Human infection with avian influenza A（H7N9） virus in Shanghai： current status and future trends

Avian influenza A（H7N9） virus is one subgroup among the larger group of H7 viruses,which normally circulate among birds.The H7N9 subtype of avian influenza viruses has not been known to infect humans until only recently.On March 31,2013,China confirmed the first three human cases of novel avian influenza A（H7N9）infection in Shanghai and Anhui,two of these patients died.1 As of February 27,2014,367 laboratory-confirmed human cases have been reported from 15 provinces/municipalities in mainland China,     

Discovery process,clinical characteristics,and treatment of patients infected with avian influenza virus （H7N9） in Shanghai

During the spring of 2013,a novel avian-origin influenza A （H7N9） virus emerged and spread in Shanghai.On May 9,2013,33 lab-confirmed cases （2 children and 31 adults） have been reported,among whom 13 died.Among the 31 adult cases of H7N9 avian influenza A virus infections in humans,80.6% （25/31） were older men （average age 65 years）.Clear history of poultry exposure was found in eight patients （8/33,24.3%） and the remaining 21 cases had been suspected poultry exposure.Clustered cases were found in two families （two cases from a father and his son,and the other two cases from a wife and her husband）.However,no evidence of human-to-human transmission had been identified.Avian influenza is one of the most dangerous contagions in poultry worldwide,and avian influenza A virus is the major pathogen responsible.Transmission from poultry to humans has now been proven.Some gene segments of the strain have mutated,and further mutations might result in human-to-human transmission.     

Clinical status and its associated early warning per emerging infectious respiratory disease in China

In the past ten years, we had experienced a series of .emerging severe acute respiratory infections （SARI）.Some of them became serious public health emergent events, such as severe acute respiratory syndrome （SARS） and novel A/H7N9 avian influenza. Tracing back to 2003, SARS originated from Guangdong province and spread to 29 countries and regions until it was completely controlled. Out of 8 096 probable SARS cases world-wide, 774 patients died; the mortality was 9.6%.1 There were 5 327 patients with SARS in China, and 1 002 （19%） of them were health care workers （HCW）. Nearly all the HCW got hospital acquired infection since there was no efficient preventive and protective system.     

Incidence of congenital heart disease in Beijing, China

Background The incidence of congenital heart disease has been studied in developed countries for many years, but rarely in the mainland of China. Fetal echocardiographic screening for congenital heart disease was first performed in Beijing in the early 2000s, but the impact was not clear. The current study was undertaken to determine the incidence of congenital heart disease in Beijing, China and to estimate the impact of fetal echocardiography on the incidence of liveborn congenital heart disease.
Methods The study involved all infants with congenital heart disease among the 84 062 total births in Beijing during the period of January 1 and December 31, 2007. An echocardiographic examination was performed on every baby suspected to have congenital heart disease, prenatally or/and postnatally.
Results A total of 686 infants were shown to have congenital heart disease among 84 062 total births. The overall incidence was 8.2/1000 total births. Mothers of 128 of 151 babies diagnosed prenatally were chosen to terminate the pregnancy. Two of the 151 infants died in utero. A specific lesion was identified for each infant and the frequencies of lesions were determined for each class of infants （total births, stillbirths and live births）. The incidence of congenital heart disease in stillbirths and live births was 168.8/1000 and 6.7/1000, respectively. The difference between the incidence of total birth and the incidence of live birth was statistically significant （P 〈0.001）.
Conclusions The incidence of liveborn congenital heart disease in Beijing is within the range reported in developed countries. Fetal echocardiography reduce significantly the incidence of liveborn congenital heart disease.     

Potential infections of H5N1 and H9N2 avian influenza do exist in Guangdong populations of China

Background Southeast China is one of the sites of influenza origin. During 2003-2004, nine avian influenza outbreaks took place in Guangdong Province. But no human case was reported. To examine the status of potential human infection by human influenza （H1N1, H3N2） and avian influenza （H5N1, H7N7, H9N2） in the avian influenza epidemic area of Guangdong Province, China, we conducted a seroepidemiologic survey in the people of this area from April to June of 2004.
Methods Three out of 9 H5N1 avian influenza affected poultry areas in Guangdong were randomly selected, and the population living within 3 kilometers of the affected poultries were chosen as the survey subjects. One thousand two hundred and fourteen people were selected from 3 villages at random. Human and avian influenza antibody titers were determined by hemagglutination-inhibition （HI） test and microneutralization test （MNT）.
Results The positive rate of antibody to H5N1 was 3.03% in the occupational exposure group and 2.34% in general citizens group; that of H9N2 was 9.52% in the occupational exposure group and 3.76% in the general citizens group. Moreover one case in the occupational exposure group was positive for H7N7. One year later, all previously positive cases had become negative except for one H5N1-positive case.
Conclusion The observations imply that H5N1 and H9N2 avian influenza silent infections exist in Guangdong populations.     

