Social demographics of informants
A total of 1073 patients meeting our inclusion criteria were invited to participate and 1068 provided specimens and completed the face-to-face survey. Of these, 51.0% were male and 49.0%, female with an average age of 51.57 years (ranging from 18 to 89 years). Over half (54.5%) of them had less than 5 years of education with 25.8% being illiterate. There were statistically significant differences between gender groups with males being older and more educated (Table 1).
Table 1
Socio-demographic characteristics of respondents
| Male | Female | Total |
N | % | N | % | N | % |
Age | | | | | | |
<=39 | 120 | 22.0 | 152 | 29.1 | 272 | 25.5 |
40–53 | 120 | 22.0 | 162 | 31.0 | 282 | 26.4 |
54–64 | 129 | 23.7 | 123 | 23.5 | 252 | 23.6 |
>=65 | 174 | 31.9 | 86 | 16.4 | 260 | 24.3 |
Missing | 2 | 0.4 | 0 | 0.0 | 2 | 0.2 |
p | | 0.000 | | 0.000 | | 0.000 |
Education | | | | | | |
0 | 89 | 16.3 | 187 | 35.8 | 276 | 25.8 |
1–5 | 157 | 28.8 | 149 | 28.5 | 306 | 28.7 |
6–8 | 155 | 28.4 | 74 | 14.1 | 229 | 21.4 |
> 8 | 141 | 25.9 | 109 | 20.8 | 250 | 23.4 |
Missing | 3 | 0.6 | 4 | 0.8 | 7 | 0.7 |
p | | 0.000 | | 0.000 | | 0.000 |
Total | 545 | 51.0 | 523 | 49.0 | 1068 | 100.0 |
Clinical symptoms and antibiotic use
Antibiotics were prescribed for 87.8% of all RTI patients and 35.5% of these prescriptions contained two or more types of antibiotics (Table 2). The most common symptoms of RTIs were sore throat (561, 34.2%), cough with white sputum (525, 49.2%) and breathing difficulties (365, 34.2%). The most commonly prescribed antibiotics were penicillin (404, 43.1%), followed by cephalosporins (359, 38.3%) and fluoroquinolones (335, 35.7%). Patients presenting cough with green sputum, dry throat/ burning throat/hoarse voice, and sore throat had higher antibiotics prescription rate as compared with those without these symptoms (p < 0.05). Fluoroquinolones was more commonly prescribed among patients with runny nose (clear/watery discharge), cough with white sputum, breathing difficulties, and weakness than patients without these symptoms. Use of cephalosporins was more frequent among patients with cough with green sputum, cough with white sputum, itchy throat, weakness and other symptoms and use of penicillins, more common among patients with weakness and fever. Patients with sore throat were more likely to be prescribed with a single antibiotic; while patients with breathing difficulties were more likely to get a prescription containing two or more types of antibiotics. An increasing number of symptoms was associated with prescribing of fluoroquinolones and with combined use of two or more types of antibiotics, but there was a mixed trend for prescription of any antibiotics.
