazil, sampled by rural sector, from September 2012 to November 2013. Blood samples from 627 dairy cows were randomly collected from 63 farms belonging to six rural sectors. Leptospirosis was diagnosed by the microscopic serum agglutination technique. Of the 627 animals tested, 255 had anti-Leptospira antibodies (40.48%, 95% CI: 36.64-44.31) and 57 of the 63 studied dairy farms (90.5%, 95% CI: 83.23-97.72) had at least one reactive animal. The results indicate that serovar Hardjo had the highest (12.38%. 95% CI: 10.03-15.18) followed by serovars Shermani, Wolffi, Hebdomadis and Canicola occurrence in dairy cows. Additionally, infection was also associated with abortion occurrences in cows of 36 farms (57.14%) and the presence of dogs roaming free with access to pasture, water and cattle in 47 farms (74.60%). Therefore, free-roaming animals are considered a predisposing factor, highlighting the need for adopting prophylactic measures while raising the awareness from rural producers about the importance and the economic losses that leptospirosis may cause.

Leptospiral infection: a serosurvey in urban and rural communities in Olavarría county, Argentina.

Leptospirosis is a neglected zoonotic disease, affecting mainly poor and vulnerable populations. A cross sectional-study was carried out in 557 subjects from Olavarría county (Argentina) to estimate the seroprevalence of leptospirosis and the factors associated with seropositivity. A survey was carried out to obtain clinical and epidemiological data. Serum was tested for anti-leptospiral antibodies by Microscopic Agglutination Test (MAT). Chi-square or Fisher Exact tests were used to assess association between the MAT results and the exploratory variables. For the variables statistically associated, odds ratios (ORs) and 95% confidence intervals (95% CI) were calculated. Individuals from Olavarría city were georeferenced to describe the spatial distribution and to detect clusters of seropositivity for leptospiral antibodies. The overall prevalence of leptospirosis infection was 7.00%, higher in rural (19.66%) than in urban populations (3.64%) (p < 0.001). Sejroe was the most predominant serogroup in rural communities while Icterohaemorrhagiae was the most prevalent in urban populations. The factors associated with Leptospira infection were the presence of rodents inside households (OR = 3.9) in rural populations, while contact with cats (OR = 4.97) and male gender (OR = 7.75) represented higher risk of infection for the urban ones. Cases with positive serology have been found near Tapalqué stream or in the peripheral areas of Olavarría city. The results from data obtained during the study period were similar to other reports and demonstrate the importance of continuous epidemiological surveillance system and specific community educational campaigns to prevent the leptospirosis infection in Olavarría county and other communities with similar characteristics especially in rural areas.

Seroprevalence of anti-Leptospira antibodies in equines and associated workers-Isolation of Leptospira interrogans serogroup Canicola from equine urine.

To investigate seroprevalence of anti-Leptospira antibodies in equines and associated workers in Uruguay, 891 equine and 150 human sera were drawn; 212 equine urine samples were also taken for culture. Environmental conditions and equine raising or managing practices were recorded in all 72 visited establishments; epidemiological information was obtained from each worker. Microscopic agglutination technique (MAT) was performed with 10 Leptospira strains for equines and 18 for human sera, that were also studied with IgM indirect immunofluorescence (IgM-IIF). Equine titres ≥100 were considered positive, and human sera titres ≥200 suggested probable recent or past infection. Urines were cultured in Ellinghausen-McCullough-Johnson-Harris (EMJH) media; local identification of one obtained isolate with lipL32 PCR, Multiple Locus Variable number tandem repeat Analysis and partial rrs gene sequencing, were completed at Institut Pasteur, Paris. Estimated reactivity was 61.3% for equines, which was higher than the studied bovine national levels (21%) and mainly observed with Icterohaemorrhagiae serogroup (40.3%), Sejroe, Canicola, Pomona or Ballum. Aged animals from slaughterhouses and cattle farms were the most frequently positive. Multiple regression analysis confirmed a significant association between seropositivity and equine age. Only one positive culture could be fully studied, and confirmed to be Leptospira interrogans serogroup Canicola; it was added to the MAT antigen panel and revealed fairly frequent reaction with equine and human sera. Three workers (2%) showed titres=200 with Icterohaemorrhagiae or Canicola serogroups, without recent clinical manifestations. Their attended equines reacted with the same serogroups, suggesting common source infections or infection transmitted by equines. Three other humans yielded titres=100, and none of the 150 showed an IgM-IIF-positive result. Equines seem not to be an important origin of regional human leptospirosis, except perhaps during acute animal infection. More culture work is required to study intensity and lapses of leptospiruria, as well as to further identify circulating strains.

