@article{Wang_Fang_2017, title={Extensive surveillance for avian influenza A(H5N6) virus in Southern China}, volume={9}, url={https://ojphi.org/ojs/index.php/ojphi/article/view/7683}, DOI={10.5210/ojphi.v9i1.7683}, abstractNote={<div style="left: 78.2727px; top: 278.962px; font-size: 12.3207px; font-family: sans-serif; transform: scaleX(1.0823);" data-canvas-width="55.467823232323234">Objective</div><div style="left: 91.3182px; top: 291.965px; font-size: 12.3207px; font-family: serif; transform: scaleX(1.03122);" data-canvas-width="330.0236916666663">To determine avian influenza A(H5N6) virus infection in human</div><div style="left: 78.2727px; top: 306.46px; font-size: 12.3207px; font-family: serif; transform: scaleX(1.01864);" data-canvas-width="344.84303813131294">and environment using extensive surveillances. To evaluate the</div><div style="left: 78.2727px; top: 320.955px; font-size: 12.3207px; font-family: serif; transform: scaleX(1.00136);" data-canvas-width="288.80969444444435">prevalence of H5N6 infection among high risk population.</div><div style="left: 78.2727px; top: 348.538px; font-size: 12.3207px; font-family: sans-serif; transform: scaleX(1.11884);" data-canvas-width="71.86668434343434">Introduction</div><div style="left: 91.3182px; top: 361.541px; font-size: 12.3207px; font-family: serif; transform: scaleX(1.04036);" data-canvas-width="330.0717424242424">Since the emergence of avian influenza A(H7N9) virus in 2013,</div><div style="left: 78.2727px; top: 376.036px; font-size: 12.3207px; font-family: serif; transform: scaleX(1.01875);" data-canvas-width="342.9284002525253">extensive surveillances have been established to monitor the human</div><div style="left: 78.2727px; top: 390.531px; font-size: 12.3207px; font-family: serif; transform: scaleX(0.987956);" data-canvas-width="341.66799191919193">infection and environmental contamination with avian influenza virus</div><div style="left: 78.2727px; top: 405.026px; font-size: 12.3207px; font-family: serif; transform: scaleX(0.980289);" data-canvas-width="341.71234646464626">in southern China. At the end of 2015, human infection with influenza</div><div style="left: 78.2727px; top: 419.521px; font-size: 12.3207px; font-family: serif; transform: scaleX(1.01566);" data-canvas-width="342.5982053030304">A(H5N6) virus was identified in Shenzhen for the first time through</div><div style="left: 78.2727px; top: 434.016px; font-size: 12.3207px; font-family: serif; transform: scaleX(0.976871);" data-canvas-width="343.5493638888891">these surveillances. These surveillances include severe pneumonia</div><div style="left: 78.2727px; top: 448.511px; font-size: 12.3207px; font-family: serif; transform: scaleX(1.00813);" data-canvas-width="344.56089393939425">screening, influenza like illness (ILI) surveillance, follow-up on</div><div style="left: 78.2727px; top: 463.006px; font-size: 12.3207px; font-family: serif; transform: scaleX(0.985183);" data-canvas-width="341.7271313131314">close contact of the confirmed case, serological survey among poultry</div><div style="left: 78.2727px; top: 477.501px; font-size: 12.3207px; font-family: serif; transform: scaleX(1.00142);" data-canvas-width="262.45570202020195">workers, environment surveillance in poultry market.</div><div style="left: 78.2727px; top: 505.084px; font-size: 12.3207px; font-family: sans-serif; transform: scaleX(1.07424);" data-canvas-width="50.65042676767676">Methods</div><div style="left: 91.3182px; top: 518.086px; font-size: 12.3207px; font-family: serif; transform: scaleX(0.966659);" data-canvas-width="330.4364353535353">Severe pneumonia screening was carried out in all hospitals of</div><div style="left: 78.2727px; top: 532.581px; font-size: 12.3207px; font-family: serif; transform: scaleX(0.955374);" data-canvas-width="343.2179368686869">Shenzhen. When a patient with severe pneumonia is suspected for</div><div style="left: 78.2727px; top: 547.076px; font-size: 12.3207px; font-family: serif; transform: scaleX(1.03419);" data-canvas-width="343.17851060606046">infection with avian influenza virus, after consultation with at least</div><div style="left: 78.2727px; top: 561.571px; font-size: 12.3207px; font-family: serif; transform: scaleX(1.03904);" data-canvas-width="343.3682494949492">two senior respiratory physicians from the designated expert panel</div><div style="left: 78.2727px; top: 576.066px; font-size: 12.3207px; font-family: serif; transform: scaleX(0.999402);" data-canvas-width="342.22858409090907">and gaining their approval, the patient will be reported to local CDC,</div><div style="left: 78.2727px; top: 590.561px; font-size: 12.3207px; font-family: serif; transform: scaleX(1.02683);" data-canvas-width="342.85817222222227">nasal and pharyngeal swabs will be collected and sent for detection</div><div style="left: 78.2727px; top: 605.056px; font-size: 12.3207px; font-family: serif; transform: scaleX(1.01549);" data-canvas-width="135.87275757575753">of H5N6 virus by RT-PCR.