Ahead of Print -Active Surveillance for Avian Influenza Virus, Egypt, 2010–2012 - Volume 20, Number 4—April 2014 - Emerging Infectious Disease journal - CDC

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Ahead of Print -Active Surveillance for Avian Influenza Virus, Egypt, 2010–2012 - Volume 20, Number 4—April 2014 - Emerging Infectious Disease journal - CDC

Volume 20, Number 4—April 2014

Research

Active Surveillance for Avian Influenza Virus, Egypt, 2010–2012

Article Contents

• Materials and Methods
• Results
• Discussion
• Acknowledgment
• References
• Figure 1
• Figure 2
• Figure 3
• Figure 4
• Figure 5
• Table 1
• Table 2
• Table 3
• Technical Appendix - 461 KB 
• Suggested Citation

Ghazi Kayali , Ahmed Kandeil, Rabeh El-Shesheny, Ahmed S. Kayed, Mokhtar M. Gomaa, Asmaa M. Maatouq, Mahmoud M. Shehata, Yassmin Moatasim, Ola Bagato, Zhipeng Cai, Adam Rubrum, Mohamed A. Kutkat, Pamela P. McKenzie, Robert G. Webster, Richard J. Webby, and Mohamed A. Ali

Author affiliations: St. Jude Children's Research Hospital, Memphis, Tennessee, USA (G. Kayali, A. Rubrum, P.P. McKenzie, R.G. Webster, R.J. Webby); National Research Center, Giza, Egypt (A. Kandeil, R. El-Shesheny, A.S. Kayed, M.M. Gomaa, A.M. Maatouq, M.M. Shehata, Y. Moatasim, O. Bagato, M.A. Kutkat, M.A. Ali);Georgia State University, Atlanta, Georgia, USA (Z. Cai)

Suggested citation for this article

Abstract

Continuous circulation of influenza A(H5N1) virus among poultry in Egypt has created an epicenter in which the viruses evolve into newer subclades and continue to cause disease in humans. To detect influenza viruses in Egypt, since 2009 we have actively surveyed various regions and poultry production sectors. From August 2010 through January 2013, >11,000 swab samples were collected; 10% were positive by matrix gene reverse transcription PCR. During this period, subtype H9N2 viruses emerged, cocirculated with subtype H5N1 viruses, and frequently co-infected the same avian host. Genetic and antigenic analyses of viruses revealed that influenza A(H5N1) clade 2.2.1 viruses are dominant and that all subtype H9N2 viruses are G1-like. Cocirculation of different subtypes poses concern for potential reassortment. Avian influenza continues to threaten public and animal health in Egypt, and continuous surveillance for avian influenza virus is needed.

In 2008, highly pathogenic avian influenza (HPAI) A(H5N1) virus became enzootic among poultry in Egypt, and the country became an epicenter for virus activity (1). As the established viruses drifted over time, viral genetic and antigenic diversity was generated. During 2010–2011, subclade 2.2.1 viruses (direct-drift progeny of the initially introduced virus) and 2.2.1.1 viruses (which might have emerged because of vaccine pressure) were cocirculating among poultry in Egypt (2). These subclades differed genetically and antigenically, hence complicating control efforts, especially vaccination (3). Subclade 2.2.1 viruses, commonly isolated from backyard flocks that are not vaccinated, caused all of the human cases in Egypt; from 2006 through September 2013, the toll rose to 173 cases and 63 deaths (4,5). Subclade 2.2.1.1 viruses were more prevalent on commercial farms, where vaccines are more frequently used (6). Furthermore, recent reports have indicated that very few mutations are needed for subtype H5N1 to become transmissible among ferrets, the best mammalian model of human influenza infection (7,8). In Egypt, a subtype H5N1 virus was found to have 2 of the 4 mutations needed to gain the transmissibility function, thereby underlying the need and urgency for surveillance among poultry (8). The Nile Delta region of Egypt was also identified as an area where substantial reassortment of influenza viruses can take place (9). As a further complication, in 2011, subtype H9N2 viruses were detected in poultry from areas in Egypt where subtype H5N1 viruses circulate (10).

