|Year : 2017 | Volume
| Issue : 2 | Page : 94-96
Utility of automated blood cultures in the diagnosis of childhood brucellosis
Nivedhana Subburaju1, Suresh Natarajan2, Ramaswamy Ganesh1, Sulochana Putlibai1
1 Department of Clinical Microbiology, Kanchi Kamakoti Childs Trust Hospital and Childs Trust Medical Research Foundation, Chennai, Tamil Nadu, India
2 Department of Paediatrics, Kanchi Kamakoti Childs Trust Hospital and Childs Trust Medical Research Foundation, Chennai, Tamil Nadu, India
|Date of Web Publication||19-Jan-2018|
Dr. Nivedhana Subburaju
Kanchi Kamakoti Childs Trust Hospital and Childs Trust Medical Research Foundation, 12-A, Nageswara Road, Nungambakkam, Chennai - 600 034, Tamil Nadu
Source of Support: None, Conflict of Interest: None
Brucellosis, a zoonoses, is an important yet underdiagnosed and underreported cause of fever of unknown origin (FUO) in India. This may be both due to lack of awareness and lack of simple diagnostic tests for confirmation. The serological and molecular diagnostic tests may pose trouble in interpretation due to lack of standardisation. Culture is the gold standard and needs 6 weeks, which can be minimised with automated blood culture system. We describe four cases of culture-proven childhood brucellosis in the past 1 year. In our case series, fever and lymphadenopathy were seen in 100%, arthralgia in 50% and hepatomegaly in 75%. Use of automated blood culture system and good clinician–microbiologist communication aided in early diagnosis (<5 days) and appropriate treatment. On follow-up, all the cases are doing well.
Keywords: Automated blood cultures, brucellosis, children, fever, zoonoses
|How to cite this article:|
Subburaju N, Natarajan S, Ganesh R, Putlibai S. Utility of automated blood cultures in the diagnosis of childhood brucellosis. J Patient Saf Infect Control 2017;5:94-6
|How to cite this URL:|
Subburaju N, Natarajan S, Ganesh R, Putlibai S. Utility of automated blood cultures in the diagnosis of childhood brucellosis. J Patient Saf Infect Control [serial online] 2017 [cited 2018 May 24];5:94-6. Available from: http://www.jpsiconline.com/text.asp?2017/5/2/94/223686
| Introduction|| |
Brucellosis More Details is a zoonoses which is transmitted to humans by contact with fluids from infected animals (goat, sheep, cattle, pig) or by ingestion of animal products such as unpasteurised milk and cheese. The disease is endemic in developing countries like India. The incidence of brucellosis in endemic areas varies from <0.01 to 200/1,00,000 population worldwide. But for few case reports, the exact data of incidence of brucellosis is lacking in the Indian scenario., Possible reasons for this may be due to lack of awareness in diagnosis, lack of simple laboratory methods for confirmation and underreporting (<10%). We herewith report a series of four culture-proven childhood brucellosis in the past 1 year from a tertiary care paediatric hospital in Chennai. This article also highlights the importance of utilising automated blood culture systems for clinching the definitive diagnosis in brucellosis.
| Case Reports|| |
A 4-year and 6-month-old girl from rural background was admitted for fever, rash and arthralgia of both knee and ankle joints for 1 month. There was no history of loss of appetite/weight and contact with tuberculosis. On examination, she was febrile, had pallor, cervical lymphadenopathy, hepatosplenomegaly and arthritis involving knees and ankles. Peripheral smear for the malarial parasite (MP) was negative. Her Widal, anti-nuclear antibody and HIV tests were negative. Bone marrow study was normal. Blood culture grew Brucella More Details melitensis. Serum Brucella IgM and IgG were positive, but polymerase chain reaction (PCR) was negative. She responded to the treatment [Table 1] and is doing well on follow-up.
|Table 1: Clinical and laboratory profile of children diagnosed with brucellosis|
Click here to view
An 11-month male infant from rural background was brought for prolonged fever (2 months). There was no history of cough, loose stools, rash or weight loss. He was on cow's milk and complementary feeds. On examination, he was febrile, had erythematous rashes over anterior chest and back and generalised lymphadenopathy. His blood culture grew B. melitensis on the 4th day. Brucella IgM antibody was positive, but PCR was negative. He recovered completely with appropriate treatment [Table 1].
