Rev. Sci. Tech. Off. Int. Epiz., 2003, 22 (3),1003-1012

 

A method of accelerated eradication of bovine brucellosis in the Czech Republic

V. Kouba

Former Vice-Director and Chief Epizootiologist, Czechoslovak State Veterinary Service and Professor, Brno University of Veterinary Sciences, P.B. 516, 17000 Praha 7, Czech Republic

Submitted for publication: 9 December 2000

Accepted for publication: 15 May 2003

Summary

A method of accelerated eradication of bovine brucellosis was developed and applied in the Czech Republic, where livestock was reared primarily in large-scale units. Before this method was adopted, annual economic losses were about US$ 20 million and thousands of people were estimated to suffer from brucellosis (e.g. 32.4% of tested veterinarians were positive). Initial mass serological testing confirmed 654 outbreaks with 99,787 intrafocal bovines distributed in half of the regions of the Republic. Disease incidence was 213 with a prevalence of 676 per 100,000 bovines. Systematic investigations detected all affected herds, including 91 new outbreaks. A depopulation policy was applied on farms and ranches with brucellosis-infected cattle, with the aim of totally eradicating the disease by a fixed deadline. Breeding on diseased ranches was temporarily discontinued and affected herds were replaced by healthy cattle from brucellosis-free regions. Since then, the incidence of the disease in cattle and humans has been maintained at level zero. Eradication without recurrence was achieved within five years, without reducing the cattle population, the rate of cattle production, or the income of farmers. Ten years after eradication of the disease, the cumulative benefit/eradication cost ratio reached 7:1. Post-eradication surveillance has confirmed a brucellosis-free status. The eradication of bovine brucellosis has resulted in an increase in cattle production and trade. By 2000, eradication had averted losses of approximately US$ 700 million and saved more than two thousand people from becoming affected with this zoonosis.

Keywords

Benefit/cost – Bovine brucellosis – Depopulation – Disease control – Eradication – Surveillance – Zoonosis.

Introduction

The Czech Republic comprises an area of 78,858 km2 with ten million inhabitants and about three million head of cattle (in 1960). Brucellosis caused by Brucella abortus was reported since 1924, affecting mainly large-scale ranches located in the fertile lowlands which had a high concentration of dairy cows. Vaccination of calves (four to seven months old) with the strain B-19 started before the Second World War. Adult cattle from affected farms were also vaccinated, excepting animals in advanced pregnancy. Serological control in that period was rather ad hoc. Mandatory reporting was introduced in 1952. Two decades after mass vaccination with strain B-19 and despite all the efforts and measures deployed, the brucellosis situation worsened with many new diseased animals and outbreaks being detected. Measures such as isolation of diseased animals and affected herds, as well as veterinary control of cattle movement, regulation of trade and breeding (even some insemination stations were found to be affected) were not always perfect (relying too heavily on vaccination). False negative results of serological tests contributed to disease spread. Direct and indirect economic losses in the livestock industry and trade were about Kcs 200 million (US$ 20 million) annually. In the human population, in addition to the estimated thousands chronically suffering from brucellosis, many new acute cases were reported as a consequence of exposure to affected animals, ranches or slaughterhouses and due to consumption of infected or contaminated milk or milk products. A special survey among 479 veterinarians was carried out with the following results: 32.4% were serologically positive and 17.5% manifested clinical symptoms (19). Such alarming findings led to the initiation of an eradication programme covering the entire territory of former Czechoslovakia.

By 1960, most countries in the world had reported the occurrence of bovine brucellosis. Only a few countries managed to eradicate the disease using the ‘test and slaughter’ method, namely Cyprus in 1932 (17), Norway in 1953 (18), Sweden in 1957 (17), Bulgaria in 1958 (17) and Finland in 1960 (5). International recommendations at that time dealt with laboratory diagnosis, immunisation and local case solutions, but not with country level eradication procedures (6). Rapid eradication at national level required developing suitable and feasible procedures, appropriate to the given epizootiological situation, country-specific conditions and subjected to fixed deadlines.

This paper deals only with the eradication of the disease in the Czech Republic. An eradication programme was implemented simultaneously in Slovakia.

