The diagnosis of brucellosis by use of BACTEC 9240 blood culture system

Urological infections in the developing world: an increasing problem in developed countries

PURPOSE

Infectious diseases that often follow geographical distribution patterns are increasingly crossing such boundaries, aided by human travel and commerce. These pose a new challenge to physicians who are required to diagnose previously unseen conditions and address drug-resistant organisms. We review some such common infections.

METHODS

A literature review was performed for six common urological infections and a narrative review based on recent publications on these infections was compiled.

RESULTS

In Urology, some infections that are now crossing geographical boundaries include Brucellosis, Schistosomiasis, Tuberculosis, Filariasis, Hydatidosis and emphysematous pyelonephritis. Brucellosis, a zoonotic infection, is common in the Mediterranean areas, Asia, South America and Africa. Infection can involve all parts of the genitourinary tract. Schistosomiasis, a parasitic disease, is particularly common in Sub-Saharan Africa and may have bacterial superinfection. Voiding symptoms are common and bladder carcinoma may develop. Tuberculosis affects almost every organ in the body and in the male genital system, often presents with abscesses, nodules, ulcers and infertility that is difficult to manage. Filariasis is caused by two species of worms and is transmitted through a bite from a mosquito carrying larvae of the worm. It causes lymphatic obstruction leading to scrotal edema, hydrocoele to elephantiasis of scrotum. Emphysematous pyelonephritis is a life-threatening suppurative necrotizing infection of the renal parenchyma. While not being geographically limited, it is more common in developing areas with poor health care access. Genitourinary hydatidosis is a rare disease that is associated mainly with renal involvement in the genitourinary tract. Large cysts with destruction of renal parenchyma may be found.

CONCLUSIONS

Although uncommon, these urological infections are associated with significant morbidity and mortality and awareness in all healthcare settings is now an essential requirement.

Laboratory Diagnosis of Human Brucellosis

The clinical presentation of brucellosis in humans is variable and unspecific, and thus, laboratory corroboration of the diagnosis is essential for the patient's proper treatment. The diagnosis of brucellar infections can be made by culture, serological tests, and nucleic acid amplification assays. Modern automated blood culture systems enable detection of acute cases of brucellosis within the routine 5- to 7-day incubation protocol employed in clinical microbiology laboratories, although a longer incubation and performance of blind subcultures may be needed for protracted cases. Serological tests, though they lack specificity and provide results that may be difficult to interpret in individuals repeatedly exposed to Brucella organisms, nevertheless remain a diagnostic cornerstone in resource-poor countries. Nucleic acid amplification assays combine exquisite sensitivity, specificity, and safety and enable rapid diagnosis of the disease. However, long-term persistence of positive molecular test results in patients that have apparently fully recovered is common and has unclear clinical significance and therapeutic implications. Therefore, as long as there are no sufficiently validated commercial tests or studies that demonstrate an adequate interlaboratory reproducibility of the different homemade PCR assays, cultures and serological methods will remain the primary tools for the diagnosis and posttherapeutic follow-up of human brucellosis.

Clinical spectrum, susceptibility profile, treatment and outcome of culture-confirmed brucellosis from South India

Brucellosis, a common zoonosis, is under reported in India despite its endemicity and increased exposure to livestock among the population. This study was conducted to determine the clinical manifestations, antibiotic susceptibility pattern, treatment and outcome of culture confirmed brucellosis. Adult patients with culture confirmed brucellosis who presented to a large teaching hospital in South India between 2009 and 2015 were included. A diagnosis of brucellosis was confirmed on automated culture. Clinical profile, laboratory parameters, drug susceptibility, treatment and outcome were documented by reviewing the medical records. The cohort comprised of 22 patients with mean ± SD age of 42 ± 13 years. Twenty one (95.5%) was male. Thirteen (59%) patients were from rural area and risk of acquisition of brucellosis including occupational exposure or consumption of unpasteurized milk was evident in 16 (72.7%) patients. The mean duration of symptoms before presentation was 54.5 ± 52 days. The commonest clinical presentation was prolonged fever without a definite focus in 18 patients (82%), whereas 2 (9%) patients had osteoarticular involvement and one patient (4.5%) each had genital involvement and endocarditis. Eighteen patients (82%) with uncomplicated brucellosis were treated with aminoglycoside and doxycycline for 6 weeks. There was no relapse or mortality at 18 ± 9 months of follow up. Brucellosis in this cohort had acute or subacute presentation with prolonged fever and bacteremia. High index of clinical suspicion based on significant epidemiological history along with automated blood culture improves the efficiency of diagnosis. Cure with lack of relapse among these cases suggests a combination therapy with doxycycline and aminoglycoside is highly effective for the treatment.

A rare case of seronegative culture--proven infection with Brucella suis

Brucellosis is a chronic infection produced by members of the Brucella family. Diagnosis of this condition requires either isolation of the organism in culture or positive serological tests.We describe a 27-year-old male admitted as a case of pyrexia of unknown origin (PUO), who tested negative for Brucella IgM ELISA test on preliminary evaluation but was subsequently diagnosed on the strength of positive blood and bone marrow cultures to be a case of brucellosis secondary to Brucella suis infection. In addition to highlighting the pathogenic potential of an unusual organism, this case demonstrates the unreliability of standard serological tests based on the Brucella melitensis antigen for infection with other species of Brucella.

Human brucellosis

Human brucellosis still presents scientists and clinicians with several challenges, such as the understanding of pathogenic mechanisms of Brucella spp, the identification of markers for disease severity, progression, and treatment response, and the development of improved treatment regimens. Molecular studies have shed new light on the pathogenesis of Brucella spp, and new technologies have permitted the development of diagnostic tools that will be useful in developing countries, where brucellosis is still a very common but often neglected disease. However, further studies are needed to establish optimum treatment regimens and local and international control programmes. This Review summarises current knowledge of the pathogenic mechanisms, new diagnostic advances, therapeutic options, and the situation of developing countries in regard to human brucellosis.

Prevention of Laboratory-Acquired Brucellosis

Brucellosis is one of the most common laboratory-acquired infections, mostly because aerosolization is a mechanism of transmission in this setting. We report an exposure to Brucella melitensis that occurred in a large microbiology laboratory and describe the strategy chosen for antibiotic prophylaxis and serological follow-up of exposed workers.

Ovarian abscess due to Brucella melitensis

The case of a 25-y-old woman with brucellar ovarian abscess is reported. Cultures of blood, ascites and a pus specimen yielded Brucella melitensis. The possibility of ovarian abscess being caused by Brucella melitensis should be considered in countries where the infection is endemic.