Human influenza A (H5N1) cases, urban areas of People's Republic of China, 2005-2006.We investigated potential sources of infection for 6 confirmed influenza A influenza A
Influenza caused by infection with a strain of influenza virus type A.
influenza A Infectious disease An avian virus, especially of ducks–which in China live near the pig reservoir and 'vector'; (H5N1) patients who resided in urban areas of People's Republic People's Republic
A political organization founded and controlled by a national Communist party. of China. None had known exposure to sick poultry or poultry that died from illness, but all had visited wet poultry markets before illness.
Although >280 confirmed human cases of avian influenza avian influenza: see influenza. A (H5N1) virus infection from 12 countries have been reported (1), detailed data on sources of infection for most patients are limited (2). In Vietnam, 8 of 9 patients with influenza A (H5N 1) reported close contact with sick or dead poultry (3). In Thailand, 9 of 12 such patients lived in households where backyard chickens died, and 8 reported direct contact with dead chickens (4). Case-control studies case-control study,
n an investigation employing an epidemiologic approach in which previously existing incidents of a medical condition are used in lieu of gathering new information from a randomized population. in Thailand and Vietnam found that the most statistically significant risk factor was recent exposure to sick or dead poultry, especially directly touching dead poultry (5,6).
Avian influenza (H5N1) poultry outbreaks have been reported in mainland People's Republic of China since 2004 (7); since late 2005, human cases have also been reported (8). Most Chinese patients had exposure to backyard poultry, although some had no apparent direct exposure to poultry that were sick or died. We describe findings of investigations of urban patients with influenza A (H5N1), who had no known direct contact with sick poultry or poultry that died of illness in China.
Enhanced surveillance for influenza-like illness and pneumonia of unknown origin was established in China after the outbreak of severe acute respiratory syndrome Severe Acute Respiratory Syndrome (SARS) Definition
Severe acute respiratory syndrome (SARS) is the first emergent and highly transmissible viral disease to appear during the twenty-first century. (SARS) (9). All suspected cases of influenza A (H5N1) are reported through a national surveillance system to the Chinese Center for Disease Control and Prevention Noun 1. Center for Disease Control and Prevention - a federal agency in the Department of Health and Human Services; located in Atlanta; investigates and diagnoses and tries to control or prevent diseases (especially new and unusual diseases)
CDC (China CDC See Control Data, century date change and Back Orifice.
CDC - Control Data Corporation ). Laboratory testing is performed by the National Influenza influenza or flu, acute, highly contagious disease caused by a virus; formerly known as the grippe. There are three types of the virus, designated A, B, and C, but only types A and B cause more serious contagious infections. Center of China CDC. A confirmed case of influenza (H5N1) was defined according to according to
1. As stated or indicated by; on the authority of: according to historians.
2. In keeping with: according to instructions.
3. World Health Organization case definitions (10). This study was part of an ongoing public health outbreak investigation and determined by the ministry of health to be exempt from institutional review board assessment.
China CDC conducted epidemiologic ep·i·de·mi·ol·o·gy
The branch of medicine that deals with the study of the causes, distribution, and control of disease in populations.
[Medieval Latin epid investigations by interviewing confirmed influenza (H5N1) patients and their relatives, reviewing medical records, and visiting patient households and places visited by patients within 2 weeks of illness onset. A standardized standardized
pertaining to data that have been submitted to standardization procedures.
standardized morbidity rate
see morbidity rate.
standardized mortality rate
see mortality rate. questionnaire was used to collect demographic, clinical, and exposure history data. For 3 severely ill patients, only relatives and contacts were interviewed to assess possible influenza (H5N1) subtype (programming) subtype - If S is a subtype of T then an expression of type S may be used anywhere that one of type T can and an implicit type conversion will be applied to convert it to type T. exposures. Particular attention was paid to potential exposures such as contact with well-appearing, sick, or dead poultry; visits to poultry markets; or contact with persons with febrile febrile /feb·rile/ (feb´ril) pertaining to or characterized by fever.
Of, relating to, or characterized by fever; feverish. respiratory symptoms in the 2 weeks before onset. A rural case was 1 that occurred in a village resident; an urban case was 1 that occurred in a city resident.