Table 2
Antibiotic use by clinical symptoms
| Patients N (%) | Quinolones | Cephalosporins | Penicillins | Others | Any | Number of antibiotics used |
1 | 2 | 3+ |
Symptom |
Blocked nose |
| 257(24.06) | 69(26.85) | 82(31.91) | 93(36.19) | 0(0.00) | 226(87.94) | 146(56.81) | 64(24.90) | 16(6.23) |
Runny nose (clear/watery discharge) |
| 277(25.94) | 106(38.27) | 104(37.55) | 108(38.99) | 3(1.08) | 245(88.45) | 129(46.57) | 90(32.49) | 26(9.39) |
Snotty nose (yellow/green discharge) |
| 70(6.55) | 19(27.14) | 22(31.43) | 19(27.14) | 1(1.43) | 59(84.29) | 41(58.57) | 13(18.57) | 5(7.14) |
Dry cough |
| 137(12.83) | 41(29.93) | 45(32.85) | 57(41.61) | 2(1.46) | 125(91.24) | 77(56.20) | 39(28.47) | 9(6.57) |
Cough with green sputum |
| 250(23.41) | 77(30.80) | 95(38.00) | 83(33.20) | 1(0.40) | 208(83.20) | 121(48.40) | 65(26.00) | 22(8.80) |
Cough with white sputum |
| 525(49.16) | 181(34.48) | 194(36.95) | 185(35.24) | 2(0.38) | 461(87.81) | 265(50.48) | 156(29.71) | 40(7.62) |
Dry throat / burning throat/hoarse voice |
| 258(24.16) | 68(26.36) | 86(33.33) | 101(39.15) | 3(1.16) | 216(83.72) | 129(50.00) | 67(26.00) | 20(7.75) |
Itchy throat |
| 258(24.16) | 79(30.62) | 101(39.15) | 87(33.72) | 2(0.78) | 224(86.82) | 137(53.10) | 65(25.19) | 22(8.53) |
Sore throat |
| 561(52.53) | 177(31.55) | 187(33.33) | 224(39.93) | 6(1.07) | 508(90.55) | 308(54.90) | 155(27.63) | 45(8.02) |
Breathing difficulties |
| 365(34.18) | 142(38.90) | 126(34.52) | 145(39.73) | 4(1.10) | 321(87.95) | 159(43.56) | 128(35.07) | 34(9.32) |
Headache |
| 201(18.82) | 69(34.33) | 62(30.85) | 77(38.31) | 2(1.00) | 173(86.07) | 100(49.75) | 55(27.36) | 18(8.96) |
Weakness |
| 139(13.01) | 50(35.97) | 58(41.73) | 36(25.90) | 1(0.72) | 120(86.33) | 70(50.36) | 41(29.50) | 9(6.47) |
Fever |
| 146(13.67) | 47(32.19) | 55(37.67) | 45(30.82) | 1(0.68) | 131(89.73) | 84(57.53) | 36(24.66) | 11(7.53) |
Other symptoms |
| 213(19.94) | 62(29.11) | 54(25.35) | 88(41.31) | 3(1.41) | 179(84.04) | 105(49.30) | 59(27.70) | 15(7.04) |
P | | 0.026 | 0.076 | 0.036 | 0.899 | 0.134 | 0.365 |
Number of symptoms |
-1 | 83(7.77) | 15(18.07) | 23(27.71) | 32(38.55) | 2(2.41) | 70(84.34) | 49(59.04) | 14(16.87) | 7(8.43) |
-2 | 221(20.69) | 63(28.51) | 66(29.86) | 85(38.46) | 2(0.90) | 192(86.88) | 119(53.85) | 55(24.89) | 18(8.14) |
-3 | 287(26.87) | 92(32.06) | 96(33.45) | 120(41.81) | 2(0.70) | 257(89.55) | 151(52.61) | 76(26.48) | 30(10.45) |
-4 | 222(20.79) | 88(39.64) | 86(38.74) | 76(34.23) | 1(0.45) | 207(93.24) | 115(51.80) | 84(37.84) | 8(3.60) |
-5 | 164(15.36) | 51(31.10) | 50(30.49) | 62(37.80) | 2(1.22) | 137(83.54) | 82(50.00) | 40(24.39) | 15(9.15) |
-6+ | 91(8.52) | 26(28.57) | 38(41.76) | 29(31.87) | 1(1.10) | 75(82.42) | 43(47.25) | 24(26.37) | 8(8.79) |
P | | 0.046 | 0.146 | 0.310 | 0.661 | 0.020 | 0.003 |
Total | 1068(100) | 335(35.7) | 359(38.3) | 404(43.1) | 10(1.1) | 938(87.8) | 559(52.3) | 293(27.4) | 86(8.1) |
Additional file 1 compares use of different kinds of antibiotics among patients with one of the 14 specific symptoms studied versus those without the symptom. Levofloxacin witnessed the greatest number of prescriptions for all of the symptoms, followed by amoxicillin, erythromycin and amoxicillin clavulanic acid. For patients without the specific symptoms, the same order of frequencies of prescriptions of these antibiotics was also observed.
