Epidemiological aspects of brucellosis in Jordan

From January 1988 to December 1997, a total of 7842 cases of human brucellosis were registered at the Ministry of Health in Jordan. A link was found to exist between the lambing season and the occurrence of the infection. The number of cases was found to be the lowest in children below 4 years and highest in the 5-14-years age group. Incidence of the infection was calculated per 100,000 population. The lowest incidence of brucellosis was 16.7 and this was detected in the year 1988, whereas the highest was 29.9 and this was observed in 1991. Evidence is provided which indicates that notified cases of human brucellosis in Jordan do not reflect the actual frequency but rather underestimate the extent of the infection.

Conditional dependence between tests affects the diagnosis and surveillance of animal diseases

Dependence between the sensitivities or specificities of pairs of tests affects the sensitivity and specificity of tests when used in combination. Compared with values expected if tests are conditionally independent, a positive dependence in test sensitivity reduces the sensitivity of parallel test interpretation and a positive dependence in test specificity reduces the specificity of serial interpretation. We calculate conditional covariances as a measure of dependence between binary tests and show their relationship to kappa (a chance-corrected measure of test agreement). We use published data for toxoplasmosis and brucellosis in swine, and Johne's disease in cattle to illustrate calculation methods and to indicate the likely magnitude of the dependence between serologic tests used for diagnosis and surveillance of animal diseases.

Brucella abortus infection acquired in microbiology laboratories

We report an outbreak of laboratory-acquired Brucella abortus infection originating in the accidental breakage of a centrifuge tube. A total of 12 laboratory workers were infected (attack rate of 31%), with an incubation time ranging from 6 weeks to 5 months. Antibody titers were evaluated weekly in all personnel exposed, allowing the diagnosis of the infection in most cases before the onset of clinical symptoms, so that specific therapy could be administrated.

Risk factors for brucellosis seroprevalence of sheep and goat flocks in Spain

Risk factors for ovine and caprine brucellosis in the Avila region (center of Spain) were evaluated using data from a cross-sectional study of the most important diseases of small ruminants in this Spanish region between 1996 and 1997. Questionnaire data from 56 herds (35 ovine and 21 caprine) were used. Sixteen (29%) flocks (3 caprine and 13 ovine) were brucellosis-seropositive. Overall, 0.7% of sheep and 0.1% of goats were seropositive. Eleven risk factors were studied at the group level by logistic regression using flock brucellosis-status as outcome, and by linear regression using percentage of brucellosis-seropositivity as outcome. Both final models contained the same variables: contact with sheep and grazing in communal pastures as risk factors, and frequency of disinfecting practices as a protective factor.

[History of the eradication of bovine brucellosis in the Czech Republic]

In the Czech republic, the program of recovery of the livestock from brucellosis caused by the micro-organisms Brucella abortus was successfully completed in 1964. The campaign started in 1959 by the exploration of the complete cattle population by agglutination tests. Incidence of the disease was 211 positive cases for each 100 thousands, prevalence was 0.676% (20,481 animal in 654 foci of 34 districts). The prevalence was significantly higher in large cattle units. Tens of new cases of the human brucellosis infections were reported. The process of sanitation was first based on the elimination of infected animals. In the later phase the more radical method was employed--the whole herds with infected individuals were eliminated and replaced. During the recovery program more than 41 thousands of infected animals were eliminated. It required solving many complex methodological, legislative, organisational, economical and social problems. Serological test applied to more the half of the livestock population together with epizootiological, epidemiological and laboratory investigation helped to detect all foci. Eradication brought about substantial improvement of the productive and reproductive features of the cattle and eliminated the risks of infection with this zoonosis to the human population.

Exposure of hospital personnel to Brucella melitensis and occurrence of laboratory-acquired disease in an endemic area

In 1997, 7 cases of laboratory-acquired Brucella melitensis infections were detected among the hospital personnel of a medical centre serving an endemic area in southern Israel. Although the onset of symptoms in 6 of the 7 patients occurred during a 2-week period, suggesting a point source exposure, biotype analysis showed that the outbreak was caused by 3 different B. melitensis serovars, indicating multiple exposures. Review of the laboratory records showed that during 1997, the microorganism was recovered from 146 blood and synovial fluid cultures, and that during the 2 months in which the laboratory-acquired cases occurred (April and June), 53 of 530 positive aerobic blood culture bottles (10.0%) grew B. melitensis. The epidemiological investigation did not reveal the source of the outbreak, and no noticeable breaches in laboratory safety practices could be demonstrated. It is concluded that in areas endemic for brucellosis, hospital personnel are frequently exposed to Brucella microorganisms. Under these circumstances, significant morbidity may occur despite observance of recommended safety practices. Biotyping of Brucella isolates may contribute to the elucidation of complex epidemiological situations.

