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Influenza epidemiology and characterization of influenza viruses in patients seeking treatment for acute fever in Cambodia

  • P. J. BLAIR (a1), T. F. WIERZBA (a2), S. TOUCH (a3), S. VONTHANAK (a4), X. XU (a5), R. J. GARTEN (a5), M. A. OKOMO-ADHIAMBO (a5), A. I. KLIMOV (a5), M. R. KASPER (a1) and S. D. PUTNAM (a1)...
Summary
SUMMARY

The epidemiology, symptomology, and viral aetiology of endemic influenza remain largely uncharacterized in Cambodia. In December 2006, we established passive hospital-based surveillance to identify the causes of acute undifferentiated fever in patients seeking healthcare. Fever was defined as tympanic membrane temperature >38°C. From December 2006 to December 2008, 4233 patients were screened for influenza virus by real-time reverse-transcriptase polymerase chain reaction (rRT–PCR). Of these patients, 1151 (27·2%) were positive for influenza. Cough (68·8% vs. 50·5%, P<0·0001) and sore throat (55·0% vs. 41·9%, P<0·0001) were more often associated with laboratory-confirmed influenza-infected patients compared to influenza-negative enrollees. A clear influenza season was evident between July and December with a peak during the rainy season. Influenza A and B viruses were identified in 768 (66·3%) and 388 (33·7%) of the influenza-positive population (n=1153), respectively. In December 2008, passive surveillance identified infection of the avian influenza virus H5N1 in a 19-year-old farmer from Kandal province who subsequently recovered. From a subset of diagnostic samples submitted in 2007, 15 A(H1N1), seven A(H3N2) and seven B viruses were isolated. The predominant subtype tested was influenza A(H1N1), with the majority antigenically related to the A/Solomon Island/03/2006 vaccine strain. The influenza A(H3N2) isolates and influenza B viruses analysed were closely related to A/Brisbane/10/2007 or B/Ohio/01/2005 (B/Victoria/2/87-lineage) vaccine strains, respectively. Phylogenetic analysis of the HA1 region of the HA gene of influenza A(H1N1) viruses demonstrated that the Cambodian isolates belonged to clade 2C along with representative H1N1 viruses circulating in SE Asia at the time. These viruses remained sensitive to oseltamivir. In total, our data suggest that viral influenza infections contribute to nearly one-fifth of acute febrile illnesses and demonstrate the importance of influenza surveillance in Cambodia.

