Table 2. Socio-demographic and biological characteristics according to malaria attacks and results of random-effect negative binomial regression models exploring factors associated with clinical malaria cases (n = 3,812).
| Characteristics | Subcategory | Number of persons n = 199 (100%) | Number of person-trimester n = 3,812 (100%) | Clinical malaria cases | Simple regression analysis | Multiple regression analysis | |||
|---|---|---|---|---|---|---|---|---|---|
| No n = 3,572 n (%) | Yes n = 240 n (%) | IRR (95% CI) | P-value | aIRR (95% CI) | P-value | ||||
| Mosquitoes collectors | No | - | 2,440 (64) | 2,286 (64) | 154 (64) | 1 | 1 | ||
| yes | - | 1,372 (36) | 1,286 (36) | 86 (36) | 0.97 (0.71–1.33) | 0.85 | 0.89 (0.65–1.22) | 0.47 | |
| Number of nights of collections | 0 | - | 2,440 (64) | 2,286 (64) | 154 (64) | 1 | |||
| 1 | - | 461 (12) | 430 (12) | 31 (13) | 0.94 (0.62–1.42) | 0.77 | |||
| 2 | - | 445 (12) | 418 (12) | 27 (11) | 0.94 (0.60–1.48) | 0.80 | |||
| 3 and more | - | 466 (12) | 438 (12) | 28 (12) | 1.05 (0.67–1.66) | 0.83 | |||
| Age group | 15–29 years old | - | 1,615 (42) | 1,478 (41) | 137 (57) | 1 | 1 | ||
| 30–44 years old | - | 1,002 (26) | 937 (27) | 65 (27) | 0.59 (0.41–0.87) | <0.01 | 0.59 (0.40–0.88) | <0.01 | |
| 45 years old and over | - | 1,195 (31) | 1,157 (32) | 38 (16) | 0.27 (0.16–0.45) | <0.01 | 0.31 (0.18–0.53) | <0.01 | |
| Born at Dielmo | No | 65 (33) | 796 (21) | 714 (20) | 82 (34) | 1 | 1 | ||
| Yes | 134 (67) | 3,016 (79) | 2,858 (80) | 158 (66) | 0.32 (0.19–0.54) | <0.01 | 0.38 (0.24–0.61) | <0.01 | |
| Biological characteristics | |||||||||
| HB type | AA | 167 (84) | 3,330 (87) | 3,120 (87) | 210 (88) | 1 | |||
| AS | 22 (11) | 401 (11) | 381 (11) | 20 (8) | 0.82 (0.39–1.76) | 0.62 | |||
| AC | 2 (1) | 54 (1) | 51 (1) | 3 (1) | 0.50 (0.06–4.15) | 0.52 | |||
| ABO Group | O | 63 (32) | 1,273 (33) | 1,187 (33) | 86 (36) | 1 | |||
| A | 57 (29) | 1,316 (35) | 1,224 (34) | 92 (38) | 1.08 (0.61–1.91) | 0.80 | |||
| B | 48 (24) | 1,028 (27) | 978 (27) | 50 (21) | 0.70 (0.37–1.32) | 0.27 | |||
| AB | 9 (5) | 131 (3) | 126 (4) | 5 (2) | 0.59 (0.15–2.29) | 0.45 | |||
| Others characteristics | |||||||||
| Treatment period | Quinimax | 104 | 1,104 (29) | 1,031 (29) | 73 (30) | 1 | 1 | ||
| Chloroquine | 106 | 1,006 (26) | 913 (26) | 93 (39) | 1.07 (0.76–1.49) | 0.70 | 1.16 (0.77–1.75) | 0.49 | |
| AQ+SP/ACT | 110 | 720 (19) | 678 (19) | 42 (18) | 0.58 (0.38–0.88) | 0.01 | 0.74 (0.48–1.16) | 0.19 | |
| ACT+LLINs | 119 | 982 (26) | 950 (27) | 32 (13) | 0.28 (0.18–0.45) | <0.01 | 0.43 (0.27–0.70) | <0.01 | |
| Quarter of the year | First quarter of the year | 166 | 841 (22) | 801 (22) | 40 (17) | 1 | 1 | ||
| Second quarter of the year | 169 | 948 (25) | 899 (25) | 49 (20) | 0.98 (0.66–1.46) | 0.92 | 0.96 (0.65–1.42) | 0.84 | |
| Third quarter of the year | 182 | 1,040 (27) | 963 (27) | 77 (32) | 1.41 (0.97–2.04) | 0.07 | 1.31 (0.88–1.95) | 0.19 | |
| Fourth quarter of the year | 173 | 983 (25) | 909 (25) | 74 (31) | 1.53 (1.06–2.20) | 0.02 | 1.47 (1.02–2.13) | 0.04 | |
| EIR (Entomological Inoculation Rate per person-trimester) | - | 1.007 (1.004–1.01) | <0.01 | 1.003 (0.999–1.007) | 0.10 | ||||
IRR: Incidence rate ratio; aIRR: adjusted incidence rate ratio.