A 7-year-boy was admitted for fever (2 months) and abdominal distension (1 month). There was no history of abdominal pain, vomiting, dysuria, icterus, arthralgia, rash and bony tenderness. On examination, he was febrile, had pallor and bilateral upper deep cervical lymphadenopathy. Abdomen examination revealed hepatosplenomegaly. Peripheral smear for MP, Widal and HIV were negative. His blood and bone marrow cultures yielded growth of B. melitensis. He responded well to treatment [Table 1].
A 4-year-old girl was evaluated for intermittent fever and arthralgia of both knee joints for 2 weeks. She had been investigated outside and treated with antibiotics. On examination, she was afebrile, had pallor, cervical lymphadenopathy and hepatosplenomegaly. Her blood cultures grew B. melitensis on the 3rd day. The parents retrospectively revealed the history of feeding with unpasteurised goat's milk for 2 months. The child recovered dramatically on treatment [Table 1].
| Discussion|| |
Brucellosis usually presents as remittent fever over weeks to months, affects all age groups and both sexes but children are at increased risk because of their close contact with animals. The incubation period is 1–4 weeks. The species pathogenic to humans include B. melitensis (ruminants) the most common and the most virulent, Brucella abortus (cattle), Brucella suis (swine) and Brucella canis (dogs). The characteristic triad of brucellosis includes fever, arthralgia/arthritis and hepatosplenomegaly. In our case series, fever of >2 weeks duration and lymphadenopathy was seen in 100%, hepatomegaly in 75%, arthralgia of both knees in 50% only. Total white cell counts are usually normal with pancytopenia reported in 20% of cases. All our patients had normal WBC counts with lymphocytic predominance [Table 1].
Laboratory tools for the diagnosis of brucellosis include culture, serology and PCR. If compatible with clinical findings standard agglutination tests (SAT) titres of >1:160 is diagnostic, but in endemic areas, titres of >1:320 are considered highly specific (99%) for diagnosis of acute brucellosis. However, the limitations of SAT are its inability to diagnose B. canis, cross-reactions with other Gram-negative organisms such as Yersinia More Details enterocolitica, Francisella tularensis and Vibrio cholerae. False-negative reactions might be due to blocking antibodies, prozone phenomenon. Positive titres may persist long after recovery, so it does not always distinguish between past and persistent infections.
The IgM and IgG enzyme-linked immunosorbent assays are the second most common serological tests used, but different studies have demonstrated varying sensitivity and specificity. This may be due to issues related to standardisation, reagent quality and result interpretation.
Molecular tests such as PCR performed on blood or body tissues can give positive reaction 10 days after inoculation. PCR cannot be considered a routine diagnostic method, given the need for standardisation, infrastructure, equipment, expertise and a better understanding of the clinical significance of the results. Brucella DNA PCR can remain positive for most of the patients even after successful treatment and in the absence of relapse. Conversely, relapses may be seen in PCR-negative patients.