</div><div style="left: 91.3182px; top: 619.551px; font-size: 12.3207px; font-family: serif; transform: scaleX(1.02941);" data-canvas-width="329.87461111111116">ILI surveillance was conducted in 11 sentinel hospitals, 5-20 ILI</div><div style="left: 78.2727px; top: 634.046px; font-size: 12.3207px; font-family: serif; transform: scaleX(1.0184);" data-canvas-width="339.17797702020204">cases were sampled for detection of seasonal influenza virus by RT-</div><div style="left: 78.2727px; top: 648.541px; font-size: 12.3207px; font-family: serif; transform: scaleX(0.972167);" data-canvas-width="341.55464141414143">PCR test every week for one sentinel. If swab sample is tested positive</div><div style="left: 78.2727px; top: 663.036px; font-size: 12.3207px; font-family: serif; transform: scaleX(1.00912);" data-canvas-width="342.46144545454547">for influenza type A and negative for subtypes of seasonal A(H3N2)</div><div style="left: 78.2727px; top: 677.531px; font-size: 12.3207px; font-family: serif; transform: scaleX(0.982605);" data-canvas-width="339.14594318181815">and A(H1N1), it will be detected further for influenza A(H5N6) virus.</div><div style="left: 91.3182px; top: 692.026px; font-size: 12.3207px; font-family: serif; transform: scaleX(0.967049);" data-canvas-width="330.5534820707072">Follow-up on close contacts was immediately carried out when</div><div style="left: 78.2727px; top: 706.521px; font-size: 12.3207px; font-family: serif; transform: scaleX(0.988601);" data-canvas-width="344.3625305555554">human case of infection with H5N6 was identified. All of close</div><div style="left: 78.2727px; top: 721.016px; font-size: 12.3207px; font-family: serif; transform: scaleX(1.03398);" data-canvas-width="343.1255315656565">contacts were requested to report any signs and symptoms of acute</div><div style="left: 78.2727px; top: 735.511px; font-size: 12.3207px; font-family: serif; transform: scaleX(0.981334);" data-canvas-width="343.82657979798">respiratory illness for 10 days, nasal and pharyngeal swabs were</div><div style="left: 78.2727px; top: 750.006px; font-size: 12.3207px; font-family: serif; transform: scaleX(1.05153);" data-canvas-width="343.37810606060594">collected and tested for influenza A(H5N6) virus by RT-PCR test.</div><div style="left: 78.2727px; top: 764.501px; font-size: 12.3207px; font-family: serif; transform: scaleX(0.989444);" data-canvas-width="341.85280252525257">In the meantime, environmental samples were collected in the market</div><div style="left: 78.2727px; top: 778.996px; font-size: 12.3207px; font-family: serif; transform: scaleX(1.03196);" data-canvas-width="343.1427805555555">which was epidemiologically associated with patient and tested for</div><div style="left: 78.2727px; top: 793.491px; font-size: 12.3207px; font-family: serif; transform: scaleX(1.01486);" data-canvas-width="142.72307070707072">H5N6 virus by RT-PCR test.</div><div style="left: 91.3182px; top: 807.985px; font-size: 12.3207px; font-family: serif; transform: scaleX(1.03256);" data-canvas-width="329.93621464646475">Serological survey among poultry workers was conducted in ten</div><div style="left: 78.2727px; top: 822.48px; font-size: 12.3207px; font-family: serif; transform: scaleX(1.0009);" data-canvas-width="344.51037904040385">districts of Shenzhen. Poultry workers were recruited in poultry</div><div style="left: 78.2727px; top: 836.975px; font-size: 12.3207px; font-family: serif; transform: scaleX(0.979542);" data-canvas-width="341.7948952020201">markets and screened for any signs and symptoms of acute respiratory</div><div style="left: 78.2727px; top: 851.47px; font-size: 12.3207px; font-family: serif; transform: scaleX(0.97351);" data-canvas-width="339.04121717171716">illness, blood samples were collected to detect haemagglutination-</div><div style="left: 78.2727px; top: 865.965px; font-size: 12.3207px; font-family: serif; transform: scaleX(1.00396);" data-canvas-width="265.88085858585856">inhibition (HI) antibody for influenza A(H5N6) virus.