Volume 29, Issue 12 (3-2023)                   RJMS 2023, 29(12): 80-88 | Back to browse issues page

Research code: LU.ECRA.2017.18
Ethics code: LU.ECRA.2017.18
Clinical trials code: IR.LUMS.REC.1401.099

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Assistant Professor, Department of Clinical Sciences, Faculty of Veterinary Medicine, Lorestan University, Khorramabad, Iran , maleki.sh@lu.ac.ir
Abstract:   (702 Views)
Background & Aims: Leptospirosis is a common infectious disease between humans and animals, which is of particular importance in terms of global spread. The cause of the disease is Leptospira bacteria. This bacterium is gram-negative and spiral-shaped and belongs to the Leptospiraceae family and the Spirochetes branch (1,2). The genus Leptospira is divided into 20 species (9 pathogenic, 5 intermediate and 6 saprophytic) based on phylogenic and DNA analysis. Saprophytic species (eg L. biflex).
Leptospira species cause a common disease called leptospirosis. Leptospira settle in the kidney tubules of animals (susceptible mammals) and because of this the host animals remain infected for a long time and expel the bacteria (7). Livestock (cows and sheep) are sources of leptospirosis and should be taken care of to prevent transmission of the disease to humans (8,9). Leptospira species remain in the environment for a long time, transfer to humans through damaged skin and mucous membranes, mortality and economic losses are considered as an important global health issue (2,7,10). Every year, half a million cases of leptospirosis (45 cases per 100,000 people) are reported worldwide (11). Leptospirosis is more common in hot seasons and in tropical and rainy regions of the world (11,12). The incubation period of leptospirosis in humans is about 10 days and may be asymptomatic (12).
The clinical face of this disease is so variable that it is considered as a disease with a thousand faces and it can never be diagnosed based on clinical signs and symptoms alone, so diagnosis is more based on trusting the laboratory in showing and observing the cause of the disease. And the accuracy of laboratory methods is stable. Definitive diagnosis of leptospirosis is based on laboratory tests such as bacterial culture, ELISA test, MAT and PCR (16), which is the standard serological method for identifying leptospirosis antibodies according to the World Health Organization (WHO) Microscopic agglutination test (MAT), which is a method It is cheap with acceptable sensitivity and it is possible to access it (17) and it shows the wide presence of Leptospira in the world (16). Bacteremia develops within 7-10 days after symptoms of infection by Leptospira and antibodies can be detected in the blood (18,19). The aim of the present study was to investigate leptospirosis seroepidemiologically among the farmers of Kohdasht in Lorestan province by microscopic agglutination method (MAT) and also to determine and obtain the serovars infecting people in Kohdasht region. The results obtained from the present research can provide a lot of help to researchers in medical and veterinary sciences of the country, and it is also very useful in human and animal health and rapid diagnosis and treatment of patients.
Methods: The study was conducted on the blood samples of 200 cattle farmers of Kohdasht in February 2013. After selecting the livestock farms, he went to the livestock farm and took 10 cc of blood samples from the hand veins of the people who were active in livestock farming. After the complete collection of samples, microscopic agglutination test (MAT) and measurement of serum contamination were performed to determine the contamination of serum samples with Leptospira serovars on blood serum samples. The results obtained from the MAT method were analyzed with SPSS software (Version 16) through Chi-square and Fisher's test. P<0.01 was considered as significant difference.
Results: 48 serum samples (24%) were positive among 200 tested sera at the 1:100 dilution. Serum samples were shown positive reaction with two L. Grippotyphosa and L. canicola serovars. The prevalence of Grippotyphosa 66.67% and Canicola 33.33% were resulted by MAT. 31 samples (64.58%) were related to males and 17 cases (35.42%) females among 60 positive samples. The highest prevalence of Leptospira serovars was founded in more than 50 years group with 16 cases. P. value based on gender was 0.01. (p<0.01).
Conclusion: Leptospira pathogenic species can survive for a long time under suitable environmental conditions (humidity and temperature). Domestic animals (cows, sheep and dogs) are considered important as hosts of this bacterium in the spread of leptospirosis and play a significant role (20). Leptospira is released into the environment through the urine of animals. Human infection with leptospirosis is caused by contact with the urine of infected animals (21). Diagnosis of leptospirosis is difficult for many doctors, and its definitive diagnosis is possible with laboratory methods. The MAT method is universally used as a reference test for the diagnosis of leptospirosis. In the present study, the prevalence of leptospirosis among farmers in Kohdasht was 24%, and the serovars Gripotiphosa and Canicula had the highest prevalence, respectively. The P value of p<0.01 was significant for gender and showed that leptospiral infection is different according to gender. All over the world, studies on the prevalence of leptospirosis have been carried out. In Iran, in 2004, the prevalence of leptospirosis in Gilan University Hospital was reported by Honarmand et al. to be 24.6% (22). In 2016, in a serological study of leptospiral infection of sheep using the MAT method in Ahvaz, Hajikolaei et al. reported the occurrence of 14.9% leptospirosis and the highest number of leptospirosis serovars was related to Pomona with 14 cases (43.8%), respectively. canicula with 7 cases (21.9%) and ictrohemorrhage with 4 cases (14.5%) (23). This study showed that transmission of leptospirosis is carried out by sheep as hosts, so livestock farmers are prone to leptospirosis. A study was conducted on dairy cows in Hamedan industrial farms in 2009 by Bahari et al., out of 80 blood samples, 18 were positive for Leptospira and the highest serovar prevalence was Canicula (21.25%) (24). This study is another proof of the susceptibility of livestock farmers to leptospirosis. In 2008, Agampodi et al. conducted a study on 404 patients with fever in Sri Lanka using the MAT method, of which 155 patients were found to have leptospirosis. In this study, the prevalence of serovars Pyrogenesis (28.7%) and Hardjo (18.8%) was reported (25). In 2012, Ngbede et al. conducted a study in Nigeria using the MAT method on 142 blood samples of cows slaughtered in a slaughterhouse, and 5 samples were found to have antibodies against Hardjo serovar (26). Goris et al. in 2013 in the Netherlands in a study they conducted on sick people concluded that serovars Ictrohemorrhagia, Hardjo, and Gripotyphosa cause severe leptospirosis in humans (27). In 2014, Dreyfus et al. used the MAT method to investigate the risk factors of leptospirosis among 567 slaughterhouse workers in New Zealand. They found that 11% of the workers had antibodies against Hardjo and Pomona serovars in their blood serum (28). Leptospirosis is related to occupation and environment (29). Floods and inundation as well as contact with animal waste are the most important factors of leptospirosis infection (30). Leptospirosis may lead to failure of liver, kidney and many organs of the body. In general, leptospirosis is spreading, so disease control should be considered. it is concluded that livestock farmers are one of the groups at risk of leptospirosis due to the presence of different leptospira serovars in animals. Livestock farmers can prevent the occurrence of leptospiral infection by controlling their safety and health. The results of this study are very useful in the research of medical and veterinary sciences as well as human and animal health and rapid diagnosis and treatment of patients and provide a lot of information to researchers in disease control.

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Type of Study: Research | Subject: Medical

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