Zeynep Özge ÖZGÜLER, Fehminaz TEMEL, Pınar DUMAN, Çağrı Emin ŞAHİN

Ünye İlçesinde Ağustos 2017de Meydana Gelen Norovirüs İlişkili Su Kaynaklı Bir Salgın Üzerinden Epidemiyolojik Yaklaşım, Kontrol Önlemleri, Zorluklar

Amaç: Ünye ilçesindeki hastanelere 20-23 Ağustos 2017 tarihleri arasında 1426 akut barsak enfeksiyonu ABE başvurusu olduğu saptanmıştır. İncelemenin amacı vaka sayısındaki artışın sebeplerini saptamak olası kaynakları kontrol altına almak ve salgının tekrarlanmaması için önlem almaktır. Çalışmanın bir diğer amacı da sahada karşılaşılan zorlukları ve salgına müdahalenin akışını ortaya koymaktır.Yöntem: İnceleme için yüz yüze anket uygulanmak istenmiş ancak bölgenin fındık toplama zamanı olması ve kurban bayramı tatili döneminin başlaması nedeni ile vakalara ulaşılamayacağı anlaşılmıştır. Yüz yüze veri toplama çalışması yapılamamış olup vaka tespiti için hastane kayıtları kullanılarak tanımlayıcı bir çalışma yapılmıştır. Şüpheli vaka, ilçedeki hastanelere 2023 Ağustos 2017 tarihleri arasında ABE ilişkili ICD-10; A09, R11 veya K52.8/9 tanı kodlarıyla başvuran kişidir. Otuz adet su örneğinin mikrobiyolojik, iki su örneğinin virolojik, yedi adet gaita örneğinin mikrobiyolojik, parazitolojik ve virolojik incelemeleri yapılmıştır.Bulgular: Ünye’deki hastanelerden 1092 şüpheli vaka tespiti yapılmıştır ilçe nüfusu: 125722 . En sık tanı kodu R11: bulantı ve kusmadır %41 . Hastaların %53’ü kadındır. 125722 . Most common diagnostic code was R11: nausea and vomiting 41% . Fifty-three percent of cases were female. Mean age was 28.0±18.5 and median value was 25 Min.: 0-Max.: 86 . Epidemic curve revealed personto-person transmission with propagated peaks. There was no clustering in a certain neighborhood nor common food exposure. Environmental investigation showed that structure of water tanks didn’t comply with regulations and chlorine levels were inadequate. Escherichia coli was detected in ten water samples, coexistence of E.coli and Clostridium perfringens was detected in two samples. No virus was detected in two water samples. Norovirus was detected in six stool specimens, while bacteriological, parasitological examination revealed no detected pathogen. Decrease in cases was observed after hyperchlorination.Conclusion: Results of microbiological examinations that showed contamination in water, sudden increase of cases and it’s spread throughout district along with results of clinical samples, indicated that outbreak was a norovirus-associated water-borne outbreak. In order to avoid gastroenteritis outbreaks,regular chlorination, investigation of the causes for contamination, to examine water tanks/networks and improvement for detected problems in case of detected pathogens or low chlorine levels in routine water-inspections, prior to an increase in cases, were recommended. It was thought that portable detection methods or provincialbased analysis centers for norovirus-related analyses are necessities for conducting pathogen-specific, evidencebased interventions. For public health action, decisions were taken on issues such as general hygiene education, hospital preparedness and hyperchlorination

Anahtar Kelimeler:

Gastroenterit, içme suyu, su kaynaklı salgın, salgın, norovirüs

Epidemiological Approach, Control Measures and Challenges of a Norovirus-Associated Waterborne Outbreak in Unye District in August 2017