Since 2009, we have been conducting systematic, active surveillance of avian influenza virus (AIV) among poultry in Egypt; the same locations are sampled over time, regardless of whether a clinical outbreak of disease is present. We previously reported that the threat of HPAI (H5N1) virus is widespread beyond rural areas and that the commercial sector is a key reservoir for virus transmission (11). Here we provide an update on the changing epizootiology and genetic features of AIV in Egypt and report co-infection of poultry in Egypt with influenza virus subtypes H5N1 and H9N2.

Materials and Methods

Sample Collection and Processing

Figure 1

Figure 1. . Location of surveillance governorates and percentage of avian influenza virus detection in each governorate, Egypt, 2010–2012.

A team of veterinarians collected cloacal and oropharyngeal swab samples from 11,452 birds from 4 poultry production sectors: commercial farms, backyard flocks, live-bird markets, and abattoirs. One swab sample was collected per bird, and depending on the size of the population, as many as 5 birds were sampled per flock. Birds were not randomly selected; samples were also collected from sick or dead birds found on site. From August 2010 through January 2013, a total of 6,904 cloacal and 4,548 oropharyngeal samples were collected from 63 sites in 7 governorates in Egypt, including Cairo (4 neighborhoods); 4 Nile Delta governorates (Qalubiya [12 villages], Menofiya [9 villages], Sharqiya [3 towns], and Daqahliya [4 towns]); and 2 mid-Egypt governorates (Fayyoum [22 villages] and BeniSuef [9 villages]) (Figure 1). The selected governorates represent the main foci of the poultry industry in Egypt and sites of previous AIV detection (11). The selected sampling sites were areas at which the veterinarian was known to the local population and thus had access to the poultry. The sites were routinely visited on a monthly basis regardless of the occurrence of clinical signs or poultry deaths. Study veterinarians subjectively recorded their field observations. Swab samples were collected in medium containing 50% glycerol, 50% phosphate-buffered saline (PBS), penicillin (2×106 U/L), streptomycin (200 mg/L), and amphotericin B (250 mg/L) (antimicrobial drugs from Lonza, Walkersville, MD, USA). Samples were chilled on ice until delivered to the laboratory (within 24 hours). All samples were stored at –80°C until used.

Acknowledgment

This work was funded by the US Department of Health and Human Services, National Institutes of Health, National Institute of Allergy and Infectious Diseases, under contract no. HHSN266200700005C, and supported by the American Lebanese Syrian Associated Charities.

