Background
Methods
Design, location and study population
Eligibility criteria and enrollment procedures
Collection of baseline data and follow-up
Blood samples
Stool samples and parasitological examination
Collection of dust samples
Assessment and validation of clinical outcomes
Data analysis
Sample size
Results
Demographic characteristics of the population
Baseline | 24 months (n = 274) | |||
---|---|---|---|---|
Factor | (n = 326) | non wheezers (n = 169) | wheezers (n = 105) | |
Maternal age at child birth [n (%)] | ||||
14-18 | 80 (24.5) | 39 (23.1) | 27 (25.7) | |
19-24 | 139 (42.6) | 68 (40.2) | 50 (47.6) | |
25-30 | 67 (20.6) | 36 (21.3) | 19 (18.1) | |
31-35 | 22 (6.7) | 15 (8.9) | 5 (4.8) | |
36-42 | 18 (5.5) | 11 (6.5) | 4 (3.8) | |
Maternal age (Mean ± SD) | 23.2 ± 5.83 | 23.6 ± 6.15 | 22.5 ± 5.37 | |
Maternal education | ||||
None | 5 (1.5) | 2 (1.2) | 2 (1.9) | |
Primary school only | 57 (17.4) | 28 (16.5) | 15 (14.3) | |
High school incomplete | 142 (43.6) | 69 (40.8) | 48 (45.7) | |
High school complete | 72 (22.1) | 42 (24.9) | 23 (21.9) | |
Technical studies | 46 (14.1) | 26 (15.4) | 15 (14.3) | |
University | 4 (1.2) | 2 (1.2) | 2 (1.9) | |
Parity | Primipara | 134 (41.1) | 73 (43.2) | 41 (39.0) |
No. of other children (Mean ± SD) | 1.17 ± 1.35 | 1.14 ± 1.32 | 1.19 ± 1.31 | |
Socioeconomic stratum | ||||
1 (poorest) | 257 (78.8) | 135 (79.9) | 79 (75.2) | |
2 | 59 (18.1) | 29 (17.2) | 22 (21.0) | |
3 | 10 (3.1) | 5 (3.0) | 4 (3.8) | |
Type of house | ||||
Brick | 243 (74.5) | 127 (75.1) | 79 (75.2) | |
Wood | 83 (25.5) | 42 (24.9) | 26 (24.8) | |
Type of house floor | ||||
Tile | 90 (27.6) | 49 (29.0) | 28 (26.7) | |
Bare concrete | 172 (52.7) | 87 (51.5) | 58 (55.2) | |
Soil | 64 (19.6) | 33 (19.5) | 19 (18.1) | |
Tap water | Yes | 290 (89) | 147 (87.0) | 95 (90.5) |
Sewage system | Yes | 191 (58.6) | 101 (59.8) | 61 (58.1) |
Exposure to pests at home* | ||||
Cockroaches | 255 (78.2) | 137 (81.1) | 80 (76.2) | |
Rodents (mice, rats) | 275 (84.4) | 139 (82.2) | 92 (87.6) | |
Smoking and contaminants during pregnancy | ||||
Maternal smoking (ever) | 16 (4.9) | 9 (5.3) | 3 (2.9) | |
Maternal smoking during pregnancy | 8 (2.5) | 5 (3.0) | 2 (1.9) | |
Intradomiciliary passive exposure | 142 (43.6) | 67 (39.6) | 48 (45.7) | |
Type of domestic cooking fuel | ||||
Wood/Coal | 39 (12) | 19 (11.2) | 13 (12.4) | |
Propane | 69 (21.2) | 36 (21.3) | 20 (19.0) | |
Natural Gas | 244 (74.8) | 124 (73.3) | 82 (78.0) | |
Electricity | 3 (0.9) | 2 (1.18) | 1 (0.96) | |
Trash burning at home during pregnancy | Yes | 65 (19.9) | 34 (20.1) | 22 (21.0) |
Passive exposure to trash fume at neighborhood | Yes | 172 (52.8) | 88 (52.1) | 60 (57.1) |
Exposure to pets and to other domestic animals | ||||
Living with pet during pregnancy | 157 (48.2) | 82 (48.5) | 52 (49.5) | |
Dog during pregnancy | 143 (43.9) | 77 (45.6) | 48 (45.7) | |
Cat during pregnancy | 41 (12.6) | 23 (13.6) | 10 (9.5) | |