Symptoms and bacteria identification
Of all the specimens tested, 329 (30.8%) specimens were isolated with pathogenic bacteria or conditional pathogens (pathogens that cause infections only under certain conditions), and 23 of them, with two strains of bacteria. These 352 isolates comprised 85 (24.15%) for K. pneumonia, 57 (16.19%) for H. influenzae, 52(14.77%) for H. parainfluenzae, 18 (5.11%) for S.aureus, 12 (3.41%) for M. catarrhalis, 8 (2.27%) for S. pneumoniae, and 6 (1.70%) for B. haemolytic streptococci. Table 3 provides bacterial detection results from sputum and throat swab specimens by symptoms (the results from sputum and throat swab specimens separately are given in Additional file 2 and 3). When all kinds of bacteria were concerned, patients with runny nose (clear/watery discharge), cough with green sputum and cough with white sputum were more likely to be tested positive than patients without these symptoms; while the chances of detecting bacteria were lower in patients with dry cough and sore throat than in those without these symptoms. Looking specific kinds of bacteria, greater chances were observed for: detecting K.pneumonia from patients with cough with white sputum but without dry cough and sore throat; H. influenzae from patients with Cough with green sputum; H. parainfluenzae from patients with blocked nose; and S. pneumoniae from patients with Snotty nose (yellow/green discharge) and Cough with green sputum. In addition, number of symptoms witnessed a general increasing trend with the chances of detecting H. influenzae and H. parainfluenzae.
Table 3
Bacterial detection by clinical symptoms (n = 1086, sputum and throat swabs)
| AB | KP | HI | HP | SA | MC | SP | BS |
Symptom |
Blocked nose |
| 86(33.46) | 21(8.17) | 22(8.56) | 21(8.17) | 7(2.72) | 3(1.17) | 0(0.00) | 1(0.39) |
Runny nose (clear/watery discharge) |
| 100(36.10) | 24(8.66) | 17(6.14) | 17(6.14) | 3(1.08) | 5(1.81) | 1(0.36) | 1(0.39) |
Snotty nose (yellow/green discharge) |
| 19(27.14) | 5(7.14) | 4(5.71) | 2(2.86) | 1(1.43) | 1(1.43) | 2(2.86) | 0(0.00) |
Dry cough |
| 29(21.17) | 5(3.65) | 4(2.92) | 7(5.11) | 2(1.46) | 1(0.73) | 0(0.00) | 1(0.73) |
Cough with green sputum |
| 90(36.00) | 21(8.40) | 24(9.60) | 13(5.20) | 7(2.80) | 2(0.80) | 4(1.60) | 0(0.00) |
Cough with white sputum |
| 188(35.81) | 55(10.48) | 31(5.90) | 30(5.71) | 7(1.33) | 8(1.52) | 4(0.76) | 1(0.19) |
Dry throat / burning throat/hoarse voice |
| 82(31.78) | 17(6.59) | 14(5.43) | 16(6.20) | 6(2.33) | 4(1.55) | 0(0.00) | 1(0.39) |