The following data concerns brucellosis in Slovakia (figures in brackets refer to the whole of Czechoslovakia). In 1959, 57.88% (54.6%) of the cattle population was tested. The disease was discovered in 18 (52) out of 33 (108) regions, involving 1,177 (1,831) outbreaks with 98,860 (198,647) intrafocal bovines, i.e. 7.51% (4.61%). The incidence reached 2,259 (8,558) diseased animals, i.e. 174 (202) per 100,000 animals and disease prevalence on 31 December 1959 was 78,115 (98,596) diseased animals, i.e. 5.93% (2.29%).

The pre-eradication (preparatory) phase

The first countrywide serological survey in 1959 covered 52.49% of the cattle population, including all females of reproductive age. The disease was discovered or confirmed in 34 of 75 regions, including 654 localities with 99,787 intrafocal bovines (3.34%), i.e. 153 animals per outbreak (half of these were dairy cows). Of all the outbreaks, 99% occurred in dairy ranches and only 1% in small farms. The number of newly detected positive cattle was 6,299 animals, i.e. 213 per 100,000 with a prevalence on 31 December 1959 of 20,481 diseased animals, i.e. 676 per 100,000 animals. Territorial distribution shown in Figure 1.

Knowledge of bovine brucellosis characteristics and diagnosis was considered to be sufficient for eradication. The decision was therefore made to initiate the programme as soon as possible, without waiting for further results of national and international research, considering that later, the situation would worsen (with the risk of introducing the disease into wildlife), i.e. be much more difficult and expensive to manage. The same approach was applied to bovine tuberculosis control.

Initially, the veterinary community and decision-makers had to be convinced about the methodology to be adopted and the economic feasibility of brucellosis eradication at national level within a short period of time. In 1959, based on complex analysis and recommendations presented by veterinary and public health services, the Government of the former Czechoslovakia adopted a resolution to eradicate bovine brucellosis (goal – zero incidence) and to eliminate bovine tuberculosis (goal – zero prevalence). The Government created a special committee (representing relevant ministries and institutions), chaired by the Director of the State Veterinary Service, identified subsidies, introduced obligatory pasteurisation of market milk and issued appropriate directives for administrative authorities and cattle owners (12, 13, 14). The aim of the programme was to eradicate bovine brucellosis using simple depopulation of affected farms and ranches and to meet the objective, by 1965, of zero prevalence and incidence without recurrence (eradication of all sources of Brucella abortus) without reducing national milk and beef production, cow populations or the income of farmers. For the first time, a fixed deadline was imposed upon a national animal health programme. This was different compared to the previous attempts of trying to fulfil long-term disease control programmes without fixed deadlines for achieving the specific targets of reducing or eliminating disease occurrence.

One of the first steps implemented was to discontinue vaccination with strain B-19, which had been useful in reducing negative impacts (abortions, disease spread, etc.), but was not suitable for the new task, i.e. speedy final eradication. An additional reason for stopping B-19 vaccination was that distinguishing between post-vaccination and post-infection antibodies was impossible. This complicated interpretation of serological test results, as well as identification of affected and non-affected herds. Relying on the vaccination weakened the motivation for and consistency in applying other demanding measures necessary for success.

Materials and methods

Sources of information for this article include the literature, official statistics and documents of agriculture and health ministries as well as those of the veterinary service administration, publications (12, 13, 14, 15) and the experience of the author (responsible for the preparation and management of the programme). Diagnostic methods adhered to international recommendations (6).

The accelerated eradication methodology was based upon the results of comparative experiments carried out in selected regions by national specialists such as Anderle (2) and Drazan (4). The eradication philosophy and procedure were based upon exploitation of the current replacement (‘turnover’) policy of older generations of the national cattle population. Culling was performed in priority in diseased herds to avoid risky breeding of affected animals. This approach also supported the development of a new generation of calves born from brucellosis- and tuberculosis-free parents and the sale of selected, healthy, genetically suitable animals to depopulated ranches.

