Etken Olarak Norovirüs Saptanan Akut Gastroenteritli

Çocuklarda Hastalığın Klinik ve Laboratuvar

Bulguları

Ö. Küçük1, D.Çöl1, S. Biçer1, Gülay Çiler Erdağ1, T.Giray1, Y. Gürol2, İ.

Acuner2, Gülden Yılmaz2, Ayça Vitrinel1

1Yeditepe Üniversitesi, Tıp Fakültesi, Çocuk Sağlığı ve Hastalıkları,

2Yeditepe Üniversitesi, Tıp Fakültesi, Tıbbi Mikrobiyoloji

Akut gastroenteritler,gelişmekte olan ülkeler başta olmak üzere; tüm dünyada her yıl 3–5 milyon insanın ölümüne yol açan büyük bir sağlık sorunudur.

AGE’e neden olan birçok patojen olup, calicivirüsler (noro ve sapovirüs) başta olmak üzere rotavirüs, enterik adenovirüs ve astrovirüsler viral etiyolojiyi oluştururlar.

Semptomlar çok çeşitli, klinik tablonun ağırlığı değişik -GI semptomlar:

bulantı, kusma, diyare, karın ağrısı, kramp

-Jeneralize semptomlar:ateş, yorgunluk, başarısı, miyalji

Norovirüsler, tüm dünyada non-bakteriyal gastroenteritlerin en yaygın nedenlerindendir.

İlk kez 1968 yılında Amerika’nın Ohio eyaletine bağlı Norwalk’ta ortaya çıkan bir akut gastroenterit salgınından dört yıl sonra, immunoelektron mikroskop ile identifiye edilmiştir. Adler JL, Zickl R. Winter vomiting disease. J.Infect Dis 1969; 119:668–673. Kapikian AZ, Gerin JL, Wyatt RG, et al: 

Density in cesium chloride of the Norwalk agent: Determination by ultracentrifugation and immune electron microscopy. Proc Soc Exp Biol Med  1973; 142:874-877.

Dolin R, Blacklow NR, DuPont H, et al: Biological properties of Norwalk agent of acute infectious nonbacterial gastroenteritis. Proc Soc Exp Biol Med  1972; 140:578-583.

Noroviruslar

Ufak tek iplikli RNA virusları Dirençli viruslar Su ve gıda ile fekal-oral yolla Sporadik ve epidemik gastroenterit Genellikle 48 saatte iyileşir 2-3 hafta (nadiren aylarca)virus atımı

sürebilir İmmünsuprese hastalarda uzar

Noroviruslar

-epidemik gastroenteritlerin 90%’ı-sporadik çocukluk çağı gastroenteritlerin 30%’u (2. en sık neden)

5 genogrup, 25 genotip İnsanlarda infeksiyonları :GI,II, IV (GII.4) Düşük infeksiyöz doz(18-1000 vp) Yüksek ikinci atak hızı Uzun süre atılım Yüksek genetik değişiklik, uzun süre bağışıklık yok

Noroviruslar

Ani başlayan diyare, kusma, abdominal kramp,ateş

Kanlı diyare yapmaz:Sulu,mukussuz ve lökositsiz

Virüsün ve genotiplerinin saptanması için moleküler yöntemlerin kullanımı giderek artmaktadır.

Norovirus

RT-PCR için Örnek: Dışkı Kusmuk İçme suyu, kontamine gıda

“Immunokromatografi”, NoroVirus tanısında kullanılan basit ve hızlı bir metoddur.

AMAÇ

Akut gastroenterit tanısı alıp, gaita örneğinde Norovirus saptanan olguların; insidans, mevsimsel dağılım ve klinik

karakteristiklerinin, NoV genotiplerinin gözden geçirilmesi

YÖNTEM

Ocak 2009- Ocak 2010 tarihleri arasında akut gastroenterit tanısı almış ve etken olarak Norovirus saptanmış hastalar retrospektif olarak değerlendirildiler.

Taze gaita örneklerinin mikroskopik muayenesi ve

viral antijen testleri Yeditepe Üniv.Tıp Fak

Mikrobiyoloji Lab.’da bir saat içinde çalışılmış;

Norovirus tespitinde immuno-chromatographic assay

(RidaQuick NoV, biopharm, Germany) yöntemi

kullanıldı.

Pozitif saptanan olguların 28’inde multiplex-PCR

yöntemi ile (Seeplex Diarrhea ACE Detection kit -

Seegene, Korea) genogrup çalışması yapılmıştır.

BULGULAR

YAŞ GRUPLARI

NoV (n)

AÇISINDAN

İNCELENEN

GAİTA ÖRNEĞİ

NoV (n, %)

SAPTANAN

GAİTA

ÖRNEKLERİ

0-5 YAŞ

0-24 AY

25-60 AY

412

189

223

44

25

19

10.7%

13.2%

8.5%

6-16 YAŞ 108 6 5.5%

TOPLAM 520 50 9.6%

Hastaların semptom ve klinik bulguları

Semptomlar N %

İshal 44 100

Kusma42 95.5

İştahsızlık 38 83.4

Huzursuzluk 37 86.4

Dehidratasyon 26 59

İntravenöz sıvı tedavi ihtiyacı 26 59

Ateş (>38°C)11 25

Toplam 44 100

Norovirus saptanan olguların aylara göre dağılımı

Genogrup çalışılan 28 olgunun tamamı NoV Genogup II olarak saptanmıştır.

Scand J Infect Dis. 2009;41(9):685-8.

