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Table 3 Univariate and multivariate analysis of factors associated with nasopharyngeal S. pneumoniae and S. aureus colonisation

From: Prevalence and antimicrobial resistance profiles of respiratory microbial flora in African children with HIV-associated chronic lung disease

Variable

No. observations (n = 410) §

Streptococcus pneumoniae

Staphylococcus aureus

No. isolates (n = 173)φ

OR [95% CI]

p

Adjusted OR [95% CI]

p

No. isolates (n = 86)λ

OR [95% CI]

p

Adjusted OR [95% CI]

p

Group

 CLD-

18% (74)

11% (19)

Reference

 

Reference

 

10% (9)

Reference

 

Reference

 

 CLD+

82% (336)

89% (154)

2.5 [1.4–4.4]

0.002

2.0[1.1–3.9]

0.04

90% (77)

2.2 [1.1–4.8]

0.04

1.8 [0.8–4.5]

0.17

Study site

 Malawi

28% (114)

32% (56)

Reference

 

Reference

 

31% (27)

Reference

 

Reference

 

 Zimbabwe

72% (296)

68% (117)

0.7 [0.4–1.1]

0.08

1.3 [0.7–2.4]

0.42

69% (59)

0.8 [0.5–1.4]

0.40

0.7 [0.4–1.5]

0.39

Sex

 Female

52% (212)

54% (94)

Reference

 

Reference

 

41% (35)

Reference

 

Reference

 

 Male

48% (198)

46% (79)

0.8 [0.6–1.2]

0.36

0.7 [0.4–1.0]

0.07

59% (51)

1.8 [1.1–2.9]

0.02

1.7 [1.0–2.9]

0.05

Season of sample collection

 Dec - Apr - Rainy season

36% (149)

32% (56)

Reference

 

Reference

 

36% (31)

Reference

 

Reference

 

 May–Aug - Cool season

39% (160)

43% (74)

1.4 [0.9–2.3]

0.30

1.7 [1.0–2.9]

0.13

29% (25)

0.7 [0.4–1.3]

0.03

0.9 [0.5–1.6]

0.11

 Sep - Nov - Hot season

25% (101)

25% (43)

1.2 [0.7–2.1]

1.3 [0.7–2.3]

35% (30)

1.6 [0.9–2.9]

1.7 [0.9–3.2]

Enrolment age category

 17-19y

32% (131)

20% (35)

Reference

 

Reference

 

28% (24)

Reference

 

Reference

 

 13-16y

41% (168)

47% (81)

2.6 [1.6–4.2]

<0.001

2.2 [1.3–3.8]

<0.001

43% (37)

1.3 [0.7–2.3]

0.66

1.1 [0.6–2.1]

0.83

 6-12y

27% (111)

33% (57)

2.9 [1.7–5.0]

3.2 [1.8–5.8]

29% (25)

1.3 [0.7–2.4]

1.2 [0.6–2.5]

Number of years on ART

 6 m- < 2y

9% (35)

14% (23)

Reference

 

Reference

 

7% (6)

Reference

 

Reference

 

 2- < 4y

18% (72)

18% (30)

0.4 [0.2–0.9]

0.02

0.4 [0.2–1.0]

0.04

18% (15)

1.3 [0.5–3.9]

0.94

1.2 [0.4–3.9]

0.78

 4y- < 6y

20% (81)

22% (36)

0.4 [0.2–0.9]

0.4 [0.2–1.0]

22% (18)

1.4 [0.5–4.1]

1.4 [0.5–4.4]

 6y+

53% (214)

47% (78)

0.3 [0.1–0.6]

0.3 [0.1–0.7]

53% (44)

1.3 [0.5–3.5]

1.0 [0.4–3.0]

CD4 count

  > 500

63% (257)

62% (108)

Reference

   

63% (54)

Reference

   

 200–500

27% (112)

24% (42)

0.8 [0.5–1.3]

0.09

  

30% (26)

1.1 [0.7–1.9]

