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Microbes & Immunity Childhood brucellosis in Saudi Arabia

affects livestock animals; however, it can be transmitted to Research Committee of the Unit of Biomedical Ethics,
humans and causes serious complications if left untreated. Faculty of Medicine, King Abdulaziz University, Jeddah,
The principal signs and symptoms of brucellosis Saudi Arabia (approval reference no. 128-18).
include fever accompanied by malaise, arthralgia, arthritis, Patients aged 18 years or younger at the time of
weight loss, hepatosplenomegaly, and lymphadenopathy. brucellosis diagnosis, confirmed through blood culture
2,3
The two primary risk factors for brucellosis are the and/or serology, were eligible for inclusion in the study.
consumption of raw, unpasteurized, or non-sterilized A list of patients was obtained using test codes for the
2
dairy products and direct contact with infected animals. Brucella antibody test and Brucella culture. Both paper
In pediatric patients, the main source of infection is the and electronic medical records were reviewed to identify
consumption of unpasteurized milk. The most frequent pediatric inpatient and outpatient patients (age <18 at the
3,4
complications of brucellosis involve bone and joint tissues, time of diagnosis).
occurring in up to 40% of cases. Numerous uncommon
2
complications of brucellosis have been described, such 2.2. Laboratory diagnosis
as cardiac complications (for example, endocarditis and Patients included in this study had a confirmed diagnosis
myocarditis), testicular complications in male patients, of brucellosis, either through a positive blood culture or
and neurological complications such as meningitis and an antibody titer for B. abortus, B. melitensis, or both, and
encephalitis. Brucellosis may also have ophthalmic received antibiotic treatment. The serological test used
complications. However, these are considered rare in in our hospital was the serum agglutination test (SAT),
pediatrics. 4 which measured total antibodies (Immunoglobulin [Ig]G
The global annual incidence rate of human brucellosis is and IgM) and provided a semi-quantitative result (titer).
estimated at 2.1 million cases. The disease remains a major Two types of antigens were used in the test – one for
5
threat to human health in many developing countries, B. abortus and the other for B. melitensis. After mixing the
particularly in North and East Africa, the Mediterranean antigen suspension with the patient’s serum, the tubes were
basin, and the Indian subcontinent. It is also endemic incubated at 37°C for up to 48 h. The test was validated
4
in the Middle East, the Arabian Peninsula, and parts using positive and negative controls supplied with the
of Central Asia and South America. On the contrary, kit (different commercial tests were used). The SAT has a
human brucellosis has been eradicated from several reported sensitivity of 95.6 – 100% and a specificity of 96
8,9
developed countries, including many Northern European – 100%. In Saudi Arabia, where brucellosis is endemic,
countries. In Saudi Arabia, the number of reported cases an antibody titer of at least 1:640 for either Brucella spp. is
4
between 2004 and 2012 was 37,477, with the incidence considered positive for confirming the diagnosis.
risk significantly decreasing from 22.9 in 2004 to 12.5 in Microbiologically, blood samples from patients
2012. The Saudi cities with the highest percentage of cases suspected of having brucellosis were labeled as “Brucella”
are Alqassim, followed by Aseer, Hail, and the northern and incubated at 37℃ for up to 14 days in the BD
region, whereas the western region of Saudi Arabia has BACTEC FX system (Beckton, Dickinson and Company,
3,6
™
a lower incidence. In 2014, the Saudi Pediatric Infectious United States [US]). Positive samples were subcultured
4
Diseases Society published clinical practice guidelines for onto blood and chocolate agar plates, which were incubated
brucellosis in children. 7 for 24 – 48 h in a 5 – 10% CO environment. If growth
2
Given that brucellosis is one of the most frequently was observed on the plate, the bacteria were identified
reported diseases in Saudi Arabia and the limited number through the morphology of the colonies, Gram staining,
of published reports on childhood brucellosis, this study and biochemical testing for urease and oxidase (as Brucella
aimed to describe the characteristics, course of therapy, and spp. produces both enzymes). While microbiological
outcomes of pediatric brucellosis cases in Saudi Arabia. culture facilitated the identification of the genus Brucella,
it does not provide species-level identification. The results
2. Materials and methods from serological testing were used to identify the specific
species.
2.1. Study design and patients
The current retrospective descriptive study was conducted 2.3. Data collection
at King Abdulaziz University Hospital, Jeddah, in the Collected data included demographics, clinical
western region of Saudi Arabia. Data were collected from variables (including complications and organ or system
pediatric patients over 11 years, from January 2008 to involvement), date of admission (for inpatients), duration
February 2019. Ethical approval was obtained from the of hospital stay, antibiotic therapy administered, and

Volume 2 Issue 1 (2025) 71 doi: 10.36922/mi.4634