Leptospira in slaughtered fattening pigs in southern Vietnam: presence of the bacteria in the kidneys and association with morphological findings.
ABSTRACT One kidney was collected from each of 32 fattening pigs at an abattoir in southern Vietnam in 2001 in order to demonstrate infecting Leptospira serovar and to associate renal macro- and microscopic findings with the presence of renal leptospires. Leptospires were demonstrated in 22 (69%) of the investigated kidneys by immunofluorescence. Multifocal interstitial nephritis (MFIN) and gross renal lesions (white spots) were each demonstrated in 24 (75%) kidneys. Leptospira interrogans serovar bratislava was isolated from one kidney. There was no association between presence of leptospires and MFIN (P=0.19), respectively and white spots (P=0.98), respectively. These data suggest that Leptospira infection is common among fattening pigs in the study area and that these animals may be considered as an occupational human health hazard. It is also suggested that the presence of white spots is an unreliable indicator of the presence of renal leptospires.
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ABSTRACT: In 1998, a total of 424 sows had sera collected in the Mekong delta in Vietnam. Of these, 283 sows were from 151 small-scale family farms in 19 villages, and 141 from seven large-scale state farms. The sera were subjected to the microscopic agglutination test (MAT) for antibodies to 13 Leptospira serovars. The overall leptospiral seroprevalence for titres > or =1:100 and > or =1:400, was 73 and 29%, respectively, and was higher (P=0.001) at small- than at large-scale farms. The highest seroprevalence was recorded for Leptospira interrogans serovar (sv) bratislava (52%). At small-scale farms, higher prevalences were found to serovars L. interrogans sv icterohaemorrhagiae (P=0.04) and L. interrogans sv pomona (P=0.02). Epidemiological information (at the individual-animal and herd-levels) was collected with a questionnaire. The data were analysed using logistic multiple regression. At the animal-level, sows seropositive for L. interrogans sv australis and sv autumnalis had less direct contact with sows in neighbouring pens (odds ratio (OR)=0.3 and 0.4, respectively) and sows seronegative for L. interrogans sv bratislava were of lower age (OR=0.1 for seropositivity). Also, sows seropositive for L. interrogans sv icterohaemorrhagiae had higher odds (OR=5.8) if they had not been born on the farm (had been introduced to it as gilts). Herds seropositive for sv javanica showed association with farms not taking measures to control the local rodent population (OR=7.8). Serovar pomona was also linked to the use of artificial insemination (AI), as opposed to natural-breeding services (OR=11.2). These results indicate that housing and management could affect the seroprevalence of Leptospira infection in pigs.Preventive Veterinary Medicine 03/2002; 53(3):233-45. · 2.39 Impact Factor
- Australian Veterinary Journal 09/1987; 64(8):258-9. · 0.92 Impact Factor
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ABSTRACT: A serologic survey was conducted among sows in the Mekong delta in southern Viet Nam to investigate associations between leptospiral seropositivity and reproductive performance. Data were collected from a total of 339 sows in lactation or gestation, from four large-scale state farms on three occasions. The seroprevalence for Leptospira interrogans serovar (sv) autumnalis was 32%, for L. interrogans sv bratislava 29%, for L. kirschneri sv grippotyphosa 13%, for L. interrogans sv icterohaemorrhagiae 27%, for L. interrogans sv pomona 5%, and for L. borgpetersenii sv tarassovi 13%. The reproductive parameters number of days from weaning to service (WSI), number of piglets born, number of piglets born dead, and number of piglets born weak, were evaluated. Seropositivity for sv tarassovi was associated with 0.8 more dead piglets per litter (P = 0.06), and sv grippotyphosa with a 1 day longer WSI (P = 0.06). There were no significant associations between reproductive performance and sv autumnalis, sv bratislava, sv pomona, and sv icterohaemorrhagiae. It is concluded that seropositivity for Leptospira can be associated with impaired reproductive performance even in areas where a high degree of immunity among sows is expected.Theriogenology 11/2002; 58(7):1327-35. · 2.08 Impact Factor