Virus culture and real-time RT-PCR in identifying influenza viruses from influenza-like illness cases in Indonesia 2007-2008

Abstract

Latar belakang: Adanya perbedaan hasil antara kultur virus dengan real-time polymerase chain reaction (RT-PCR) yang digunakan dalam surveilans influenza-like illness (ILI) menunjukkan perlunya mengevaluasi hasil kultur virus yang didapatkan dengan hasil RT-PCR sebagai pembanding.Tujuan penelitian ini adalah untuk mengevaluasi apakah kultur virus masih dapat diandalkan untuk studi surveilans ILI.Metode: Usap hidung dan usap tenggorok didapatkan dari 20 sentinel ILI di Indonesia selama tanun 2007-2008. Identifikasi kultur virus dilakukan dengan menggunakan metode hemaglutinasi dan hemaglutinasi inhibisi. RT-PCR menggunakan primer yang bersifat spesifik untuk influensa A (A/H1N1, A/H3N2 and A/H5N1) dan influensa B. Primer disediakan oleh Center for Disease Control and Prevention, USA. Hasil positif kultur virus dibandingkan dengan hasil RT-PCR berdasarkan persentase kesamaan hasil.Hasil: Sebanyak 112 spesimen dari 4277 spesimen kasus ILI didapatkan hasil positif influenza dengan metode kultur. Kesamaan hasil positif influenza kultur virus dibandingkan dengan real-time RT-PCR adalah 69.6%. Pada penelitian ini juga ditemukan bahwa 30,4 % (n=112) hasil real-time RT-PCR yang ditemukan positif influenza tidak dapat dideteksi oleh metode kultur.Kesimpulan: Metode kultur masih relevan untuk surveilans ILI meskipun hasil positif Influenza dari kultur virus lebih sedikit dari pada hasil positif Influenza yang terdeteksi dengan metode PCR. (Health Science Indones 2011;2:92-5).AbstractIntroduction: From the influenza-like illness (ILI) surveillance in Indonesia, we learned that there was disagreement between virus culture and reverse trancriptase polymerase chain reaction (RT-PCR). This implies the need to evaluate whether virus culture is still a relevant method to be used in ILI surveillance.Methods: The ILI specimens obtained from 20 ILI sentinels in Indonesia in 2007-2008. Real-time RT-PCR using primers were specific for influenza A (A/H1N1, A/H3N2 and A/H5N1) and Influenza B. The sequence of these primers was provided by the CDC, Atlanta. Virus culture identification was conducted with hemagglutination and hemagglutination inhibition methods. We evaluated the percentage of concordance between positive culture results vs its RT-PCR results.Results: A number of 112 influenza positive in culture method from 4277 ILI specimens were compared with real-time RT-PCR result. There was 69.6% of virus culture result was in concordant with real-time RT-PCR result. We also found that 30.4% of positive result using real-time RT-PCR were not detectable by virus culture.Conclusion: Virus culture was still essential and considerably efficient to support real-time RT-PCR detection in ILI cases in Indonesia although the positive Influenza results by virus culture less than RT-PCR. (Health Science Indones 2011;2:92-5).

Keywords

• influenza-like illness, RT-PCR, influenza, culture