The eradication (attack) phase

Initially, the traditional ‘test and slaughter’ method was applied without interrupting the herd breeding process. A ranch could be declared brucellosis-free after three years of observation following elimination of the last positive case discovered during repeated testing of all intrafocal cattle. This method helped to gradually ‘clean’ affected localities with very low prevalence and showing no clinical manifestation. However, the method was not always reliable, particularly in outbreaks with higher morbidity, and was found to be too slow considering the deadline for final eradication. New cases were often discovered during next herd tests and sometimes, even after declaration of the herd as brucellosis-free (= recurrence). Isolation measures complicating husbandry and trade were demanding, costly and difficult to sustain over a prolonged period. Continuing exposure of animals and people caused new cases, thus aggravating the situation. Consequently, eradication, particularly in larger ranches with brucellosis abortions, required a more drastic approach.

The decision was therefore made to adopt the accelerated radical method without recurrence (tested previously in a selected region as one of alternative procedures), based upon affected ranch depopulation after previous interruption of breeding. Artificial insemination and natural mating were stopped one year prior to farm depopulation to avoid new conceptions and slaughter of pregnant animals (the calves were not used for breeding) and to prevent further disease spread. Intrafocal testing was no longer required with this approach. All cattle and other susceptible animals were sent to slaughter on the planned depopulation day(s). Following thorough, final mechanical and chemical disinfection, the ranch was left without cattle for at least six months, assuming that natural devitalisation of Brucella abortus would take place in the environment.

Another procedure consisted in introducing negatively tested castrated male or female cattle into the depopulated and disinfected cattle facilities. This was to enable fattening (temporary feedlot), to maintain the production process and provide income to farmers. These animals, serving as biological filters, were again tested before slaughter. New, healthy cattle from brucellosis-free regions were then introduced following final sanitation.

The depopulation policy was applied to gradually expand the brucellosis-free territory to cover the entire country. To facilitate this expansion, a network of selected highly affected farms, i.e. ‘isolators’, was established, especially in the region of Melnik. The purpose was to temporarily exploit selected, high-yielding pregnant milking cows introduced from other brucellosis farms where all other cattle were sent for slaughter. The numbers of brucellosis isolator farms were as follows: 1961 – 133, 1962 – 80, 1963 – 51 and 1964 – 64. These farms were depopulated by the end of 1964.

Complex and demanding eradication procedures required extraordinary professional, organisational, economic and social measures, as well as temporary adjustment of national trade policy. Specific trade regulations consisted of allocating a temporary meat and milk purchase quota to the national agency in charge of purchasing agriculture products. Brucellosis-free regions reduced cattle slaughter and thus, affected regions were given a chance to increase slaughter as required by the accelerated eradication programme. The national demand for meat was met in this manner. The meat of cattle with clinical symptoms of brucellosis was classified as conditionally comestible after heat-treatment. Brucellosis-free provinces and regions delivered healthy cattle, mainly pregnant heifers, to depopulated ranches to recommence breeding and production. The quota for milk trade was set in the opposite manner, i.e. lower in affected regions because of the reduction in number of milking cows due to premature slaughter. In the free regions, the quota was increased to maintain national milk trade level.

The brucellosis eradication campaign covering the entire area of former Czechoslovakia was accompanied by the bovine tuberculosis elimination programme between 1960 and 1968 (32% of affected cows in 1959). The majority of brucellosis-affected ranches were also infected by bovine tuberculosis. Depopulation and repopulation of these ranches helped both programmes. The planned replacement of brucellosis and tuberculosis animals was carried out between 1962 and 1965. This involved the organised transfer of 695,042 healthy cattle from disease-free regions (in 1962 – 179,641; in 1963 – 179,821; in 1964 – 160,067 and in 1965 – 175,513 head).

Diagnosis and surveillance

International methods available at that time were used for intravital diagnosis. The tube agglutination test was used as recommended by the Food and Agriculture Organization of the United Nations (FAO) and the World Health Organization (WHO) (6). To increase detection of all affected cattle, the test was combined, in dubious and suspect cases, with a complement fixation test and, eventually, with Coomb’s test as modified by Hajdu (9), as well as Kolar’s allergic test (11). The agglutination test, with a titre of 1:80 and 1:40 in exposed or suspect animals, was interpreted as positive. To detect and isolate all foci, total populations of cows, heifers and non-castrated bulls were tested every year. Additionally, animals were tested before moving into newly established large-scale units, before sale for breeding, in quarantine and in the areas under risk identified by thorough epizootiological investigation. Positive animals were visibly marked with a triangular hole in the right auricle (the left auricle was used for similar marking of tuberculosis cattle) and not subjected to repeated testing to avoid problems with potential false negative results. Aborted foetuses, retained placentas, vaginal discharges, milk, etc. were subjected to bacteriological investigations to diagnose new outbreaks and in all suspect cases. Preventive serological testing was carried out in exposed groups of the human population.

