Radzuan Razali -et al., IJSIT, 2013, 2(5),359-366 IJSIT (www.ijsit.com), Volume 2, Issue 5, September-October 2013 359 ESTIMATION OF THE REPRODUCTION NUMBER OF THE NOVEL INFLUENZA A, H1N1 IN MALAYSIA Radzuan Razali * and SamsulAriffin Abdul Karim Fundamental and Applied Sciences Department, UniversitiTeknologiPetronas, Bandar Seri Iskandar, 31750 Tronoh, Perak DarulRidzuan, Malaysia. ABSTRACT In June 2009, the World Health Organization (WHO) confirmed that the novel influenza A, H1N1 as a pandemic. After six months, as of December 29, 2009, it was reported by WHO that more than 208 countries and territories were affected by the pandemic accounting for about 150,000 infected cases and at least 11,516 death. In Malaysia, during the first wave, there are about 14,912 cases were reported from May, 15, 2009 until June, 4, 2010 and a total number of 88 deaths were recorded across the country in 2010. The aim of this study is to assess the transmissibility of this pandemic in Malaysia by estimating the basic reproduction number, Ro, which is the average number of secondary cases generated by a single primary case. The value of Ro is a summary measure of the transmission potential in a given epidemic setting and has been estimated to range from 1.4 – 1.6 in Mexico, from 2.0 – 2.6 in Japan, 1.96 in New Zealand and 1.68 in China for this current pandemic.