Risk factors for human infection with avian influenza A H5N1, Vietnam, 2004

To evaluate risk factors for human infection with influenza A subtype H5N1, we performed a matched case-control study in Vietnam. We enrolled 28 case-patients who had laboratory-confirmed H5N1 infection during 2004 and 106 age-, sex-, and location-matched control-respondents. Data were analyzed by matched-pair analysis and multivariate conditional logistic regression. Factors that were independently associated with H5N1 infection were preparing sick or dead poultry for consumption < or =7 days before illness onset (matched odds ratio [OR] 8.99, 95% confidence interval [CI] 0.98-81.99, p = 0.05), having sick or dead poultry in the household < or =7 days before illness onset (matched OR 4.94, 95% CI 1.21-20.20, p = 0.03), and lack of an indoor water source (matched OR 6.46, 95% CI 1.20-34.81, p = 0.03). Factors not significantly associated with infection were raising healthy poultry, preparing healthy poultry for consumption, and exposure to persons with an acute respiratory illness.     

Surveillance for Avian Influenza A(H7N9), Beijing,China, 2013

During surveillance for pneumonia of unknown etiology and sentinel hospital–based surveillance in Beijing, China, we detected avian influenza A(H7N9) virus infection in 4 persons who had pneumonia, influenza-like illness, or asymptomatic infections. Samples from poultry workers, associated poultry environments, and wild birds suggest that this virus might not be present in Beijing.     

Human illness from avian influenza H7N3, British Columbia

Avian influenza that infects poultry in close proximity to humans is a concern because of its pandemic potential. In 2004, an outbreak of highly pathogenic avian influenza H7N3 occurred in poultry in British Columbia, Canada. Surveillance identified two persons with confirmed avian influenza infection. Symptoms included conjunctivitis and mild influenzalike illness.     

Novel Reassortant Influenza A(H5N8) Viruses among Inoculated Domestic and Wild Ducks,South Korea, 2014

An outbreak of highly pathogenic avian influenza, caused by a novel reassortant influenza A (H5N8) virus, occurred among poultry and wild birds in South Korea in 2014. The aim of this study was to evaluate the pathogenesis in and mode of transmission of this virus among domestic and wild ducks. Three of the viruses had similar pathogenicity among infected domestic ducks: the H5N8 viruses were moderately pathogenic (0%–20% mortality rate); in wild mallard ducks, the H5N8 and H5N1 viruses did not cause severe illness or death; viral replication and shedding were greater in H5N8-infected mallards than in H5N1-infected mallards. Identification of H5N8 viruses in birds exposed to infected domestic ducks and mallards indicated that the viruses could spread by contact. We propose active surveillance to support prevention of the spread of this virus among wild birds and poultry, especially domestic ducks.     

The organization of work: implications for injury and illness among immigrant Latino poultry-processing workers

The US poultry-processing industry employs a large number of immigrants and has among the highest occupational illness rates for manufacturing. Previous research has not studied the potential health effects of psychosocial indicators of how poultry-processing work is organized. The investigators collected survey data from 200 immigrant Latinos working in poultry processing. Management practices (eg, poor commitment to safety, abusive supervision) and indicators of job design (eg, authority, variety, psychological workload, frequent awkward posture, and repetitive movement) were associated with risk of recent musculoskeletal problems, respiratory problems, and self-reported injury/illness. The results provide preliminary evidence suggesting that the organization of work underlies injury and illness among immigrant workers in poultry processing.     

中国2013-2017年人感染H7N9禽流感的流行病学特征

目的 对我国人感染H7N9禽流感的流行病学特点进行分析，为H7N9禽流感的预防控制提供依据。方法 以2013年3月至2017年4月公开发表的人感染H7N9禽流感数据为对象，利用Excel 2007软件对数据进行统计学分析，描述其三间分布、暴露史及聚集性。结果 中国共确诊人感染H7N9禽流感病例1 416例，死亡559例，病死率为39.5%，2016年病例最少（127例），病死率最高（57.5%）；报告病例前三位的省份主要是浙江、广东、江苏；发病年龄M＝55岁，男女性别比为2.3∶1，男性病例远多于女性。66%的病例在发病前确定有活禽相关暴露史，31%的病例暴露情况不详，仅有3%的病例无相关活禽暴露史。共发生35起家庭聚集性病例，共涉及72例病例，占总发病例数的5%。结论 H7N9禽流感疫情有较明显的季节分布及区域分布特点；存在有限的家庭聚集性；感染病例多与禽类接触有关。     