Brucellosis surveillance and monitoring was based upon intensive serological testing, as follows (Fig. 2):

–   pre-eradication phase (1955-1959) 5,517,733 tests,

–   eradication (attack) phase (1960-1964) 6,743,901 tests,

–   initial post-eradication phase (1965-1969) 5,581,964 tests,

–   follow-up period (1970-1999) 16,199,954 tests.

Altogether, between 1955 and 1999, 34,043,552 tests were carried out, i.e. the annual average was 756,523 tests. A maximal annual test/population ratio of 0.5 was reached in the first year of the attack phase while the average annual value for the 45 evaluated years was 0.25 (Table I).

Particular attention was paid to clinical and post-mortem suspect cases, newly discovered outbreaks, contact animals and new cases in man. Immediate action was taken to trace the disease source and route of spread using complex diagnostic methods and thorough epizootiological analysis. Every case was different, requiring different approaches. The national reference centre for brucellosis was referred to for a final opinion in dubious cases.

Programme management

Programme management played a very important role, establishing a dense network of well-staffed and equipped veterinary diagnostic laboratories operating according to international standards. Specific antigens, sera and allergens produced by a veterinary biologics factory were tested by the new Institute for Control of Veterinary Biologics. A new Veterinary Sanitation Institute with a network of rendering plants was made responsible for the processing of dead animals and non-consumable animal products, but also for carrying out demanding intrafocal disinfection by specially trained staff provided with modern equipment.

Specific legislation (ministerial decrees), instructions from the Director of the State Veterinary Service and diagnostic standards were issued (12). A national register of all diseased herds was established, and a particular target-oriented information system of reporting was introduced (number of tests, results, diseased animals and herd incidence and prevalence, programme achievement, etc.), together with data processing, evaluation and feedback. Postgraduate training of all professional staff involved was organised to ensure uniformity in application of instructions and standards. Intensive extension activities, supported by national mass media, played an important role in the effective implementation of the accelerated eradication programme. The eradication process was stimulated by financial motivation (premiums) and by competitions. Entrances of brucellosis-free ranches were identified with signboards declaring this status.

Streamlining the national brucellosis eradication programme required adapting the organisational structure of the State Veterinary Service (mainly expanding laboratory diagnostic capacities), improving the manpower of the organisation, providing material, logistic and financial backups, and strengthening the vertical management of the structure. For example, a network of regional and provincial epizootiologists was established and placed under the direct technical supervision of the national chief epizootiologist. This resulted in an uniform professional approach, programme preparation, management, co-ordination and evaluation. This structure was linked with a similar network of epidemiologists in the public health service. The veterinary and public health services played a key role in undertaking intensive surveillance with adequate follow-up response. Their collaboration in the field, in laboratories,  as well as at managerial level was excellent.

Plans for brucellosis control were elaborated in all affected provinces, regions and ranches, and implemented as an integral part of their production and managerial programmes. Individual plans, respecting national instructions and local conditions, contained the objectives, i.e. final date(s) for depopulation of brucellosis ranches and lists of anti-brucellosis activities with deadlines and responsibilities of personnel. Provincial and regional inter-sectorial committees for zoonoses control co-ordinated the activities of participating organisations.

The eradication programme was supported by direct financial aid to the farmers and co-operatives, mainly to offset the difference between real and slaughter prices. All activities in implementing the programme were financed by the state, i.e. they were free of charge. Insurance agencies contributed as well.

Results and post-eradication period

The main result of the preparatory phase was identification of specific epizootiological situations and influencing factors, selection of an appropriate eradication method and creation of indispensable conditions.

During the eradication phase, 19,247 new brucellosis-positive bovines were detected. All existing 39,835 diseased animals (i.e. 20,841 found at the beginning plus new ones) and more than one hundred thousand intrafocal serologically negative cattle and contacts were eliminated and replaced by healthy animals. Finally, previously vaccinated animals were eliminated to avoid future diagnostic complications. Total eradication comprised 654 initial and 91 new outbreaks, i.e. 745 outbreaks (Table II).

