Background Typhoid fever remains a significant health problem in many developing countries. and 57 were other non-salmonella infections. Thirteen hemolyzed samples were excluded. Using all non – S. Typhi isolates as controls we showed a sensitivity of 79% and a specificity of 89%. When the analysis was repeated excluding NTS from the pool of controls we showed a sensitivity of 79% and a specificity of 97%. There was no significant difference in the test performance using the two different control groups (p > 0.05). Conclusion This first evaluation of the Tubex test in an African setting showed GRI 977143 a similar performance to those seen in some Asian GRI 977143 settings. Comparison with the earlier results of a Widal test using the same samples showed no significant difference (p > 0.05) for any of the performance indicators irrespective of the applied control group. Keywords: Salmonella Tubex? Widal Africa Rapid Diagnostic Test Background Typhoid fever remains a significant health problem in many developing countries. Estimates suggest an incidence rate of more than 21.5 million cases globally in the year 2000 . Recent data from Tanzania mainland have found a strong variation of prevalence rates among blood culture positive isolates collected in local hospitals ranging from 9%  to 21.4%  for Salmonella enterica serovar Typhi (S. Cdc14A2 Typhi) no data from Zanzibar are available to date. As the clinical picture of typhoid fever is often unspecific misdiagnosis and insufficient or inadequate treatment are potential risks associated with the disease. In the absence of difficult-to-obtain bone marrow specimens microbiologic culture of a blood sample is considered to be the current state-of-the art test for the diagnosis of typhoid fever even GRI 977143 though its sensitivity may be as low as 40% [4 5 Culture may take up to seven days and requires a well-run and equipped laboratory which is often not available in settings with endemic typhoid fever. The widely in use Widal test provides a cost efficient alternative  for serological diagnosis however its performance remains unsatisfying with sensitivity reported from Tanzania of 75% using blood culture as the gold standard and applying a cut off titer of 1 1:80 . The test further requires the establishment of a local cut off titer prior to use which is complicated. Therefore a rapid test with a performance comparable to that of blood culture would be desirable. A rapid diagnostic test for typhoid fever Tubex? is commercially available that uses particle separation to detect immunoglobulin M (IgM) directed towards Salmonella enterica serovar Typhi (S. Typhi) O9 lipopolysaccharide in patient sera. Performance of the test has previously been evaluated in a number of studies in Asia but none in Africa. Using blood culture results for comparison we assessed the sensitivity and specificity of the Tubex test among Tanzanian children hospitalized with febrile illness and compared our results with those from previous studies. Methods For evaluation GRI 977143 of the Tubex test GRI 977143 we GRI 977143 used a selected subset of serum samples that was obtained for a fever surveillance study  from Teule Hospital in Muheza District Tanzania. In order to accommodate the required sample size for the test validation we included randomly selected and age-matched Salmonella enterica serotype Typhi (S. Typhi) positive serum samples from a second fever surveillance study conducted at Chake Chake Hospital in Pemba Zanzibar. All samples were collected from children between the ages of 2 months to 14 years from 2008 to 2009. At Teule Hospital in Muheza sera and blood was collected for culture from children with a history of three days of fever or a history of less than three days of fever but with at least one of the following severity criteria: respiratory distress; deep breathing; respiratory distress in combination with severe pallor; prostration; capillary refill ≥3 seconds; temperature gradient; systolic blood pressure <70 mm Hg; coma defined by Glasgow Coma Scale (GCS) ≤ 10 or Blantyre Coma Scale (BCS) ≤ 2; severe jaundice; history of two or more convulsions in the last.