Notes from the field: multistate outbreak of Salmonella Altona and Johannesburg infections linked to chicks and ducklings from a mail-order hatchery - United States, February-October 2011

Salmonella infections from contact with live poultry (chickens, ducks, turkeys, and geese) continue to be a public health problem. In summer 2011, two clusters of human Salmonella infections were identified through PulseNet, a molecular subtyping network for foodborne disease surveillance. Standard outbreak and traceback investigations were conducted.?From February 25 to October 10, 2011, a cluster of 68 cases caused by Salmonella serotype Altona and a cluster of 28 cases caused by Salmonella Johannesburg were identified in 24 states. Among persons infected, 32% of those with Salmonella Altona and 75% of those with Salmonella Johannesburg were aged ≤5 years. Forty-two of 57 (74%) Salmonella Altona patients and 17 of 24 (71%) of Salmonella Johannesburg patients had contact with live poultry in the week preceding illness. Most patients or their parents reported purchasing chicks or ducklings from multiple locations of an agricultural feed store chain that was supplied by a single mail-order hatchery. Live poultry were purchased for either backyard flocks or as pets.     

Past, Present, and Possible Future Human Infection with Influenza Virus A Subtype H7

Influenza A subtype H7 viruses have resulted in >100 cases of human infection since 2002 in the Netherlands, Italy, Canada, the United States, and the United Kingdom. Clinical illness from subtype H7 infection ranges from conjunctivitis to mild upper respiratory illness to pneumonia. Although subtype H7 infections have resulted in a smaller proportion of hospitalizations and deaths in humans than those caused by subtype H5N1, some subtype H7 strains appear more adapted for human infection on the basis of their virus-binding properties and illness rates among exposed persons. Moreover, increased isolation of subtype H7 influenza viruses from poultry and the ability of this subtype to cause severe human disease underscore the need for continued surveillance and characterization of these viruses. We review the history of human infection caused by subtype H7. In addition, we discuss recently identified molecular correlates of subtype H7 virus pathogenesis and assess current measures to prevent future subtype H7 virus infection.     

Circulation of Reassortant Influenza A(H7N9) Viruses in Poultry and Humans,Guangdong Province,China, 2013

Influenza A(H7N9) virus emerged in eastern China in February 2013 and continues to circulate in this region, but its ecology is poorly understood. In April 2013, the Guangdong Provincial Center for Disease Control and Prevention (CDC) implemented environmental and human syndromic surveillance for the virus. Environmental samples from poultry markets in 21 city CDCs (n = 8,942) and respiratory samples from persons with influenza-like illness or pneumonia (n = 32,342) were tested; viruses isolated from 6 environmental samples and 16 patients were sequenced. Sequence analysis showed co-circulation of 4 influenza A(H7N9) virus strains that evolved by reassortment with avian influenza A(H9N2) viruses circulating in this region. In addition, an increase in human cases starting in late 2013 coincided with an increase in influenza A H7 virus isolates detected by environmental surveillance. Co-circulation of multiple avian influenza viruses that can infect humans highlights the need for increased surveillance of poultry and potential environmental sources.     

禽类及非禽类从业人员禽流感认知状况调查

目的 了解广东省东莞市禽类从业人员和非禽类从业人员人禽流感知识、态度和行为状况,为制定人禽流感防控措施提供依据.方法 对259名禽类和129名非禽类从业人员进行人禽流感知识、态度、行为调查.结果 禽类和非禽类从业人员人禽流感相关知识总知晓率分别为34.03%和29.75%.农贸市场及批发市场销售的家禽95.83%有检疫证明,但散养家禽禽流感疫苗接种率仅为62.69%.禽类从业人员每天穿工作服、戴手套、戴口罩人数所占比例分别为19.79%,32.81%和29.17%.禽类和非禽类从业人员对病死禽能采取正确处理措施的分别占25.87%和21.71%;接触病死禽后能每次洗手的分别占81.85%和92.25%;对"家禽实行定点屠宰,禁售活禽"的赞成率分别为20.08%和31.78%;对"定期对市场进行清洗消毒、宰杀当天所有活禽"的支持率分别为33.98%和54.26%.结论 东莞市禽类从业人员存在人禽流感防治知识缺乏、个人防护不足、对病死禽处理措施欠妥、散养家禽禽流感疫苗接种率偏低等现象.应加强宣传教育和管理措施.     