Zero prevalence in cattle was achieved by the end of 1964 (Table III), followed by zero incidence (Fig. 3). Simultaneous zero incidence was achieved in humans (Fig. 4). Complete recovery of the cattle population was reached by removing and replacing all diseased and suspect intrafocal animals (Table IV). No recurrence appeared during the post-eradication period (14, 15). Eradication was achieved simultaneously in the Slovak Republic, i.e. the entire country of Czechoslovakia was free of bovine brucellosis by 1964.

Eradication cost about US$ 28 million (US$ 15 million – state subsidies, US$ 6 million – services, US$ 4 million – local source expenses and US$ 3 million – insurance agencies). All expenses included, replacement of one diseased bovine with a healthy animal cost an average of US$ 703 (eradication cost/number of replaced diseased animals) and eradication of one outbreak cost an average of US$ 37,584. A simple annual benefit/cost ratio of > 1 was reached by the third year of the programme. The cumulative benefit was represented by the specific disease-free status being transferred to following cattle generations, thereby preventing repetition of previous losses. A cumulative benefit/cumulative cost ratio of > 1 was reached by the fourth year of the programme.

Ten years after eradication of the disease, this indicator reached the value of 5:1, taking into account the cost of post-eradication surveillance. The ratio of cumulative benefits to the cost of eradication was 7:1 and to the discounted eradication cost, 12:1 (Fig. 5). However, the discount method could not be used on the cumulative public health, biological, ecological and economic benefits which were increasing, i.e. multiplying (not decreasing), in time. The difference between the total cumulative benefit (US$ 236 million) and the total cumulative cost (US$ 43 million) reached a value of US$ 193 million by the tenth year of the programme.

Brucellosis eradication in cattle helps to prevent the occurrence of new cases in the human population (Table V). Monetary criteria are not suitable for evaluating the benefit to human health.

To retain the success achieved, the post-eradication period was dedicated to a special surveillance system consisting mainly of intensive serological investigation with priority being given to critical places and strategic timing (Table VI). Following international recommendations (7), the Rose Bengal plate agglutination test was also used for mass preventive investigation from the beginning of the nineties.

During the post-eradication period, in spite of extraordinary strict protection measures, the disease was introduced twice from abroad. In 1973, affected cattle penetrated from a neighbouring country in one border pasture. The country concerned eliminated the Brucella-infected animals in the frontier zone after an official request of the Minister of Agriculture (referring to the current inter-governmental bilateral veterinary agreement). In 1974, brucellosis was reintroduced through the exceptional import of cattle with official guarantee of being from a brucellosis-free ranch based on negative serological tests. All tests carried out after the import as well as the tests after first parturition were negative. However, abortions occurred in the quarantine ranch on second parturition. The outbreaks were immediately eliminated upon detection. Several persons were infected. Foreigners were responsible for a new, exceptional occurrence of the disease in humans. Some cases were caused by Brucella suis (eradicated in 1994), while Brucella melitensis has never occurred.

Conclusion

Eradication of bovine brucellosis at national level is not an easy task (8, 16). Approximately half the countries in the world are still reporting the occurrence of the disease (17). Vaccination and ‘test and slaughter’ control methods continue to prevail in these countries (1, 3, 7, 10, 17). However, the imposition of a relatively short final eradication deadline and the more radical approach described above proved to be useful and effective in the Czech (and Slovak) Republics.

Accelerated eradication in less than one cattle generation consisted of exploiting the reproduction process of the national cattle population with a temporary quota regulating national trade in meat and milk. Discovering and isolating all outbreaks and a consistent system approach were the most important preconditions to the programme.

The active participation of about two thousand veterinarians in the field, slaughterhouses, laboratories, research and service management, as well as the close co-operation of the public health service, were crucial to the success achieved. A centralised State Veterinary Service, strong in manpower, material, facilities and budget proved to be the backbone of this extremely complex and demanding programme. Co-operation with farmer organisations and support of the public and their representatives were exemplary. Strict measures for very limited imports of cattle, due to increasing self-sufficiency in meat and milk production, helped to protect the country from re-infection.

