Afr. J. Integ. Health Vol 1: No1; 2013 Correspondence to: Tebit Kwenti Emmanuel Email: kwentitebit@yahoo.com Tel.: 00237 3301158 21 NJUNDA et al.: Establishing antibody baseline titres for the Widal agglutination tests in the Buea Health District using stool culture as standard: A cross sectional study: AJIH 2013, 01:21-24 Original Articles Establishing Antibody Baseline Titres for the Widal Agglutination Tests in the Buea Health District Using Stool Culture as Standard: A Cross Sectional Study Anna Longdoh NJUNDA 1* , Jules Clement Nguedia ASSOB 2 , Dickson Shey NSAGHA 3 , Henri-Lucien Fouamno KAMGA 1 , Njimbia Anthony CHEBE 1 , Tebit Emmanuel KWENTI 1 1 Department of Medical Laboratory Sciences, University of Buea, P.O.Box 63, Buea, Cameroon 3 Department of Public Health and Hygiene, University of Buea, P.O.Box 63, Buea, Cameroon 2 Department of Biomedical Sciences, University of Buea, P.O.Box 63, Buea, Cameroon Source of Support: this work was funded through the departmental research grant of the Department of Medical Laboratory Scienc- es, Faculty of Health Science, University of Buea, Buea, Cameroon. Keywords Salmonella sp; typhoid; Widal test; diagnosis Abstract Background:Baseline titres for somatic and flagella (O and H) antibodies should be established in every community to avoid false positive results with the Widal test given that a proportion of healthy individuals have antibodies capable of reacting at variable titres. The objective of this study was to determine baseline antibody titres for the Widal test in the Buea Health District. Method: A cross sectional study was carried out involving 150 participants (100 patients and 50 controls). Blood and stool samples were collected from patients presenting with symptoms of typhoid at the Buea Regional Hospital. Widal tests were run for the blood samples while the stool samples were cultured for Salmonella species. Result: Out of 100 patients, 21 (21%) were culture-positive for Salmonella. None of the control members was culture-positive. Among the culture positive cases, 17 were positive with the Widal tube test among whom 13 (76.5%) had anti-O antibody titre ≥1/160 and 16 (94.1%) had anti-H antibody titre ≥1/320, meanwhile 14 were positive for both stool culture and the slide test, among whom 12 (85.7%) presented anti-O antibody titre ≥1/160 and 11 (78.6%) had anti-H antibody titres ≥1/320. Conclusion: The sensitivity was higher with the Widal tube test (85%) relative to the Widal slide test (66.66%). When using solely a Widal test to diagnose typhoid, an anti-O and anti-H antibodies titres of ≥1/160 and ≥1/320 respectively together with clinical features can be considered diagnostic Introduction Typhoid fever is caused by Salmonella enteric serovartyphi (S. typhi). Though Salmonella paratyphi A, B and C cause a similar disease [1] called paratyphoid fever. Paratyphoid fever is not clinically distinguishable from typhoid fever so S. typhi, paratyphi A, B and C are collectively referred to as typhoidal Salmonella serovars [2]. Many factors influence the severity and overall clinical outcome of the infection: duration of illness before initiation of therapy, choice of antimicrobial treatment, age, amount of inoculum etc[3]. It should be noted that the gold standard for the diagnosis of typhoid fever is the isolation of S. typhi from blood, bone mar- row, stool, urine or other body fluids [4]. The above samples can be used for definitive diagnosis of typhoid fever [5] because they are reliable [6]. However, bacterial culture facilities are often unavailable in laboratories of endemic areas [7]. The Widal agglutination test is the most widely used in these under- developed countries [8]. The principle of the test is to demon- strate the presence of antibodies in the serum of an infected pa- tient, against the O (somatic) and H (flagellar) antigens of Sal- monella typhi and Salmonella paratyphi A, B and C through agglutination. It was reported by Punia et al., [9] that in endemic countries, a proportion of healthy individuals contain antibodies capable of reacting to variable titres in Widal test. This could be due to cross reacting antigens such as malaria, brucellosis, den- gue fever, healthy carriers, chronic liver disease, endocarditis or other enterobacteriaceae infections [10]. A fourfold rise in the antibody titres between the acute and the convalescent phases is considered a significant change in an individual but this compar- ison is not helpful in establishing diagnosis in acute infections [11]. It is therefore important that baseline titres for anti-O and anti-H antibodies be established to avoid false positive results. Each country should find the appropriate titre with which to di- agnose typhoid fever [5]. In Cameroon, a studied carried out by Nsutebu et al.,[12] showed that a baseline titre of 1/100 for anti- O and 1/400 for the anti-H is diagnostic for typhoid in the town of Yaounde. The aim of this study was to determine antibody cut-off titres for the diagnosis of typhoid and paratyphoid fever with the Widal tube agglutination test. Materials and Methods Study site and participants This study was approved by the Faculty of Health Sciences Eth- ical Review Board of the University of Buea, Cameroon. Blood