A pertussis outbreak was studied in a primary school in Xi’an, China in March, 2016. The school consisted of 536 pupils aged 6 to 12 years who were divided into 12 classes of 6 grades (2 classes for each grade). The identified index case was an 11-year-old girl at Class 2 of grade 5.
Interview was conducted and nasopharyngeal (NP) swabs were taken from all pupils (N=94) in the two classes of grade 5. NP swabs were tested by both culture and PCR.
Four culture and 17 PCR positive cases were identified in 94 pupils. Infection rate was significantly higher in Class 2 compared to that in Class 1 (37.0% (17/46) vs 14.6% (7/48), χ2=4.26, P<0.05). All B. pertussis isolates were macrolide resistant, harbored prn1/ptxP-1/fim3-1 as previously reported and belonged to MLVA type MT 195. Of the 17 DNAs positive for diagnostic PCR, 12 were also positive for 23S rRNA PCR. All the 12 DNAs had the A2047G mutation of 23S rRNA gene of B. pertussis.
This study described a pertussis outbreak caused by macrolide-resistant B. pertussis in a primary school and indicated that close contact of index case causes the bacterial transmission.
1 No 3 Department of Infectious Diseases, Xi’an Children Hospital, 69 Xijunyuan Road, Xi’an, China, 710002.
2 Department of Vaccine Preventable Diseases, Xi’an Center for Disease Control and Prevention, 599 Xiying Road, Xi’an, China, 710054
3Department of Medical Microbiology, Capital Medical University, No.10 Xi Tou Tiao, You'an Men Wai, Feng Tai District, Beijing, China,100069
4Department of Medical Microbiology and Immunology, University of Turku, Kiinamyllynkatu 13, 20520 Turku, Finland
* The authors contributed equally
Funding: This study is supported by National Nature Science Foundation of China (No.81602902).
Authorship Yarong Li and Qiushui He contributed to the study design, data analysis and writing. Xiaoguai Liu and Zengguo Wang carried out the experimental work,date analysis and interpretation, preparation of the manuscript. Juansheng Zhang, Fang Li and Yang Luan contributed to acquisition of samples. Hao Li carried out the interviews and statistical analysis. All authors reviewed and approved the final manuscript as submitted.
Transparency declarations and Funding All the authors declare that they have no conflicts of interest.
Funding This study is supported by National Nature Science Foundation of China (No.81602902).
Corresponding authors: Yarong Li, E-mail: email@example.com; Phone: +86 29 8769 2116 or Qiushui He, Email: Qiushui.He@utu.fi; Phone: +358 2 333 7429