The Epidemiology of Human and Animal Brucellosis in Algeria

Review Article

J Bacteriol Mycol. 2016; 3(2): 1025.

The Epidemiology of Human and Animal Brucellosis in Algeria

Kardjadj M*

Ecole Superieur en Science de l’Aliments (ESSA), Algiers, Algeria

*Corresponding author: Kardjadj Moustafa, Ecole Superieur en Science de l’Aliments, Algiers, Algeria

Received: April 13, 2016; Accepted: May 13, 2016; Published: May 16, 2016


In this review we summarize the published literatures end research paper on human and animal brucellosis in Algeria, to describe the incidence of human brucellosis and the seroprevalence of animal brucellosis in Algeria with special emphasis on epidemiological assessment of the deployed control measures. Comparatively, the number of new human cases reported from Algeria followed a similar trend in animals, highlighting the impact of the animal reservoir on the public health. Human incidence might reflect the true epidemiological situation of brucellosis in animals. The transmission of Brucella infection to humans in Algeria depends largely on the animal reservoir and several factors like food habits, methods of processing milk and milk products, social customs, climatic conditions, socioeconomic status, husbandry practices and environment hygiene. Cattle brucellosis is more prevalent in the north of the country, against the steppes and interior regions were brucellosis is more common among small ruminants. Consumption of milk and raw milk products has been implicated in 85% of human infections. In Algeria, Mass vaccination of all livestock (cattle, sheep and goats) throughout the territory is the most appropriate given the epidemiology of the disease. Therefore the small ruminants Rev 1 vaccination should cover the entire Algerian district and for cattle, the recommended vaccine is the RB51. Collaboration between the department of health and department of veterinary services is important for the control of brucellosis in animals and thereby eliminate transmission to humans. Training of the livestock farmers on the effective implementation of sanitary and hygienic livestock management practice following abortion helps reduce spreading the disease amongst animals as well as to the humans.

Keywords: Algeria; Animal; Brucellosis; Human; Vaccination


Brucellosis is one of the most important worldwide zoonoses affecting live stock and humans [1-3]. Described Brucella species (Brucella.spp) as facultative intracellular parasites; however, this definition does not honor their true nature which is better understood as a facultative extracellular intracellular parasite. This means that Brucella’s preferred niche is the in tra-cellular environment of the host cells. This environment supports and sustains extensive replication, allowing bacterial expansion and subsequent transmission to new host cells which is frequentlyachieved through the heavily infected aborted foetus [2]. Nine Brucella species are currently recognized, seven of which affects terrestrial animals: B. abortus, B. melitensis, B. suis, B. ovis, B. canis, B. neotomae, and B. microti and two that affect marine mammals: B. ceti and B. pinnipedialis [4]. The first three species are called classical Brucella within which we have seven biovars for B. abortus, three for B. melitensis and five for B. suis. Serovars are yet to be associated with the remaining species. The bacteria are host specie specific and are therefore named after the host specie infected. The strains of brucellae were named based on the host animal preferentially infected [5].

Brucella infection is responsible for up to 20 - 25% decrease in milk production, 10 to15% in meat production, 15% loss of calves due to abortions, 30% increase in the rate of animal replacement, and increased calving interval of to 11.5 to 20 months in domestic animals. In addition, every five infected cows abort once or become permanently infertile [6]. Besides the loss of animal productivity, brucellosis is a zoonosis of major health public importance; five out of the nine known Brucella species can infect humans and the most pathogenic and invasive species for human is B. melitensis, followed in descending order by B.suis, B. abortus and B. canis [6]. The zoonotic nature of the marine brucellae (B. ceti) has been documented by several workers [7-9]. B. melitensis, B. suis and B. abortus are listed as potential bio-weapons by the Centers for Disease Control and Prevention (CDC) in the USA. This is due to the highly infectious nature of the three species, as they can be readily aerosolized. Moreover, an outbreak of brucellosis would be difficult to detect because the initial symptoms are easily confused with those of influenza [10].

The geographical distribution of brucellosis is constantly changing, with new foci emerging or re-emerging. The epidemiology of human brucellosis has drastically changed over the past few years because of various sanitary, socioeconomic, and political reasons, together with increased international travel. New foci of human brucellosis have emerged, particularly in central Asia, while the situation in certain countries of the Middle East and North Africa is rapidly worsening [11]. Brucellosis is a notifiable disease in most countries; it is reportable to both local and national health authorities by health workers. However, it is under reported and official numbers constitute only a fraction of true incidence of the disease. Thus the true incidence of human brucellosis is unknown and the estimated burden of the disease varies widely, from <0.03 to >160 per 100,000 population [11,12]. Although estimates of the costs associated with brucellosis infections remain limited to specific countries, all data suggest that worldwide economic losses due to brucellosis are extensive not only in animal production (reduced milk, abortion and delayed conception), but also in public health (cost of treatment and productivity loss) [6].

Human brucellosis remains the most common zoonotic disease worldwide, with more than 500,000 new cases reported annually [11]. Globally this disease is highly under-reported because of its vague (pathognomonic) clinical flu like symptoms, difficulty to diagnose in the laboratory and lack of familiarity by medical professionals [13]. Therefore, the true incidence of human brucellosis is unknown for most developing countries of the world including Algeria. Data documenting human and animal brucellosis are very meager in Algeria. However, brucellosis has been reported in humans and ruminants in Algeria causing huge economic losses [14,15].

Diagnosis of brucellosis in humans and animals is mainly based on detection of Brucella LPS specific antibodies in milk and serum samples using serological tests. These tests do not differentiate between an acute and a chronic infection [16]. Cross reaction can occur with other Gram negative bacteria such as: Yersinia enterocolitica O:9, Escherichia coli and some Salmonella spp. That have antigenic similarities with Brucella LPS and can lead to false positive reactions [17]; isolation of Brucella is required for confirmatory diagnosis of brucellosis. Published bacteriological investigations in Algeria did characterize Brucella at the species and biovar levels [14,15,18]. Recently a real-time PCR based assay was used to identify the Brucella at the molecular level inhuman sera [19].

In this review we summarize the published literatures end research paper on human and animal brucellosis in Algeria. Data reviewed were also obtained from the Algerian Ministry of Agriculture and Rural Development (MADR) and the Algerian Ministry of Public Health (MPH). The objectives of this review are to describe the incidence of human brucellosis and the seroprevalence of animal brucellosis in Algeria with special emphasis on epidemiological assessment of the deployed control measures.

Geographical Area

Algeria is the largest country in Africa. It is located between latitudes 19° and 37°N and longitudes 9°W and 12°E. It is bounded by the Mediterranean Sea to the north, Tunisia to the east, Morocco to the west, Mali and Niger to the south. It has a long coastline at the Mediterranean Sea (1600km); Most of the coastal area (northern region) is hilly, sometimes even mountainous. South of the northern region is a steppe; farther south, there is the Sahara desert. For reasons of animal health, transportation of animals is forbidden between Sahara and northern Algeria. Administratively, Algeria is divided into 48 districts but for the present study and according to geographical and farming management specificity, five regions were delimited and each region contained 7 to 12 districts; north-central (35.3°-36.8°N and 1°E-4.7°E), north-western (35°-36.3°N and 2°W-1°E), northeastern (35.3°-37°N and 4.7°E-8.5°E), steppe region (33°-35.3°N and 2°W-8.5°E). And the Sahara (19°-33°N and 8.8°W-12°E). Algeria has 2,147,570 km2 area of land with about 40 million people (Table 1). More than 80% of the people live in coastal areas [20].