References

1. WHO/OIE/FAO H5N1 Evolution Working Group. Continuing progress towards a unified nomenclature for the highly pathogenic H5N1 avian influenza viruses: divergence of clade 2.2 viruses. Influenza Other Respir Viruses. 2009;3:59–62.PubMed
2. WHO/OIE/FAO H5N1 Evolution Working Group. Continued evolution of highly pathogenic avian influenza A (H5N1): updated nomenclature. Influenza Other Respir Viruses.2012;6:1–5.PubMed
3. El-Shesheny R, Kayali G, Kandeil A, Cai Z, Barakat AB, Ghanim H, Antigenic diversity and cross-reactivity of avian influenza H5N1 viruses in Egypt between 2006 and 2011. J Gen Virol. 2012;93:2564–74. DOIPubMed
4. World Health Organization. Cumulative number of confirmed human cases for avian influenza A(H5N1) reported to WHO, 2003–2013 [cited 2013 Apr 15];http://www.who.int/influenza/human_animal_interface/EN_GIP_20130426CumulativeNumberH5N1cases.pdf 
5. Younan M, Poh MK, Elassal E, Davis T, Rivailler P, Balish AL, Microevolution of highly pathogenic avian influenza A(H5N1) viruses isolated from humans, Egypt, 2007–2011.Emerg Infect Dis. 2013;19:43–50. DOIPubMed
6. Arafa A, Suarez DL, Hassan MK, Aly MM. Phylogenetic analysis of hemagglutinin and neuraminidase genes of highly pathogenic avian influenza H5N1 Egyptian strains isolated from 2006 to 2008 indicates heterogeneity with multiple distinct sublineages.Avian Dis. 2010;54(Suppl):345–9. DOIPubMed
7. Herfst S, Schrauwen EJ, Linster M, Chutinimitkul S, de Wit E, Munster VJ, Airborne transmission of influenza A/H5N1 virus between ferrets. Science. 2012;336:1534–41 .DOIPubMed
8. Imai H, Shinya K, Takano R, Kiso M, Muramoto Y, Sakabe S, The HA and NS genes of human H5N1 influenza A virus contribute to high virulence in ferrets. PLoS Pathog.2010;6:e1001106. DOIPubMed
9. Fuller TL, Gilbert M, Martin V, Cappelle J, Hosseini P, Njabo KY, Predicting hotspots for influenza virus reassortment. Emerg Infect Dis. 2013;19:581–8. DOIPubMed
10. Arafa AS, Hagag N, Erfan A, Mady W, El-Husseiny M, Adel A, Complete genome characterization of avian influenza virus subtype H9N2 from a commercial quail flock in Egypt. Virus Genes. 2012;45:283–94. DOIPubMed
11. Kayali G, El-Shesheny R, Kutkat MA, Kandeil AM, Mostafa A, Ducatez MF, Continuing threat of influenza (H5N1) virus circulation in Egypt. Emerg Infect Dis. 2011;17:2306–8. DOIPubMed
12. World Health Organization. WHO manual on animal influenza diagnosis and surveillance. 2nd ed. 2002 [cited 2011 Dec 12].http://whqlibdoc.who.int/hq/2002/WHO_CDS_CSR_NCS_2002.5.pdf 
13. Lee MS, Chang PC, Shien JH, Cheng MC, Shieh HK. Identification and subtyping of avian influenza viruses by reverse transcription-PCR. J Virol Methods. 2001;97:13–22. DOIPubMed
14. Centers for Disease Control and Prevention. CDC realtime RTPCR protocol for detection and characterization of influenza. Atlanta: the Centers; 2007.
15. Shanmuganatham K, Feeroz MM, Jones-Engel L, Smith GJ, Fourment M, Walker D,Antigenic and molecular characterization of avian influenza A(H9N2) viruses, Bangladesh.Emerg Infect Dis. 2013;19:1393–402. DOIPubMed
16. Tamura K, Dudley J, Nei M, Kumar S. MEGA4: Molecular Evolutionary Genetics Analysis (MEGA) software version 4.0. Mol Biol Evol. 2007;24:1596–9. DOIPubMed
17. Cai Z, Zhang T, Wan XF. A computational framework for influenza antigenic cartography.PLOS Comput Biol. 2010;6:e1000949. DOIPubMed
18. Ruppel A, Diesfeld HJ, Rother U. Immunoblot analysis of Schistosoma mansoni antigens with sera of schistosomiasis patients: diagnostic potential of an adult schistosome polypeptide. Clin Exp Immunol. 1985;62:499–506 .PubMed
19. Kayali G, Webby RJ, Ducatez MF, El Shesheny RA, Kandeil AM, Govorkova EA, The epidemiological and molecular aspects of influenza H5N1 viruses at the human–animal interface in Egypt. PLoS ONE. 2011;6:e17730. DOIPubMed
20. Kim JK, Negovetich NJ, Forrest HL, Webster RG. Ducks: the “Trojan horses” of H5N1 influenza. Influenza Other Respir Viruses. 2009;3:121–8.
21. Uyeki TM. Global epidemiology of human infections with highly pathogenic avian influenza A (H5N1) viruses. Respirology. 2008;13(Suppl 1):S2–9 .DOIPubMed
22. Aly MM, Arafa A, Kilany WH, Sleim AA, Hassan MK. Isolation of a low pathogenic avian influenza virus (H7N7) from a black kite (Milvus migrans) in Egypt in 2005. Avian Dis.2010;54(Suppl):457–60. DOIPubMed
23. Amin A, Shalaby MA, Imam IZ. Studies on influenza virus isolated from migrating birds in Egypt. Comp Immunol Microbiol Infect Dis. 1980;3:241–6. DOIPubMed
24. Soliman A, Saad M, Elassal E, Amir E, Plathonoff C, Bahgat V, Surveillance of avian influenza viruses in migratory birds in Egypt, 2003–09. J Wildl Dis. 2012;48:669–75 and. DOIPubMed
25. Aamir UB, Wernery U, Ilyushina N, Webster RG. Characterization of avian H9N2 influenza viruses from United Arab Emirates 2000 to 2003. Virology. 2007;361:45–55. DOIPubMed
26. Brown IH, Banks J, Manvell RJ, Essen SC, Shell W, Slomka M, Recent epidemiology and ecology of influenza A viruses in avian species in Europe and the Middle East. Dev Biol (Basel). 2006;124:45–50 .PubMed
27. Moosakhani F, Shoshtari AH, Pourbakhsh SA, Keyvanfar H, Ghorbani A. Phylogenetic analysis of the hemagglutinin genes of 12 H9N2 influenza viruses isolated from chickens in Iran from 2003 to 2005. Avian Dis. 2010;54:870–4. DOIPubMed
28. Perk S, Banet-Noach C, Shihmanter E, Pokamunski S, Pirak M, Lipkind M, Genetic characterization of the H9N2 influenza viruses circulated in the poultry population in Israel. Comp Immunol Microbiol Infect Dis. 2006;29:207–23. DOIPubMed
29. Roussan DA, Khawaldeh GY, Al Rifai RH, Totanji WS, Shaheen IA. Avian influenza virus H9 subtype in poultry flocks in Jordan. Prev Vet Med. 2009;88:77–81. DOIPubMed
30. Khalenkov A, Perk S, Panshin A, Golender N, Webster RG. Modulation of the severity of highly pathogenic H5N1 influenza in chickens previously inoculated with Israeli H9N2 influenza viruses. Virology. 2009;383:32–8 and. DOIPubMed