From October 2005 through October 2006, 20 confirmed cases were reported from 12 provinces. Six cases were identified in 6 cities of 5 provinces; each city had an average population of 8.3 million and was at least 112 km away from cities with another case (Figure 1). More urban cases were reported in 2006 (5 [42%] of 12) than in 2005 (1 [13%] of 8), but this difference was not statistically significant (p = 0.325) (Figure 2). Demographic and clinical characteristics of the 6 urban patients with influenza (H5N1) cases are presented in Table 1. All 6 urban patients were adults, median age 30 years (range 21 to 41); 5 died.
[FIGURES 1-2 OMITTED]
Five of the 6 urban case-patients had no direct contact with poultry. One patient prepared freshly slaughtered chicken that she purchased for cooking at a live (wet) poultry market. No patients kept poultry or other animals at home, and no poultry or poultry outbreaks were identified in their neighborhoods. Five patients had visited wet poultry markets within a week of illness onset, and all had visited a wet market during the 2 weeks before their illness. Three patients visited wet markets at least once a day before illness onset. Only 1 patient (case-patient 5) had any travel history in the 2 weeks before illness onset. That patient had visited his parents' home in a rural area, where healthy backyard poultry were kept outside the house, and he had visited a wet market in the same area 2 weeks before illness onset (Table 2).
All 6 patients had no known contact with other confirmed influenza A (H5N1) patients or with anyone with febrile respiratory symptoms. A total of 640 persons were followed up for medical observation for 2 weeks, including 136 close contacts of the 6 patients, 389 healthcare workers who provided care for them, and 115 persons who worked in the poultry markets visited by the patients. Febrile respiratory illness Noun 1. respiratory illness - a disease affecting the respiratory system
respiratory disease, respiratory disorder
adult respiratory distress syndrome, ARDS, wet lung, white lung - acute lung injury characterized by coughing and rales; inflammation of the developed in 5 contacts: case-patient 1's mother, case-patient 3's girlfriend, case-patient 6's daughter, a nurse who cared for case-patient 6, and a patient hospitalized on the same ward as case-patient 6. All 5 ill contacts recovered, and all respiratory specimens collected from them tested negative for influenza A (H5N1) by reverse-transcriptase-PCR. Paired acute- and convalescent-phase serum samples collected from these 5 ill contacts tested negative for subtype (H5N1) neutralizing antibodies neu·tral·iz·ing antibody
An antibody that reacts with an infectious agent, usually a virus, and destroys or inhibits its infectiveness and virulence. by microneutralization assay.
Our study suggests that exposure to wet poultry markets may be an important influenza A (H5N1) risk factor for persons in urban areas of China. None of the 6 case-patients had known direct contact with poultry that were sick or died of illness. Two patients (case-patients 1 and 3) had no identified potential exposures except for visiting a wet poultry market during the week before illness onset. Four other case-patients visited wet markets, although other exposures could have potentially led to virus transmission. Case-patient 2 was an egg seller and could have also been infected in·fect
tr.v. in·fect·ed, in·fect·ing, in·fects
1. To contaminate with a pathogenic microorganism or agent.
2. To communicate a pathogen or disease to.
3. To invade and produce infection in. by contact with fecally contaminated contaminated,
v 1. made radioactive by the addition of small quantities of radioactive material.
2. made contaminated by adding infective or radiographic materials.
3. an infective surface or object. eggs. In 2005, influenza A (H5N1) virus was isolated from eggs brought to China by travelers from Vietnam (11). Case-patient 4 could potentially have been exposed to the virus through preparation of freshly slaughtered chickens purchased at a wet market. Case-patient 5 could have been exposed to the virus by visiting his parents' home, which had healthy backyard poultry outside, or by transporting eggs. Case-patient 6 could have been exposed to the virus at home when his wife prepared a freshly slaughtered chicken purchased from a wet market. No epidemiologic evidence suggested human-to-human transmission of influenza A (H5N1) associated with the urban patients.
These observations are consistent with results of a case-control study conducted during the 1997 influenza A (H5N1) outbreak in Hong Kong Hong Kong (hŏng kŏng), Mandarin Xianggang, special administrative region of China, formerly a British crown colony (2005 est. pop. 6,899,000), land area 422 sq mi (1,092 sq km), adjacent to Guangdong prov. Special Administrative Region A special administrative region may be:
In China, wet markets are sustained by demand for freshly slaughtered poultry. Wet markets are considered a reservoir and amplifier of avian influenza A viruses be cause they bring together avian avian /avi·an/ (a´ve-an) of or pertaining to birds.
