Brucellosis among hospital employees in Saudi Arabia

Occupational exposure to Brucella spp.: A systematic review and meta-analysis

Brucellosis is a neglected zoonotic disease of remarkable importance worldwide. The focus of this systematic review was to investigate occupational brucellosis and to identify the main infection risks for each group exposed to the pathogen. Seven databases were used to identify papers related to occupational brucellosis: CABI, Cochrane, Pubmed, Scielo, Science Direct, Scopus and Web of Science. The search resulted in 6123 studies, of which 63 were selected using the quality assessment tools guided from National Institutes of Health (NIH) and Case Report Guidelines (CARE). Five different job-related groups were considered greatly exposed to the disease: rural workers, abattoir workers, veterinarians and veterinary assistants, laboratory workers and hunters. The main risk factors and exposure sources involved in the occupational infection observed from the analysis of the articles were direct contact with animal fluids, failure to comply with the use of personal protective equipment, accidental exposure to live attenuated anti-brucellosis vaccines and non-compliance with biosafety standards. Brucella species frequently isolated from job-related infection were Brucella melitensis, Brucella abortus, Brucella suis and Brucella canis. In addition, a meta-analysis was performed using the case-control studies and demonstrated that animal breeders, laboratory workers and abattoir workers have 3.47 [95% confidence interval (CI); 1.47-8.19] times more chance to become infected with Brucella spp. than others individuals that have no contact with the possible sources of infection. This systematic review improved the understanding of the epidemiology of brucellosis as an occupational disease. Rural workers, abattoir workers, veterinarians, laboratory workers and hunters were the groups more exposed to occupational Brucella spp. infection. Moreover, it was observed that the lack of knowledge about brucellosis among frequently exposed professionals, in addition to some behaviors, such as negligence in the use of individual and collective protective measures, increases the probability of infection.

Biological Risks and Laboratory-Acquired Infections: A Reality That Cannot be Ignored in Health Biotechnology

Advances and research in biotechnology have applications over a wide range of areas, such as microbiology, medicine, the food industry, agriculture, genetically modified organisms, and nanotechnology, among others. However, research with pathogenic agents, such as virus, parasites, fungi, rickettsia, bacterial microorganisms, or genetic modified organisms, has generated concern because of their potential biological risk - not only for people, but also for the environment due to their unpredictable behavior. In addition, concern for biosafety is associated with the emergence of new diseases or re-emergence of diseases that were already under control. Biotechnology laboratories require biosafety measures designed to protect their staff, the population, and the environment, which may be exposed to hazardous organisms and materials. Laboratory staff training and education is essential, not only to acquire a good understanding about the direct handling of hazardous biological agents but also knowledge of the epidemiology, pathogenicity, and human susceptibility to the biological materials used in research. Biological risk can be reduced and controlled by the correct application of internationally recognized procedures such as proper microbiological techniques, proper containment apparatus, adequate facilities, protective barriers, and special training and education of laboratory workers. To avoid occupational infections, knowledge about standardized microbiological procedures and techniques and the use of containment devices, facilities, and protective barriers is necessary. Training and education about the epidemiology, pathogenicity, and biohazards of the microorganisms involved may prevent or decrease the risk. In this way, the scientific community may benefit from the lessons learned in the past to anticipate future problems.

A literature review of laboratory-acquired brucellosis

Brucellosis is a bacterial zoonotic disease which has been associated with laboratory-acquired infections. No recent reviews have addressed the characteristics of laboratory-acquired brucellosis (LAB). English-language literature was reviewed to identify reports of laboratory exposures to Brucella spp. and LAB cases between 1982 and 2007. Evaluation of 28 case reports identified 167 potentially exposed laboratory workers, of whom 71 had LAB. Nine reports were identified that summarized an additional 186 cases of LAB. Only 18 (11%) exposures were due to laboratory accidents, 147 (88%) exposures were due to aerosolization of organisms during routine identification activities, and the circumstances of 2 (1%) exposures were unknown. Brucella melitensis was the causative agent in 80% (135/167) of the exposures. Workers with high-risk exposures were 9.3 times more likely to develop LAB than workers with low-risk exposures (95% confidence interval [CI], 3.0 to 38.6; P < 0.0001); they were also 0.009 times likelier to develop LAB if they took antimicrobial PEP than if they did not (95% CI, 0 to 0.042; P < 0.0001). The median incubation period in case and summary reports was 8 weeks (range 1 to 40 weeks). Antimicrobial PEP is effective in preventing LAB. The incubation period may be used to identify appropriate serological and symptom surveillance time frames for exposed laboratory workers.

Characteristics of B. melitensis versus B. abortus bacteraemias

OBJECTIVE

To determine the epidemiological and the clinical characteristics of bacteremic brucellosis.

METHODS

A prospective study, performed in the First Infectious Diseases Clinic of Ankara Numune Education and Research Hospital. All the patients had positive culture result for Brucella spp.

RESULTS

Fifty-four acute bacteremic brucellosis cases were included. The majority of patients (76%) were from rural Anatolia. Brucella melitensis serotypes were more common than Brucella abortus (83% versus 17%). Fever and arthralgia were the most common symptoms. The number of patients with back pain and arthralgia was higher in B. abortus infected group (p = 0.014 and p = 0.009).

CONCLUSIONS

B. melitensis is the most common subtype of Brucella infection in Turkey. The infections with B. abortus spp. are not less severe than the infections with B. melitensis.