The drastic method adopted proved to be not only biologically, but also economically effective under the given conditions. The results have been reflected in substantial improvement of the breeding, production and reproductive performances of the cattle population and in ensuring brucellosis-free milk and milk products. The absence of an effective eradication programme would probably have resulted in the disease spreading and the economic losses and number of new diseased humans would be at least the same as at the beginning of the programme. Up to the year 2000, eradication has prevented economic losses of about seven hundred million US$ and saved more than two thousand people from being affected by the zoonosis.

 

References

1.      Acha P.N. & Szyfres B. (2001). – Zoonoses and communicable diseases common to man and animals. In Bacterioses and mycoses, 3rd Ed., Vol. I. Pan American Health Organization, Washington, DC, 392 pp.

2.      Anderle O. (1962). – Eradikace brucelozy skotu metodou radikalni likvidace [Eradication of brucellosis by radical liquidation method]. Vet. Med. (Praha), 7, 335-338.

3.      Cin J. (2000). – Brucellosis. In Control of communicable diseases manual, 17th Ed. (J. Cin, Ed.). American Public Health Association, Washington, DC, 75-78.

4.      Drazan J. (1962). – Metody ozdravovani chovu skotu zamorenych brucelozou [Methods for the recovery of cattle herds affected by brucellosis]. Veterinárství, 7, 331-334.

5.      Erkintalo M.L. & Simula I. (1976). – Brucellosis and its eradication from Finland. Duodecim, 92 (9), 477-483.

6.      Food and Agriculture Organization (FAO)/World Health Organization (WHO) (1952). – Report of the Second Joint FAO/WHO Expert Committee on brucellosis. FAO, Rome, 49 pp.

7.      Food and Agriculture Organization (FAO)/World Health Organization (WHO) (1986). – Report of the Sixth Joint FAO/WHO Expert Committee on brucellosis. Technical Report Series No. 740. WHO, Geneva, 132 pp.

8.      Garin-Bastuji B. (1994). – Brucelloses humaines et animales: une evolution favorable, une eradication difficile. Point vét., 26, 851-858.

9.      Hajdu S. (1961). – Najnovejsi poznatky v serodiagnostice brucelozy [New methods for serodiagnosis of brucellosis]. Vet. cas. Bratislava, 10, 258-265.

10.    Kasyanov A.N. (1982). – Methods of brucellosis control in animals. In Zoonoses control, Vol. II. United Nations Environment Programme, Moscow, 109-115.

11.    Kolar J. (1953). – Alergicka diagnostika bruceloz [Allergic diagnosis of brucellosis]. Veterinárství, 3, 163-164.

12.    Kouba V. (1962). – Problematika brucelozy hospodarskych zvirat v Ceskoslovensku [Problems of brucellosis in domestic animals in Czechoslovakia]. Vet. Med. (Praha), 7, 285-300.

13.    Kouba V. (1964). – Konecna faze eradikace brucelozy skotu v Ceskoslovensku [Final phase of cattle brucellosis eradication in Czechoslovakia]. Veterinárství, 14, 423-430.

14.    Kouba V. (1965). – Eliminace brucelozy skotu v Ceskoslovensku [Elimination of Brucellosis in cattle in Czechoslovakia]. Cs. epid. mikr. a imunol., 14, 233-243.

15.    Kouba V. (2000). – Historie eradikace bovinni brucelozy v Ceske Republice [History of bovine brucellosis eradication in Czech Republic]. Cas. lek. ces., 139 (8), 227-230.

16.    Nolen S. (1999). – Brucellosis deadline came and went, but USDA’s campaign continues. J. Am. vet. med. Assoc., 214 (8), 114.

17.    OIE (World organisation for animal health) (2001). – World animal health in 2000. OIE, Paris, 701 pp.

18.    Sandvik O. & Naess B. (1994). – Animal health standards in Norway. The Royal Ministry of Agriculture, Oslo, 107 pp.

19.    Suntych F. & John C. (1956). – Nemocnost brucelozou u veterinarnich lekaru v Cechach [Brucellosis among veterinarians in Czech Republic]. Veterinárství, 6, 293-295.