Seroprevalence of brucellosis in Kashmir (India) among patients with pyrexia of unknown origin

Over a period of 5 years from 1992 to 1997 a total of 3,532 patients of pyrexia of unknown origin (PUO) were subjected to Wright's tube agglutination test for brucellosis. Of the 3,532 patients tested, 28 (0.8%) were found seropositive for brucellosis. Males outnumbered females by a ratio of 3:1. Whereas the seroprevalence among males clearly was age-related, the seroprevalence among women was not. The highest number (43%) of positive males belonged to the age group 21-30 years. The majority of patients had titres of 1:160 or 1:256, high titres of 1:512 and 1:1024 were found in 21.4% patients.

Serosurvey for selected infectious disease agents in free-ranging black and white rhinoceros in Africa

Two hundred and eighty one serum samples collected from free-ranging black (Diceros bicornis) and white (Ceratotherium simum) rhinoceros, in the Republic of South Africa (RSA), Namibia, and Kenya from 1987-97, were examined for antibody to 16 different infectious agents. Positive antibody titers were detected against Akabane (59.8%), bluetongue (55%), African horse sickness (27.9%), epizootic haemorrhagic disease of deer (19.4%), parainfluenza type 3 (25.3%), bovine herpes virus 1 (3.1%), equine herpes virus 1 (8.8%) and bovine viral diarrhea (1.2%) viruses, and four serovars of Leptospira interrogans, (ranging 1.2 to 8.8%). No antibody was detected against Rift Valley fever virus, encephalomyocarditis virus, Brucella abortus, and Trypanosoma equiperdum. Interspecies differences were detected for African horse sickness, epizootic haemorrhagic disease of deer and parainfluenza type 3 viruses. There appeared to be some geographic variation in the prevalence of antibody for African horse sickness, bluetongue, epizootic haemorrhagic disease of deer, parainfluenza type 3, equine herpes virus 1 and Leptospira interrogans serovar bratislava.

Clinical profile of neurobrucellosis--a report on 12 cases from Bikaner (north-west India)

OBJECTIVE

To study the spectrum of neurobrucellosis in a prospective study at Bikaner which is supposed to be uncommon in India.

METHOD

This study was done on admitted patients of brucellosis from June 1996 to June 1999 in whom the diagnosis was done by history of exposure to animals, fever and arthralgia and demonstration of brucella antibody titres in serum 1:160. CSF examination was done in all the patients. All cases were treated by combination of doxycycline 100 mg twice daily, rifampicin 900 mg daily for 6-8 weeks and injection streptomycin 0.75 to 1 gm i.m. per day for initial 14 days. Detailed neurological examination and antibody titres of serum and CSF again measured at the end of treatment.

RESULTS

Twelve out of 92 patients revealed evidence of neurobrucellosis in which four cases were of meningoencephalitis, two cases of myelitis leading to spastic paraparesis, five cases of polyradiculoneuropathy and one case of polyneuroradiculomyeloencephalopathy. The treatment regimen used was associated with a high cure rate and significant reduction in antibody titres in serum and CSF.

CONCLUSION

Neurobrucellosis is an uncommon but serious manifestation affecting central and peripheral nervous system. The clinical profile of the disease mimicks closely to commonly seen neurological infective diseases like tubercular meningitis, viral encephalitis, aseptic meningitis, cerebral malaria and viral encephalopathy. Serum and CSF testing for brucella antibody titre is an important test for the diagnosis. Blood culture is not an ideal test for neurobrucellosis because of low yield and longer time required for the diagnosis. High degree of suspicion is prudent for the diagnosis. High degree of cure rate can be achieved by treatment with present regimen in a disease which is otherwise having high mortality and morbidity.

[Seroepidemiological study of brucellosis in a rural endemic area]

BACKGROUND

This study investigated the prevalence of Brucella spp. antibodies in the general population in the Health Area of Tremp (Region of Pallars Jussà, Lleida). It also identified the risk factors with the presence of these.

PATIENTS AND METHODS

A total of 346 (191 men and 155 women) were studied. Information about the sex, age, location, the personal and familiar antecedents of brucellosis, occupational risk, contact with the animals and the consumption of non-hygienic dairy products was recorded. The estimation of the seroprevalence was carried out by the ELISA IgG test. The association of independent variables with the presence of antibodies was assessed by the Coombs to Brucella and the ELISA IgG tests. It was assessed by using the calculation of the analysis variance.

RESULTS

The personal antecedents, the contact with the animals and the occupational risk all showed a statistically significant relation (p < 0.05) with the Coombs and ELISA IgG tests. The familiar antecedents showed a significant relation with the ELISA IgG. The consumption of dairy products and the location showed no statistically significant relation. A seroprevalence was obtained among the researched population of 11.9%, the maximum occurred in Isona surgery (25.6%) and the minimum in Tremp (9.8%).

