Bovine tuberculosis (TB) in Italy: epidemiology and eradication

Stefano Marangon

TB control in Italy

Since 1964 bovine tuberculosis (TB) has been

submitted to a national eradication

programme in breeding herds (L. 615/64),

which became compulsory in 1977 (DM

30/6/77)

Current TB eradication programme based on

EU (Council Directive 64/432/EEC, Annexes A,

I and B) and Italian legislation (DM 592/95

and DLgs 196/99)

TB legislation

DLgs 196/99

The provisions of Directive 64/432/ECC have

been transposed in the Italian legislation

These provisions define the rules for the

intra-Community trade of live bovines and

for TB eradication programmes

TB legislation

DM 592/95

Measures to be enforced in affected holdings

TB positive bovines shall be slaughtered

movements of live animals are prohibited

epidemiological investigation shall be carried out

cleansing and disinfection must be guaranteed

……………………………………………………………….

Rules for the compensation of bovines slaughtered in the affected premises

TB eradication programme: key points

Single intradermal cervical tuberculin test

(SICTT)

Certification of officially-tuberculosis-free (OTF)

herds

Certification of OTF provinces/regions

Movement control (identification and

traceability system, pattern of cattle movement,

possible application of risk modulating

measures,……..)

Risk-based surveillance programme

TB control: critical points

Execution, reading and interpretation of the

skin test

Management of inconclusive skin tests

Control of beef fattening herds

Sanitary control of animals introduced from

other OTF MS (??)

Risk-based surveillance: key points

Close cooperation between National, Local

Veterinary Services, Epidemiological Centre

and Farmers

Testing frequency in OTF (skin test every two,

three or four years), modulated in different epi

situations

Tracing-back of TB lesions detected at the

abattoir

Data collection and information flow

Epidemiological investigation

Epidemiological investigation

Carried out using a standard procedure

(format)

Tracing-back to identify the origin

Tracing forward to identify newly infected

herds

Identification of TB risk factors in the

Country

Risk-based surveillance

Ireland: major factors associated with TB were

introduction of cattle in the herd and presence of

badgers

Epidemiological studies carried out in other

geographical areas indicated the possible

involvement of wild species such as badgers, wild

boars, deer

Identification of TB risk factors, in order to

modulate disease control measures

Most frequent origin of TB outbreaks in non-OTF areas in Italy

Possible introduction of infected animals (illegal movement)

Mixed herds (reproduction + fattening/dealers)

Common pastures (cross-contamination)

Most frequent origin of TB outbreaks in OTF areas in Italy

Latency (one case latency period of 10 years)

Persistence of M. bovis in the environment (selective culling vs stamping out, disinfection?)

Possible introduction of infected animals from OTF and non-OTF areas (Member States?)

Promiscuity with goats (possible reservoir of infection?)

Rare causes of persistence, introduction or recurrence of TB

Promiscuous transports or non disinfected

means of transportation

Contacts with non OTF cattle at market places

and exhibitions

Contacts between domestic animals and wildlife

(e.g. wild boars)

Contaminated whey (cheese factory)

Farm workers

Programme coverage

Prevalence

Incidence

Slaughterhouse submission rate

Reactors with visible lesions (if many – failure to detect infection early by test)

Testing history of infected herds (important in herds detected at slaughter: late detection)

Human cases (may indicate undetected infection in animals)

Performance indicators

a) No. of herds/animalsb) No. of herds/animals testedc) No. of herds/animals positived) No. of new herds positive

Prevalence (c/b) Incidence (d/b)Coverage (b/a)

Commission Decision 2008/940/EC

6 million bovines

TB overview in Italy – OTF provinces

Tested herds and TB outbreaks in Italy(1995 - 2009)

TB outbreaks: prevalence and incidence

(1995 - 2009)

During the last three years the time to ‘clear’ infected herds is decreasing

TB prevalence and incidence in non-OTF regions (1995 - 2009)

1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009

prevalenza 1,31%1,16%1,05%0,88%0,85%0,87%0,71%0,83%0,95%1,08%1,16%1,16%1,07%1,03%0,89%

incidenza 0,60%0,53%0,47%0,35%0,31%0,56%0,45%0,53%0,52%0,60%0,65%0,60%0,66%0,64%0,55%

0,00%

0,20%

0,40%

0,60%

0,80%

1,00%

1,20%

1,40%

prevalenza incidenza

Herd prevalence is slightly decreasing, whilst herd incidence is more or less the same

PUGLIA 4,607 4,469 4,388 83 24 3 3.61 98.19 1.89 0.55

SARDEGNA 9,136 5,643 5,629 16 11 0 0.00 99.75 0.,8 0.20

SICILIA 10,844 10,585 10,551 391 264 1 0.26 99.68 3..1 2.50

TOSCANA 2,104 680 680 0 0 0 0.00 100.00 0.00 0.00

UMBRIA 4,031 1,988 1,988 4 4 0 0.0 100.00 0.20 0.20

VALLE D'AOSTA 1,199 1,124 1,124 18 7 0 0.00 100.00 1.60 0.62

Total 110,785 74,861 73,954 666 407 18 2.70 98.79 0.90 0.55          

Statistics in non-OTF regions (IT-2009): herds

REGIONtotal

herds

total eligible herds

herds controlled

positive herds

new positive herds

herds stamped

out

% positive herds

stamped out

Indicators

coverage (%)

Prevalence(%)

Incidence(%)