 

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Table I
Bovine brucellosis surveillance – serological tests in cattle, Czech Republic, 1955-1969

Year

Number of serological tests

Ratio tests/total population

Pre-eradication (preparatory) phase

 

 

1955

713,597

0.2499

1956

974,108

0.3367

1957

1,023,803

0.3601

1958

1,238,204

0.4255

1959

1,568,021

0.5249

Eradication (attack) phase

 

 

1960

1,515,000

0.5000

1961

1,412,843

0.4511

1962

1,333,487

0.4294

1963

1,226,446

0.3949

1964

1,256,125

0.4098

Initial post-eradication phase

 

 

1965

1,276,203

0.4238

1966

1,244,231

0.4101

1967

1,268,323

0.4176

1968

1,003,252

0.3405

1969

789,955

0.2687

 

Table II
Brucellosis in cattle – affected regions and outbreaks (new, extinct), Czech Republic, 1960-1969

Year

Number of regions with cattle with brucellosis
(on 31 December)

Number of outbreaks of brucellosis

Beginning of the year

new

extinct – eliminated

End of the year

1960

34

654

29

165

518

1961

32

518

17

107

428

1962

22

428

17

61

384

1963

15

384

15

110

289

1964

6

289

10

85

214

1965

0

214 *

3

107

110 *

1966

0

110 *

0

110 *

0

1967

0

0

0

0

0

1968

0

0

0

0

0

1969

0

0

0

0

0

*   in observation, i.e. without diseased animals

 

Table III
Prevalence of brucellosis in cattle, Czech Republic, 1955-1969

Year
(on 1 January)

Number of diseased animals

Prevalence per 100,000 heads

1955

19,500 *

683 *

1956

22,000 *

760 *

1957

26,186

921

1958

24,000 *

824 *

1959

22,000 *

736 *

1960

20,481

676

1961

33,211

1,060

1962

36,656

1,083

1963

25,288

750

1964

7,998

261

1965

0

0

1966

0

0

1967

0

0

1968

0

0

1969

0

0

*   estimates

 

Table IV
Elimination of cattle affected by Brucella abortus in former Czechoslovakia, 1960-1964

Year

Number at the beginning of the year

New cases

Eliminated

Number at the end of the year

1960

98,596

9,823

2,186

106,133

1961

106,133

4,279

22,091

88,421

1962

88,421

1,188

20,649

68,960

1963

68,960

1,511

42,184

28,287

1964

28,287

2,631

30,918

0

Total 1960-1964

98,596

19,432

118,028

0

 

Table V
Incidence of brucellosis in the human population, Czech Republic, 1955-1999

Year

New Cases

Year

New Cases

Year

New Cases

1955

39

1971

0

1987

1

1956

75

1972

0

1988

2

1957

38

1973 *

11

1989

1

1958

45

1974 *

4

1990

1

1959

32

1975

1

1991

1

1960

67

1976

0

1992

0

1961

71

1977

0

1993

0

1962

74

1978

0

1994

0

1963

49

1979

1

1995

1

1964

37

1980

0

1996

0

1965

2

1981

1

1997

0

1966

10

1982

0

1998

0

1967

3

1983

1

1999

1

1968

2

1984

4

2000

0

1969

0

1985

1

 

 

1970

0

1986

1

 

 

The exceptional cases observed during the post-eradication period occurred among foreigners and some were caused by Brucella suis

*   Cases related to imported cattle infected by Brucella abortus

Table VI
Bovine brucellosis post-eradication surveillance – tests in cattle, Czech Republic, 1970-1999

Year

Total serological tests

Positive results

Annual average of tests

Annual ratio tests/total population

1970-1974

2,172,708

111 *

434,542

0.1412

1975-1979

2,314,050

0

462,812

0.1394

1980-1984

1,547,611

0

309,522

0.0877

1985-1989

686,896

0

137,379

0.0395

1990-1994

6,038,143

0

1,207,629

0.4640

1995-1999

3,440,539

0

688,108

0.3952

Total 1970-1999

16,199,954

111 *

539,999

0.1825

*   imported cattle

 

Fig. 1 Distribution of brucellosis-infected cattle in Czechoslovakia, January 1959

Fig. 2 Cattle brucellosis investigations, Czech Republic, 1955-1990

Fig. 3 Brucellosis incidence in cattle, Czech Republic, 1955-2000

Fig. 4 Brucellosis incidence in man, Czech Republic, 1955-2000

Fig. 5 Bovine brucellosis control – benefit to cost ratio, Czech Republic, 1960-1974