</div><div style="left: 91.3182px; top: 880.46px; font-size: 12.3207px; font-family: serif; transform: scaleX(0.981867);" data-canvas-width="330.92187121212135">Environment surveillance was conducted twice a month in ten</div><div style="left: 78.2727px; top: 894.955px; font-size: 12.3207px; font-family: serif; transform: scaleX(1.01431);" data-canvas-width="344.62988989898986">districts of Shenzhen. For each district, 10 swab samples were</div><div style="left: 78.2727px; top: 909.45px; font-size: 12.3207px; font-family: serif; transform: scaleX(1.01857);" data-canvas-width="345.0414015151517">collected at a time. All environmental samples were tested for</div><div style="left: 78.2727px; top: 923.945px; font-size: 12.3207px; font-family: serif; transform: scaleX(1.01384);" data-canvas-width="208.74973989898984">influenza A(H5N6) virus by RT-PCR test.</div><div style="left: 78.2727px; top: 951.528px; font-size: 12.3207px; font-family: sans-serif; transform: scaleX(1.08542);" data-canvas-width="44.50239393939395">Results</div><div style="left: 91.3182px; top: 964.531px; font-size: 12.3207px; font-family: serif; transform: scaleX(0.989895);" data-canvas-width="331.3013489898991">From Nov 1, 2015 to May 31, 2016, 50 patients with severe</div><div style="left: 78.2727px; top: 979.026px; font-size: 12.3207px; font-family: serif; transform: scaleX(0.993917);" data-canvas-width="342.0400772727273">pneumonia were reported and detected for H5N6 virus, three patients</div><div style="left: 78.2727px; top: 993.521px; font-size: 12.3207px; font-family: serif; transform: scaleX(0.975312);" data-canvas-width="341.66799191919193">were confirmed to be infected with H5N6 virus. Case 1 was a 26 years</div><div style="left: 78.2727px; top: 1008.02px; font-size: 12.3207px; font-family: serif; transform: scaleX(1.01348);" data-canvas-width="342.55754696969706">old woman and identified on Dec 29, 2015. She purchased a duck at</div><div style="left: 78.2727px; top: 1022.51px; font-size: 12.3207px; font-family: serif; transform: scaleX(1.00914);" data-canvas-width="342.4848547979798">a live poultry stall of nearby market, cooked and ate the duck 4 days</div><div style="left: 78.2727px; top: 1037.01px; font-size: 12.3207px; font-family: serif; transform: scaleX(0.948999);" data-canvas-width="343.20561616161615">before symptom onset. After admission to hospital on Dec 27, her</div><div style="left: 78.2727px; top: 1051.5px; font-size: 12.3207px; font-family: serif; transform: scaleX(1.01154);" data-canvas-width="342.47253409090905">condition deteriorated rapidly, on Dec 30 she died. The case 2 was a</div><div style="left: 443.545px; top: 277.47px; font-size: 12.3207px; font-family: serif; transform: scaleX(1.01234);" data-canvas-width="342.52551313131306">25 years old man and confirmed on Jan 7, 2016. He visited a market</div><div style="left: 443.545px; top: 291.965px; font-size: 12.3207px; font-family: serif; transform: scaleX(1.03687);" data-canvas-width="342.89267020202004">everyday and had no close contact with poultry, except for passing</div><div style="left: 443.545px; top: 306.46px; font-size: 12.3207px; font-family: serif; transform: scaleX(0.993504);" data-canvas-width="342.03022070707067">by live poultry stalls. He recovered and was discharged from hospital</div><div style="left: 443.545px; top: 320.955px; font-size: 12.3207px; font-family: serif; transform: scaleX(1.02648);" data-canvas-width="342.7743914141412">on Jan 22. The case 3 was is a 31 years old woman and reported on</div><div style="left: 443.545px; top: 335.45px; font-size: 12.3207px; font-family: serif; transform: scaleX(0.999458);" data-canvas-width="339.1829053030302">Jan 16, 2016, she had no contact with live poultry and died on Feb 8.