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Abstract SUMMARY - ١٢٦ - 7. SUMMARY Leptospirosis, as a zoonotic infectious bacterial disease with global distribution caused by pathogenic spirochetes of leptospira species. Many wild and domestic animals are the main reservoirs for the leptospira species. Transmission usually results from direct or indirect exposure to the urine or other tissues of the infected Animal. Indirect exposure, which is more common, occurs via contact contaminated water and wet soil. When Leptospira species enters the body through abrasions in skin, intact skin, mucosa such as respiratory tract and conjunctiva. Early symptoms of leptospirosis are usually undiagnosed clinically. Early diagnosis is essential, since the untreated illness can progress rapidly and mortality rates are high in severe cases. Due to the public and zoonotic importance of leptospirosis, the following points were investigated: Investigate occurrence of leptospirosis among the examined rats and dogs by using culturing on a specific medium and Polymerase Chain Reaction (PCR) in El-Menoufia Governorate. Investigate the seroprevalence of leptospirosis among some animals ( Rats and dogs in El- Menoufia Governorate by using microscopic agglutination test (MAT). Study the extent of the disease among human population in El-Menoufia, Governorate by using Enzyme Linked Immunosorbent Assay (ELISA) and microscopic agglutination test (MAT). In this study, a total of 135 Dog samples were collected from 46 dogs arranged in 46 blood samples, 46 kidney samples and 43 urine samples from El- Menoufia governorate as well as a total of 53 rat samples were collected from black rats (Rattus rattus) were arranged in 21 blood samples, 21 kidney samples and 11 urine samples from 21 rats. All kidney and urine samples were subjected SUMMARY - ١٢٧ - for culturing on specific medium for leptospires , the isolation give no growth on the medium. The negative kidney and urine cultures were subjected after that to Polymerase Chain Reaction (PCR), A total of 47 negative cultures (18 rat samples and 29 dog samples) were subjected to PCR. The overall detection by PCR was 31.9% (15 out of 47) including 33.3% for rats (6 out of 18) and 31% for dogs (9 out of 29), as well as positive control by using PCR at the expected size 362 bp. Regarding to the seropositivity of the detected leptospira serovars from the examined rat and dog samples by MAT.The overall detection was 42.85% for rats (9/21) with titres ranged ( 1/200- 1/12800). The reactive serovars were serovar canicola (9.52%) with titre 1/12800, serovar Icterohaemorragiae (9.52%) with titre 1/6400- 1/12800 and 4.76% for each serovar Alexi, Georgia, Hebdomadis, Pyrogens and Wolfii with titre ranged( 1/200- 1/12800) as well as the overall detection by MAT was 34.78%(16/46) for dogs with titres (1/200- 1/6400) arranged in descending order as serovar canicola 21.73%, followed by serovar Icterohaemorragiae 8.69% then serovar Grippotyphosa 2.17% and serovar Australis 2.17%. Concerning to the animal sex, The detection rate of leptospiral antibodies in male and female rats was 50.00% and 36.36%, respectively and it was found that male dogs had higher seroprevalence 41.93% (13/31) than female dogs 20% (3/15) by MAT. According to animal age, The seroprevalence of leptospirosis among the examined rat samples was 53.84 and 25.00% in adult and juvenile rats, respectively and the seropositivity for the examined dogs was 28.57% (age group <1year), 25% (age group 1 < 3years) and 43.47% (age group 3 – 6years) by MAT. SUMMARY - ١٢٨ - Regarding to the prevailing climatic condition, the seropositivty in rats was 44.4 and 41.66% in warm and cold climate, respectively. As well as The overall detection of leptospira serovars in dogs was 45% in warm climate and 26.92% in cold climate. Concerning to the presence of visceral lesions in rats, the overall detection of leptospiral antibodies in the presence of visceral lesions was 60% by MAT. Regarding to the infestation of dogs with fleas, It was found that dogs infestated with fleas showed higher seroprevalence for leptospirosis (37.83%) than dogs did not infestated with fleas (22.22%) by MAT. According to habitat, the seropositivity was 25% for the household dogs and 38.23% for the strayed dogs. A total of 184 serum samples were taken from febrile patients suffering from fever of unknown origin (FUO). All human