Frequency of norovirus in stool samples from hospitalized children due to acute gastroenteritis in Anatolia, Turkey, 2006-2007.Altindis M, Bányai K, Kalayci R, Gulamber C, Koken R, Yoldas Y, Aykurt P, Martella V.

SourceDepartment of Microbiology, School of Medicine, Afyon Kocatepe University, Afyonkarahisar, Turkey. maltindis@gmail.com

AbstractNoroviruses are among the most common causes of sporadic enteritis in childhood. In this pilot study, the frequency of norovirus infection in children in mid-western Turkey

was investigated from November 2006 to June 2007. Noroviruses were detected in 17% of samples (15/88) by a combination of 2 different RT-PCR assays, both targeting an overlapping region of the RNA-dependent RNA polymerase gene. By sequence analysis, most strains were characterized as GIIb/Hilversum. One strain was characterized as GII.4/2006a, a variant that appeared worldwide in 2006, while another strain was characterized as a rare genotype, GII.6. This study demonstrates the importance of norovirus in paediatric diarrhoea and suggests the heterogeneity of circulating strains in Turkey.

Mikrobiyol Bul. 2008 Oct;42(4):607-15.[Evaluation of laboratory diagnosis of the first norovirus outbreak in Turkey in 2008].[Article in Turkish]Uyar Y, Carhan A, Ozkaya E, Ertek M.SourceRefik Saydam Hifzissihha Merkezi Başkanliği, Viroloji Tani ve Araştirma Laboratuvari, AnkaraNorovirus (NoV) is one of the most prominent agents of gastroenteritis and water/food-borne outbreaks affecting all of the age groups in the world. As the identification of the etiologic agent is important during gastroenteritis outbreaks, it is recommended to combine two different methods for rapid and reliable laboratory diagnosis of NoV. Although NoV outbreaks have been observed in many different countries of the world, there was no report on "NoV outbreak" in Turkey till 2008 due to the absence of a regular surveillance system for non-bacterial gastroenteritis. This study aimed to present the laboratory results for "the first NoV outbreak" in Turkey in 2008. A number of cases with diarrhea and nausea/vomiting initially emerged in Aksaray (located at the southern part of central Anatolia) in May 2008, followed by cases from Sereflikochisar, Kirsehir, and Adana provinces (located at central and southern Anatolia; geographically closer regions). However, regional laboratories declared that no known bacterial (Salmonella spp., Shigella spp., enterotoxigenic Escherichia coli), viral (Rotavirus, Adenovirus) and parasitic agents were detected. A total of 50 stool samples were sent to the Virology Reference Laboratory (Refik Saydam Hygiene Center, Ankara) for further investigations including NoV. For the investigation of NoV, the samples were analysed by using antigen-ELISA (Ridascreen, R-Biopharm, Germany) and real-time polymerase chain reaction(PCR) (Roche Diagnostics GmbH, Germany) methods. Of the samples, 26% (13/50) were found antigen positive, whereas 33% (13/40) were positive for viral nucleic acids. The positivity rates determined by ELISA and PCR were as follows, respectively; 57% (4/7) and 71% (5/7) in Aksaray, 25% (1/4) and 25% (1/4) in Sereflikochisar, 28% (7/25) and 40% (6/15) in Kirsehir, 7% (1/14) and 7% (1/14) in Adana. Nine (69.2%), and 4 (30.8%) out of 13 positive samples were genotyped as NoV GI and GII, respectively. The sensitivity and specificity of antigen-ELISA method were found as 61.5% and 100%, respectively, when compared with real-time PCR. In conclusion, further epidemiological studies and genomic analysis are needed for the detection and control of circulating strains in Turkey, since NoV outbreaks spread rapidly and cause serious economical and workforce loss..

J Clin Virol. 2011 Jul;51(3):160-4. Epub 2011 May 17.Frequency and phylogeny of norovirus in diarrheic children in Istanbul, Turkey.Ozkul AA, Kocazeybek BS, Turan N, Reuter G, Bostan K, Yilmaz A, Altan E, Uyunmaz G, Karaköse AR, Muratoglu K, Elevli M, Helps CR, Yilmaz H.SourceBaşkent University Hospital, Clinic of Child Health and Diseases, Altunizade, Istanbul, Turkey.BACKGROUND: Norovirus (NoV) is recognised as one of the most common causes of foodborne infections. Contaminated shellfish, food, water and hospitals are well documented sources of the virus.OBJECTIVE: NoV in diarrheic children has not previously been investigated in Istanbul, Turkey, hence the aim of this study was to detect and investigate the frequency and phylogeny of human NoV genogroups I and II in children with acute gastroenteritis.STUDY DESIGN: 238 stool samples were collected from diarrheic children from 2 hospitals (Cerrahpasa Medical School and Haseki) in Istanbul and analysed by ELISA, RT-PCR and real-time RT-PCR using both SYBR Green and probe-based assays for human NoV. Primers targeting the RNA-polymerase gene were used for RT-PCR to allow DNA sequencing of Turkish NoV strains and phylogenetic analysis to be performed.RESULTS: NoV GII was detected in 36 (15.1%) of 238 samples by SYBR Green real-time RT-PCR, 10.9% by a probe-based real-time RT-PCR and 10.5% by ELISA (Ridascreen). Genogroup II (GII) the Turkish NoVs clustered with including GII4 (72.2%), GII16 (5.5%), GIIb (16.7%) and GIIe (5.5%). Two variants of GII4 (GII4-2006b and GII4-2008), GII16 and recombinant noroviruses (GIIb and GIIe) were identified.CONCLUSION: This study shows a high frequency and genetic diversity of NoV GII infections in children with acute gastroenteritis in Istanbul, Turkey.

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