This study provides with a first insight on Mycobacterium tuberculosis complex epidemiology and genetic diversity in the Cross River State, Nigeria. Starting with 137 smear positive patients recruited over a period of 12 months (June 2008 to May 2009), we obtained 97 pure mycobacterial isolates out of which 81 (83.5%) were identified as M. tuberculosis complex. Genotyping revealed a total of 27 spoligotypes patterns with 10 clusters (n = 64% or 79% of clustered isolates, 2–32 isolates/cluster), with patients in the age group range 25–34 years being significantly associated with shared-type pattern SIT61 (p = 0.019). Comparison with SITVIT2 database showed that with the exception of a single cluster (SIT727/H1), all other clusters observed were representative of West Africa; the two main lineages involved were LAM10-CAM (n = 42/81% or 51.8%) of M. tuberculosis and AFRI_2 sublineage of Mycobacterium africanum (n = 27/81% or 33.3%). Subsequent 12-loci MIRU typing resulted in a total of 13 SIT/MIT clusters (n = 52 isolates, 2–9 isolates per cluster), with a resulting recent n − 1 transmission rate of 48.1%. Available drug-susceptibility testing (DST) results for 58/81 clinical isolates revealed 6/58% or 10.4% cases of multiple drug-resistance (MDR); 5/6 MDR cases were caused by strains belonging to LAM10-CAM lineage (a specific cluster SIT61/MIT266 in 4/6 cases, and an orphan spoligotype pattern in 1/6 case). Additionally, MIT266 was associated with streptomycin resistance (p = 0.016). All the six MDRTB isolates were concomitantly resistance to streptomycin and ethambutol; however, 4/6 MDR strains with identical MIRU patterns were characterized by consecutive strain numbers hence the possibility of laboratory cross contamination could not be excluded in 3/4 serial cases. The present preliminary study underlines the usefulness of spoligotyping and 12-loci MIRU–VNTRs to establish a baseline of circulating genotypic lineages of M. tuberculosis complex in Nigeria.

The tuberculin skin test (TST) is used to detect latent Mycobacterium tuberculosis infection. WHO guidelines recommend 10mm as tuberculosis (TB) infection threshold for high risk individuals and 15mm for persons with no risk factors for TB. Nigeria is one of the 22 high burden countries for TB and her population is at risk of exposure to the TB germ. In an attempt to investigate indigenous TST indurations in a local population, 200 apparently healthy new students of tertiary institutions and other residents of Calabar-Nigeria metropolis that required the test for routine medical examination were examined. Each subject was injected intradermally with 0.1mL of 5TU of purified protein derivative (PPD) into the dorsal surface of the forearm. Indurated areas were measured after 48-72 hours of administration and results expressed in millimeters. 200 smear positive TB patients receiving treatment at the treatment center of the National TB Control program were used as the reference group. Results were statistically analysed using Chi square and T-test. Data obtained from the apparently healthy group show that approximately 31% of the individuals had indurations measuring 5-7mm while 29% were non-reactive. At least 25% of these individuals had indurations of >10mm compared to 95% of TB patients. Nine (4.5%) of TB patients have indurations <10mm. The results of this study imply that at least 25% of the healthy subjects are at risk of progressing to active disease when exposed to conditions that lower the individual's immune status.

treatment. There was no significant difference between difficulty in concentration pre-and post-treatment (21% versus 23%, respectively, P = 0.9). Disability affecting colour vision, communication, washing and dressing, and sensation were uncommon, affecting <10% of patients. Prevalence of any disability (defined as any disability identifier reported as 'some difficulty', 'a lot of difficulty', or 'cannot do at all') was 77% pre-treatment, and 68% post-treatment (P = 0.1). There was no evidence of an association between pretreatment disability and previous TB (n = 16, P = 0.1), diabetes (n = 6, P = 0.2), or HIV (n = 4, P = 0.3). Pre-treatment disability was strongly associated with increasing age strata (OR = 6.5, P = 0.01). However, there was no association between increasing age strata and posttreatment deterioration in visual disability (P = 0.96) or auditory disability (P = 0.9). Conclusion:Disability is frequent in patients with TB. There is a rising burden of visual and auditory disability in patients following TB treatment. Appropriate-technology visual acuity and audiometry monitoring of patients with TB in resource-limited settings may allow therapy to be modified to prevent permanent disability.