Itchy throat |
| 73(28.29) | 22(8.53) | 15(5.81) | 14(5.43) | 3(1.16) | 2(0.78) | 1(0.39) | 1(0.39) |
Sore throat |
| 152(27.09) | 33(5.88) | 27(4.81) | 32(5.70) | 6(1.07) | 5(0.89) | 3(0.53) | 5(0.89) |
Breathing difficulties |
| 118(32.33) | 24(6.58) | 28(7.67) | 21(5.75) | 6(1.64) | 4(1.10) | 2(0.55) | 1(0.27) |
Headache |
| 62(30.85) | 14(6.97) | 10(4.98) | 12(5.97) | 2(1.00) | 2(1.00) | 0(0.00) | 1(0.50) |
Weakness |
| 48(34.53) | 13(9.35) | 5(3.60) | 7(5.04) | 2(1.44) | 1(0.72) | 2(1.44) | 2(1.44) |
Fever | | | | | | | | |
| 46(31.52) | 10(6.85) | 6(4.11) | 6(4.11) | 0(0.00) | 2(1.37) | 1(0.68) | 2(1.44) |
Other symptoms |
| 70(32.86) | 16(7.51) | 10(4.69) | 11(5.16) | 7(3.29) | 1(0.47) | 4(1.88) | 0(0.00) |
P | 0.028 | 0.349 | 0.159 | 0.966 | 0.384 | 0.984 | 0.066 | 0.557 |
Symptom Numbers |
-1 | 28(33.73) | 9(10.84) | 5(6.02) | 3(3.61) | 1(1.20) | 3(3.61) | 0(0.00) | 2(2.41) |
-2 | 55(24.89) | 19(8.60) | 5(2.26) | 3(1.36) | 4(1.81) | 1(0.45) | 4(1.81) | 1(0.45) |
-3 | 85(29.62) | 19(6.62) | 13(4.53) | 15(5.23) | 5(1.74) | 3(1.05) | 2(0.70) | 0(0.00) |
-4 | 78(35.14) | 21(9.46) | 19(8.56) | 11(4.95) | 5(2.25) | 2(0.90) | 0(0.00) | 2(0.90) |
-5 | 51(31.10) | 11(6.71) | 7(4.27) | 14(8.54) | 2(1.22) | 1(0.61) | 2(1.22) | 1(0.61) |
->=6 | 32(35.16) | 6(6.59) | 8(8.79) | 6(6.59) | 1(1.10) | 2(2.20) | 0(0.00) | 0(0.00) |
-P | 0.226 | 0.695 | 0.0397078 | 0.040778 | 0.964 | 0.222 | 0.233 | 0.172 |
Total | 329(30.8) | 85(24.15) | 57(16.19) | 52(14.77) | 18(5.11) | 12(3.41) | 8(2.27) | 6(1.70) |
Note: AB = detection of any bacteria, KP = K.pneumonia, HI = H.influenzae, HP = H.parainfluenzae, SA = S.aureus, MC = M.catarrhalis, SP = S.pneumoniae, BS = B.haemolytic streptococci. |
Antibiotics prescription and bacteria sensitivity
Figure 1 portraits the prescription rate of specific antibiotics and resistance rate of 8 common bacteria isolated from sputum and swab specimens. These bacteria were tested sensitive to most of the antibiotics studied. The most frequently prescribed antibiotics were levofloxacin (31.0%), amoxicillin clavulanic acid (14.8%), and cefuroxime (9.8%), ceftriaxone (5.4%) and ceftazidime (5.1%). The highest resistance rate was estimated as 100% for E.cloacae to cefazolin, followed by 97.4% for K. pneumoniae to ampicillin and 92.3 for S. aureus to penicillin. There witnessed no clear associations between the frequency of antibiotics prescription and the rates of resistance. The highest resistance rate to the top five most frequently prescribed antibiotics was 30.0%.
