Objective. To provide virological and epidemiological information on patients laboratory-tested for
influenza A/ H1N1pdm during the pandemic season April 2009/May 2010.
Materials and methods: Demographic and other data were obtained from the request form arriving
with the samples of patients whose symptoms met the clinical definition of influenza A infection.
The RNA was tested for the presence of influenza virus using the CDC real-time RT-PCR assay. A
total of 3010 suspect patients (pts) were tested from week 18 2009 to week 20 2010.
Results: 1632 pts (54.2%) were oositive for influenza. From them 1556 samples were confirmed as
H1N1pdm. There was a domination of H1N1pdm positivity among young persons in age groups 5–17
(34.4%) and 18–49 (31.4%) years. The pandemic influenza was presented in two waves. The first
wave started on 20 June with the first positive case and peaked early in August (week 32). The
second wave started from week 44. The majority of positive cases were between week 45 and week
52. 37.7% of the positive pts were hospitalized – 66.7% of pts at age 65+ and 63.3% of children in
the age group 0–4 years. The highest percentage of patients with underlying medical conditions were
in the age group 50–64 (49.35%) years and 65+ (88.23%) years. 1.15% of the positive pts for
H1N1pdm gave data for vaccination with seasonal influenza.
Conclusions: Data obtained from laboratory and epidemiological surveillance of pandemic influenza
will serve public health to a full understanding of the pandemic 2009/2010 influenza in R. Macedonia
and dealing with future challenges.