Latent tuberculosis among household contacts of pulmonary tuberculosis cases in Nairobi, Kenya

Pan Afr Med J. 2020 Sep 25:37:87. doi: 10.11604/pamj.2020.37.87.21102. eCollection 2020.

Abstract

Introduction: Household Contacts (HHCs) of Pulmonary Tuberculosis (PTB) patients have a higher risk of latent tuberculosis infection (LTBI). However, its prevalence and risk factors among adults living with PTB patients are poorly documented in Kenya.

Objective: to determine the prevalence and risk factors for LTBI among adult HHCs of PTB patients in Kenya.

Methods: this was an analytical cross-sectional study of HHCs of PTB patients in Nairobi, Kenya. Socio-demographic data was captured on questionnaires and blood samples drawn for Interferon gamma (IFN-γ) quantification. Univariate and multivariate analyses using the Statistical Package for Social Scientists (SPSS) was used to determine the prevalence of LTBI and risk factors at 95% Confidence Interval (CI).

Results: a total of 166 PTB patients yielded 175 HHCs of whom 29.7% (52/125) were males and 70.3% (123/125) were females. A majority of HHCs [65.7% (115/175)] lived in a single-room house with the patient and [37.7% (66/175)] were in the age group 30-39-years. The overall prevalence of LTBI was 55.7%, peaking among spouses of the patients [70.0% (14/20) and the 30-39 year age group [63.5% (42/66)]. Potential risk factors for LTBI included cohabiting with a PTB patient for 8 to 12 weeks [OR = 3.6 (0.70-18.5), p = 0.107], being a spouse of the patient [OR = 2.0 (0.72-5.47), p = 0.173] and sharing a single room with the patient [OR = 1.58 (0.84 - 2.97), p = 0.158].

Conclusion: the high prevalence of LTBI among adult HHCs of PTB patients in this population demonstrates the need for targeted contact-screening programs in high TB transmission settings.

Keywords: Kenya; Latent TB infection; TB household contacts; prevalence; risk factors.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Contact Tracing*
  • Cross-Sectional Studies
  • Family Characteristics
  • Female
  • Humans
  • Kenya / epidemiology
  • Latent Tuberculosis / diagnosis
  • Latent Tuberculosis / epidemiology*
  • Male
  • Mass Screening / methods*
  • Middle Aged
  • Prevalence
  • Risk Factors
  • Surveys and Questionnaires
  • Tuberculosis, Pulmonary / epidemiology*
  • Tuberculosis, Pulmonary / transmission
  • Young Adult