CONCLUSIONS

The seroprevalence is high and the epidemiological profile associated with the fact of being seropositive is associated with the profession of the study subject and it coincides with de infection mechanisms present in the area.

[Incidence, etiology and epidemiology of brucellosis in a rural area of the province of Lleida]

BACKGROUND

This a prospective study of the incidence, etiology and epidemiological profile of human brucellosis in the regions of Pallars Jussà y Sobirà (Lleida) for the 1995-1998 period.

METHODS

Fifty-five patients diagnosed as having brucellosis were studied. Information was recorded regarding the gender, age, town where residing, occupational hazard, contact with animals and intake of unsterilized dairy products, blood samples having been taken for blood cultures.

RESULTS

A total of ten cases were reported in 1995, fourteen in 1996, fifteen in 1997 and sixteen in 1998, the average cumulative rates being 52 in Pallars Jussà and 129 in Pallars Sobirà. Four times more cases were reported among males (81.8%) than among females (18.2%) (RR: 4.4; CI95% 2.2-8.7). The largest number of cases occurred in March-April, and the fewest during the summer months. Seventy-one percent (71%) of these patients were working at an occupation involving this risk, the direct contagion mechanism being clearly prevalent (71%). The animal species most frequently considered to be the source of infection was that of sheep (65%), followed by cows (47%) and goats (25%). In Pallars Jussà, mainly sheep (RO: 0.3 CI95% 0.1-0.9) and in Pallars Sobirà, cows (RO: 6.6; CI95% 1.8-26.2). Twenty-seven strains of Brucella sp, all of the melitensis species, were isolated.

CONCLUSIONS

The number of cases of brucellosis in the regions studied have risen in the 1995-1998 period. The results of study of this are indicative of the characteristic profile of an occupational disease. The etiological agent was Brucella melitensis, biovariety 1 clearly being the most prevalent.

Epidemiology and control of brucellosis in ruminants from 1986 to 1996 in Malta

The epidemiology and control of Brucella melitensis in Malta was analysed using herd test data made available by the Veterinary Service of Malta. The eradication scheme commenced in 1987 with the introduction of a test and slaughter scheme using the Rose Bengal test. Herds registered with Malta Dairy Products Limited (MDP) showed a herd prevalence of 23% in 1987 which fell to less than 1.5% by 1993. Prevalence rose to 13% in 1995. Herds not delivering milk to the MDP showed an initial herd prevalence of 4% which fell below 1% in 1994, remaining under 2% in 1995. The epidemic in 1995 caused approximately 300 human brucellosis cases. Large herds and herds with small ruminants were most at risk to brucellosis infection. Seasonal fluctuation of prevalence was apparent. Increased enforcement of regulations and motivation of farmers would accelerate eradication of brucellosis in Malta.

Reliability of results of the Rose Bengal test performed for export control in northern Somalia

Sera from sheep and goats in northern Somalia which are exported to countries of the Persian Gulf are systematically checked for brucellosis by local veterinary teams. The standard test used is rapid seroagglutination using the Rose Bengal test (RBT) and seropositive animals are not exported. In order to assess the reliability of the serological results, three randomised batches of samples (653 sera), corresponding to an equivalent number of shipments (October and December 1994 and March 1995) were counterchecked. Control RBTs were carried out by expatriate veterinarians working on behalf of international non-governmental organisations and by the Istituto Zooprofilattico Sperimentale of Padua, Italy, which also performed the complement fixation test (CFT). A fourth batch (n = 100), including a group of sera found positive by the local veterinary teams, was also checked. Agreement ranged from 96.3% to 98.5%.

[Brucellosis]

Brucellosis is a zoonosis, reported for the first time in 1859 by Marston, in Malta. It has also been referred to as Mediterranean Fever, Malta Fever and Bang's disease. Its causative agent was isolated by David Bruce in 1886; this was Brucella melitensis: five different strains were later described: B. abortus, B. suis, B. ovis, B. neotomae and B. canis. Recently, in 1994, the isolation of Brucella was reported in marine mammals, eventually pathogenic to man and unofficially designated "B. maris". Human brucellosis is still a public health problem in countries where the infection has not been eradicated from the animal hosts. When manifested, human disease may assume different courses, widely known, but whose physiopathology is still not totally clear. Much is already known about the agent's molecular biology and in vitro behaviour, but, doubts persist about its in vivo activity, including in human infection. We review some aspects of brucellosis, focusing on the pathogenesis, and referring to new and potential diagnostic methods, therapy and prevention.