Detection of Leptospira interrogans in Wild Sambar Deer (Rusa unicolor), Brazil.

Leptospirosis is an emerging zoonotic disease caused by bacteria of the genus Leptospira. Wild animals may present acute disease or become chronic hosts. The present study aimed to identify Leptospira spp. infection and determine circulating serogroups in free-ranging sambar deer (Rusa unicolor) in a fragment of peri-urban tropical forest in northeastern Brazil. Blood samples were collected and subjected to microscopic agglutination testing (MAT) and PCR analysis (genes lipL32 and secY). Anti-Leptospira antibodies were detected in 60% of the animals tested, with serogroups Cynopteri (33.4%), Hebdomadis (22.2%) and Grippotyphosa (22.2%) identified as most prevalent. DNA corresponding to the pathogenic species Leptospira interrogans was detected in 2/15 (13.3%) of the samples tested. Sambar deer experience a high level of exposure to Leptospira spp. in our epidemiological setting. It is important to emphasize the implementation of effective measures (i.e., maintaining habitats and reducing human contact) for the conservation of endangered species.

The effect of natural infection with different Leptospira interrogans serovars on oxidative stress biomarkers and acute-phase responses in horses and cattle.

Leptospirosis is one of the important zoonotic bacterial diseases with a worldwide distribution that is often subclinical. We aimed to investigate the oxidant/antioxidant balance and acute-phase response in naturally infected horses and cattle with Leptospira interrogans. A total of 600 serum samples from horses and cattle were examined for L. interrogans antibodies using the microscopic agglutination test to determine anti-Leptospira IgG antibodies against a panel of eight important Leptospira antigens in Iran. Then, serum total antioxidant capacity, catalase, glutathione peroxidase, and malondialdehyde activities, and nitric oxide, total protein, serum amyloid A, haptoglobin, and albumin concentrations were measured in seropositive and seronegative samples. Serum catalase activities and malondialdehyde, serum amyloid A, and haptoglobin ‌concentrations in seropositive cattle and horses were significantly higher (P<.05) than in those that were seronegative. Antibody titers increased from 1:100 to 1:200 in cattle with L. interrogans infection, resulting in a decrease in the serum total antioxidant capacity (P<.05), an increase in serum glutathione peroxidase (P<.01) activity and nitric oxide (P<.05) , serum amyloid A (P<.01), and haptoglobin (P<.05) concentrations. Following the increase in the agglutinating antibody titers in horses infected with L. interrogans, the serum total antioxidant capacity (P<.01) decreased, and serum nitric oxide (P<.05), malondialdehyde (P<.05), and serum amyloid A (P<.01) concentrations were increased. In this study, horses and cattle had extensive changes in oxidant/antioxidant equilibrium and acute-phase protein concentrations when infected with L. interrogans. We also demonstrated a direct link between antibody titers and the type of leptospiral serovar using serum oxidative and inflammatory markers.

Occupational Risk Factors for Seropositive Leptospirosis among Town Service Workers in Northeastern Malaysia

