Serological determination of Salmonella typhi and Para typhi infection in clinical acute febrile illness in Bangladesh
Nayem khan
Department of Laboratory Medicine, Impulse Hospital, Dhaka, Bangladesh
Adiatuj Jahan Rimu
Department of Public Health & Life Sciences, University of South Asia, Dhaka, Bangladesh
Md. Rashidul Islam
Department of Biochemistry & Cell Biology, Bangladesh University of Health Sciences, Bangladesh
Md. Aliul Islam
Department of Pathology, United Hospital Limited, Dhaka, Bangladesh
Md. Al-Amin Hossen
Department of Pathology, United Hospital Limited, Dhaka, Bangladesh
DOI: https://doi.org/10.59429/ersr.v3i2.12215
Keywords: Enteric fever, Salmonella Typhi, Widal test, Seroprevalence, Bangladesh
Abstract
Enteric fever remains a significant public health concern in Bangladesh and other low- and middle-income countries, largely due to inadequate sanitation and limited access to safe drinking water. Although blood culture is considered the diagnostic gold standard, serological tests such as the Widal test continue to be widely used in resource-limited settings. This cross-sectional study was conducted in the Immunology Laboratory of the Bangladesh Institute of Health Sciences (BIHS) and Bangladesh University of Health Sciences (BUHS), Dhaka, from October to December 2020, to determine the serological prevalence of enteric fever among clinically suspected acute febrile patients and to analyze antigen-specific reactivity patterns. A total of 35 blood samples were collected and analyzed using slide and tube Widal agglutination methods to detect antibodies against Salmonella Typhi and Salmonella Paratyphi antigens. Of the 35 samples, 16 (45.71%) showed positivity for at least one Widal antigen, while 19 (54.29%) were negative. Seropositivity was slightly higher among males (25.71%) than females (20%). The TH antigen (Salmonella Typhi H) demonstrated the highest positivity in both males (20%) and females (27%). Positivity for the BO antigen was observed in both genders, whereas TO antigen positivity was limited and detected only among females (7%). No reactivity was observed for AO or AH antigens in either group. The predominance of TH antigen positivity suggests previous exposure or immune sensitization to Salmonella Typhi rather than acute infection in many cases. While the Widal test remains a useful screening tool in resource-poor settings, its results should be interpreted cautiously and correlated with clinical findings and local epidemiological data. Strengthening diagnostic capacity, surveillance systems, and vaccination strategies is essential to reduce the burden of enteric fever in Bangladesh.
References
1.Khanam F, Sheikh A, Sayeed MA, Bhuiyan MS, Choudhury FK, Salma U, Pervin S, Sultana T, Ahmed D, Goswami D, Hossain ML. Evaluation of a typhoid/paratyphoid diagnostic assay (TPTest) detecting anti-Salmonella IgA in secretions of peripheral blood lymphocytes in patients in Dhaka, Bangladesh. PLoS neglected tropical diseases. 2013 Jul 11;7(7):e2316.
2.Sheikh A, Bhuiyan MS, Khanam F, Chowdhury F, Saha A, Ahmed D, Jamil KM, LaRocque RC, Harris JB, Ahmad MM, Charles R. Salmonella enterica serovar Typhi-specific immunoglobulin A antibody responses in plasma and antibody in lymphocyte supernatant specimens in Bangladeshi patients with suspected typhoid fever. Clinical and vaccine immunology. 2009 Nov;16(11):1587-94.
3.Mahmood A. Nationwide Surveillance on enteric fever to estimate the disease burden in Bangladesh (Doctoral dissertation, BRAC Univeristy).
4.Nuzhat SN. Prevalence and patterns of antimicrobial resistance in salmonella enterica serovar Typhi and Salmonella enterica serovar Paratyphi, Bangladesh (Doctoral dissertation, BRAC University).
5.Naser MJ, Alam SS, Rahman MF, Shamsuzzaman SM. Study of Bloodstream Salmonella Infection and Antibiotic Susceptibility Patterns of Salmonella Enterica Serover Typhi and Paratyphi in A 1000 Bedded Tertiary Care Hospital in Dhaka, Bangladesh.