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Corresponding author
*Author for correspondence: Dr S. D. Putnam, JMI Laboratories, 345 Beaver Kreek Centre, North Liberty, IA 52240, USA. (Email: shan8299@hotmail.com)
References
Hide All
1. Nicholson KG, Wood JM, Zambon M. Influenza. Lancet 2003; 362: 17331745.
2. Russell CA, et al. The global circulation of seasonal influenza A (H3N2) viruses. Science (New York) 2008; 320: 340346.
3. Stohr K. Influenza – WHO cares. Lancet Infectious Diseases 2002; 2: 517.
4. Flahault A. Global monitoring of influenza: potential contribution of national networks from a French perspective. Expert Review of Anti-infective Therapy 2006; 4: 387393.
5. Fouchier RA, et al. Characterization of a novel influenza A virus hemagglutinin subtype (H16) obtained from black-headed gulls. Journal of Virology 2005; 79: 28142822.
6. Hampson AW, Mackenzie JS. The influenza viruses. Medical Journal of Australia 2006; 185: S39–43.
7. Nelson MI, et al. Phylogenetic analysis reveals the global migration of seasonal influenza A viruses. PLoS Pathogens 2007; 3: 12201228.
8. Sampath R, et al. Global surveillance of emerging influenza virus genotypes by mass spectrometry. PLoS ONE 2007; 2: e489.
9. Katz JM, et al. Immunity to influenza: the challenges of protecting an aging population. Immunology Research 2004; 29: 113124.
10. Williams JR, et al. Influenza: prospect for prevention and control. Kaohsiung Journal of Medical Science 2002; 18: 421434.
11. Zhang WD, Evans DH. Detection and identification of human influenza viruses by the polymerase chain reaction. Journal of Virological Methods 1991; 33: 165189.
12. Wright KE, et al. Typing and subtyping of influenza viruses in clinical samples by PCR. Journal of Clinical Microbiology 1995; 33: 11801184.
13. Davydov OV. Micromethod for the HI test in the diagnosis of influenza and para-influenza infections [in Russian]. Voprosy Virusologii 1966; 11: 613616.
14. Pechirra P, et al. Molecular characterization of the HA gene of influenza type B viruses. Journal of Medical Virology 2005; 77: 541549.
15. Bush RM, et al. Effects of passage history and sampling bias on phylogenetic reconstruction of human influenza A evolution. Proceedings of the National Academy of Sciences USA 2000; 97: 69746980.
16. Fitch WM, et al. Long term trends in the evolution of H(3) HA1 human influenza type A. Proceedings of the National Academy of Sciences USA 1997; 94: 77127718.
17. Ciccozzi M, et al. Evolutionary analysis of HA and NS1 genes of H5N1 influenza viruses in 2004–2005 epidemics. Avian diseases 2007; 51: 455460.
18. Martin V, et al. History and evolution of HPAI viruses in southeast Asia. Annals of the New York Academy of Sciences 2006; 1081: 153162.
19. Boivin G, et al. Predicting influenza infections during epidemics with use of a clinical case definition. Clinical Infectious Diseases 2000; 31: 11661169.
20. Navarro-Mari JM, et al. Influenza-like illness criteria were poorly related to laboratory-confirmed influenza in a sentinel surveillance study. Journal of Clinical Epidemiology 2005; 58: 275279.
21. Nicholson KG. Clinical features of influenza. Seminars in Respiratory Infections 1992; 7: 2637.
22. Vong S, et al. Environmental contamination during influenza A virus (H5N1) outbreaks, Cambodia, 2006. Emerging Infectious Diseases 2008; 14: 13031305.
23. Kendal AP, Cate TR. Increased sensitivity and reduced specificity of hemagglutination inhibition tests with ether-treated influenza B/Singapore/222/79. Journal of Clinical Microbiology 1983; 18: 930934.
24. Tamura K, et al. MEGA4: Molecular Evolutionary Genetics Analysis (MEGA) software version 4.0. Molecular Biology and Evolution 2007; 24: 15961599.
25. Sheu TG, et al. Surveillance for neuraminidase inhibitor resistance among human influenza A and B viruses circulating worldwide from 2004 to 2008. Antimicrobial Agents and Chemotherapy 2008; 52: 32843292.
26. McKimm-Breschkin J, et al. Neuraminidase sequence analysis and susceptibilities of influenza virus clinical isolates to zanamivir and oseltamivir. Antimicrobial Agents and Chemotherapy 2003; 47: 22642272.
27. Bright RA, et al. Incidence of adamantane resistance among influenza A (H3N2) viruses isolated worldwide from 1994 to 2005: a cause for concern. Lancet 2005; 366: 11751181.
28. Deyde VM, et al. Surveillance of resistance to adamantanes among influenza A(H3N2) and A(H1N1) viruses isolated worldwide. Journal of Infectious Diseases 2007; 196: 249257.
29. Cox NJ, Subbarao K. Global epidemiology of influenza: past and present. Annual Review of Medicine 2000; 51: 407421.
30. Finkelman BS, et al. Global patterns in seasonal activity of influenza A/H3N2, A/H1N1, and B from 1997 to 2005: Viral coexistence and latitudinal gradients. PLoS ONE 2007; 2: e1296.
31. Viboud C, Alonso WJ, Simonsen L. Influenza in tropical regions. PLoS Medicine 2006; 3: e89.
32. Viboud C, et al. Association of influenza epidemics with global climate variability. European Journal of Epidemiology 2004; 19: 10551059.
33. Park AW, Glass K. Dynamic patterns of avian and human influenza in east and southeast Asia. Lancet Infectious Diseases 2007; 7: 543548.
34. Tang JW, et al. Seasonality of influenza A(H3N2) virus: a Hong Kong perspective (1997–2006). PLoS ONE 2008; 3: e2768.
35. Nguyen HL, et al. Epidemiology of influenza in Hanoi, Vietnam, from 2001 to 2003. Journal of Infection 2007; 55: 5863.
36. Hsieh YC, et al. Influenza in Taiwan: seasonality and vaccine strain match. Journal of Microbiology, Immunology, and Infection 2005; 38: 238243.
37. Jian JW, et al. Genetic and epidemiological analysis of influenza virus epidemics in Taiwan during 2003 to 2006. Journal of Clinical Microbiology 2008; 46: 14261434.
38. Lin JH, et al. Genetic and antigenic analysis of epidemic influenza viruses isolated during 2006–2007 season in Taiwan. Journal of Medical Virology 2008; 80: 316322.
39. Shek LP, Lee BW. Epidemiology and seasonality of respiratory tract virus infections in the tropics. Paediatric Respiratory Reviews 2003; 4: 105111.
40. Doraisingham S, et al. Influenza surveillance in Singapore: 1972–86. Bulletin of the World Health Organization 1988; 66: 5763.
41. Chew FT, et al. Seasonal trends of viral respiratory tract infections in the tropics. Epidemiology and Infection 1998; 121: 121128.
42. Claas EC, et al. Human influenza A H5N1 virus related to a highly pathogenic avian influenza virus. Lancet 1998; 351: 472477.
43. Peiris JS, et al. Re-emergence of fatal human influenza A subtype H5N1 disease. Lancet 2004; 363: 617619.
44. Liang W, et al. Severe acute respiratory syndrome, Beijing, 2003. Emerging Infectious Diseases 2004; 10: 2531.
45. Buchy P, et al. Influenza A/H5N1 virus infection in humans in Cambodia. Journal of Clinical Virology 2007; 39: 164168.
46. Brankston G, et al. Transmission of influenza A in human beings. Lancet Infectious Diseases 2007; 7: 257265.
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Epidemiology & Infection
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