Leptospirosis is speculated to be one of the most prevalent re-emerging zoonotic diseases to date, and town service workers are continuously exposed to occupational hazards that may increase their risk of infection. This study aimed to determine the occupational risk factors for leptospirosis among town service workers in northeastern Malaysia. A cross-sectional study was conducted among town service workers from four municipal councils. All sera samples were tested for the presence of anti-leptospiral antibodies using an enzyme-linked immunosorbent assay (ELISA) followed by a microscopic agglutination test (MAT). We found that 82 serum samples from 321 respondents were positive in the MAT (seroprevalence rate of 25.5%). Multiple logistic regression analysis identified overtime work (adj. OR 2.13; 95% CI 1.19, 3.84), contact with animals while working (adj. OR 2.09; 95% CI 1.06, 4.11), sighting of rats at the worksite (adj. OR 2.17; 95% CI 1.11, 4.25) and living less than 200 m from a river (adj. OR 1.84; 95% CI 1.03, 3.28) as risk factors for leptospiral infection. Whereas age (adj. OR 0.95; 95% CI 0.93, 0.98), wearing boots while working (adj. OR 0.44; 95% CI 0.25, 0.80) and washing hands with soap after work (adj. OR 0.20; 95% CI 0.10, 0.42) were recognised as protective factors. In conclusion, an association was observed between leptospirosis seropositivity among town service workers and the occupational factors. Prevention and control strategies for leptospirosis will require more focus on curbing the possible sources of leptospirosis transmission and maintaining safe work practices in high-risk working environments.

Carrier Status ofLeptospiraspp. in Healthy Companion Dogs in Sri Lanka

Dogs are asymptomatic chronic carriers of Leptospira spp. and excrete these bacteria in their urine, resulting in environmental contamination and potentially leading to zoonotic transmission. Although a previous study in Sri Lanka detected anti-Leptospira antibodies in companion dogs, the urinary shedding of Leptospira spp. and the Leptospira species and serogroups prevalent in them remain unclear. Thus, the current study identified the prevalent Leptospira serogroups and the carrier status of Leptospira spp. in apparently healthy, client-owned dogs in the Kandy District of Sri Lanka. Serum and urine samples were collected from 96 unvaccinated and 82 vaccinated dogs. Anti-Leptospira antibodies and Leptospira DNA in urine were detected using the microscopic agglutination test (MAT) and nested PCR that targeted the pathogenic leptospiral gene, flaB. The flaB sequences were compared with those of Leptospira spp. using the public databases. MAT detected anti-leptospiral antibodies in 15.6% (15/96) of the unvaccinated dogs, and the reactive serogroups were observed to be Sejroe (11.5%), Canicola (2.1%), Icterohemorrhagiae (1.0%), and Javanica (1.0%). Furthermore, MAT results revealed that 11.0% (9/82) of the vaccinated dogs tested positive for the anti leptospira antibodies and the only reactive serogroup was Sejroe. Leptospira DNA was detected in 15.6% (15/96) and 15.9% (13/82) of urine samples collected from unvaccinated and vaccinated dogs, respectively, and phylogenetic analysis revealed that the animals were infected with L. borgpetersenii, L. interrogans, L. kmetyi, and L. weilii. The L. interrogans sequence detected in the canine sample was identical to the one that was previously reported in a human sample from the Kandy District. This study demonstrated that both unvaccinated and vaccinated dogs excrete various pathogenic Leptospira spp. in their urine, suggesting that they may play an important role in environmental contamination that poses a health risk to the dog owners and the general public.

English

BACKGROUND Leptospirosis is a zoonotic disease usually reported from South India. The clinical spectrum may range from asymptomatic infection, subclinical to a fatal hepatorenal syndrome. Most physicians are sensitized to diagnose leptospirosis, sometimes the diagnosis is missed, especially when associated with neurological manifestations. About 10-15 percent of cases can have neurological manifestations. These patients are referred to a tertiary care hospital due to poor therapeutic response. Since early management can be lifesaving, this study was carried out to evaluate the laboratory profile and clinical features in patients with neuroleptospirosis in a tertiary care centre in South India. METHODS This retrospective single centre study was conducted at Government Medical College, Thiruvananthapuram, Kerala. Neuroleptospirosis was diagnosed by clinical and laboratory findings of hepatorenal syndrome, and anti leptospira antibody detection by ELISA. RESULTS Total of 160 patients with leptospirosis were admitted during the period of study. 31 patients were diagnosed clinically as neuroleptospirosis. Out of 31 patients 21 (67.7 %) were males and 10(32.3 %) were females. The mean age was 56.9  14.61 years. (M: F 2:1, range 18-68 years,). The chief manifestations were fever in 29 (93.5 %), myalgia in 23(74.2 %), headache in 17 (54 %), jaundice in 14 (45 %), and conjunctival suffusion in 9 patients (29 %). Two patients (6.4 %) had altered sensorium and neck stiffness in 23 patients (74.19 %). Most common neurological manifestation was aseptic meningitis (87) followed by encephalitis (19.4 %), seizures in 9.7 %, mean WBC count was 17297.10  8948.413 cells/microliter. Mean platelet count at admission was 88258.06  108727.478 cell/microliter. Mean serum creatinine was 3.9  2.3 mg/dl. Seven  patients (22.58 %) succumbed to death. Mean age of patients who died were 50.63  11.94 years (p &lt; 0.084), mortality was more common in females (50 %) (p &lt; 0.074). Irrespective of age and sex, WBC count at admission &gt; 18,800 cell/ μL is associated with increased mortality (p+0.032). CONCLUSIONS Early recognition of neuroleptospirosis in patients with hepatorenal dysfunction and altered sensorium is critical in the treatment of patients. Female gender and elevated WBC count at admission indicates poor prognosis. KEY WORDS Neuroleptospirosis, Prognosis, Aseptic Meningitis.

