Journal of Tropical Medicine

Review Article

Utility of the Rose Bengal Test as a Point-of-Care Test for Human Brucellosis in Endemic African Settings: A Systematic Review

Table 2

Reported sensitivity and specificity of RBT in patient groups used in reviewed studies.


Patient groups	Test	RBT positive, n/N	DSe	DSp

Patients with acute brucellosis (diagnosis of brucellosis was based on clinical findings and on either positive blood cultures for Brucella spp. or the presence of serum antibodies (SAT titer => 160)) [23].	Titrated RBT	NR	100	97
	MAT	NR	92	100
	Brucellacapt	NR	100	100
	IgG ELISA	NR	84	100
	IgM ELISA	NR	60	100
	IgA ELISA	NR	96	98

Patients with clinical suspicion of brucellosis [28].	RBT (acute + subacute)	49/52	94.2	NS
	RBT (chronic)	6/11	54.5	NS
	RBT (total)	45/63	71.4	NS
	SAT ≥ 1 : 200 (acute + subacute)	26/52	50	NS
	SAT ≥ 1 : 200 (chronic)	6/11	54.5	NS
	SAT ≥ 1 : 200 (total)	32/63	50.8	NS
	LFA IgM and/or IgG (acute + subacute)	52/52	100	NS
	LFA IgM and/or IgG (chronic)	11/11	100	NS
	LFA IgM and/or IgG (total)	63/63	100	NS
	LFA IgM (acute + subacute)	47/52	90.4	NS
	LFA IgM (chronic)	8/11	72.7	NS
	LFA IgM (total)	55/63	87.3	NS
	LFA IgG (acute + subacute)	39/52	75	NS
	LFA IgG (chronic)	11/11	100	NS
	LFA IgG (total)	50/63	79.4	NS

Patients presented with clinical signs of brucellosis; clinical features along with epidemiological evidence were considered for presumptive clinical diagnosis of brucellosis [34].	Titrated RBT	78/200	88.9	87.7

Patients presented with clinical suspicion of brucellosis [36].	RBT	20/20	100	100
Patients with diseases mimicking brucellosis clinically [36].	RB screening test	0/280	NS	NS
	STAT (≥1/160)^b	0/280	NS	NS

Patients with signs of brucellosis at presentation [20].	RBT	91/91	100	NS
	ELISA IgM	59/91	64.8	NS
	ELISA IgG		56.1	NS

Patients with signs of brucellosis at presentation [31].	RBT	NS	NS	NS

Healthy, voluntary blood donors [21].	RBT	NS	NS	NS
	Coombs	NS	NS	NS
	2-ME	NS	NS	NS
	CFT	NS	NS	NS
	Indirect ELISA	NS	NS	NS
	cELISA	0/10	NS	NS
	FPA	NS	NS	NS
	PCR	0/30	NS	NS
Healthy people from endemic areas [21].	RBT	NS	7	NS

Individuals with no history of brucellosis or regular exposure to Brucella spp. (patients with different infectious, autoimmune, or neoplastic processes with a precise aetiological diagnosis, but which involved an initial differential diagnosis with brucellosis) [15].	RB screening test	288/307	93.8	94.3
Patients with a previous history of brucellosis/asymptomatic individuals infected with Brucella who had received appropriate treatment during the previous 12 months [15].	RB screening test	49/51	96.1	76.9
Asymptomatic individuals exposed repeatedly to Brucella infection during their work [15].	RB screening test	311/339	91.7	94.3

Patients with primary infection (no personal history of brucellosis) and showing acute clinical symptoms [19].	RB screening test^c	38/38	100	99
	Tube agglutination test (≥1/160)	NS	97	99
	Coombs (≥1/320)	NS	100	98
	ELISA IgG	NS	78	83
	ELISA IgM	NS	94	98
	CFT	NS	91	99

