Brucellosis among Hospitalized Febrile Patients in Northern Tanzania

Abstract

Abstract. Acute and convalescent serum samples were collected from febrile inpatients identified at two hospitals in Moshi, Tanzania. Confirmed brucellosis was defined as a positive blood culture or a 4-fold increase in microagglutination test titer, and probable brucellosis was defined as a single reciprocal titer 160. Among 870 participants enrolled in the study, 455 (52.3%) had paired sera available. Of these, 16 (3.5%) met criteria for confirmed brucellosis. Of 830 participants with 1 serum sample, 4 (0.5%) met criteria for probable brucellosis. Brucellosis was associated with increased median age (P = 0.024), leukopenia (odds ratio [OR] 7.8, P = 0.005), thrombocytopenia (OR 3.9, P = 0.018), and evidence of other zoonoses (OR 3.2, P = 0.026). Brucellosis was never diagnosed clinically, and although all participants with brucellosis received antibacterials or antimalarials in the hospital, no participant received standard brucellosis treatment. Brucellosis is an underdiagnosed and untreated cause of febrile disease among hospitalized adult and pediatric patients in northern Tanzania.

Etiology of Severe Non-malaria Febrile Illness in Northern Tanzania: A Prospective Cohort Study

“…Standardized Brucella abortus strain 1119-3 killed antigen (National Veterinary Services Laboratory, Ames, IA) was used for MAT at a 1∶25 working dilution described elsewhere [24]. Results were read on a Scienceware Plate Reader (Bel-Art Products, Wayne, NJ).…”

Brucellosis in low-income and middle-income countries

“…All 275 cases of Brucella bacteremia were derived from a hospital-based fever etiology study in Egypt, where Brucella was the second most common cause of bloodstream infection, behind Salmonella enterica serotype Typhi [46]. A hospital-based fever etiology study in northern Tanzania found 16 (3.5%) of 455 febrile hospital admissions met the US Centers for Disease Control and Prevention (CDC) confirmed case definition for acute brucellosis [47,48 ▪ ]. Although relatively few cases were identified, laboratory-confirmed brucellosis was a more common cause of fever in this cohort than laboratory-confirmed malaria (3.5 vs. 1.8%), and none of the 16 patients received a clinical diagnosis of brucellosis.…”

“…This is reflected in a higher risk of disease in marginalized livestock-keeping communities, as well as veterinary and abattoir workers. However, there is also evidence from cities in sub-Saharan Africa that brucellosis is a cause of febrile illness in urban settings, linked to the sale and distribution of contaminated raw milk [48 ▪ ,64,65]. …”

“…Whether disease manifestations might vary by region or by infecting Brucella species merits further investigation. For instance, whereas hematologic abnormalities such as anemia and leukopenia are common in Mediterranean populations, thrombocytopenia is fairly uncommon [66,67]; in contrast, over 40% of the brucellosis cases in the northern Tanzania fever cohort had thrombocytopenia [48 ▪ ]. Compared to B. melitensis infections, B. suis appears to cause marked elevation in alanine aminotransferase [31] and B. abortus is thought to cause more mild disease [68]; but in general, data are limited regarding species-specific manifestations.…”

Etiologies of Illness Among Patients Meeting Integrated Management of Adolescent and Adult Illness District Clinician Manual Criteria for Severe Infections in Northern Tanzania: Implications for Empiric Antimicrobial Therapy

“…[9][10][11][16][17][18][19][20] In brief, a confirmed etiologic diagnosis required detection of Plasmodium spp. on peripheral blood smear ( 500 trophozoites/μL), 10,11 nucleic acid detection in serum (dengue, chikungunya, or flaviviruses), 19 serum antigen detection (Cryptococcus neoformans 1:8), 21 urine antigen detection (Histoplasma capsulatum, 20 Streptococcus pneumoniae, Legionella pneumophila serogroup 1), 10,11 4-fold rise between acute and convalescent serology (microscopic agglutination tests [MAT] for Brucella spp., 18 and Leptospira spp., 17 and immunofluorescent antibody [IFA] for Coxiella burnetii, Rickettsia conorii, and Rickettsia typhi), 16 or isolation of clinically relevant bacteria, mycobacteria, or fungi from blood culture. 10,11 Illness was attributed to tuberculosis based solely on isolation of Mycobacterium tuberculosis complex from blood culture (i.e., bacteremic disseminated tuberculosis), 22 and not based on a clinical diagnosis of tuberculosis or positive acid-fast bacilli smear or culture of respiratory specimens, which were not collected as part of the febrile illness cohort study.…”