Of, relating to, or characteristic of birds. host species in a high-density setting that can facilitate viral persistence, cross-species infection, and genetic reassortment (14). Our findings suggest that wet markets pose a risk that is likely to be low for avian-to-human transmission of subtype (H5N1) in urban settings. Viral RNA RNA: see nucleic acid.
in full ribonucleic acid
One of the two main types of nucleic acid (the other being DNA), which functions in cellular protein synthesis in all living cells and replaces DNA as the carrier of genetic for subtype (H5N1) was detected in a specimen collected from a goose cage at an urban wet market visited by case-patient 3 (15), which suggests the potential for influenza (H5N1) transmission through environmental contamination.
We were limited by inability to elicit e·lic·it
tr.v. e·lic·it·ed, e·lic·it·ing, e·lic·its
a. To bring or draw out (something latent); educe.
b. To arrive at (a truth, for example) by logic.
2. complete exposure histories from all case-patients because of their severe illness or death. However, we interviewed household and family members, friends, and co-workers, and investigated places that patients had visited in the 2 weeks before illness onset. We were unable to ascertain how human infection with the virus occurred through the patients' visits to wet poultry markets. Possibilities include self-inoculation of the respiratory tract respiratory tract
The air passages from the nose to the pulmonary alveoli, including the pharynx, larynx, trachea, and bronchi.
Respiratory tract after touching subtype (H5N1)--contaminated surfaces, or inhalation inhalation /in·ha·la·tion/ (in?hah-la´shun)
1. the drawing of air or other substances into the lungs.inhala´tional
2. the drawing of an aerosolized drug into the lungs with the breath.
3. of aerosolized Adj. 1. aerosolized - in the form of ultramicroscopic solid or liquid particles dispersed or suspended in air or gas
gaseous - existing as or having characteristics of a gas; "steam is water is the gaseous state" debris with influenza (H5N1) virus.
We did not perform testing on poultry or environmental specimens and can only speculate about potential exposures and sources of influenza A subtype (H5N1) infection in wet markets, homes, and neighborhoods. Future studies should test tracheal tracheal
pertaining to or emanating from trachea.
see transtracheal aspiration.
tracheal band sign
on contrast radiography of a dilated esophagus, the impression made ventrally by the trachea. , cloacal cloacal
emanating from or pertaining to cloaca.
the contact which occurs during insemination in birds when the vent of the female is everted exposing the cloacal mucosa against which the phallus of the male is pressed. , and blood specimens from poultry; swabs of fecal fecal /fe·cal/ (fe´k'l) pertaining to or of the nature of feces.
Relating to or composed of feces.
pertaining to or of the nature of feces. material, cages, and other potentially contaminated surfaces; and air specimens in wet markets, for evidence of influenza (H5N1). More research studies, including case-control studies, are needed to better clarify the risk for subtype (H5N1) transmission that occurs from visiting wet poultry markets. Close collaborations are needed between animal health and public health agencies to reduce the public health risk for this virus in wet poultry markets and to understand the impact of poultry vaccination on the risk for transmission.
We thank the CDCs of Chengdu, Sanming, Shenzhen, Guangzhou, and Wuhan Prefectures for assisting in coordinating field investigations and providing logistic support Noun 1. logistic support - assistance between and within military commands
support - the activity of providing for or maintaining by supplying with money or necessities; "his support kept the family together"; "they gave him emotional .
The Ministry of Health of China has generously facilitated this study. This study was supported by grants from the National Task Force of China (2004BA519A71).
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(2.) World Health Organization. Epidemiology epidemiology, field of medicine concerned with the study of epidemics, outbreaks of disease that affect large numbers of people. Epidemiologists, using sophisticated statistical analyses, field investigations, and complex laboratory techniques, investigate the cause of WHO-confirmed human cases of avian influenza A (H5N1) infection. Wkly Epidemiol Rec. 2006;81:249-57.
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1. to invade and produce infection in.
2. to transmit a pathogen or disease to.
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The state of being prepared, especially military readiness for combat.
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Any of three viruses of the genus Influenzavirus designated type A, type B, and type C, that cause influenza and influenzalike infections. from eggs of Vietnamese waterfowl waterfowl, common term for members of the order Anseriformes, wild, aquatic, typically freshwater birds including ducks, geese, and screamers. In Great Britain the term is also used to designate species kept for ornamental purposes on private lakes or ponds, while in . [E pub 2006 Mar 13]. Arch Virol. 2006;151:1615-24.