Objective: There were 1426 acute gastroenteritis hospital admissions in Unye district between 20-23 August 2017. Aim of this investigation conducted by field epidemiology unit was to identify possible reasons for the increase of cases, control probable sources and take preventive measures to prevent re-occurrence of the outbreak. Further aim of this study was revealing the difficulties encountered on the field and the flow of this intervention.Methods: A face-to-face survey was intended but as it was hazelnut harvesting period of district and the beginning of a national holiday, it was understood that it wouldn’t be possible to reach the cases. The survey couldn’t be carried out, for case detection, a descriptive study using hospital records was conducted. The suspected case was a person admitted to district hospitals between 20-23 August 2017 with gastroenteritis related ICD-10 codes: A09, R11 or K52.8/9. Microbiological tests for 30; virological tests for two water samples; microbiological, parasitological and virological tests for seven stool samples were investigated.Results: A total of 1092 suspected cases were identified from hospitals in Ünye district population: sağlık sorunlarından olup akut gastroenterit sporadik Gastroenteritler günümüzde hala en çok rastlanan GIRIŞ 125722 . Most common diagnostic code was R11: nausea and vomiting 41% . Fifty-three percent of cases were female. Mean age was 28.0±18.5 and median value was 25 Min.: 0-Max.: 86 . Epidemic curve revealed personto-person transmission with propagated peaks. There was no clustering in a certain neighborhood nor common food exposure. Environmental investigation showed that structure of water tanks didn’t comply with regulations and chlorine levels were inadequate. Escherichia coli was detected in ten water samples, coexistence of E.coli and Clostridium perfringens was detected in two samples. No virus was detected in two water samples. Norovirus was detected in six stool specimens, while bacteriological, parasitological examination revealed no detected pathogen. Decrease in cases was observed after hyperchlorination.Conclusion: Results of microbiological examinations that showed contamination in water, sudden increase of cases and it’s spread throughout district along with results of clinical samples, indicated that outbreak was a norovirus-associated water-borne outbreak. In order to avoid gastroenteritis outbreaks,regular chlorination, investigation of the causes for contamination, to examine water tanks/networks and improvement for detected problems in case of detected pathogens or low chlorine levels in routine water-inspections, prior to an increase in cases, were recommended. It was thought that portable detection methods or provincialbased analysis centers for norovirus-related analyses are necessities for conducting pathogen-specific, evidencebased interventions. For public health action, decisions were taken on issues such as general hygiene education, hospital preparedness and hyperchlorination

Keywords:

