Predictors of bronchiectasis among 95 human T-cell leukaemia virus type 1 (HTLV-1)-infected subjects

Unadjusted OR (95% CI)p-valueAdjusted OR (95% CI)p-value
Age#1.01 (0.88–1.16)0.870
Remote residence1.14 (1.01–1.28)0.0342.30 (0.92–6.52)0.115
Admitted in childhood1.78 (0.76–4.17)0.183
Any LRTI admission+
 Childhood2.79 (1.18–6.58)0.0192.11 (1.11–4.02)0.023
 Adulthood3.02 (1.28–7.14)0.012
Respiratory admissions§
 Childhood1.49 (1.03–2.16)0.032
 Adulthood1.41 (1.17–1.71)<0.001
Severe LRTIƒ3.92 (0.97–15.85)0.0555.45 (1.78–16.71)0.003
HTLV-1 PVL##1.07 (1.02–1.12)0.006
HTLV-1 PVL (categorical)¶¶
 Low HTLV-1 PVLReferenceReference
 High HTLV-1 PVL5.33 (1.86–15.22)0.0025.68 (1.81–17.89)0.003
Sputum cultures
 Yield++4.24 (1.55–11.60)0.005
 Haemophilus influenzae1.67 (1.16–2.42)0.006
 Streptococcus pneumoniae3.56 (1.36–9.29)0.010
 Pseudomonas aeruginosa1.27 (0.08–20.89)0.686
 NTM§§2.60 (0.23–29.70)0.442
Eosinophiliaƒƒ2.54 (1.09–5.91)0.030
Strongyloides###2.53 (1.40–4.58)0.0022.44 (1.22–4.89)0.012
Infective dermatitis¶¶¶3.76 (1.15–12.34)0.029
Scabies+++7.23 (1.49–35.09)0.014
Tobacco§§§0.94 (0.40–2.24)0.897
Alcoholƒƒƒ1.79 (0.72–4.42)0.208

LRTI: lower respiratory tract infection; PVL: pro-viral load; NTM: nontuberculous mycobacteria. #: risk of bronchiectasis per 5 years. : residence >80 km from Alice Springs in adulthood. +: admitted with any non-severe LRTI prior to diagnosis (cases) or date of recruitment (controls). §: number of LRTI admissions prior to diagnosis (cases) or date of recruitment (controls). ƒ: severe pneumonia (n=8), severe bronchiolitis (n=1), and pulmonary tuberculosis (n=1) at any age (see Methods); three controls with HTLV-1 had a severe LRTI (pulmonary tuberculosis n=1, pulmonary abscess n=1, severe pneumonia n=1). ##: odds of bronchiectasis per 100 unit increase in HTLV-1 copies per 105 peripheral blood leukocytes (PBLs). ¶¶: low HTLV-1 PVL, <1000 copies per 105 PBLs; high HTLV-1 PVL, ≥1000 copies per 105 PBLs. ++: the number of pathogens isolated divided by the number of sputum samples collected, calculated once for each admission. §§: NTM isolated from four cases prior to diagnosis included 1) Mycobacterium avium complex in a patient with pulmonary TB and 2) Mycobacterium simiae (isolated twice); NTM were not identified to species level in two cases from which an NTM was isolated only once. ƒƒ: peripheral blood eosinophilia recorded on at least two occasions 12 months apart (prior to diagnosis for cases). ###: Strongyloides seropositive or larvae identified in stool at any time prior to date of recruitment (cases n=18 (Strongyloides seropositive n=18, larvae in stool n=0); controls n=6 (Strongyloides seropositive n=5, larvae in stool n=1)). ¶¶¶: infective dermatitis recorded in case notes (cases HTLV-1+ n=10, HTLV-1 n=2; controls HTLV-1+ n=1, HTLV-1 n=5). +++: clinical diagnosis of scabies recorded in case notes (no case diagnosed by microscopy). §§§: any history of tobacco smoking recorded in case notes. ƒƒƒ: any history of harmful alcohol consumption recorded in case notes.