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(13.) Savill NJ, St Rose SG, Keeling keeling
the marking of ewes by the ram when they are mated by the marking on the ewe of paint or chalk from the sternum of the ram. MJ, Woolhouse MEJ MEJ Mouvement Eucharistique des Jeunes (Organistion Catholique)
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Hongjie Yu, * (1) Zijian Feng, (1) Xianfeng Zhang, ([dagger]) (1) Nijuan Xiang, * Yang Huai This article or section may fail to make a clear distinction between fact and .
Please [ edit this article], according to the fiction guidelines, to meet Wikipedia's . ,* ([double dagger double dagger
A reference mark () used in printing and writing. Also called diesis.
Noun 1. ]) Lei Zhou, * Zhongjie Li, * Cuiling Xu, ([section]) Huiming Luo, ([paragraph]) Jianfeng He, ([paragraph]) Xuhua Guan guan: see curassow. , ([dagger]) Zhengan Yuan Yuan (yüän), river, 540 mi (869 km) long, rising in S Guizhou prov. and flowing generally NE to Donting lake, Hunan prov., SE China. Navigation above Changde is limited by rapids to small craft. , (#) Yanting Li, (#) Longshan Xu, ** Rongtao Hong, ** Xuecheng Liu, ([dagger]) ([dagger])Xingyu Zhou, ([dagger])([dagger]) Wenwu Yin ,* Shunxiang Zhang, ([double dagger]) ([double dagger]) Yuelong Shu, * Maowu Wang, * Yu Wang, * Chin-Kei Lee, ([section]) ([section]) Timothy M. Uyeki, ([paragraph]) ([paragraph]) and Weizhong Yang yang (yang) [Chinese] in Chinese philosophy, the active, positive, masculine principle that is complementary to yin; see yin, under principle. , * for the Avian Influenza H5N1 Study Group (2)
* Chinese Center for Disease Control and Prevention, Beijing, People's Republic of China; ([dagger]) Hubei Center for Disease Control and Prevention, Wuhan, People's Republic of China; ([double dagger]) International Field Epidemiology Training Program, Bangkok, Thailand; ([section]) National Institute for Viral Disease Control and Prevention, Beijing, People's Republic of China; ([paragraph]) Guangdong Center for Disease Control and Prevention, Guangzhou, People's Republic of China; (#) Shanghai Center for Disease Control and Prevention, Shanghai, People's Republic of China; ** Fujian Center for Disease Control and Prevention, Fuzhou, People's Republic of China; ([dagger]) ([dagger]) Sichuan Center for Disease Control and Prevention, Chengdu, People's Republic of China; ([double dagger]) ([double dagger]) Shenzhen Center for Disease Control and Prevention, Shenzhen, People's Republic of China; ([section])([section])World Health Organization, Beijing, People's Republic of China; and [paragraphs] Centers for Disease Control and Prevention Centers for Disease Control and Prevention (CDC), agency of the U.S. Public Health Service since 1973, with headquarters in Atlanta; it was established in 1946 as the Communicable Disease Center. , Atlanta, Georgia, USA
(1) These authors contributed equally to this work.
(2) Members of the Chinese Center for Disease Control and Prevention Avian influenza H5N1 Study Group are Shuyun Xie, Zhitao Liu, Xuefeng Tang tang, in zoology
tang: see butterfly fish. , and Jun Li. Members of the Provincial Center for Disease Control and Prevention Avian influenza H5N1 Study Group are Gongping Liu, Jianming Ou, Shaojian Cai, Ting Huang, Tie Song, De Wu, and Xiaodong Sun.
Address for correspondence: Weizhong Yang, Chinese Center for Disease Control and Prevention, 27 Nanwei Rd, Beijing, 100050, People's Republic of China; email: email@example.com
Dr Yu is a medical epidemiologist epidemiologist
an expert in epidemiology. in the Office for Disease Control and Emergency Response, China CDC. His research interests include surveillance, prevention, and control of emerging infections, including SARS, avian influenza, and Streptococcus suis Streptococcus suis is spherical, Gram-positive bacteria, and an important pathogen of pigs. Endemic in nearly all countries with an extensive pig industry, S. suis is also a zoonotic disease, capable of transmission to humans from pigs. .