Sero-prevalence of anti-Leptospira antibodies and associated risk factors in rural Rwanda: A cross-sectional study.

BackgroundLeptospirosis is a zoonotic disease transmitted through the urine of wild and domestic animals, and is responsible for over 50,000 deaths each year. In East Africa, prevalence varies greatly, from as low as 7% in Kenya to 37% in Somalia. Transmission epidemiology also varies around the world, with research in Nicaragua showing that rodents are the most clinically important, while studies in Egypt and Chile suggest that dogs may play a more important role. There are no published studies of leptospirosis in Rwanda.Methods & findingsWe performed a cross-sectional survey of asymptomatic adults recruited from five occupational categories. Serum samples were tested using ELISA and Microscopic Agglutination Test (MAT). We found that 40.1% (151/377) of asymptomatic adults had been exposed to Leptospira spp. Almost 36.3% of positive subjects reported contact with rats (137/377) which represent 90.7% among positive leptospira serology compared with 48.2% of negative subjects (182/377) which represent 80.5% among negative leptospira serology (OR 2.37, CI 1.25–4.49) and 1.7 fold on prevalence ratio and 2.37 of odd ratio. Furthermore, being a crop farmer was significantly associated with leptospirosis (OR 2.06, CI 1.29–3.28). We identified 6 asymptomatic subjects (1.6%) who met criteria for acute infection.ConclusionsThis study demonstrates a high prevalence of leptospiral antibodies infection among asymptomatic adults in rural Rwanda, particularly relative to neighboring countries. Although positive subjects were more likely to report rat contact, we found no independent association between rats and leptospirosis infection. Nonetheless, exposure was high among crop farmers, which is supportive of the hypothesis that rats together with domestic livestock might contribute to the transmission.Further studies are needed to understand infecting Leptospira servers and elucidate the transmission epidemiology in Rwanda and identify means of host transmitters.

Prevalence of anti-Leptospira antibodies and associated risk factors in the Malaysian refugee communities

BackgroundRefugees in Malaysia, who are afflicted by poverty, conflict and poor health, are vulnerable to a range of zoonotic infections in the deprived environmental and social conditions under which they live. Exposure to infections such as leptospirosis, for which rodents are primary hosts, is of particular concern.MethodsA wellness program was conducted to determine the presence of antibodies against Leptospira (seroprevalence) in 11 refugee community schools and centers in the Klang Valley, Malaysia. A total of 433 samples were assessed for IgG and IgM antibodies against Leptospira, using enzyme-linked immunosorbent assays (ELISA).ResultsOverall Leptospira seroprevalence was 24.7%, with 3.0% being seropositive for anti-Leptospira IgG and 21.7% for anti-Leptospira IgM. Factors significantly associated with overall Leptospira seroprevalence included: age, ethnicity, pet ownership, knowledge of disease and awareness of disease fatality. For IgM seroprevalence, significant risk factors included sex, ethnicity, eating habits with hands, pet ownership, the presence of rats, walking in bare feet and water recreation visits.ConclusionsThese findings highlight the need for improvements in health and well-being among the refugee community through disease awareness programs and provision of healthy behavior programs, particularly in hygiene and sanitation through community engagement activities.