Living with dog/cat during the whole pregnancy | Yes | 107 (32.8) | 55 (32.5) | 37 (35.2) |
Intradomiciliary contact poultry/pigs during pregnancy | Yes | 44 (13.5) | 20 (11.8) | 17 (16.2) |
Antibiotics during pregnancy | ||||
Yes | 159 (48.7)** | 80 (47.3) | 57 (54.2) | |
None | 157 (48.1) | 84 (49.7) | 46 (43.8) | |
Missing/no remember | 10 (3.06) | 5 (2.95) | 2 (1.90) |
Phenotype | n (%) | |
---|---|---|
Current asthma | 21 (6.44)†
| |
Duration of asthma (Mean, SD) | 14.0 ± 9.01 years | |
Current rhinitis | 84 (25.7)‡
| |
Eczema | 0 (0) | |
Food allergy | 23 (7.1) | |
Drug allergy | 5 (1.5) | |
Family history of asthma* | 53 (16.3) | |
Allergic sensitization (n = 265)**
|
n (%)
|
Any allergy symptom (%)***
|
Atopy (at least 1 positive test) | 93 (35) | (50.5) |
Mite sensitized | 82 (30.9) | (54.8) |
D. pteronyssinus
| 59 (22.3) | (59.3) |
B. tropicalis
| 61 (23.0) | (54) |
Cockroach | 12 (4.5) | (58) |
Cat | 7 (2.6) | (42) |
Dog | 7 (2.6) | (57) |
Molds (Pen, Asp, Alt) | 8 (3.0) | (100) |
Pollens (Art, Phl, Bet, Acacia) | 7 (2.6) | (57) |
Living conditions of children and particular environmental exposures
0-6 months (n = 200) | 0-12 months (n = 258) | 13-24 months (n = 153) | |
---|---|---|---|
Any parasite
| 17 (8.5%) | 62 (21.3%) | 58 (37.9%) |
Polyparasitism
| 1 (0.5%) | 2 (1.13%) | 9 (5.88%) |
Protoozoan
| |||
Entamoeba ssp. | 12 (6%) | 34 (13.1%) | 31 (20.2%) |
Giardia lamblia
| 1 (0.5%) | 12 (4.65%) | 18 (11.7%) |
Blastocystis hominis
| 1 (0.5%) | 3 (1.16%) | 3 (1.96%) |
Endolinax nana
| 0 (0%) | 1(0.38) | 2 (1.30%) |
Balantidium coli
| 0 (0%) | 0 (0%) | 1 (0.65%) |
Helminths
| |||
Ascaris lumbricoides
| 2 (1%) | 7 (2.71%) | 8 (5.22%) |
Trichuris trichiura
| 0 (0%) | 2 (0.77%) | 2 (1.30%) |
Ancylostoma duodenalis
| 2 (1%) | 3 (1.16%) | 3 (1.96%) |
Strongyloides stercolaris
| 0 (0%) | 0 (0%) | 1 (0.65%) |
Prevalence of wheezing and atopic eczema
0-6 months (n = 286) | 7-12 months (n = 280) | 13-24 months (n = 274) | Cumulative 0-12 months (n = 280) | Cumulative 0-24 months (n = 274) | |
---|---|---|---|---|---|
Wheezers (n) | 50 | 59 | 64 | 87 | 105 |
Non-wheezers (n) | 236 | 221 | 210 | 193 | 169 |
Prevalence of wheeze (%) | 17.5 | 21.1 | 23.4 | 31.1 | 38.3 |
Occasional wheezers (1 or 2 episodes) | - | - | - | 67 (23.9%) | 66 (24.1%) |
Recurrent wheezers (3 or more episodes) | - | - | - | 20 (7.1%) | 39 (14.2%) |
Children that only wheeze at time interval (n) | 21 | 17 | 19 |
-
|
-
|
Number of children that wheeze for the first time at each time interval | 50 | 37 | 19 |
-
|
-
|
Risk factors for wheezing during the first two years
6 months | 7 - 12 months | 0 - 24 months | ||||||
---|---|---|---|---|---|---|---|---|
Factor/exposure | Wheezing ever (n = 50/236) | Wheezing ever (n = 59/221) | Wheezing ever* (n = 105/169) | Recurrent wheezing* (n = 39/235) | ||||
OR (95%CI) |
P value | OR (95%CI) |
P value | OR (95%CI) |
P value | OR (95%CI) |
P value | |