Analysis of risk factors for laboratory-acquired brucella infections

The aim of the study was to determine the risk factors for acquiring brucella infection among healthcare workers (HCWs). The study was performed in Ankara Numune Education and Research Hospital, Turkey, before the introduction of Biosafety III measures. A questionnaire was given to HCWs, who were at risk of brucella infection. Twelve HCWs with brucella infection were detected, an incidence of 8% per employee-year. A multivariate analysis of risk factors in seven of the cases and 48 control HCWs was performed. Male physicians were found to be associated with a higher risk of acquiring brucella infection [odds ratio, 25.3; confidence interval (CI), 2.3-283.7; P=0.008]. Using gloves was found to be protective (odds ratio, 0.02; CI, 0.008-0.4; P=0.017).

Incidence and control of brucellosis in the Near East region

In countries of the Near East region, brucellosis was reported in almost all domestic animals, particularly cattle, sheep and goats. Brucellosis in camels has been reported in Saudi Arabia, Kuwait, Oman, Iraq, Iran, Sudan, Egypt, Libya and Somalia. It has been reported even in racing camels in the United Arab Emirates. In Egypt, brucellosis has been reported also in buffaloes, equines and swine. Brucella melitensis biovar 3 is the most commonly isolated species from animals in Egypt, Jordan, Israel, Tunisia and Turkey. B. melitensis biovar 2 was reported in Turkey and Saudi Arabia, and B. melitensis biovar 1 in Libya, Oman and Israel. B. abortus biovar 1 was reported in Egypt, biovar 2 in Iran, biovar 3 in Iran and Turkey, and biovar 6 in Sudan. The countries with the highest incidence of human brucellosis are Saudi Arabia, Iran, Palestinian Authority, Syria, Jordan and Oman. Bahrain is reported to have zero incidence. Most human cases are caused by B. melitensis, particularly biovar 3. However, B. abortus has been responsible for an increasing number of cases in recent years, e.g. in Yemen, where B. abortus was identified in 45 cases and B. melitensis in 7 cases out of 330 cultures performed in 1995. Concerning control of brucellosis in animals, there is a controversy on the choice of policy. In some countries, the test and slaughter policy together with the vaccination of young females is adopted, in others, particularly with regard to sheep and goats; mass vaccination has been recently started. The most commonly used vaccines are B. abortus S19 and B. melitensis Rev.1 vaccines. B. abortus RB51 vaccine is used in some countries on small scale. Vaccination is limited to cattle and small ruminants.

Endophlebitis of the leg caused by brucella infection

Brucellosis is hyperendemic in Saudi Arabia where, despite rapid urbanisation, a large segment of the population has a nomadic background and clings to cultural traditions such as the drinking of raw milk. We report here an unusual complication of brucellosis in a microbiology technologist. A 41-year-old male presented with an 8-day history of right ankle pain which, over a 3-day period, extended up to his calf where swelling and tightness developed. The leg symptomatology occurred on a background of fever, seats and rigors. X-ray of the limb was normal but a venogram revealed thrombosis of the deep veins of the right calf. Although his blood culture was negative, he developed high brucella antibody titres. Treatment with anticoagulants combined with a course of doxycycline and rifampin produced a full recovery.

Brucellosis in laboratory workers at a Saudi Arabian hospital

BACKGROUND

Saudi Arabia is hyperendemic for brucellosis, with more than 8000 cases reported each year to public health authorities. During 1998, brucellosis ranked as the No. 1 reportable communicable disease (22.5%) in Saudi Arabian National Guard communities. King Fahad Hospital is the major referral center for National Guard personnel in the nation's central region.

METHODS AND RESULTS

From 1991 to 2000, brucellosis developed in 7 expatriate hospital employees. Six employees were bacteriology technologists, and one was a pathologist. Each had a clinical syndrome compatible with brucellosis (headache, fever, rigors, sweats, and myalgias) plus elevated Brucella sp serum agglutinin titers > or = 1:1280; one patient also had positive blood cultures. All patients responded to anti-Brucella therapy. Two patients had relapses, and complications occurred in four patients (septic endophlebitis of the leg, infected prosthesis, epididymoorchitis, and lumbar spondylitis). In all these employees except the pathologist, the infection was associated with processing Brucella sp cultures.

CONCLUSION

Despite the enforcement of stringent infection control measures including the use of a class II biosafety hood in the laboratory, the problem of nosocomial brucellosis persists because of the large number of infected specimens handled by the laboratory (17,500 specimens per year). Ultimately, risk reduction depends on efforts to reduce disease endemicity in the country. In the meantime, conversion of the laboratory to biosafety level 3 is under way.

Surveillance of brucellosis in a rural area of Greece: application of the computerized mapping programme

Long term active surveillance of brucellosis was implemented in a rural area (Fokida) of Greece from 1989 to 1993 while the rural area of Grevena was selected as a control area. The computerised mapping programme was used to identify and protect the suspected animal brucellosis free zones. Health education of the inhabitants was further used to teach them how to avoid the risk factors. Three suspected brucellosis free zones were identified and two of them were successfully protected. The incidence for the 10 year period (1979-1988) was estimated at 1.4/1000/year for the study area and 1.6/1000/year for the control area. During the surveillance period the incidence in the study area dropped to 0.2/1000/year while in the control area it decreased to 1.0/1000/year. The methodology of identification and protection of suspected brucellosis free zones combined with health education proved to be efficient in reducing the incidence of the disease. The same methodology could be used in the country level, in countries where it is difficult to implement and maintain an animal control programme in the whole country.