0.55

  

  < 200

10% (40)

13% (23)

1.9 [1.0–3.7]

  

7% (6)

0.7 [0.2–1.6]

  

Enrolment viral load

 Unsuppressed

42% (174)

46% (80)

Reference

 

Reference

 

55% (47)

Reference

 

Reference

 

 Suppressed

58% (236)

54% (93)

0.8[0.5–1.1]

0.18

0.6 [0.4–1.0]

0.03

45% (39)

0.5 [0.3–0.9]

0.01

0.5 [0.3–0.9]

0.02

ART regimen

 PI-based regimen - 2nd line

24% (98)

25% (44)

Reference

 

Reference

 

33% (28)

Reference

 

Reference

 

 NNRTI-based regimen -1st line

76% (312)

75% (129)

0.9 [0.6–1.4]

0.55

0.8 [0.5–1.4]

0.44

67% (58)

0.6 [0.3–1.0]

0.03

0.6 [0.3–1.1]

0.07

Ever treated for TB

 No

74% (302)

70% (120)

Reference

 

Reference

 

71% (61)

Reference

 

Reference

 

 Yes

26% (106)

30% (52)

1.5 [0.9–2.3]

0.10

1.5 [0.9–2.5]

0.12

29% (25)

1.2 [0.7–2.1]

0.46

0.9 [0.5–1.7]

0.83

Enrolment weight- for-age- z-score

 Not underweight

54% (220)

49% (85)

Reference

   

49% (42)

Reference

   

 Underweight

46% (190)

51% (88)

1.4 [0.9–2.0]

0.12

  

51% (44)

1.3 [0.8–2.1]

0.31

  

Enrolment height-for-age- z-score -

 Not stunted

54% (220)

45% (78)

Reference

 

Reference

 

52% (45)

Reference

 

Reference

 

 Stunted

46% (190)

55% (95)

1.8 [1.2–2.7]

0.003

1.6 [1.1–2.6]

0.03

48% (41)

1.1 [0.7–1.7]

0.78

0.8 [0.5–1.3]

0.39

Ever repeated a grade

 No

46% (183)

41% (69)

Reference

   

42% (36)

Reference

   

 Yes

54% (218)

59% (100)

1.4 [0.9–2.1]

0.10

  

58% (49)

1.2 [0.7–1.9]

0.49

  

MRC dyspnoea score

 1 or 0

60% (244)

53% (91)

Reference

 

Reference

 

56% (48)

Reference

 

Reference

 

  > 1

40% (165)

47% (81)

1.6 [1.1–2.4]

0.02

1.3 [0.7–2.2]

0.36

44% (37)

1.2 [0.7–1.9]

0.50

1.0 [0.5–1.8]

0.94

  1. § Missing values: Number of years on ART (8), CD4 count (1), Ever treated for TB (2), Ever repeated a grade (9) and MRC dyspnoea score (1). φ Number of years on ART (n = 167), ART regimen(n = 172), Ever treated for TB (n = 172), Ever repeated a grade (n = 169), MRC dyspnoea score (n = 172). λn = 83, 85 and 85 for the number of years on ART, ever repeated a grade and MRC dyspnoea score. Variables with two levels where a level is less than 10% of total observations are not tested for associations. These included current school attendance and taking cotrimoxazole. Variables that have values in the adjusted odd ratios column were included in the multivariate model for that bacteria. Variables with p values <0.25 were included in the multivariate model except where they are colinear with another variable within the model. Weight-for-age was colinear with height-for-age and hence excluded from the model. Ever repeated a grade was excluded because of co-linearity with MRC score. CD4 count is colinear with viral load suppression. Clinically relevant variables (a priori-defined) that were included in the multivariate model regardless of significance were group, age, sex, site, season of sample collection, number of years on ART, enrolment viral load, ART regimen, ever treated for TB, enrolment height-for-age z-score and MRC dyspnoea score
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BMC Infectious Diseases

ISSN: 1471-2334

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