Invasive Salmonellosis among Children Admitted to a Rural Tanzanian Hospital and a Comparison with Previous Studies

George Mtove,Abraham Mwambuli,Ilse Hendriksen,Jacqueline L Deen,Stephen Magesa,Juma Kimera,Rajabu Mallahiyo,Hugh Reyburn,R Leon Ochiai,Ben Amos,Deok Ryun Kim,John D Clemens,Lorenz Von Seidlein

doi:10.1371/journal.pone.0009244

Abstract

BackgroundThe importance of invasive salmonellosis in African children is well recognized but there is inadequate information on these infections. We conducted a fever surveillance study in a Tanzanian rural hospital to estimate the case fraction of invasive salmonellosis among pediatric admissions, examine associations with common co-morbidities and describe its clinical features. We compared our main findings with those from previous studies among children in sub-Saharan Africa.Methodology/Principal FindingsFrom 1 March 2008 to 28 Feb 2009, 1,502 children were enrolled into the study. We collected clinical information and blood for point of care tests, culture, and diagnosis of malaria and HIV. We analyzed the clinical features on admission and outcome by laboratory-confirmed diagnosis. Pathogenic bacteria were isolated from the blood of 156 (10%) children, of which 14 (9%) were S. typhi, 45 (29%) were NTS and 97 (62%) were other pathogenic bacteria. Invasive salmonellosis accounted for 59/156 (38%) bacteremic children. Children with typhoid fever were significantly older and presented with a longer duration of fever. NTS infections were significantly associated with prior antimalarial treatment, malarial complications and with a high risk for death.Conclusions/SignificanceInvasive salmonellosis, particularly NTS infection, is an important cause of febrile disease among hospitalized children in our rural Tanzanian setting. Previous studies showed considerable variation in the case fraction of S. typhi and NTS infections. Certain suggestive clinical features (such as older age and long duration of fever for typhoid whereas concomitant malaria, anemia, jaundice and hypoglycemia for NTS infection) may be used to distinguish invasive salmonellosis from other severe febrile illness.

Highlights

Salmonella enterica serotype Typhi (S. typhi) and several non-Typhi serotypes of S
The data is sparse, there seems to be a relatively low burden of pediatric typhoid fever across sub-Saharan Africa [2] whereas non-Typhi serotypes of S. Enterica (NTS) has consistently been reported as a leading cause of bacteremia in African children [3,4]
Bacteria were isolated from the blood of 298 (20%) of these children, of which 142 (10%) were considered as likely contaminants

Summary

Introduction

Salmonella enterica serotype Typhi (S. typhi) and several non-Typhi serotypes of S. Enterica (NTS) are important causes of childhood bacteremia in African children [1]. The data is sparse, there seems to be a relatively low burden of pediatric typhoid fever across sub-Saharan Africa [2] whereas NTS has consistently been reported as a leading cause of bacteremia in African children [3,4]. We estimated the case fraction of invasive salmonellosis among our pediatric admissions, examined associations with common co-morbidities and described its clinical features in comparison with other febrile illnesses. We conducted a fever surveillance study in a Tanzanian rural hospital to estimate the case fraction of invasive salmonellosis among pediatric admissions, examine associations with common co-morbidities and describe its clinical features. We compared our main findings with those from previous studies among children in sub-Saharan Africa

Methods

Results

Conclusion