Prevalence of Tuberculosis among bedside contacts of Smear Positive Tuberculosis Patients at The University Teaching Hospital, Lusaka, Zambia

Abstract

background

Screening of contacts of TB patients is not routinely done in resource-limited countries like Zambia despite WHO recommendations, leading to missed opportunities for prevention, early diagnosis and high mortality.

OBJECTIVES

Main objective was to establish the prevalence of latent and active tuberculosis in bedside contacts of smear-positive index patients and associated risk factors.

METHODS

We recruited bedside contacts of smear-positive TB patients in medical wards and contacts of surgical patients as a comparison group using a questionnaire to collect data on various variables. Active TB was diagnosed microbiologically and radiologically, while LTBI by TST.

RESULTS

We had 64 TB-unexposed and 70 TB-exposed, with a mean age of 41.2 [±13.5] years and 40.2 [±14.7] years respectively. Prevalence of active TB in the two groups was 10.0% and 0% respectively while that of LTBI was 83.1% and 38.3% respectively. TB exposure was significantly associated with active TB (p=0.014), LTBI (p<0.001) and type of contact (p<0.001)] but not duration of exposure (p=0.057).    

CONCLUSION

Bedside contacts were at increased risk of contracting both latent and active TB. Given the significant burden of LTBI in the general population without documented TB exposure, there is an urgent to institute preventive measures to protect/treat contacts of TB patients.