长沙市1例人感染H3N8禽流感病例的流行病学调查和病原学分析

目的 了解人感染H3N8禽流感病例的流行病学特征和临床特征及其病原的分子生物学特征，为人感染H3N8禽流感防控提供科学依据。方法 采用流行病学调查方法对长沙市2022年5月1例人感染H3N8禽流感病例的可疑暴露史、感染途径、发病及就诊经过，以及密切接触者、可疑暴露者等涉疫重点人员进行现场调查，并进行描述性分析；采用核酸检测和基因测序技术，进行病原学检测和基因特征分析。结果 病例发病前6 d有活禽交易市场暴露史，在活禽交易市场、活禽来源批发市场均检测出禽流感H3、N8亚型阳性。深度基因测序显示，病毒对哺乳动物发生适应性突变，对烷胺类药物敏感性降低，未检测到神经氨酸酶抑制剂类药物和聚合酶抑制剂类药物相关的耐药性突变。结论 病例暴露于被H3N8禽流感病毒污染的活禽交易市场环境而感染，未发现人际间传播。     

Human salmonellosis associated with young poultry from a contaminated hatchery in Michigan and the resulting public health interventions, 1999 and 2000

Although approximately 95% of disease caused by nontyphoidal salmonella is transmitted by foodborne vehicles, four documented salmonella outbreaks in the 1990s have been traced to contact with young poultry. No environmental studies of source hatcheries were completed. This case-control study was performed by comparing culture-confirmed Salmonella Infantis in Michigan residents, identified between May and July 1999, with two age- and neighbourhood-matched controls. Eighty environmental and bird tissue samples were collected from an implicated hatchery; all salmonella isolates underwent pulsed-field gel electrophoresis (PFGE) analysis. The study included 19 case-patients sharing the same PFGE subtype and 37 matched controls. Within 5 days before illness onset, 74% of case-patients resided in households raising young poultry compared with 16% of controls (matched OR 19.5; 95% CI 2.9, 378.1). Eight hatchery samples yielded Salmonella Infantis with PFGE subtypes matching the patients' isolates. This investigation identified birds from a single hatchery as the source of human illness and confirmed the link by matching PFGE patterns from humans, birds and the hatchery environment. Subsequent public health interventions reduced, but did not eliminate, transmission of poultry-associated salmonellosis. Five additional PFGE-linked cases were identified in Spring 2000, necessitating quarantine of the hatchery for depopulation, cleaning and disinfection.     

The relationship between Triatoma infestans, poultry, and humans in a rural settlement in Santiago del Estero, Argentina

An association was determined between Triatona infestans, poultry, and humans in Trinidad, in the Province of Santiago del Estero, Argentina. To collect triatomines, four samples were taken at the area immediately surrounding six houses by the one hour/man capture method (December 1991 - October 1992). Peridomiciliary ecotopes were classified as arthropic (where humans carry out daily activities) or non-anthropic. Tratomine feeding habits were also determined. Of 134 biotopes, 21% had T. infestans, 22% had poultry, and 54% were anthropic. Some 25% of the latter harboured both poultry and T. infestans. Poultry were the only domestic animals associated with T. infestans, a finding that was exclusive to anthropic ecotopes. The proportion of feedings on individual fowl (61/146) was highly significant. Chicken coops are not used in Trinidad, and poultry brood in anthropic structures. Due to the materials used for making their nests and their repeated use, a periodic bug flow can be established from the intra- to the peridomiciliary area and vice versa, through passive transport. The close relationship among T, infestans, poultry, and humans in anthropic biotopes where other T. cruzi reservoirs such as dogs are also present contributes to the maintenance of domestic triatomine colonies and transmission of Chagas' disease to humans.     

Low frequency of infection with avian influenza virus (H5N1) among poultry farmers, Thailand, 2004

In Thai provinces where avian influenza outbreaks in poultry had been confirmed in the preceding 6 months, serum from 322 poultry farmers was tested for antibodies to avian influenza virus subtype H5N1 by microneutralization assay. No study participant met the World Health Organization serologic criteria for confirmed infection.     

