To the editor,
The emerging H7N9 influenza infection in China is a present concern in medicine. This infection is considered a new cross-species zoonosis [Citation1]. The new H7N9 influenza virus crosses from avian to human and cause atypical influenza. Adding to classical acute respiratory illness, there are many observed clinical presentations. Thrombocytopenia is an important finding, seen in 73% of infected cases [Citation2]. However, there is no report on bleeding complication. Rapid dropping of platelet count can be seen after start of infection [Citation3]. However, the decreasing is only about 10% of the normal reference value [Citation4, Citation5]. Exact pathogenesis for thrombocytopenia in H7N9 influenza is still a myth that needs further studies. In fact, thrombocytopenia is usually an important observation among the patients infected with new atypical influenza infections (H1N1 swine flu and H5N1 bird flu). Nevertheless, it should be noted that the induction of autoimmune thrombocytopenia due to atypical influenza is observed in case of H1N1 swine flu [Citation6] and this might contribute to some cases of thrombocytopenia in H7N9 bird flu.
Declaration of interest
The authors report no conflicts of interest.
References
- Dai C, Jiang M. Understanding H7N9 avian flu. BMJ 2013;346:f2755
- Gao HN, Lu HZ, Cao B, Du B, Shang H, Gan JH, Lu SH, Yang YD, Fang Q, Shen YZ, et al. Clinical Findings in 111 Cases of Influenza A (H7N9) Virus Infection. N Engl J Med 2013;368(24):2277--2285
- Lu SH, Xi XH, Zheng YF, Cao Y, Liu XN, Lu HZ. Analysis of the clinical characteristics and treatment of two patients with avian influenza virus (H7N9). Biosci Trends 2013;7(2):109–112
- Lu S, Zheng Y, Li T, Hu Y, Liu X, Xi X, Chen Q, Wang Q, Cao Y, Wang Y, et al. Clinical findings for early human cases of influenza A(H7N9) virus infection, Shanghai, China. Emerg Infect Dis. 2013 Jul http://dx.doi.org/10.3201/eid1907.130612 DOI: 10.3201/eid1907.130612
- Chen Y, Liang W, Yang S, Wu N, Gao H, Sheng J, Yao H, Wo J, Fang Q, Cui D, et al. Human infections with the emerging avian influenza A H7N9 virus from wet market poultry: Clinical analysis and characterisation of viral genome. Lancet 2013;381(9881):1916--1925
- Lee CY, Wu MC, Chen PY, Chou TY, Chan YJ. Acute immune thrombocytopenic purpura in an adolescent with 2009 novel H1N1 influenza A virus infection. J Chin Med Assoc 2011;74(9):425–427