Maternal asthma | 1.19 (0.38-3.74) | 0.76 |
2.73 (1.06-7.03)
|
0.03†
| 2.35 (0.91-6.06) | 0.069 |
3.10 (1.10-8.73)
|
0.025¶
|
Maternal rhinitis |
2.80 (1.50-5.24)
|
0.001
‡
| 1.14 (0.61-2.11) | 0.67 |
1.73 (1.02-2.93)
|
0.041
| 1.78 (0.88-3.58) | 0.10 |
Mother education | ||||||||
< 5 | 0.81 (0.33-1.98) | 0.65 | 0.76 (0.31-1.85) | 0.54 | 0.99 (0.48-2.01) | 0.98 | 0.92 (0.33-2.55) | 0.88 |
> 11 | 1.22 (0.50-2.99) | 0.65 | 1.31 (0.54-3.19) | 0.54 | 1.00 (0.49-2.05) | 0.98 | 1.07 (0.39-2.97) | 0.88 |
Parity | ||||||||
Primiparous | 0.96 (0.52-1.79) | 0.91 | 1.03 (0.57-1.84) | 0.91 | 0.84 (0.51-1.38) | 0.49 | 0.97 (0.48-1.93) | 0.93 |
Type of house | ||||||||
Wood | 0.60 (0.27-1.31) | 0.20 | 0.89 (0.45-1.75) | 0.74 | 0.99 (0.56-1.74) | 0.98 | 0.40 (0.15-1.07) | 0.069 |
Type of floor | ||||||||
Soil | 0.94 (0.37-2.36) | 0.90 | 0.73 (0.31-1.73) | 0.48 | 1.00 (0.48-2.09) | 0.98 | 0.76 (0.28-2.07) | 0.59 |
Tap water | ||||||||
No | 0.64 (0.21-1.93) | 0.43 | 0.35 (0.10-1.20) | 0.09 | 0.70 (0.31-1.55) | 0.38 | 0.59 (0.17-2.04) | 0.40 |
Sewage | ||||||||
No | 1.05 (0.56-1.96) | 0.86 | 0.87 (0.48-1.58) | 0.66 | 1.07 (0.65-1.75) | 0.78 | 0.60 (0.29-1.24) | 0.16 |
Socioeconomic strata | ||||||||
1 (poorest) | 1.10 (0.51-2.35) | 0.80 | 0.59 (0.31-1.14) | 0.12 | 0.76 (0.42-1.36) | 0.36 | 0.92 (0.41-2.07) | 0.84 |
Prenatal exposure to cigarette smoke | ||||||||
Yes | 1.43 (0.77-2.64) | 0.24 | 0.99 (0.55-1.77) | 0.98 | 1.28 (0.78-2.09) | 0.32 | 0.95 (0.48-1.90) | 0.89 |
Exposure to fume wood/coal | ||||||||
Yes | 0.42 (0.12-1.43) | 0.16 | 1.23 (0.52-2.88) | 0.63 | 1.11 (0.52-2.36) | 0.77 | 1.46 (0.55-3.81) | 0.43 |
Exposure to fume trash burning: | ||||||||
at home | 0.95 (0.44-2.04) | 0.90 | 0.87 (0.42-1.81) | 0.71 | 1.05 (0.57-1.92) | 0.86 | 0.67 (0.26-1.69) | 0.40 |
at neighborhood | 1.33 (0.71-2.47) | 0.36 | 1.08 (0.61-1.93) | 0.77 | 1.22 (0.75-2.00) | 0.41 | 1.62 (0.80-3.28) | 0.17 |
Pets during pregnancy | ||||||||
Intradomicilliary (9 mo) | 1.01 (0.55-1.87) | 0.95 | 1.23 (0.67-2.23) | 0.49 | 1.12 (0.67-1.88) | 0.64 | 1.12 (0.55-2.28) | 0.74 |
Intradomicilliary (ever) | 1.09 (0.58-2.07) | 0.77 | 0.92 (0.52-1.64) | 0.79 | 1.04 (0.64-1.69) | 0.87 | 0.99 (0.50-1.95) | 0.98 |
Dog at home | 0.97 (0.52-1.80) | 0.93 | 0.91 (0.51-1.63) | 0.77 | 1.00 (0.61-1.64) | 0.98 | 0.80 (0.40-1.59) | 0.53 |
Cat at home | 0.93 (0.36-2.38) | 0.89 | 0.78 (0.30-1.98) | 0.60 | 0.66 (0.30-1.46) | 0.31 | 0.81 (0.26-2.45) | 0.71 |
Poultry/pigs at home | 1.39 (0.62-3.15) | 0.41 | 1.64 (0.76-3.55) | 0.20 | 1.43 (0.71-2.89) | 0.30 | 1.49 (0.60-3.68) | 0.38 |
Rodents at home | 0.84 (0.38-1.88) | 0.68 | 1.24 (0.54-2.83) | 0.60 | 1.52 (0.75-3.08) | 0.23 | 0.82 (0.33-2.01) | 0.67 |
Cockroaches at home | 0.92 (0.44-1.94) | 0.84 | 0.93 (0.46-1.86) | 0.83 | 0.74 (0.41-1.35) | 0.33 | 0.85 (0.38-1.92) | 0.70 |
Gender | ||||||||
Male |
1.87 (0.99-3.51)
|
0.052
§
| 1.37 (0.76-2.45) | 0.28 | 1.61 (0.98-2.64) | 0.055 | 1.47 (0.74-2.93) | 0.26 |