Leptospirosis represents an important widespread re-emerging zoonosis. Climatic changes, modifications of ecological niches and new potential maintenance-hosts could represent the most important factors involved in leptospirosis epidemiology. This study aim was to evaluate the diffusion of Leptospira in Central Italy. From January 2002 to December 2016, 8488 sera belonging to cow (1328), sheep (2682), swine (1332), dog (1144), wild boar (479), goat (327), hare (162), fox (94), coypu (70), horse (74), roe deer (74), fallow deer (65), red deer (56), wolf (43), rat (34), mouflon (8), mouse (8), cat (4), donkey (2), guinea pig (2), ferret (1), bear (1), alpaca (1) and man (329) were analysed for Leptospira. They were sampled in Central Italy from healthy and ill subjects. Serological investigation was carried out by Micro Agglutination Test using as live antigens Icterohaemorrhagiae (strain Bianchi), Canicola (strain Alarik), Pomona (strain Mezzano), Tarassovi (strain Jhonson), Grippotyphosa (strain Moscow V), Bratislava (strain Riccio 2), Ballum (strain Castellonis 3) and Hardjo (strain Hardjoprajitno). Titers of 1:100 were considered positive; 2-fold serial dilutions were tested to determine the endpoint titer. Positive sera for Leptospira were 8.35% (709/8488) at 1:100 titer and 2.57% (218/8488) for titer ≥1:400. Table 1 shows the positive sera distribution in relation to serovars and animal species. The highest positive sera percentages were recorded for coypu, swine and cow at low (22.86%, 19.67% and 13.10%, respectively) and high titer (5.61%, 6.23% and 3.16%, respectively). Wild boar, fox and hare sera resulted positive at titer ≥1:100 (8.56%, 3.04% and 1.85%, respectively). Positive human sera were 4.26% (10/329), while 3 (1.06%) showed a titer ≥1:400. Serovars Pomona and Bratislava resulted more often detected, with 267 and 224 at titer 1:100, and with 68 and 67 at titer ≥1:400 positive reactions, respectively. Low number of positive sera was detected for serovars Ballum, Canicola and Tarassovi (13, 28 and 32, respectively). Hare and goat sera were the only samples negative to serovar Icterohaemorrhagiae and Bratislava, respectively. Serovars Icterohaemorrhagiae and Canicola were found mainly in dog sera, though Pomona and Bratislava in swine sera. Serovar Tarassovi was detected mainly in wild boar and serovars Grippotyphosa and Hardjo especially in cow sera. Icterohaemorrhagiae was the most detected serovar in human sera (Table 1). Percentage of positive sera for each year decreased from 2002 to 2008 and increased from 2009. In 2008 only 0.17% (1/597) sera was positive and in 2014, 2015 and 2016 high positive percentages were recorded (17.23%, 19.61% and 38.05%, respectively). Although Leptospira prevalence seems to be decreasing, some serovars has been increased during last years. Moreover, some wild species seems to play a key role in leptospirosis epidemiology.

Epidemiology of Leptospirosis in Central Italy: fifteen years of serological data (2002-2016)

Cilia Giovanni
;
Bertelloni Fabrizio;Turchi Barbara;Pinzauti Paolo;Cerri Domenico;Fratini Filippo
2018

Abstract

Leptospirosis represents an important widespread re-emerging zoonosis. Climatic changes, modifications of ecological niches and new potential maintenance-hosts could represent the most important factors involved in leptospirosis epidemiology. This study aim was to evaluate the diffusion of Leptospira in Central Italy. From January 2002 to December 2016, 8488 sera belonging to cow (1328), sheep (2682), swine (1332), dog (1144), wild boar (479), goat (327), hare (162), fox (94), coypu (70), horse (74), roe deer (74), fallow deer (65), red deer (56), wolf (43), rat (34), mouflon (8), mouse (8), cat (4), donkey (2), guinea pig (2), ferret (1), bear (1), alpaca (1) and man (329) were analysed for Leptospira. They were sampled in Central Italy from healthy and ill subjects. Serological investigation was carried out by Micro Agglutination Test using as live antigens Icterohaemorrhagiae (strain Bianchi), Canicola (strain Alarik), Pomona (strain Mezzano), Tarassovi (strain Jhonson), Grippotyphosa (strain Moscow V), Bratislava (strain Riccio 2), Ballum (strain Castellonis 3) and Hardjo (strain Hardjoprajitno). Titers of 1:100 were considered positive; 2-fold serial dilutions were tested to determine the endpoint titer. Positive sera for Leptospira were 8.35% (709/8488) at 1:100 titer and 2.57% (218/8488) for titer ≥1:400. Table 1 shows the positive sera distribution in relation to serovars and animal species. The highest positive sera percentages were recorded for coypu, swine and cow at low (22.86%, 19.67% and 13.10%, respectively) and high titer (5.61%, 6.23% and 3.16%, respectively). Wild boar, fox and hare sera resulted positive at titer ≥1:100 (8.56%, 3.04% and 1.85%, respectively). Positive human sera were 4.26% (10/329), while 3 (1.06%) showed a titer ≥1:400. Serovars Pomona and Bratislava resulted more often detected, with 267 and 224 at titer 1:100, and with 68 and 67 at titer ≥1:400 positive reactions, respectively. Low number of positive sera was detected for serovars Ballum, Canicola and Tarassovi (13, 28 and 32, respectively). Hare and goat sera were the only samples negative to serovar Icterohaemorrhagiae and Bratislava, respectively. Serovars Icterohaemorrhagiae and Canicola were found mainly in dog sera, though Pomona and Bratislava in swine sera. Serovar Tarassovi was detected mainly in wild boar and serovars Grippotyphosa and Hardjo especially in cow sera. Icterohaemorrhagiae was the most detected serovar in human sera (Table 1). Percentage of positive sera for each year decreased from 2002 to 2008 and increased from 2009. In 2008 only 0.17% (1/597) sera was positive and in 2014, 2015 and 2016 high positive percentages were recorded (17.23%, 19.61% and 38.05%, respectively). Although Leptospira prevalence seems to be decreasing, some serovars has been increased during last years. Moreover, some wild species seems to play a key role in leptospirosis epidemiology.
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Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11568/933815
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