Comparative Evaluation of Three Screening Methods (Conventional, Molecular and Immunological) in the Diagnosis of Overt and Latent TB Infection in Mixed Population in Cross River State, Nigeria

Abstract

Challenges in TB diagnostic methods is the major global set back in the fight against TB infection, and the reason for increase in TB new cases baseline to 7.5 million in 2022. Investigating the efficiency and the sensitivity of combinational (Tuberculin Skin Test (TST), Acid Fast Bacilli (AFB), and GeneXpert (GXPT)) TB screening methods in the detection of overt, latent and HIV co-infection in mix population was the major focus of this study. Sampling areas were; Akamkpa (AKP), Calabar Municipal (CCM) and Ogoja all in Cross River State. Three hundred and ninety (390) individuals were enrolled in the exercise, 180 concerted for TST administration, of which 128 (77.11 %) were TST Positive (TST P+), 80 (62.5 %) males and 48 (37.5 %) females. All TST tested individuals 50 (27.78 %) in AKP came out positive for TST, 38 (21.11 %) males and 12 (6.67 %) females. In CCM, 20 (11.11 %) TST P+ were male, 19 (10.56 %) females and 5 (2.78 %) negative. Of the 34 (18.89 %) tested in OGO, 17 (9.44 %) were negative (16 (8.89 males and 1 (0.56 females), only 14 (7.78 %) were TST P+ for males, with no positive TST female among them. At P = 0.05, there was no significance different in TST positivity of males to females. There was a significance increase in the rate of TST P+ cases with induration diameter (ID) 5-0, 9-13 and >13 mm across the experimented locations. This was not applicable to ID 6-9, though had a higher mean value of 20.5 ± 8.6. The research report significance AFB positive data with a two tail value of 0.19** for age 39-48 and 0.22 * for age > 59 years compare to a younger age like 18-28 years. A repeated 2 in 4 AFBHIV co-infection at lower ID of 5.0 mm were observed with a higher mean score of 10.17 ± 5.8 in OGO. The research data also shows better TB detection output with the use of combinational (TST, AFB and GXPT) screening technique. In this study, GXPT was 82.8 % sensitive in detecting TB positive cases from the 128 (71.11 %) TST P+ individuals while sputum microscopy detected 64.1 % TB P+ cases from that same poll. Again GXPT was effective in diagnosing 50.5 % TB from 210 individuals that enrolled for AFB while sputum microscopy screened 39.1 % of that number. But, the combinational sensitivity synergy was 89.5 % efficient suggesting that, this method could serve as an improve TB screening method for detection of LTBI as well as HIV co-infection with lower induration diameter. It could also serve as a better management of positive cases and ensuring early commencement of treatment.