Brucellosis outbreak: analysis of risk factors and serologic screening

Israel is one of the Mediterranean countries in which Brucellosis is endemic. As recently there has been a Brucellosis outbreak in a kibbutz, the aim of this study is to identify asymptomatic infected Kibbutz members, and to delineate the manner of infection in this setting. Therefore, all the asymptomatic Kibbutz members were screened by the Rose Bengal test for Brucellosis, while both patients and healthy members were asked to fill in a questionnaire in order to pinpoint the manner of infection, and signs and symptoms of the disease. In addition to the 14 patients with Brucellosis, 2 other Kibbutz members were also found to be infected by the screening tests. Analysis of the data of the questionnaires from 142 healthy and 16 patients disclosed that almost all of the infected patients (15/16) worked in the cowshed, as opposed to only 24 out of 142 (16.9%) of the healthy members. The infected tended to participate more in calf deliveries, and had contact with cow's blood and placenta, compared with the healthy subjects (P<0.001), while there were no significant differences with respect to having cuts on hands, or working in the cowshed without gloves. In addition, 15 out of 16 (93.8%) infected persons also drank unpasteurized milk, as compared with only 17 of the 142 (12%) healthy members (P<0.001), and thus were exposed to 2 major risk factors (working in the cowshed and consumption of unpasteurized milk). As the cows of the Kibbutz's cowshed were affected by Brucella melitensis (which usually affects flocks of goats and sheep rather than cows), the microbe was probably transmitted to the cowshed from neighboring flocks by wandering dogs, and then to the infected humans.

Chronic brucellosis in workers in a meat-packing plant

We report an outbreak of brucellosis among 9 patients in a meat-packing plant. All patients developed chronic brucellosis characterized by severe chronic musculoskeletal pains, diffuse arthralgia, myalgia and recurrent bouts of fever, which we suggest may be related to a delay in antibiotic treatment. All the patients had a prolonged recovery requiring rehabilitation therapy.

[Control of brucellosis in Taibe: multi-central collaboration]

Brucellosis is contracted from domestic animals. Poor hygiene, primitive animal breeding methods and traditional food preparation are the main contributory factors. We describe an intersectoral program for controlling brucellosis in Taibe, an Arab town in Israel, which had a particularly high incidence of the disease in 1992 and 1993. At the beginning of 1994 the Israel Ministry of Health and the Community Pediatric Center of Taibe established a community-based program for controlling brucellosis in Taibe. It included an intensive public health education campaign and periodic examination and vaccination of animals. Physicians, veterinarians, nurses, school officials and health inspectors were recruited for this purpose. Residents' awareness of brucellosis was determined before and after the study. After intervention, the incidence of the disease sharply declined from 176.6 and 175.0/100,000 in 1992 and 1993 respectively, to 5.7, 10.4 and 2.5/100,000 in 1994, 1995 and 1996, respectively, (odds-ratio 24.44; p < 00000). Residents' awareness of brucellosis and preventive measures were significantly increased by the end of the study. We conclude that intersectoral collaboration is an important tool for controlling brucellosis.

[The epidemiological trend of brucellosis in the provinces of Sicily]

The epidemiological trend of brucellosis in Italy has been uneven over the last few years since there was a decrease in incidence in some regions and an increase in others, including Sicily. The peak was reached in 1997 when 59% of the cases were reported in Sicily alone. Appropriate intervention strategies are therefore needed both as regards the general population and exposed workers in order to reduce the spread of this disease.

Serosurvey for selected disease agents in white-tailed deer from Mexico

Serum samples from 350 white-tailed deer (Odocoileus virginianus texanus) collected in March 1994 from northeastern Mexico were tested for the prevalence of antibody activity against five infectious diseases of ruminants. The prevalence rate was 81% for bluetongue virus (BTV) of all serotypes, 72% for epizootic hemorrhagic disease virus (EHDV), 3% for Borrelia burgdorferi, 69% for Anaplasma marginale, and 0% for Brucella abortus, B. melitensis, and B. ovis. These are diseases that affect domestic ruminants, and deer may act as a reservoir of infection. In addition, if deer are translocated, they may introduce pathogens to formerly disease-free areas. The high seroprevalence of BTV and EHDV cannot be related to the presence of hemorrhagic disease in the deer in this region. This is the first report to indicate the presence of B. burgdorferi infection of deer in Mexico. Despite the high prevalence of A. marginale titers, it is uncertain that deer play a role in the epizootiology of cattle anaplasmosis in the region. Apparently, white-tailed deer are unimportant in the epizootiology of brucellosis of both cattle and goats in northeastern Mexico.

Brucellosis in children in south Jordan

Retrospectively we evaluated the records of 68 children with brucellosis. We found 58.2% had consumed unpasteurized milk and dairy products. Nonspecific manifestations included: arthralgia (78%), fever (75%) and sweating (60%). Localized manifestations included limping (75%) and arthritis (54%). Leukopenia was found in 51% of children and anaemia in 24%. Brucella species was cultured for blood of 16 (23.5%) patients. Combination therapy containing streptomycin was more effective than gentamicin combinations.