Campylobacter jejuni--an emerging foodborne pathogen

Campylobacter jejuni is the most commonly reported bacterial cause of foodborne infection in the United States. Adding to the human and economic costs are chronic sequelae associated with C. jejuni infection--Guillian-Barré syndrome and reactive arthritis. In addition, an increasing proportion of human infections caused by C. jejuni are resistant to antimicrobial therapy. Mishandling of raw poultry and consumption of undercooked poultry are the major risk factors for human campylobacteriosis. Efforts to prevent human illness are needed throughout each link in the food chain.     

Observational epidemiologic studies of endemic waterborne risks: cohort, case-control, time-series, and ecologic studies

Observational studies have assessed endemic waterborne risks in a number of countries. Time-series analyses associated increased water turbidity with increased gastroenteritis risks in several public water systems. Several cohort studies reported an increased risk of gastroenteritis in populations using certain public or individual water systems. Although several case-control studies found increased waterborne risks, they also found increased risks associated with other exposures. An increased risk of campylobacteriosis was associated with drinking untreated water from non-urban areas and some tap waters; other significant risks included contaminated poultry and foreign travel. Increased risks of cryptosporidiosis and giardiasis were associated with drinking water in some populations; other risk factors included foreign travel, day care exposures, and swimming. These observational studies provide evidence that some populations may be at an increased risk of endemic or sporadic illness from waterborne exposures, but not all studies found an increased risk. Differences in waterborne risks may be due to differences in water quality. System vulnerabilities and contamination likely differed in the areas that were studied. The information from these studies may help inform estimates of waterborne illness for the US population but is inadequate to estimate a population attributable risk.     

深圳市一例人禽流感病例现场流行病学分析

目的 结合人禽流感病例的调查处理探索现场流行病学的应用效果.方法 对一例人禽流感病例开展流行病学调查和密切接触者观察,采用RT-PCR检测咽拭子或气管分泌物H5亚型核酸片段和血清中H5抗体;对气管分泌物中分离到的H5N1病毒进行主要基因片段的测序和分析.按照现场流行病学特征完成处理和控制.结果 根据临床表现和病原学检测结果,确诊为人禽流感病例;患者病前曾到过居住地附近的一间兼营活禽的菜市场,余无可疑接触史;对患者的98名接触者进行医学观察,并对其中的4名进行隔离观察,未发现人与人之间的传播.由患者气管分泌物分离到H5N1病毒[A/Guangdong/02/2006(H5N1)],基因序列分析仍为禽源性特征,但与2005年之前国内分离的病毒株明显不同.病例呈现起病急、进展快和多脏器严重损害等特征,经救治而康复.疫情处理以疾病预防控制和临床专业为技术支撑,注意了政府主导下的多部门参与、公众互动、媒体沟通、与香港交流等,收到了良好的效果.结论 及早发现和病原学确诊是病例成功救治的关键;病毒株仍为禽源性特征,未见人间传播现象,但病毒感染来源和传播因素不明;现场流行病学为突发公共卫生事件应对提供了重要的理论和方法.     

禽类养殖场人员禽流感病毒抗体水平调查

目的 调查珠海地区养殖场人员中禽流感H5和H9二种亚型血清中抗体水平，以了解上述2种禽类甲型流感病毒亚型以往的接触感染情况，为防治人问禽流感提供科学依据。方法 珠海地区养殖场人员血清277份，正常出入境人员血清270份，通过血凝抑制试验HI实验进行抗体检测。结果 养殖场人群中H9亚型抗体阳性率为2．17％，同时发现有1份血清H5抗体阳性，H5抗体阳性率为0．36％。而正常出入境人群H9亚型抗体阳性率为2．96％；未见H5亚型抗体的存在。结论 H9亚型在养殖场人群和出入境人群中的存在隐性感染，但感染率不高；养殖场人群H5亚型抗体的存在也应值得注意。     

上海市奉贤区个体家禽养殖场禽流感防控干预效果评价

[目的]通过干预提高个体家禽养殖场禽流感防控能力。[方法]整群抽取上海市奉贤区38户个体家禽养殖场及其从业人员150名,进行禽流感防控能力干预,干预后评价效果。[结果]干预前,个体家禽养殖场软硬件设施配置不足,禽流感防控卫生知识缺乏;干预后,养殖户加强了养殖场软硬件设施的建设,养殖人员禽流感防控卫生知识水平提高,＂禽流感症状＂知晓比例由24.00%提高到79.33%,＂接触病禽该怎么办＂知晓比例由9.33%提高到21.33%。[结论]对个体家禽养殖场及其养殖人员进行禽流感防控措施和能力培训必要、有效。