Figures

• Figure 1. . Location of surveillance governorates and percentage of avian influenza virus detection in each governorate, Egypt, 2010–2012.
• Figure 2. . Avian influenza virus infections, by month, Egypt, 2010–2012. Blue bars, detection of the virus in birds; red dots, cases of influenza A(H5N1) virus infections in humans; and black...
• Figure 3. . Subtypes of influenza A viruses detected in poultry, by month, by using reverse transcription PCR, Egypt, 2010–2012.
• Figure 4. . Phylogenetic tree of the hemagglutinin gene of influenza A(H5N1) viruses from Egypt, 2010–2012. Scale bar indicates phylogenetic distance (1 base substitution/100 positions).
• Figure 5. . Phylogenetic tree of the hemagglutinin gene of influenza A(H9N2) viruses from Egypt, 2010–2012. Scale bar indicates phylogenetic distance (1 base substitution/100 positions).

Tables

• Table 1. Primers used for H5 and H9 subtyping of avian influenza viruses from Egypt, 2010–2012
• Table 2. Epizootiologic data for avian influenza virus isolated from poultry in 7 governorates in Egypt, 2010–2012
• Table 3. Epizootiologic data for avian influenza virus subtypes H5N1, H9N2, and H5/H9 , Egypt, 2010–2012

Technical Appendix

• Technical Appendix. . Avian influenza A virus detection in poultry in Egypt, by month and by subtype; experimental growth of avian influenza A virus in specific pathogen–free embryonated chicken eggs and... 461 KB 

Suggested citation for this article: Kayali G, Kandeil A, El-Shesheny R, Kayed AS, Gomaa MM, Maatouq AM, et al. Active surveillance for avian influenza virus, Egypt, 2010–2012. Emerg Infect Dis [Internet]. 2014 Apr [date cited]. http://dx.doi.org/10.3201/eid2004.131295

DOI: 10.3201/eid2004.131295

Ahead of Print -Distribution of Pandemic Influenza Vaccine and Reporting of Doses Administered, New York City, New York, USA - Volume 20, Number 4—April 2014 - Emerging Infectious Disease journal - CDC

full-text ►

Ahead of Print -Distribution of Pandemic Influenza Vaccine and Reporting of Doses Administered, New York City, New York, USA - Volume 20, Number 4—April 2014 - Emerging Infectious Disease journal - CDC

Volume 20, Number 4—April 2014

Synopsis

Distribution of Pandemic Influenza Vaccine and Reporting of Doses Administered, New York City, New York, USA

Article Contents

• Distribution of pH1N1 Vaccine and Reporting of Doses Administered
• Implications for Future Pandemic Planning
• Limitations
• Lessons Learned
• Conclusions
• Acknowledgment
• References
• Table 1
• Table 2
• Table 3
• Table 4
• Suggested Citation

Roopa Kalyanaraman Marcello1, Vikki Papadouka, Mark Misener, Edward Wake, Rebecca Mandell2, and Jane R. Zucker 

Author affiliations: New York City Department of Health and Mental Hygiene, Queens, New York, USA (R.K. Marcello, V. Papadouka, M. Misener, E. Wake, R. Mandell, J.R. Zucker); Centers for Disease Control and Prevention, Atlanta, Georgia, USA (E. Wake, J.R. Zucker)