Culture is considered as the gold standard in the laboratory diagnosis of brucellosis. However, blood culture positivity rate ranges from 40% to 90% in acute cases and 5%–20% in chronic cases using conventional Castaneda method which requires 6 weeks of incubation. Brucella has a long doubling time (2.5–3.5 h) compared to that of other bacilli such as Escherichia More Details coli (20 min). The newer automated blood culture methods have shortened the mean time taken for detection (35 days to <5 days). In the present series, blood culture was performed using automated the BacT/ALERT Microbial Detection system (bioMerieux, France) and continuously monitored for the presence of microorganisms. All the blood cultures became positive 3–4 days and with the mean time to positivity being 64 h. The positive bottles were subcultured onto blood agar, chocolate agar and MacConkey agar and incubated appropriately. The tiny Gram-negative coccobacilli were identified as B. melitensis using Vitek-2 (Biomerieux, France) and standard biochemical tests. We exercise with a word of caution that there are many chances of the growth being discarded as contaminant in brucellosis due to their varied appearance and preliminary cultures in 48 h being sterile. Bone marrow culture, even though an invasive procedure is even more sensitive than blood culture in chronic cases which may be negative because of prior use of antibiotics.
The common complications include osteoarticular involvement (40%), genitourinary involvement (2%–20%), pulmonary involvement (7%), gastrointestinal involvement (3%–6%) and neurological involvement (2%–7%) of cases., But none of our patients had any complications. The reported rate of relapse following treatment is 5%–15% within 6 months. We followed up all our cases for 6 months, but there was no relapse observed. This may be due to benign nature, uncomplicated course and good response to treatment of childhood brucellosis over adult cases.
| Conclusion|| |
In Indian scenario, it is always important to consider common infections such as typhoid, scrub typhus, malaria in children presenting with fever of unknown origin (FUO), particularly when associated with hepatosplenomegaly, lymphadenopathy and arthritis. Once these are ruled out, other infections such as brucellosis should be considered. Hence, we conclude that the use of automated culture methods is of paramount importance. This helps in avoiding wide range of investigations and inappropriate antibiotics. A good communication between the clinician and the microbiologist in FUO cases could play a crucial role in the early diagnosis and treatment.
We would like to acknowledge our senior consultants Dr. Lalitha Janakiraman, Dr. K. G Ravikumar and Dr. V. S. Sankaranarayanan for their support and involvement.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Bosilkovski M, Dimzova M, Grozdanovski K. Natural history of brucellosis in an endemic region in different time periods. Acta Clin Croat 2009;48:41-6.
Mantur BG, Amarnath SK, Shinde RS. Review of clinical and laboratory features of human brucellosis. Indian J Med Microbiol 2007;25:188-202.
] [Full text]
Pappas G, Akritidis N, Bosilkovski M, Tsianos E. Brucellosis. N
Engl J Med 2005;352:2325-36.
Schutze GE, Jacobs RF. Brucellosis. Nelson Textbook of Paediatrics. Vol. 2. Ch. 207. First South Asia: Elsevier; 2016.
Alshaalan MA, Alalola SA, Almuneef MA, Albanyan EA, Balkhy HH, AlShahrani DA, et al
. Brucellosis in children: Prevention, diagnosis and management guidelines for general pediatricians endorsed by the Saudi Pediatric Infectious Diseases Society (SPIDS). Int J Pediatr Adolesc Med 2014;1:40-6.
WHO/CDS/EPR/2006.7. Brucellosis in Humans and Animals. Geneva: World Health Organization; 2006.
Raj A, Gautam V, Gupta PK, Sethi S, Rana S, Ray P, et al.
Rapid detection of Brucella by an automated blood culture system at a tertiary care hospital of North India. Indian J Med Res 2014;139:776-8.
] [Full text]
Bosilkovski M, Krteva L, Caparoska S, Dimzova M. Osteoarticular involvement in brucellosis: Study of 196 cases in the republic of Macedonia. Croat Med J 2004;45:727-33.
Bosilkovski M, Krteva L, Dimzova M, Kondova I. Brucellosis in 418 patients from the Balkan Peninsula: Exposure-related differences in clinical manifestations, laboratory test results, and therapy outcome. Int J Infect Dis 2007;11:342-7.
Gotuzzo E, Pappas G. Brucellosis. In: Guerrant RL, Walker DH, Weller PF, editors. Tropical Infectious Diseases: Principles, Pathogens and Practice. 3rd
ed. Philadelphia: Saunders Elsevier; 2011. p. 271.