</div><div style="left: 456.591px; top: 349.945px; font-size: 12.3207px; font-family: serif; transform: scaleX(1.0282);" data-canvas-width="329.9657843434343">For 60 close contacts of three cases, none of them reported signs</div><div style="left: 443.545px; top: 364.44px; font-size: 12.3207px; font-family: serif; transform: scaleX(1.01045);" data-canvas-width="342.55877904040403">or symptoms of acute respiratory illness, all of nasal and pharyngeal</div><div style="left: 443.545px; top: 378.935px; font-size: 12.3207px; font-family: serif; transform: scaleX(1.00685);" data-canvas-width="342.210103030303">swabs were tested negative for influenza A(H5N6) virus by RT-PCR</div><div style="left: 443.545px; top: 393.43px; font-size: 12.3207px; font-family: serif; transform: scaleX(0.992589);" data-canvas-width="341.93042297979804">test. Of 146 environmental swabs collected in the case’s living places</div><div style="left: 443.545px; top: 407.925px; font-size: 12.3207px; font-family: serif; transform: scaleX(1.04273);" data-canvas-width="343.1612616161611">and relevant poultry markets, 38 were tested positive for influenza</div><div style="left: 443.545px; top: 422.42px; font-size: 12.3207px; font-family: serif; transform: scaleX(1.01336);" data-canvas-width="159.82421212121216">A(H5N6) virus by RT-PCR test.</div><div style="left: 456.591px; top: 436.915px; font-size: 12.3207px; font-family: serif; transform: scaleX(1.00368);" data-canvas-width="329.30785858585836">From Nov 1, 2015 to May 31, 2016, 2812 ILI cases were sampled</div><div style="left: 443.545px; top: 451.41px; font-size: 12.3207px; font-family: serif; transform: scaleX(1.03709);" data-canvas-width="343.08733737373683">and tested for influenza type A and subtypes of seasonal influenza.</div><div style="left: 443.545px; top: 465.905px; font-size: 12.3207px; font-family: serif; transform: scaleX(1.02897);" data-canvas-width="342.87049292929294">Those samples tested positive for influenza type A could be further</div><div style="left: 443.545px; top: 480.4px; font-size: 12.3207px; font-family: serif; transform: scaleX(0.976945);" data-canvas-width="341.5398565656565">subtyped to seasonal A(H3N2) or A(H1N1), therefore no sample from</div><div style="left: 443.545px; top: 494.895px; font-size: 12.3207px; font-family: serif; transform: scaleX(1.00401);" data-canvas-width="241.54746212121213">ILI case was tested for influenza A(H5N6) virus.</div><div style="left: 456.591px; top: 509.39px; font-size: 12.3207px; font-family: serif; transform: scaleX(1.03887);" data-canvas-width="332.35107323232324">Serological surveys among poultry workers were conducted</div><div style="left: 443.545px; top: 523.884px; font-size: 12.3207px; font-family: serif; transform: scaleX(1.01805);" data-canvas-width="342.7103237373737">twice, for the first survey 186 poultry workers were recruited in Oct</div><div style="left: 443.545px; top: 538.379px; font-size: 12.3207px; font-family: serif; transform: scaleX(1.04436);" data-canvas-width="343.3510005050502">2015, for the second survey 195 poultry workers were recruited in</div><div style="left: 443.545px; top: 552.874px; font-size: 12.3207px; font-family: serif; transform: scaleX(1.04624);" data-canvas-width="343.2548989898988">Jan 2016. Blood sample were collected and tested for HI antibody</div><div style="left: 443.545px; top: 567.369px; font-size: 12.3207px; font-family: serif; transform: scaleX(0.963078);" data-canvas-width="343.35346464646466">of influenza A(H5N6) virus. 2 individuals had H5N6 HI antibody</div><div style="left: 443.545px; top: 581.864px; font-size: 12.3207px; font-family: serif; transform: scaleX(0.988751);" data-canvas-width="341.9760095959595">titer of 1:40, 5 individuals had H5N6 HI antibody titer of 1:20, rest of</div><div style="left: 443.545px; top: 596.359px; font-size: 12.3207px; font-family: serif; transform: scaleX(1.02922);" data-canvas-width="343.0577676767676">them had H5N6 HI antibody titer of <1:20. According to the WHO</div><div style="left: 443.545px; top: 610.854px; font-size: 12.3207px; font-family: serif; transform: scaleX(1.03487);" data-canvas-width="155.6105303030303">guideline, HI antibody titer of</div><div style="left: 599.138px; top: 613.194px; font-size: 12.3207px; font-family: sans-serif;">≥</div><div style="left: 605.938px; top: 610.854px; font-size: 12.3207px; font-family: serif; transform: scaleX(1.03476);" data-canvas-width="180.7041143939394">1:160 against avian influenza virus</div><div style="left: 443.545px; top: 625.349px; font-size: 12.3207px; font-family: serif; transform: scaleX(1.00138);" data-canvas-width="125.57264646464648">were considered positive.