Suggested citation for this article

Abstract

In 2009, the New York City Department of Health and Mental Hygiene delivered influenza A(H1N1)pdm09 (pH1N1) vaccine to health care providers, who were required to report all administered doses to the Citywide Immunization Registry. Using data from this registry and a provider survey, we estimated the number of all pH1N1 vaccine doses administered. Of 2.8 million doses distributed during October 1, 2009–March 4, 2010, a total of 988,298 doses were administered and reported; another 172,289 doses were administered but not reported, for a total of 1,160,587 doses administered during this period. Reported doses represented an estimated 80%–85% of actual doses administered. Reporting by a wide range of provider types was feasible during a pandemic. Pediatric-care providers had the highest reporting rate (93%). Other private-care providers who routinely did not report vaccinations indicated that they had few, if any, problems, thereby suggesting that mandatory reporting of all vaccines would be feasible.

In April 2009, a novel swine-origin influenza A (H1N1) virus (now called influenza A(H1N1)pdm09 [pH1N1]) was detected in the United States (1). During the next 2 months, more than 1 in 10 New York City (NYC) residents reported influenza-like illness; cases occurred primarily among children and young adults (2). By June 2009, the World Health Organization had declared an influenza A (H1N1) pandemic (3). In July 2009, in anticipation of limited vaccine supply, the Advisory Committee on Immunization Practices and the Centers for Disease Control and Prevention prioritized groups for receipt of monovalent pH1N1 vaccine (4,5).

Building on previous pandemic influenza preparedness planning, in the summer of 2009, the NYC Department of Health and Mental Hygiene (DOHMH) began planning for pH1N1 vaccine allocation and distribution. To efficiently provide limited doses to a diverse population of providers in a large urban setting, DOHMH developed an allocation plan that included hospitals, private care providers (including adult, pediatric, and obstetric practices), and other outpatient facilities (including federally qualified health centers, pharmacies, DOHMH walk-in immunization clinics, and NYC agencies with a medical unit). In addition, DOHMH conducted a large-scale school-located vaccination program that offered pH1N1 vaccine to virtually all of the 1.4 million NYC schoolchildren in kindergarten through grade 12 (6). DOHMH also conducted 58 point-of-dispensing mass vaccination clinics over 5 weekends (7).

In NYC, all vaccine doses administered to persons <19 years of age must be reported to the Citywide Immunization Registry (CIR), DOHMH Immunization Information System; this requirement includes influenza vaccine (8). Vaccine doses administered to patients >19 years of age can be reported to the CIR with the patient’s consent. Electronic files containing birth certificates are entered into the CIR on a weekly basis to establish a population base and to facilitate reporting among pediatric-care providers. Since 2008, the CIR has been one of the Immunization Information System sentinel sites in the United States and has met data-quality and population-capture requirements, including those of receiving complete and timely data from at least 85% of providers and participation of at least 85% of children <19 years of age (9).

On October 28, 2009, because of the pH1N1 pandemic, various provisions of New York State public health law were suspended, including the requirement to obtain consent to report vaccines given to adults. This change authorized the NYC Health Commissioner to issue a Declaration of a Public Health Emergency and to modify the NYC Health Code to require reporting to the CIR of all pH1N1 influenza vaccinations administered, including those administered to persons >19 years of age. This change was made to increase provider accountability, track vaccine uptake, and assist with estimating vaccine coverage.

Acknowledgment

We thank James Hadler for his thoughtful review and helpful comments on the manuscript. We also thank the many health department staff members who contributed to the pH1N1 vaccine distribution efforts, staff from the Citywide Immunization Registry, and the medical providers who administered pH1N1 vaccinations to help protect the health of New Yorkers.