Patients with evidence of previous Brucella infection, with either brucellosis diagnosed previously or epidemiological data compatible with long exposure and an immune response of “secondary type” (IgG predominating on IgM) [19].	RB screening test	22/24	92	52
	Tube agglutination test (≥1/160)	NS	20	98
	Coombs (≥1/320)	NS	100	80
	ELISA IgG	NS	100	70
	ELISA IgM	NS	54	76
	CFT	NS	88	78

Patients with acute brucellosis (presented with fever and had nonspecific symptoms such as headache, malaise, arthralgia, and low back pain. Other symptoms included splenomegaly, lymphadenitis, and localization of the disease including genitourinary hematological and osteoarticular involvement) [33].	RBT	83/83	100	87.5
Patients with chronic/relapsing brucellosis (defined as patients located 3–13 years following first hospital visit when they presented with acute brucellosis infection). Chronic brucellosis cases did not have signs of acute brucellosis illness on presentation the second time [33].	RBT	9/72	NS	NS

Patients categorised as acute (duration up to 12 months)/chronic (more than 12 months)/healthy [37].	RBT	3/21	NS	NS
Patients categorised as acute (duration up to 12 months)/chronic (more than 12 months)/healthy [37].	RBT	3/21	NS	NS

Patients with a diagnosis of chronic brucellar meningitis or meningoencephalitis [35].	RBT	118/123	NS	NS
	RBT	75/106	NS	NS
Patients with fever but no other symptoms of brucellosis and tested negative on culture and other tests [35].	RB screening test	0/107	NS	NS
	SAT (≥1/180)	0/107	NS	NS
	Coombs (≥1/160)	0/107	NS	NS
	ELISA IgG	NS	NS	NS
	ELISA IgM	NS	NS	NS
	ELISA IgA	NS	NS	NS
	ELISA T^d	4/107	NS	NS

Contacts with no brucellosis and had professional contact [2].	RB screening test^e	19/20	NS	NS
	RB titration test (>1 : 4)^e	0/20	NS	NS
	SAT (=160)^e	3/20	NS	NS
	Brucellacapt (≥320)^e	8/20	NS	NS
	Coombs^e	16/20	NS	NS
	LFiC-IgM^e	4/20	NS	NS
	LFiC-IgG^e	8/20	NS	NS
Patient with no recent contact and no symptoms of brucellosis sent to the lab for diagnosis of other infections [2].	RB screening test^f	1/1559	NS	NS

Patients with brucellosis categorised as acute (n = 296) [27].	RBT		98	100
Patients with brucellosis categorised as subacute (n = 44) [27].	RBT		84	100
Patients with brucellosis categorised as chronic (n = 40) [27].	RBT		61	100
Patients with brucellosis categorised as CNS brucellosis (n = 317) [27].	RBT		22	100
Patients with other infectious diseases, noninfectious diseases, and normal healthy individuals (n = 345) [27].	RBT			100

RBT positive: Rose Bengal test positive, DSe: diagnostic sensitivity, DSp: diagnostic specificity, PPV: positive predictive value, NPV: negative predictive value, and NS: not specified. RBT: standard RBT, titrated RBT: titrations made by serial dilutions of serum with saline solution, SAT: serum agglutination test, LFA: lateral flow assay, MAT: microagglutination test, Brucellacapt: immunocapture-agglutination test, LFiC: lateral flow immunochromatography assay. ^bSTAT: only low titres were obtained in 3 patients, one with malaria (1/40), one with lymphoma (1/40), and another with typhoid fever (1/20). ^cReported test values were combined values for patients with primary infection (no personal history of brucellosis) showing acute clinical symptoms and patients with evidence of previous infection by Brucella.^dELISA T: detects total specific antibodies. ^eSensitivity and specificity not reported, but number of positives in this patient group reported for each test performed. This group comprised 20 people that had had professional contact (veterinarians, slaughterhouse workers, shepherds, etc.) with B. melitensis-infected animals or their products or had accidentally injected themselves with vaccine B. melitensis Rev 1 and that were followed for a period of at least two years [2]. ^fSensitivity and specificity not reported, but number of positives in this patient subgroup reported for standard RBT (RB screening test).