Prediction of H7N9 epidemic in China

Background In March 2013,human cases of infection with a novel A （H7N9） influenza virus emerged in China.The epidemic spread quickly and as of 6 May 2013,there were 129 confirmed cases.The purpose of this study was to analyze the epidemiology of the confirmed cases,determine the impacts of bird migration and temperature changes on the H7N9 epidemic,predict the future trends of the epidemic,explore the response patterns of the government and propose preventive suggestions.Methods The geographic,temporal and population distribution of all cases reported up to 6 May 2013 were described from available records.Risk assessment standard was established by analysing the temperature and relative humidity records during the period of extensive outbreak in three epidemic regions in eastern China,including Shanghai,Zhejiang and Jiangsu provinces.Risk assessment maps were created by combining the bird migration routes in eastern China with the monthly average temperatures from May 1993 to December 2012 nationwide.Results Among the confirmed cases,there were more men than women,and 50.4％ were elderly adults （age ＞61 years）.The major demographic groups were retirees and farmers.The temperature on the days of disease onset was concentrated in the range of 9℃-19℃; we defined 9℃-19℃ as the high-risk temperature range,0℃-9℃ or 19℃-25℃ as medium risk and ＜0℃ or ＞25℃ as low risk.The relative humidity on the days of disease onset ranged widely from 25％ to 99％,but did not correlate with the incidence of infection.Based on the temperature analysis and the eastern bird migration routes,we predicted that after May,the high-risk region would move to the northeast and inland,while after September,it would move back to north China.Conclusions Temperature and bird migration strongly influence the spread of the H7N9 virus.In order to control the H7N9 epidemic effectively,Chinese authorities should strengthen the surveillance of migrating birds,increase poultry and environmental sampling,improve live poultry selling and husbandry patterns and move from a ＂passive response pattern＂to an ＂active response pattern＂ in focused preventive measures.     

Research on autosomal dominant polycystic kidney disease in China

Objective To review the history and recent development of research on autosomal dominant polycystic kidney disease （ADPKD） in China. Data sources Both Chinese and English literatures were searched in MEDLINE/CD ROM （1979 - 2006） and the Chinese Biomedical Literature Disk （1979 - 2006）. Study selection Published articles about ADPKD from mainland of China were selected. Data were mainly extracted from 58 articles which are listed in the reference section of this review. Results Some preliminary reports on cyst decompression surgeries and mutation analysis represent the contribution to the ADPKD research from China in the history. A serial of basic research and clinical studies on ADPKD in recent years also have been summarized. A technique platform for ADPKD research was firstly established. The genomics/proteomics/bioinformatics approach was introduced, which provide a lot of valuable information for understanding the pathogenesis. By denature high performance liquid chromatography （DHPLC） technique the entire PKD1 and PKD2 gene sequence screening system for Chinese Han population has been successfully established. Based on the characteristic data of Chinese patients, an integrated therapy protocol was put forward and won an advantage over the traditional therapy. Some novel experimental studies on therapy also were encouraging. Condusions Remarkable progress of ADPKD research in China have been made recently. Still many works, including the government support, international collaboration and active participation of more Chinese nephrologists, should be enhanced to advance this process in the near future.     

Highlight the significance of genetic evolution of H5N1 avian flu

Agrowing concern has focused on the recent ,identification of influenza A H5N1 virus in Asia. Previously thought to infect only wild birds and poultry, H5N1 has now infected humans, cats, pigs, and other mammals in an ongoing outbreak, often with fatal results. According to a report from the World Health Organization （WHO）, 217 human H5N1 cases have been confirmed and 123 of them have been fatal as of May 19, 2006.1 But many questions remain unanswered, for example how the H5N1 virus could cross species barriers and acquire the ability to infect humans;     

Prevalence of sensitivity to cockroach allergens and IgE cross- reactivity between cockroach and house dust mite allergens in Chinese patients with allergic rhinitis and asthma

Background Cockroaches are an important indoor allergen source causing allergic rhinitis and asthma. The aim of this study was to investigate the cockroach prevalence in mainland of China and the cross-reactivity of IgE between cockroach and house dust mite allergen in Chinese patients.Methods The cockroach sensitization pattern was based on a skin prick test （SPT） obtained from a national multicenter prevalence study, in which 6304 patients from 25 allergy centers across China participated. Factors, including different regions of China, age, gender and the correlations between the American and German cockroaches and house dust mite Der p were investigated. Eighteen out of 1236 clinical sera from south China were selected to perform the cross-inhibition assay between house dust mites and cockroaches.Results Totally 25.7% of patients were SPT positive to the American cockroach （Periplaneta Americana, Per a） and 18.7% SPT positive to the German cockroach （Blattella germanica, Bla g）. The prevalence of positive cockroach SPT was higher in southern than in northern China, higher in adults than in children, and higher in males than in females.Patients had relatively low levels of cockroach SPT reactions, mainly class 1 or 2. Of the SPT positive cockroach patients,88% were also SPT positive to house dust mite （Dermatophagoides pteronyssinus, Der p）. An IgE cross-inhibition study confirmed that Der P sensitization could cause false positive SPT reactions against cockroach.Conclusions A relatively high prevalence of cockroach sensitivity was found in mainland of China. However, a cross-inhibition study showed that only a small number of patients appear to have Bla g and/or Per a as primary sensitizing source. The importance of cockroaches as a risk factor for sensitization and triggers of allergic symptoms in mainland of China needs to be further investigated.