Table 1. Characteristics of 6 human influenza A (H5N1) case-patients from urban areas of China Case-patient no. Characteristic 1 2 3 Location Sanming, Chengdu, Guangzhou, (city, province) Fujian Sichuan Guangdong Residence Apartment Apartment Apartment Illness onset date Dec 6, 2005 Jan 10, 2006 Feb 22, 2006 Days from onset to 6 7 6 investigation Contact with ill No No No persons before onset Days from onset to 2 4 3 first medical visit Days from onset to 3 7 5 hospital admission Primary signs and Fever, Fever, Fever, symptoms at headache, cough, chills, admission cough diarrhea, cough, myalgia shortness of breath Complications * Respiratory Respiratory Respiratory failure, failure, failure, ARDS, ARDS, ARDS cardiac cardiac failure, failure, septicemia septicemia Outcome Died Died Died Days from onset to 16 14 9 death Case-patient no. Characteristic 4 5 6 Location Shanghai, Wuhan, Hubei Shenzhen, (city, province) Shanghai Guangdong Residence Temporary, Dormitory Apartment at construction site Illness onset date Mar 13, 2006 Apr 1, 2006 Jun 3, 2006 Days from onset to 8 10 8 investigation Contact with ill No No No persons before onset Days from onset to 2 5 4 first medical visit Days from onset to 9 11 7 hospital admission Primary signs and Fever, Fever, Fever, symptoms at chills, headache, chills, admission cough sore throat, productive cough, cough, myalgia back pain Complications * Respiratory Respiratory Respiratory failure, failure, failure, ARDS, ARDS, ARDS cardiac cardiac failure failure, septicemia Outcome Died Died Survived Days from onset to 9 19 Discharged death 61 d from onset * Respiratory failure was defined as the need for ventilator support; ARDS, acute respiratory distress syndrome, is a lite-threatening condition in which inflammation of the lungs and accumulation of fluid in the air sacs (alveoli) lead to low blood oxygen levels; cardiac failure was defined as the requirement of isotropic agents. Table 2. Exposure history of 6 influenza A (H5N1) case-patients from urban areas of China Case- patient no. Epidemiologic information 1 41 -y-old female factory worker, previously healthy, with a history of thymectomy for benign thymoma 6 wk before illness onset, had recovered fully, did not require any medications, and resumed working. She visited a wet market nearly every day the week before illness onset but did not purchase poultry or poultry products. No poultry were kept in her home or neighborhood. 2 29-y-old woman, previously healthy, worked at a stall that she owned at a wet market, selling groceries and eggs. Her stall was [member of] 20 m away from stalls selling and slaughtering live poultry. No poultry were kept in her home or neighborhood. 3 32-y-old man, previously healthy, quit his job 1 mo before illness onset and was planning to start his own food business. He visited up to 9 wet markets for 10-40 min every day during the week before illness onset. At 1 wet market, he spent most of his time in a sauce store that was ~5 m away from stalls where poultry were slaughtered and sold. No poultry were kept in his home or neighborhood. 4 29-y-old woman, previously healthy, moved from Guangdong to Shanghai 2 mo before illness onset. She worked as a cook for 14 people at a construction site, where she lived temporarily, and visited a wet market every day to buy fresh food, including freshly slaughtered chickens, 1 wk before illness onset. No poultry were kept in her home or neighborhood. 5 21-y-old man, previously healthy, was a security guard for an aircraft-repairing factory in Wuhan. Two wk before illness onset, he traveled to his hometown in the rural area of Enshi to attend the funeral of his uncle, who died of esophageal cancer. The man stayed there for 6 d, visited his parents' home, where healthy backyard poultry were kept (none became sick or died), and visited a wet market. One wk before onset, he traveled back to his workplace in Wuhan, bringing 200 eggs from his hometown. In Wuhan, he had no direct contact with poultry, and he did not visit any wet markets. No poultry were kept in his home or neighborhood. 6 31-y-old man, previously healthy, worked as a truck driver for shoe factories in Shenzhen city. Two d before illness onset, he visited a wet market once, but he did not purchase any poultry or poultry products. One wk before onset, his wife visited the same market and brought a live chicken that was slaughtered at the market. No abnormal die offs of poultry were reported. No poultry were kept in his home or neighborhood.