The Epidemiological Study Of Haemophilus Influenzae Infection Among 0～17Y Hospitalized Patients In West Sichuan China

Objective To explore the basic clinical characters, epidemic strains resistant dynamic, and the distribution of serology and biotype of haemophilus influenzae (Hi) infection among 0-17y hospitalized patients in west Sichuan China. Methods 1.The retrospective epidemiological investigation (the first part) and the multicenter prospective epidemiological studies (the second part) were combined for cross-sectional study.2.Haemophilus influenzae type classification using biological credits and PCR identification. Results for Part 1(The retrospective epidemiological investigation in hospitalized children with haemophilus influenzae infection) 1.117 cases were identified Hi positive among 0-17y in-patients in 24 months,111 cases were enrolled in this survey,63 males and 48 females; 7 cases (6.31%) in 0-28d children,32 cases (28.83%) in 29d-ly,37 cases (33.33%) in 2-3y,25 cases (22.52%) in 4-6y,10 cases (9.01%)in 7-17y.2. May and November were the peak Hi isolation month.3.102 cases(91.89%) were respiratory infection,the Hi positive rate in pneumonia was 30/59, followed by acute laryngotracheobronchitis 2/4, capillary bronchitis 9/26, acute bronchitis 32/132, asthmatoid bronchitis 5/28, herpangina 4/21,acute upper respiratory infection 9/76, acute tonsillitis 7/85, neumonia of neonat 3/54; other diseases were 9 cases (8.11%).3. Resistance rate to amoxicillin-clavulanate (15.38%,22.64,%2=6.705, P=0.010) and chloramphenicol (25.00%,7.55%,x2=5.892, P=0.015) with statistically significant difference; sistance rate to ampicillin, cefaclor, cefuroxime, ofloxacin, tetracycline, cotrimoxazole and rifampicin with no statistics difference in this two years. Resistance rate to cefotaxime was in low level(5.77%,7.55%).4.Both β-lactamase-nonproducing-ampicillin-resistant(BLNAR) and β-lactamase-producing-amoxicillin-clavulanate-resistant (BLPACR) increased (11.54-20.75,13.46-18.87)in two years, but with no statistics difference (x2=1.643, p=0.200; x2=0.565,p=0.452). Results for Part 2(Part2 The multicenter prospectie epidemiological studies in hospitalized Children with lower respiratory tract infection of haemophilus influenzae):1.0-17y in-patients with lower respiratory infection was 5748 cases in four hospitals being investigated in west Sichuan in 2013.11-2014.04. The totally positive rate of sputum culture was 43.53%(n=1175),and 281 Haemophilus influenzae (Hi) strain in 272 cases (10.08%)were isolated. All the strain(100%) was non-typeable Haemophilus influenzae(NTHi) indentified by PCR. The main biotype of 281 strain was I (38.79%) and I V(51.25%).2.272 cases were enrolled in this survey,13 cases (4.78%)was neonate pneumonia, and 34 csaes (12.50%) was capillary bronchitis,and the rest of lower respiratory infection was 229 cases (84.19%).6 cases was pneumonia complicated with sepsis in 272.3. In four hospitals being investigated,the totally positive rate of Hi in in-patients with lower respiratory infection was 10.21%、28.96%、4.80%、10.21%(x2=112.561, P=0.000) and the positive rate of Hi in patients with capillary bronchitis was 11.92%%20.93%> 4.76%%66.67%(P=0.001), and with the rest lower respiratory infection was 9.96%,30.90%、4.81%、9.85%(x2=108.876, P=0.000).5. In addition to the resistance of cefotaxime showed statistically difference (x2=12.617, P=0.003), other resistance rate of clinical commonly used antimicrobial has not showed statistical difference. And Cefotaxime resistance maintained at a lower level (2.50%,15.94%) among four hospitals.6. p-lactamase-nonproducing-ampicillin-resistant(BLNAR) increased and (3-lactamase-producing-amoxicillin-clavulanate-resistant (BLPACR) decreased in one of the four hospitals compared with its results of the previous retrospective study, but both did not show statistical difference (X2=3.266, P=0.071; x2=2.039, P=0.153).7. The strain storage of Hi had been established. Conclusion 1. H. influenzae played an important role in 0-17y respiratory tract infection diseases in west Sichuan China.2. H. influenzae-related infections distributed throughout the year, May and November were the peak Hi isolation month.3. In west Sichuan China, all the Hi strain resulted in 0～17y lower respiratory tract infections was NTHi, and the main biotype was Ⅰ and Ⅳ in 2013.11～2014.04.4. Neonatal infections with NTHi are not uncommon.5. The increasing trend of BLNAR and BLPACR made it harder for antibiotic selection in clinic.