Determinants of antibiotics use and bacteria identification
Table 4 summarizes main statistics of multiple logistic regression modeling of potential factors that may be associated with bacteria detection results or antibiotic prescription. In the model of detection of any bacteria from all specimens (model 1), variables found with statistical significance of bacteria detection included age (OR = 1.91 for age > = 65 group), season (OR = 0.50 and 0.55 for summer and winter group respectively), days since infection onset (OR = 1.18 for > = 5 days), runny nose (clear/watery discharge) (OR = 1.39), cough with green sputum (OR = 1.47) and cough with white sputum (OR = 1.51). For the model of detection of 7-bacteria (H.influenzae, M.catarrhalis, S.pneumoniae, H.parainfluenzae, S.aureus, K. pneumonia and B.haemolytic streptococci) from all specimens (model 2), the findings mirrored that of model 1 to a large extent. The differences in model 2 from model 1 included only: a) age and runny nose were not associated with bacteria detection; and b) males and patients presenting blocked nose were more likely to be tested with the 7-bacteria. With regard to detection of the 6-bacteria (the first six kinds of bacteria in model 2) from sputum (model 3) and the 6-bacteria (the first five kinds of bacteria in model 2 plus B.haemolytic streptococci) from throat swabs (model 4), only season was fond with statistical significance. As compared with that in spring, there witnessed a reduced likelihood in isolating bacteria from sputum in summer (OR = 0.50) and from throat swabs in winter (OR = 0.41). In the antibiotic use model (model 5), only days since infection onset (OR = 0.53) and sore throat (OR = 1.64) were found with statistical significance.
Table 4
Statistics of multiple logistic regression modeling of bacterial detection and antibiotic use
Independent variables | Any bacteria, all specimens | 7-bacteria, all specimens | 6-bacteria, Sputum | 6-bacteria, throat swabs | Antibiotics prescription |
OR | 95%CI | OR | 95%CI | OR | 95%CI | OR | 95%CI | OR | 95%CI |
Age ( < = 39 as reference) |
40–53 | 1.34 | [0.85,2.11] | 1.40 | [0.85,2.30] | 1.50 | [0.79,2.82] | 1.14 | [0.47,2.78] | 1.23 | [0.67,2.28] |
54–64 | 1.41 | [0.87,2.29] | 1.30 | [0.76,2.21] | 1.39 | [0.72,2.67] | 0.89 | [0.30,2.64] | 0.97 | [0.51,1.85] |
>=65 | 1.91 | [1.13,3.22] | 1.39 | [0.78,2.48] | 1.30 | [0.65,2.63] | 1.80 | [0.54,6.07] | 1.19 | [0.57,2.45] |
Gender(Male as reference) |
female | 0.83 | [0.60,1.13] | 0.65 | [0.46,0.92] | 0.66 | [0.43,1.00] | 0.57 | [0.29,1.12] | 0.78 | [0.50,1.21] |
Education ( 0 as reference) |
1–5 | 0.75 | [0.51,1.11] | 0.85 | [0.55,1.31] | 1.02 | [0.63,1.66] | 0.41 | [0.14,1.23] | 0.91 | [0.51,1.60] |
6–8 | 0.89 | [0.56,1.39] | 0.82 | [0.50,1.37] | 0.84 | [0.46,1.54] | 0.84 | [0.28,2.49] | 0.9 | [0.46,1.79] |
> 8 | 0.98 | [0.59,1.61] | 1.10 | [0.64,1.90] | 1.13 | [0.60,2.12] | 1.06 | [0.32,3.52] | 0.57 | [0.29,1.13] |