6.Pouzol S, Tanmoy AM, Ahmed D, Khanam F, Brooks WA, Bhuyan GS, Fabre L, Bryant JE, Gustin MP, Vanhems P, Carman B. Clinical evaluation of a multiplex PCR for the detection of Salmonella enterica Serovars Typhi and Paratyphi A from blood specimens in a high-endemic setting. The American Journal of Tropical Medicine and Hygiene. 2019 Jul 8;101(3):513.
7.Afroz H, Hossain MM, Fakruddin M. A 6-year retrospective study of bloodstream Salmonella infection and antibiotic susceptibility of Salmonella enterica serovar Typhi and Paratyphi in a tertiary care hospital in Dhaka, Bangladesh. Tzu Chi Medical Journal. 2014 Jun 1;26(2):73-8.
8.Chowdhury SR, Ahamed Z, Roy K, Al Noman A, Haroon RM, Mondol KC. Emerging threats of antibiotic resistance in Salmonella typhi and Salmonella paratyphi A among enteric fever cases of Dhaka, Bangladesh. African Journal of Bacteriology Research. 2022 Jan 31;14(1):8-15.
9.Seidman JC, Aiemjoy K, Adnan M, Dehraj IF, Iqbal J, Iqbal K, Irfan S, Islam N, Kabir MS, Katuwal N, Maria N. Evaluating the accuracy of Salmonella Typhi Hemolysin E and lipopolysaccharide IgA to discriminate enteric fever from other febrile illnesses in South Asia. medRxiv. 2025 Jun 22.
10.Sajib MS, Tanmoy AM, Hooda Y, Rahman H, Munira SJ, Sarkar A, Das D, Rahman MA, Islam N, Shahidullah M, Amin MR. Trends in antimicrobial resistance amongst Salmonella Paratyphi A isolates in Bangladesh: 1999–2021. PLOS Neglected Tropical Diseases. 2023 Nov 8;17(11):e0011723.
11.Sultana S, Al Maruf MA, Sultana R, Jahan S. Laboratory diagnosis of enteric fever: A review update. Bangladesh Journal of Infectious Diseases. 2016;3(2):43-51.
12.Maude RR, Ghose A, Samad R, de Jong HK, Fukushima M, Wijedoru L, Hassan MU, Hossain MA, Karim MR, Sayeed AA, van den Ende S. A prospective study of the importance of enteric fever as a cause of non-malarial febrile illness in patients admitted to Chittagong Medical College Hospital, Bangladesh. BMC infectious diseases. 2016 Oct 13;16(1):567.
13.Hossian M, Mahmudul M, Sultana A, Das SS, Moshiur M, Mohi MK, Sayem MA, Bashir MS. Potential role of Helicobacter pylori infection in hepatocellular carcinoma: A clinical and laboratory-based study. Integrative Biomedical Research. 2024 Dec 6;8(12):1-9.
14.Munira SJ, Islam N, Prithe NT, Sarkar A, Esfandiari J, Gunasekera D, Islam S, Akter T, Garrett DO, Saha SK, Andrews JR. Evaluation of a point-of-care immunochromatographic assay for enteric fever in Dhaka, Bangladesh: a prospective diagnostic accuracy study. The Lancet Microbe. 2025 Mar 1;6(3).
15.Shamrin T, Akter T, Sultana N, SujonAli M, AshiqurRahman M, Islam S. Antibiotic Resistance to Imipenem in Hospitalized Patients: Patterns Among Gram-Negative and Gram-Positive Bacteria in Bangladesh. Molecular Mechanism Research. 2024;2(2):7857.
16.Somily AM, Adam MH, El Rab MG, Morshed MG, Shakoor Z. Detection of Salmonella typhi agglutinins in sera of patients with other febrile illnesses and healthy individuals. Annals of African Medicine. 2011;10(1).
17.Somily AM, Adam MH, El Rab MG, Morshed MG, Shakoor Z. Detection of Salmonella typhi agglutinins in sera of patients with other febrile illnesses and healthy individuals. Annals of African Medicine. 2011;10(1).
18.Sultana S, Shamsuzzaman SM, Yusuf MA, Asifudduza M, Rahman T, Begum M, Jahan T. Bangladesh Journal of Infectious Diseases.