References

1. Novel Swine-Origin Influenza A. (H1N1) Virus Investigation Team; Dawood FS, Jain S, Finelli L, Shaw MW, Lindstrom S, Garten RJ, et al. Emergence of a novel swine-origin influenza A (H1N1) virus in humans. N Engl J Med. 2009;360:2605–15. Epub 2009 May 7.PubMed
2. Hadler JL, Konty K, McVeigh KH, Fine A, Eisenhower D, Kerker B, Case-fatality rates based on population estimates of influenza-like illness due to novel H1N1 influenza: New York City, May–June 2009. PLoS ONE. 2010;5:e11677. DOIPubMed
3. Writing Committee of the WHO Consultation on Clinical Aspects of Pandemic. (H1N1)2009 Influenza; Bautista E, Chotpitayasunondh T, Gao Z, Harper SA, Shaw M, Uyeki TM, et al. (H1N1) 2009 Influenza. Clinical aspects of pandemic 2009 influenza A (H1N1) virus infection. N Engl J Med. 2010;362:1708–19.
4. US Department of Health and Human Services, Centers for Disease Control and Prevention, Advisory Committee on Immunization Practices (ACIP). Summary Report, July 29, 2009, Atlanta, Georgia [cited 2013 Nov 8].http://www.cdc.gov/vaccines/acip/meetings/downloads/min-archive/min-jul09.pdf 
5. Centers for Disease Control and Prevention. Use of influenza A (H1N1) 2009 monovalent vaccine: recommendations of the Advisory Committee on Immunization Practices (ACIP), 2009. MMWR Recomm Rep. 2009;58(RR-10):1–8http://www.cdc.gov/mmwr/pdf/rr/rr5810.pdf .PubMed
6. Narciso HE, Pathela P, Morgenthau BM, Kansagra SM, May L, Scaccia A, Description of a large urban school–located pandemic H1N1 vaccination campaign, New York City 2009–2010. J Urban Health. 2012;89:317–28. DOIPubMed
7. Rinchiuso-Hasselmann A, McKay RL, Williams CA, Starr DT, Morgenthau BM, Zucker JR,Protecting the public from H1N1 through points of dispensing (PODs). Biosecur Bioterror.2011;9:13–21. DOIPubMed
8. New York City Department of Health and Mental Hygiene. New York City Health Code, section 11.04 [cited 2013 Jul 22].http://www.nyc.gov/html/doh/downloads/pdf/cir/healthcode2005.pdf 
9. Centers for Disease Control and Prevention. Q&A about IIS sentinel sites: what are sentinel sites? [cited 2013 Nov 7].http://www.cdc.gov/vaccines/programs/iis/activities/sentinel-sites.html
10. Zucker J. Central 2009 H1N1 Influenza Vaccine Recovery Program, June 15, 2010 [letter] [cited 2014 Jan 31].http://www.nyc.gov/html/doh/downloads/pdf/imm/imm-2009-2010-vaccine-recovery-prov-letter.pdf 
11. Hadler JL, Baker T, Papadouka V, France AM, Zimmerman C, Livingston K, Effectiveness of one dose of 2009 influenza A (H1N1) monovalent vaccine at preventing hospitalization with pandemic H1N1 influenza in children 7 months to 9 years of age, New York City. J Infect Dis. 2012;206:49–55. DOIPubMed
12. Community Preventive Services Task Force. Increasing appropriate vaccination: Immunization Information Systems [cited 2013 Nov 13].http://www.thecommunityguide.org/vaccines/imminfosystems.html
13. Health IT. gov. HealthIT regulations. Meaningful use regulations [cited 2011 Mar 20].http://healthit.hhs.gov/portal/server.pt?open=512&objID=2996&mode=2

Tables

• Table 1. Doses of pH1N1 vaccine distributed and reported to the Citywide Immunization Registry, New York City, New York, USA, October 2009–March 2010
• Table 2. Estimated pH1N1 vaccine administration among surveyed providers, New York City, New York, USA, October 1, 2009–March 4, 2010
• Table 3. Provider feedback with regard to Department of Health and Mental Hygiene communications and procedures, New York City, New York, USA, October 1, 2009–March 4, 2010
• Table 4. Provider feedback with regard to problems encountered with regard to pH1N1 vaccine, New York City, New York, USA, October 1, 2009–March 4, 2010

Suggested citation for this article: Marcello RK, Papadouka V, Misener M, Wake E, Mandell R, Zucker JR. Distribution of pandemic influenza vaccine and reporting of doses administered, New York City, New York, USA. Emerg Infect Dis [Internet]. 2014 Apr [date cited].http://dx.doi.org/10.3201/eid2004.131114

DOI: 10.3201/eid2004.131114

1Current affiliation: The Corkery Group, New York, New York, USA.

2Current affiliation: University of Michigan, Ann Arbor, Michigan, USA.