samples were subjected to ELISA test for detection of leptospira IgM then the positive samples were subjected to MAT for detecting the infective serovars. The overall detection was 21.19% (39/184) for human samples examined by ELISA IgM and the positive samples then subjected to MAT, the seroreactivity of the detected leptospira serovars from the examined human samples as examined by MAT was 33.33% (13/39) with titre ( 1/200- 1/6400). The most prominent serovar was serovar icterohaemorragiae 38.46% (5/13) followed by serovar canicola 30.76% (4/13) then serovar grippothphosa 15.38% (2/13), serovar hardjo 7.69%(1/13) and serovar hebdomadis also 7.69% (1/13). Regarding to age, It can be noticed that the majority of the positive samples was 32.07% (17/53) by ELISA and 47.05% (8/17) by MAT belonged to the age group of between (15-29 years old); 23.52% (8/34) by ELISA and 25.00%(2/8) by MAT belonged to the age group of (< 15 years old) ; 19.56% (9/46) by ELISA and 22.22% (2/9) by MAT belonged to the age group of between (30-44 years old); 15.62% (5/32) by ELISA and 20.00% (1/5) by MAT belonged to the SUMMARY - ١٢٩ - age group of between (45-59 years old) and zero result by ELISA and MAT belonged to the age group of (> 59 years old). Concerning to sex, the seroprevalence was 25.47% (27/106) by ELISA and 37.03% (10/27) by MAT for male patients, 15.38% (12/78) by ELISA and 25.00% (3/12) by MAT for female patients, respectively. The seroprevalence of leptospirosis among the examined humans in relation to their occupation. It was found that the most prevalent occupational risk group was sewer workers and fishers 57.14%(4/7) by ELISA and 75.00% (3/4) by MAT, followed by laborers 38.09% (8/21) by ELISA and 50.00% (4/8) by MAT, then farmers 25.80% (8/31) by ELISA and 25.00% (2/8) by MAT, students 23.80% (10/42) by ELISA and 20.00% (2/10) by MAT, Housewives 17.24% (5/29) and 20% by MAT, and others 7.40% (4/54) by ELISA and 25.00% by MAT. Concerning to residence, the overall detection was 27.18% (28/103) by ELISA and 35.71% (10/28) by MAT for rural patients but 13.58% (11/81) by ELISA and 27.27% (3/11) by MAT for urban patients, resectively. According to prevalent clinical signs, the seropositivity of feverish patients with pulmonary signs was 14.6% (17/116) by ELISA and 23.52% (4/17) by MAT but for feverish patients with renal signs was 32.35%(22/68) by ELISA and 40.90%(9/22) by MAT. Regarding to prevalent climatic conditions, the overall prevalence was 34.78% (32/92) by ELISA and 34.37% (11/32) by MAT for patient samples that were taken in warm climate, The overall prevalence in cold climate was 7.60% (7/92) by ELISA and 28.57% (2/7) by MAT. the relation of seropositivity among the examined samples and the detected serovars. The seroreactivity was differed according to the host and detected infected serovar as follow: SUMMARY - ١٣٠ - The seropositivity by MAT for humans was 34.21% (13/38), for dogs was 42.11% (16/38), for rats was 23.68% (9/38) and the total overall seropositivity was 35.84% (38/106) including ( 46 dog serum samples, 21 rat serum samples and 39 positive ELISA human samples). In comparing serovars frequency between human and reservoir animals. It was found that L interrogans serovar canicola was the most prevalent serovar in this study 42.11% (16/38) including 4 for human, 10 for dogs and 2 for rats. L.interrogans serovar icterohaemorragiae was seropositive about 28.94% ( 11/38) including 5 for human, 4 for dogs and 2 for rats. L.kischneri serovar grippotyphosa was 7.89% (3/38) including 2 for human and 1 for dogs. Also L.interrogans serovar hebdomadis 5.26% (2/38) one for human and one for rats. One serovar alexi in rats, one serovar australis in dogs, one serovar pyrogens in rats, one serovar wolffii for rats and one serovar Georgia for rats, one serovar hardjo for human. Finally, the presence of leptospiral antibodies in animal and human sera as well as the positive result of PCR indicates the circulation of leptospires in animal and human being in the study area. However, taking into consideration the complete lake of reports of clinical disease recently in the study area it appears more likely that these antibodies were due to along standing infection that might have maintained in animal and specially in human. Also, the seroprevalence studies in animals and human are very necessary to obtain epidemiological data about the disease in Egypt. |