1 2 3 4 5 6 78 = (7/5)x

1009 = (4/3)x

10010=(5/4)x

10011=(6/4)x10

0

ABRUZZO 4,574 3,245 2,809 6 5 0 0.00 86.56 0.21 0..18

BASILICATA 3,143 3,048 3,009 22 12 3 13.64 98.72 0.73 0.40

CALABRIA 7,827 6,794 6,794 49 25 3 6.12 100.00 0.72 0.37

CAMPANIA 12,297 9,705 9,496 42 30 1 2.38 97.85 0.44 0.32

LAZIO 12,587 7,619 7,528 23 17 6 26.09 98.81 0.31 0.23

LIGURIA 1,750 1,227 1,225 0 0 0 0.00 99.84 0.00 0.00

LOMBARDIA 13,647 4,079 4,079 2 1 0 0.00 100.00 0.05 0.02

MARCHE 4,769 1,987 1,986 0 0 0 0.00 99.95 0.00 0.00

MOLISE 3,152 2,574 2,574 2 2 0 0.00 100.00 0.08 0.08

PIEMONTE 15,118 10,094 10,094 8 5 1 12.50 100.00 0.08 0.05

Statistics in non-OTF regions (IT-2009):animals

REGION Total animals Animals to be

examined

Examined animals

Examined animals

individually

Positive animals

Slaughter Indicators

Positive animals

from slaughter or culling

Slaughtered animals

coverage P

1 2 3 4 5 6 7 8 9 =(4/3)x100 10 =(6/4)x100

ABRUZZO 37,181 33184 30062 30,062 53 12 12 90.59 % 0.18 %

BASILICATA 89,419 86591 86389 86,388 127 94 178 99.77 % 0.15 %

CALABRIA 117,064 106976 106976 106,976 197 196 200 100.00 % 0.18 %

CAMPANIA 462,221 429981 411618 369,643 958 957 1,025 95.73 % 0.23 %

LAZIO 306,749 273879 273872 273,872 236 223 316 100.00 % 0.09 %

LIGURIA 15,813 14095 14092 14,092 0 0 0 99.98 % 0.00 %

LOMBARDIA 1,370,946 541453 541453 541,453 1 0 0 100.00 % 0.00 %

MARCHE 56,762 47363 47262 50,262 0 0 0 99.79 % 0.00 %

MOLISE 49,086 44606 44606 44,806 16 16 16 100.00 % 0.04 %

PIEMONTE 794,086 526060 514779 514,779 358 260 362 97.86 % 0.07 %

PUGLIA 180,167 179053 176756 177,261 315 315 339 98.72 % 0.18 %

SARDEGNA 265405 116864 116313 124680 29 29 29 99.53 % 0.02 %

SICILIA 380,255 370,289 368,489 368,489 4,361 4,025 4,644 99.51 % 1.18 %

TOSCANA 32,628 17,114 17,114 22,387 0 0 0 100.00 % 0.00 %

UMBRIA 65,671 49,598 49,598 49,598 6 6 6 100.00 % 0.01 %

VALLE D'AOSTA 42,140 30,221 30,221 30,221 42 42 42 100.00 % 0.14 %

Totale 4,265,593 2,867,327 2,829600 2,804,969 6,699 6,175 7,169 98.68 % 0.24 %

Statistics in OTF regions/provinces (IT-2009)

REGION

Total cattle OTF herds Infected herds Single Skin testpre -

movement test

N° animals with TB

suspected lesions

N° positive animals

(isolation)herds animals herds % herds %

skin test frequency

tested animals

ABRUZZO: Pescara 836 14,100 836 100.00 0 0.00 two years 7633 0 0 0

EMILIA ROMAGNA: whole Region

7,275 470,380 7,271 99.95 4 0.05 two years 263,607 26,818 5 2

FRIULI VENEZIA GIULIA: whole Region

2,481 91,297 2,480 99.96 1 0.04 none 0 2,865 2 2

LOMBARDIA: Bergamo, Como, Lecco, Sondrio

4092 199,262 4,092 100.00 1 0.02 two years 97,965 6,135 1 1

MARCHE: Ascoli Piceno 700 11,146 700 100.00 0 0.00 two years 5,871 282 0 0

PIEMONTE: Novara, Verbania e Vercelli

604 11,283 1,052 174.17 0 0.00 two years 11,283 1,254 0 0

SARDEGNA: Oristano 1,523 64,687 1,523 100.00 0 0.00 two years 0 0 0 0

TOSCANA: whole Region 776 26,283 776 100.00 0 0.00 three years 26,283 657 6 0

TRENTINO-ALTO ADIGE (BZ) 8,538 144,295 8,538 100.00 0 0.00 none 20,244 0 14 0

TRENTINO-ALTO ADIGE (TN) 1,508 44,440 1,504 99.73 4 0.27 yearly 38,588 2,123 0 0

VENETO: whole Region 7,787 325,494 7,787 100.00 0 0.00 three years 0 0 0 0

Total 36,120 1,402,667 36,559 101.22 10 0.03   471,474 40,134 28 5

Cases reported at the abattoir (IT-2009)Region

Animals slaughtered

Notification form (10/33) *

Herds notified (10/33)

Herds notified and M bovis positive

Abruzzo 21,692 4 4 1

Basilicata 15,231 1 1 1

Calabria 46,779 34 29 27

Campania 180,730 84 60 60

Emilia-Romagna 412,063 2 2 2

Lazio 63,610 32 29 19

Liguria 14,150 0 0 0

Lombardia 666,021 7 7 1

Marche 34,084 0 0 0

Molise 11,796 1 1 1

Piemonte 474,847 10 10 1

Puglia 54,163 42 34 34

Sardegna 39,476 5 4 2

Sicilia 115,480 31 29 14

Toscana 52,283 1 1 1

Umbria 27,605 4 4 3

Valle d’Aosta 8,015 4 4 0

Veneto 697,292 4 4 4

Conclusions

TB eradication programmes should be:

properly managed (updated register of farms

and animals, information system,………)

based on reliable testing procedures

regularly monitored

modulated according to the epidemiological

situation