Gastroenteritis, drinking water, waterborne outbreaks, outbreak, norovirus,

PDF

___

Ahmed SM, Hall AJ, Robinson AE, Verhoef L, Premkumar P, Parashar UD, et al. Global prevalence of norovirus in cases of gastroenteritis: a systematic review and meta-analysis. The Lancet Infectious Diseases. 2014;14(8):725-730.
Ahmed SM, Hall AJ, Robinson AE, Verhoef L, Premkumar P, Parashar UD, et al. Global prevalence of norovirus in cases of gastroenteritis: a systematic review and meta-analysis. The Lancet Infectious Diseases. 2014;14(8):725-730.
Bulaşıcı Hastalıkların Laboratuvar Tanısı için Saha Rehberi, Norovirüs Enfeksiyonu. http:// mikrobiyoloji.thsk.saglik.gov.tr/ums/M-N/ Norovirus-enfeksiyonu.pdf (12 Nisan 2018).
Glass RI, Parashar UD, Estes MK. Norovirus gastroenteritis. The New England journal of medicine. 2009;361(18):10.1056/NEJMra0804575. doi:10.1056/NEJMra0804575.
Glass RI, Noel J, Ando T, Fankhauser R, Belliot G, Mounts A, et al. J Infect Dis. 2000 May;181
Suppl 2:S254-61. The epidemiology of enteric caliciviruses from humans: a reassessment using new diagnostics. doi:10.1086/315588.
Vinjé J. Advances in Laboratory Methods for Detection and Typing of Norovirus. J Clin Microbiol. 2015 Feb;53(2):373-81. doi:10.1128/ JCM.01535-14.
Patel MM, Hall AJ, Vinjé J, Parashar UD. Noroviruses: a comprehensive review. J Clin Virol. jcv.2008.10.009. doi:10.1016/j.
Simmons K, Gambhir M, Leon J, Lopman B. Duration of immunity to norovirus gastroenteritis. Emerg Infect Dis. 2013 Aug;19(8):1260-7. doi:10.3201/ eid1908.130472.
Lopman BA, Steele D, Kirkwood CD, Parashar UD. The Vast and Varied Global Burden of Norovirus: Prospects for Prevention and Control. PLoS Medicine. 2016;13(4):e1001999. doi:10.1371/ journal.pmed.1001999.
Şahan S, Yılmaz Ş, Topal S, Özarslan F, Çeliker Yenice A, Göktaş D ve ark. Kahramanmaraş ili Elbistan ilçesinde görülen akut barsak enfeksiyonu vaka artışı incelemesi, Ağustos 2016. Turk Hij Den Biyol Derg. 2017; 74(Su Kongresi): 13-20.
Barlas G, Tozan E, Altuğ Y, Aktaş D, Temel F, Korukluoğlu G ve ark. Kütahya ili Tavşanlı ilçesinde ishal salgını incelemesi, Temmuz 2014, Bir Olgu Kontrol Çalışması. Turk J Public Health 2016;14(2) doi: 10.20518/thsd.31346.
Gallay A, De Valk H, Cournot M, Ladeuil B, Hemery C, Castor C, et al. A large multi-pathogen waterborne community outbreak linked to faecal contamination of a groundwater system, France, Clin Microbiol Infect. 2006 Jun;12(6):561- doi:10.1111/j.1469-0691.2006.01441.x.
Tillett HE, de Louvois J, Wall PG. Surveillance of outbreaks of waterborne ınfectious disease: categorizing levels of evidence. Epidemiol Infect. ;120(1):37-42. Gönen İ. Management of a large outbreak caused by norovirus and campylobacter jejuni occurred ın a rural area ın Turkey . Nobel Med 2013; 9(2): 51, English.
Lopman BA, Reacher M, Gallimore C, Adak GK, Gray JJ, Brown DW. A summertime peak of “winter vomiting disease”: Surveillance of noroviruses in England and Wales, 1995 to 2002. BMC Public Health. 2003;3:13. doi:10.1186/1471-2458-3-13.
Mounts AW, Ando T, Koopmans M, Bresee JS, Noel J, Glass RI. cold weather seasonality of gastroenteritis associated with norwalk-like viruses. The Journal of Infectious Diseases 01 May , 181 Suppl 2:S284-7. doi:10.1086/315586.
Albayrak N, Yağcı Çağlayık D, Altaş A, Korukluoğlu G, Ertek M. Refik Saydam Hıfzıssıhha Merkezi Başkanlığı, Viroloji Referans ve Araştırma Laboratuvarı, 2009 yılı akut viral gastroenterit verilerinin değerlendirilmesi. Turk Hij Den Biyol Derg. 2011; 68(1): 9-15. doi:10.5505/ TurkHijyen.2011.64326.
Parrino T, Schreiber D, Trier J, Kapikian A, and Blacklow N. clinical ımmunity in acute gastroenteritis caused by norwalk agent. N Engl J Med 1977; 297:86-89 doi:10.1056/ NEJM197707142970204.
Morillo SG, Luchs A, Cilli A, Ribeiro CD, Calux SJ, Carmona Rde C, et al. Norovirus 3rd Generation kit: an improvement for rapid diagnosis of sporadic gastroenteritis cases and valuable for outbreak detection. J Virol Methods. 2011 Apr;173(1):13-6. doi: 10.1016/j.jviromet.2010.12.017.
Keswick BH, Satterwhite TK, Johnson PC, DuPont HL, Secor SL, Bitsura JA, et al. Inactivation of norwalk virus in drinking water by chlorine. Applied and Environmental Microbiology. 1985;50(2):261
Kitajima M, Tohya Y, Matsubara K, Haramoto E, Utagawa E, Katayama H. Chlorine inactivation of human norovirus, murine norovirus and poliovirus in drinking water. Lett Appl Microbiol. Jul;51(1):119-21. doi: 10.1111/j.1472- X.2010.02869.x. CDC “Norwalk-Like Viruses”:Public Health
Consequences and Outbreak Management. h t t p s : / / w w w. c d c . g o v / m m w r / p r e v i e w / mmwrhtml/rr5009a1.htm (12 Nisan 2018).
El-Senousy W, El-Gamal M, Mousa A, El-Hawary S, Kamel M, Fathi M, et al. Effect of chlorine on noroviruses, rotaviruses and hepatitis e virus in drinking water. World Applied Sciences Journal. 32. 2206-2212. doi: 10.5829/idosi. wasj.2014.32.11.91114.
A. Gallay, H. De Valk, M. Cournot, B. Ladeuil, C. Hemery, C. Castor et al. A large multi-pathogen waterborne community outbreak linked to faecal contamination of a groundwater system, France, 2000 Clinical Microbiology and Infection June 2006; 12(6) : 561-570 doi:10.1111/j.1469- 2006.01441.x.
Barclay L, Park GW, Vega E, Hall A, Parashar U, Vinjé J, Lopman B. Infection control for norovirus. Clin Microbiol Infect. 2014 Aug;20(8):731-40. doi:10.1111/1469-0691.12674.