</div><div style="left: 456.591px; top: 639.844px; font-size: 12.3207px; font-family: serif; transform: scaleX(0.997974);" data-canvas-width="329.13167247474735">From Nov 1, 2015 to May 31, 2016, of 1234 environmental swabs</div><div style="left: 443.545px; top: 654.339px; font-size: 12.3207px; font-family: serif; transform: scaleX(0.978421);" data-canvas-width="343.78468939393923">collected in poultry markets, 339 (27.5%)were tested positive for</div><div style="left: 443.545px; top: 668.834px; font-size: 12.3207px; font-family: serif; transform: scaleX(1.04487);" data-canvas-width="342.9973962121213">influenza A(H5N6) virus by RT-PCR test. Each of the ten districts</div><div style="left: 443.545px; top: 683.329px; font-size: 12.3207px; font-family: serif; transform: scaleX(1.00699);" data-canvas-width="342.4109305555556">had poultry markets which was contaminated by influenza A(H5N6)</div><div style="left: 443.545px; top: 697.824px; font-size: 12.3207px; font-family: serif; transform: scaleX(1.00199);" data-canvas-width="27.721590909090907">virus.</div><div style="left: 443.545px; top: 725.407px; font-size: 12.3207px; font-family: sans-serif; transform: scaleX(1.10408);" data-canvas-width="73.93656313131314">Conclusions</div><div style="left: 456.591px; top: 738.41px; font-size: 12.3207px; font-family: serif; transform: scaleX(1.02297);" data-canvas-width="332.02334242424246">In 2015-2016 winter, three cases of infection with influenza</div><div style="left: 443.545px; top: 752.905px; font-size: 12.3207px; font-family: serif; transform: scaleX(1.01247);" data-canvas-width="342.5513866161616">A(H5N6) virus were identified in Shenzhen, all of them were young</div><div style="left: 443.545px; top: 767.4px; font-size: 12.3207px; font-family: serif; transform: scaleX(0.979581);" data-canvas-width="343.8820229797982">individuals with average age of 27.3 years and developed severe</div><div style="left: 443.545px; top: 781.895px; font-size: 12.3207px; font-family: serif; transform: scaleX(0.95921);" data-canvas-width="343.620823989899">pneumonia soon after illness onset, two cases died. For acute and</div><div style="left: 443.545px; top: 796.39px; font-size: 12.3207px; font-family: serif; transform: scaleX(1.02634);" data-canvas-width="343.0380545454546">severe disease, early detection and treatment is the key measure for</div><div style="left: 443.545px; top: 810.884px; font-size: 12.3207px; font-family: serif; transform: scaleX(1.00849);" data-canvas-width="99.58827525252526">patient’s prognosis.</div><div style="left: 456.591px; top: 825.379px; font-size: 12.3207px; font-family: serif; transform: scaleX(0.987646);" data-canvas-width="330.86149974747445">H5N6 virus was identified in poultry market and other places</div><div style="left: 443.545px; top: 839.874px; font-size: 12.3207px; font-family: serif; transform: scaleX(1.0376);" data-canvas-width="343.23888207070655">where patient appeared, implying poultry market probably was the</div><div style="left: 443.545px; top: 854.369px; font-size: 12.3207px; font-family: serif; transform: scaleX(0.968926);" data-canvas-width="343.4520303030302">source of infection. Despite the high contamination rate of H5N6</div><div style="left: 443.545px; top: 868.864px; font-size: 12.3207px; font-family: serif; transform: scaleX(1.00478);" data-canvas-width="342.3616477272728">virus in poultry market, we found that the infection with H5N6 virus</div><div style="left: 443.545px; top: 883.359px; font-size: 12.3207px; font-family: serif; transform: scaleX(1.02538);" data-canvas-width="343.05776767676736">among poultry workers was not prevalent, with infection rate being</div><div style="left: 443.545px; top: 897.854px; font-size: 12.3207px; font-family: serif; transform: scaleX(0.952392);" data-canvas-width="343.46435101010087">0/381. Human infection with H5N6 virus seemed to be a sporadic</div><div style="left: 443.545px; top: 912.349px; font-size: 12.3207px; font-family: serif; transform: scaleX(1.00387);" data-canvas-width="342.3690401515151">occurrence, poultry-human transmission of H5N6 virus might not be</div><div style="left: 443.545px; top: 926.844px; font-size: 12.3207px; font-family: serif; transform: scaleX(1.00426);" data-canvas-width="71.15208333333335">very effective.</div>}, number={1}, journal={Online Journal of Public Health Informatics}, author={Wang, Xin and Fang, Shisong}, year={2017}, month={May} }