Season(spring as reference) |
Summer | 0.50 | [0.35,0.70] | 0.57 | [0.39,0.83] | 0.50 | [0.33,0.78] | 0.67 | [0.30,1.53] | 1.25 | [0.75,2.08] |
Winter | 0.55 | [0.39,0.78] | 0.60 | [0.41,0.89] | 0.77 | [0.49,1.22] | 0.41 | [0.19,0.90] | 0.88 | [0.54,1.42] |
Days since infection onset( < = 2 as reference) |
2–4 | 1.31 | [0.91,1.90] | 1.33 | [0.88,2.01] | 1.14 | [0.68,1.89] | 2.11 | [0.99,4.50] | 0.88 | [0.50,1.53] |
>=5 | 1.81 | [1.26,2.58] | 1.54 | [1.03,2.29] | 1.50 | [0.93,2.42] | 1.20 | [0.54,2.68] | 0.53 | [0.32,0.88] |
Blocked nose | 1.26 | [0.91,1.75] | 1.61 | [1.13,2.29] | 1.42 | [0.94,2.15] | 2.02 | [0.98,4.17] | 1.1 | [0.69,1.75] |
Runny nose (clear/ watery discharge) | 1.39 | [1.02,1.90] | 1.16 | [0.82,1.64] | 1.21 | [0.81,1.80] | 0.76 | [0.34,1.68] | 0.91 | [0.58,1.42] |
Snotty nose (yellow/ green discharge) | 0.78 | [0.44,1.39] | 0.95 | [0.51,1.76] | 0.98 | [0.47,2.02] | 0.59 | [0.14,2.46] | 0.91 | [0.44,1.86] |
Dry cough | 0.97 | [0.57,1.64] | 1.00 | [0.55,1.81] | 0.80 | [0.19,3.41] | 1.15 | [0.54,2.47] | 1.49 | [0.69,3.23] |
Cough with green sputum | 1.47 | [1.01,2.15] | 1.59 | [1.05,2.41] | 1.37 | [0.80,2.35] | 1.25 | [0.47,3.33] | 0.65 | [0.39,1.06] |
Cough with white sputum | 1.51 | [1.06,2.14] | 1.56 | [1.06,2.31] | 1.26 | [0.74,2.15] | 1.94 | [0.86,4.36] | 0.91 | [0.57,1.44] |
Dry/burning throat/hoarse voice | 1.21 | [0.87,1.68] | 1.12 | [0.78,1.61] | 1.35 | [0.87,2.08] | 0.81 | [0.38,1.71] | 0.66 | [0.43,1.02] |
Itchy throat | 0.8 | [0.57,1.12] | 0.93 | [0.65,1.34] | 0.85 | [0.56,1.29] | 1.18 | [0.52,2.71] | 1.05 | [0.66,1.65] |
Sore throat | 0.8 | [0.59,1.07] | 0.83 | [0.59,1.15] | 0.84 | [0.57,1.25] | 0.84 | [0.41,1.73] | 1.64 | [1.07,2.50] |
Breathing difficulties | 0.83 | [0.61,1.13] | 0.89 | [0.64,1.25] | 0.88 | [0.60,1.30] | 0.88 | [0.41,1.89] | 1.23 | [0.79,1.90] |
Headache | 1.15 | [0.79,1.68] | 1.01 | [0.66,1.54] | 0.84 | [0.49,1.42] | 1.67 | [0.77,3.59] | 0.69 | [0.41,1.14] |
Weakness | 1.25 | [0.82,1.89] | 1.19 | [0.75,1.88] | 1.30 | [0.76,2.23] | 0.90 | [0.33,2.48] | 0.87 | [0.49,1.53] |
Fever | 1.17 | [0.76,1.80] | 0.86 | [0.53,1.42] | 0.93 | [0.51,1.67] | 0.75 | [0.28,2.03] | 1.25 | [0.66,2.36] |
Other symptoms | 1.28 | [0.90,1.82] | 1.27 | [0.86,1.88] | 1.20 | [0.76,1.88] | 1.39 | [0.58,3.33] | 0.7 | [0.44,1.11] |
Antibiotics prescription | 1.23 | [0.80,1.89] | 1.26 | [0.78,2.03] | 1.41 | [0.82,2.44] | 0.94 | [0.31,2.82] | NA | NA |
Constant | 0.31 | NA | 0.17 | NA | 0.19 | NA | 0.25 | NA | 17.38 | NA |
Note: (1) the “7-bacteria” tested for all specimens included H.influenzae, M.catarrhalis, S.pneumoniae, H. parainfluenzae, S.aureus, K.pneumonia and B.haemolytic streptococci; (2) the “6-bacteria” tested for all sputum specimens included the first six kinds of bacteria of (1) ; (3) the “6-bacteria” tested for all throat swabs included the first five kinds of bacteria of (1) plus B.haemolytic streptococci. |