key: cord-1037937-d63noia4 authors: Ye, Chuchu; Zhu, Weiping; Yu, Jianxing; Li, Zhongjie; Fu, Yifei; Lan, Yajia; Lai, Shengjie; Wang, Yuanping; Pan, Lifeng; Sun, Qiao; Zhao, Genming title: Viral pathogens among elderly people with acute respiratory infections in Shanghai, China: Preliminary results from a laboratory‐based surveillance, 2012‐2015 date: 2017-07-06 journal: J Med Virol DOI: 10.1002/jmv.24751 sha: 80d10d9d8afbc696c1c774f15a6c93070eed1759 doc_id: 1037937 cord_uid: d63noia4 Acute respiratory infections (ARIs), with viral pathogens as the major contributors, are the most common illnesses worldwide, and increase the morbidity and mortality among the elderly population. The clinical and pathological features of elderly people with ARIs need to be identified for disease intervention. From January 1, 2012 through December 31, 2015, respiratory specimens from patients above 60 years old with ARIs were collected from the outpatient and inpatient settings of six sentinel hospitals in Pudong New Area. Each specimen was tested via multiplex polymerase chain reaction (PCR) for eight target viral etiologies including influenza, human rhinovirus (HRV), human para‐influenza virus (PIV), adenovirus (ADV), respiratory syncytial virus (RSV), human metapneumovirus (hMPV), human coronavirus (hCoVs), and human bocavirus (hBoV). A total of 967 elderly patients with ARIs were enrolled, including 589 (60.91%) males, and the median age was 73 years old. 306 (31.64%) patients were tested positive for any one of the eight viruses, including 276 single infections and 30 co‐infections. Influenza was the predominant virus (14.17%, 137/967), detected from 21.35% (76/356) of the outpatients and 9.98% (61/611) of the inpatients. Influenza infections presented two annual seasonal peaks during winter and summer. Compared with non‐influenza patients, those with influenza were more likely to have fever, cough, sore throat, and fatigue. This study identified influenza as the leading viral pathogen among elderly with ARIs, and two seasonal epidemic peaks were observed in Shanghai. An influenza vaccination strategy needs to be advocated for the elderly population. those with influenza were more likely to have fever, cough, sore throat, and fatigue. This study identified influenza as the leading viral pathogen among elderly with ARIs, and two seasonal epidemic peaks were observed in Shanghai. An influenza vaccination strategy needs to be advocated for the elderly population. influenza virus, public policy, respiratory track Acute respiratory infections (ARIs) are the most common illnesses worldwide. They cause nearly four million deaths per year, at a rate of more than 60 deaths/100 000 people. 1,2 Among all the individuals with ARIs, the elderly suffer disproportional morbidity and mortality rates, mostly due to viral respiratory infections. [3] [4] [5] The rates of ARIs increase with age in adults and are highest among individuals aged >65 years. 6 During the past decades, some nations, including China, have faced a rapid increase in the proportion Chuchu Ye, Weiping Zhu, and Jianxing Yu contributed equally to this work. Each specimen was tested for the following eight viral to have fever (307, 86.24%), sore throat (132, 37.8%), headache (97, 27.25%), fatigue (110, 30.90%), and runny nose (89, 25.00%) than inpatients (P = 0.000, Table 1 ). Of the 967 enrolled patients, 306 (31.64%) tested positive for at least one of the eight target viruses. Of these patients, 276 presented with a single infection, whereas 30 (9.80%) were infected with more than one virus. The predominant etiologies of the respiratory viruses in singleinfection cases were influenza (137, 44.77%), HRV (44, 14.38%) and PIV (23, 7.52%). No hBoV positive samples were detected. Influenza was also the most frequently detected pathogen among multiinfection cases; influenza plus HRV and influenza plus hMPV were the most frequent pathogen combinations among co-infections, and these combinations were detected in five specimens (16.67%), followed by influenza plus RSV (4, 13.33%). Two patients were infected with three pathogens (Fig. 1 ). Of the 356 outpatients, 41.85% tested positive for at least one virus. This rate was much higher than that among inpatients (25.70% [157/611], P = 0.000). The most common viruses were influenza and HRV; 21.35% (76/356) and 6.18% (22/356) of outpatients tested positive for these viruses, respectively, whereas 9.98% (61/611) and 3.60% (22/611) of inpatients did so, respectively. Outpatients were more likely to test positive for influenza than inpatients (21.35 vs. 9.98%, P = 0.000). The proportion of patients with co-infection was similar among outpatients (11, 3.09%) and inpatients (19, 3.11%, Table 2 ). The positive percentage of influenza virus presented two seasonal peaks, with a primary peak in the winter (January-February) and a secondary peak in the summer (July-August), with the positive percentage of 36.09% and 20.13% respectively. The winter and summer peaks among outpatients were much higher than those among inpatients (46.75 vs. 27.17%, P = 0.008; 32.14 vs. 13.09%, P = 0.000, Fig. 2 were infected with A(H1N1)pdm09, and one was infected with Similar studies have demonstrated that influenza causes the great majority of ARIs, and the impact of influenza on the elderly is substantial. More than 2/3 of influenza-related hospitalizations and more than 80% of the influenza-related deaths in the United States are estimated to involve the elderly. 