During the 17th week of 2019, (22.04-28.04.2019) the Republic of North Macedonia registered 56 influenza cases/flu-like diseases(I=2.7/100.000). Compared with the number of registered cases in the last week, are decreased for 54.5% (n=123)
The incidence this week is below the weekly limit of seasonal (low) activity of the influenza virus (Chart 1).
Over the past week, there have been no deaths associated with influenza. This week, the virological laboratory of the IPH received 6 influenza testing materials, of which 3 (50%) were positive for the presence of the influenza virus – Influenza A(H1)pdm Influenza A (H3) and Influenza А non subtyped. (Chart 4).
Chart 1. Levels of intensity and weekly distribution of influenza / influenza-like illness patients according to the expected epidemic curve 2010-2018, season 2017/2018 and season 2018/2019
This week most of the cases have been registered in a group 15-64 years (n=37; 66.1%)and the highest incidence is registered in group over 65 years, I=4.2/100 000.
This week were reported cases from 10 reporting units. Most of the cases have been registered in Gostivar (n=18)and the highest incidence is registered in Negotino, I=17.0/100 000. (chart 1).
In the 2018/2019 season, the total number of influenza cases is 21321 (I=1030.4/100.000).
Compared with the same period last season , there is a decrease in the total number of reported cases by 10.7%, and in relation to the model for the last 8 seasons (n=25869) a decrease of 17.6% .
Cumulatively this season, most of the cases have been reported from Strumica(n=2483), Kavadarci n=1889 Skopje (n=3694), Prilep (n=1576), Gostivar (n=1645) (chart2)
The highest cumulative incidence of 4389.6/100.000 habitants was registered in Kavadarci and also in Strumica(2621.5/100,000). and also high incidence over 1500,0/100 000h. was registered in Debar, Resen, Sveti Nikole, Kratovo, Prilep(chart2)
Chart 2. Distribution of cases of seasonal influenza per CPH / RO and incidence of 100,000 inhabitants, season 2018/2019
Over the season, have been registered 28 deaths associated with influenza. 13 people from Skopje. In 20 people (71,4%), pre-chronic disease has been identified, ie co-morbidity.The age of the deceased ranges from 5-86 years.
Regarding the distribution of the diseased by age groups, the cumulative number of cases was reported in the age group of 15-64 years – 13562 cases (63.6%), and the highest cumulative incidence of 2015.6 / 100.000 was registered in 0-4 years. (chart 1)
Most of the cases are reported in February – 11076 (51.9%) (chart 3)
Chart 4. Distribution of cases of seasonal flu by month, season 2018/2019
From the beginning of the season, the laboratory for virology of IPH has received 837 samples, materials for laboratory diagnostics, of which 433 (51.7%) are positive for the presence of influenza virus, all are Influenza A: 324 (74.8%) are Influenza A(H1N1)pdm, 57 (13.2%) are Influenza A(H3), аnd 52 (11.9%) are Influenza А non-subtyped(chart 5)
Chart 4. Weekly distribution of number and percentage of Influenza positive samples 2018/2019
According to records presented in Flu News Europe (16th week/2019), the activity of influenza virus in Europe is the following: of 43 countries in the European region, only 4 reported wide geographical distribution. All countries reported a low intensity of the influenza virus.17% samples were confirmed as positive.(from the sentinel surveillance tests in countries reporting to the TESSy system of the ECDC).
During the 2018/2019 season, the two subtypes of influenza A circulate, with some countries registering co-circulation, while other countries report the dominance of A (H1N1) pdm09 or the A (H3N2) subtype.
From the beginning of the 40th week, over 99% of influenza A viruses detected by SARI (severe acute respiratory infection) cases were subtyped, and 79% of them were A (H1N1) pdm09.
In general, current influenza vaccines tend to act better against influenza A (H1N1) pdm09 and influenza virus B than against influenza A (H3N2).
For the 2019-2020 season of the northern hemisphere, WHO recommends a four-valent vaccine containing:
- A / Brisbane / 02/2018 (H1N1) pdm09-like virus;
- A / Kansas / 14/2017 (H3N2) -like virus;
- B / Colorado / 06/2017-like virus (B / Victoria / 2/87 lineage);
- B / Phuket / 3073/2013-like virus (B / Yamagata / 16/88 lineage).