13, 14 In addition to their increased morbidity and mortality rates, the clinical features of influenza among showed that the vaccine effectiveness (VE) against A(H3N2) was lower than that against the A(H1N1)pdm09 strain over those years. 19 Vaccination is the most effective strategy to prevent influenza. Although elderly might experience a declining immunogenicity after vaccination due to the immunosenescence, 20 they are still an important target population for influenza vaccination because of its highest influenza-related death burden. Seasonal influenza vaccination is recommended for this population worldwide. 21, 22 A quantitative review of 31 vaccine antibody response studies showed that the protection rates of influenza vaccine against A(H1N1), A(H3N2), and B-type influenza in the elderly were 69%, 74%, and 67% respectively. 23 According to a study conducted in Brazil, no influenza virus was identified during the influenza season among a group of elderly patients with ARIs, with an influenza immunization coverage of 62.30%. 24 Influenza vaccines specifically targeting this population have been developed and might facilitate additional efforts to prevent influenza among the elderly. 25, 26 The elderly of several Chinese cities (ie, Beijing and Ningbo) are offered free annual influenza vaccinations. 19, 27, 28 However, similar public health policies have not been offered in Shanghai yet. Previous researches had showed that most of the H7N9 cases were older people with the median age over 60 years. 29, 30 One case infected with A(H7N9) was identified by our surveillance system, which was helpful to increase the timeliness of both clinical treatment and public health disposal. Several limitations exist in this study. First, because the surveillance system has been operating for only 4 years, and the quantity of the specimens was inadequate at the beginning period, seasonal trends cannot be well described yet. However, the predominant viral pathogen in elderly with ARIs and the characteristics of these individuals was clearly revealed by our preliminary results, which provide primary background information. Second, sampling bias might be caused due on convenience sampling method. Beside, although some inpatients were excluded because they previously visited outpatient clinics, the bias caused by repeated visits remains in our study, especially among inpatients. To improve future surveillance, more information (eg, detailed clinical symptoms, complications, vaccines, and the treatment histories of the patients) should be collected to evaluate the disease burden associated with target respiratory viruses and determine the risk factors. The findings of the current study showed that influenza is the leading viral pathogen among both elderly inpatients and outpatients with ARIs. Furthermore, two seasonal epidemic peaks were identified in Shanghai, China. An influenza vaccination strategy should be advocated for the elderly population to reduce the disease burden of influenza among this population at high risk for complicated diseases. Acute viral infections of upper respiratory tract in elderly people living in the community: comparative, prospective, population based study of disease burden WHO (World Health Organization). 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Influenza-vaccine use Technical guidelines for the application of seasonal influenza vaccine in China Antibody response to influenza vaccination in the elderly: A quantitative review Viral etiology among the elderly presenting acute respiratory infection during the influenza season Immunosenescence: Influenza vaccination and the elderly Correlates of protection against influenza in the elderly: Results from an influenza vaccine efficacy trial Review of 10 years of clinical experience with Chinese domestic trivalent influenza vaccine Anflu ® Influenza vaccine effectiveness in preventing hospitalization among Beijing residents in China Comparative epidemiology of human infections with avian influenza A H7N9 and H5N1 viruses in China: A populationbased study of laboratory-confirmed cases Epidemiology of human infections with avian influenza A(H7N9) virus in China Viral pathogens among elderly people with acute respiratory infections in Shanghai, China: Preliminary results from a laboratory-based surveillance The authors would like to thank the staff of the six sentinel hospitals in Pudong New Area for their assistance with throat swab acquisition and data collection. We also thank Dr. Luzhao Feng and Dr. Zhibin Peng from Chinese Center for Disease Control and Prevention for their assistance. This study was supported by the fund of Key Discipline Construction of Health System in Pudong New Area (PWZx2014-14) .