Journal article Open Access

Basic Epidemiological Parameters at the end of the 5th month of the COVID-19 Outbreak

Sarı, Oktay; Hoşbul, Tuğrul; Şahiner, Fatih

Özet

Küresel çapta neden olduğu etkileri nedeniyle yüzyılın salgını olarak niteleyebileceğimiz COVID-19 pandemisinin başlaması üzerinden 5 aylık bir süre geçti. Bu süreçte başlangıçta sınırlı sayıdaki çalışmanın veya matematiksel modelleme ve simülasyonların sunduğu veriler üzerinden anlaşılmaya çalışılan salgın epidemiyolojisine dair bilgiler, yerini farklı ülkelerden gelen yeni çalışma verilerine ve bu verilerin havuzlanarak incelendiği sistematik derlemeler ve meta analizlerin sunduğu daha güvenilir sonuçlara bırakmaktadır. Bu makalede SARS-CoV-2 enfeksiyonlarının inkübasyon periyodu, bulaştırıcılık dönemi ve süresi, bulaşma alanları (nozokomiyal bulaş, hanehalkı bulaşı, toplumsal bulaş), rezervuar hayvanlar, asemptomatik bireylerin bulaştaki rolü ve bu enfeksiyonların mevsimsel özellikleri ile ilgili genel bilgilere yer verilmiştir. Ayrıca bulaştırıcılık katsayısı (R0), sekonder atak hızı, ülkelere göre vaka sayıları ve ölüm oranları gibi salgının temel epidemiyolojik parametreleri incelenmiştir. COVID-19 salgınının sunduğu veriler SARS-CoV-2 enfeksiyonlarının önceki koronavirus enfeksiyonları (SARS ve MERS) ile karşılaştırıldığında daha yüksek bir bulaştırıcılığa sahipken virülansının daha düşük olduğuna işaret etmektedir. Mevcut veriler SARS-CoV-2 enfeksiyonlarında temel epidemiyolojik parametrelerden R0 değerinin (bölgelere ve dönemlere göre değişmek üzere) 2 ila 3 arasına sabitlenme eğiliminde olduğunu, bulaştırıcılığın semptomların ortaya çıkışından 1-2 gün önce başladığını ve inkübasyon periyodunun ortalama 5 gün civarında (1-14 gün) olduğunu göstermektedir. Sağlık Bakanlığı tarafından Türkiye’deki R0 değeri 13 Mayıs 2020 tarihinde 1.56 olarak açıklanmıştır (basın bildirisi). Salgının ilk 5 ayında (29 Mayıs itibariyle) 50’den fazla ülkede toplam olgu sayısı 10.000’i aşarken, dünya genelindeki toplam vaka sayısı 6 milyona ulaşmış ve bu olguların neredeyse yarısı sonlanmış (kapanmış) vaka durumuna gelmiştir. Aktif enfeksiyon olguları da dahil edildiğinde dünya genelindeki ölüm oranı yaklaşık %6.1 iken, sonlanan 3 milyon vakada bu oran tahmini olarak %12 civarındadır. Vaka sayılarının ve mortalite oranlarının ülkelere göre önemli ölçüde farklılıklar gösterdiği bu salgında, ülke nüfusuna oranla en yüksek vaka sayılarının görüldüğü yerler Katar, Lüksemburg, Bahreyn, İspanya, Kuveyt, Singapur, Amerika Birleşik Devletleri, İzlanda, İrlanda ve Belçika gibi genel olarak kişi başına milli geliri yüksek olan veya uluslararası ticari faaliyetlerin ve havayolu seyahatlerinin yoğun olduğu ülkeler olmuştur. Dünyanın birçok ülkesine göre daha iyi sağlık sistemlerine sahip olan, ancak şiddetli enfeksiyon için risk altındaki nüfusun yüksek oranlarda olması nedeniyle beklenmedik hasta yoğunluğu ile karşı karşıya kalan Belçika, Fransa, İtalya, İspanya, Birleşik Krallık, Hollanda ve İsveç gibi Avrupa ülkelerinde SARS-CoV-2 enfeksiyonları dünya geneline göre daha yüksek mortalite oranları ile seyretmektedir. Bununla beraber, salgının başlangıç günlerinden yakın zamana kadar olgu sayılarının düşük sayılarda seyrettiği Brezilya, Peru, Şili, Rusya, Meksika, Hindistan ve Bangladeş gibi ülkelerde son haftalarda vaka sayılarında hızlı artışlar görülmektedir. Bu ülkelerden ya da faklı ülkelerde ortaya çıkabilecek yeni artışların salgınla ilgili istatistikleri değiştirmesi muhtemeldir. Bu makalede salgının ilk 5 ayı sonunda izlenen temel epidemiyolojik parametrelerin kısa bir gözden geçirmesini sunulmuştur.

Abstract

It has been a 5-month period since the onset of the COVID-19 pandemic which can describe as the outbreak of the century due to its global effects. Information on epidemic epidemiology was initially attempted to be understood through data provided by a limited number of studies or by mathematical modeling and simulations, but today the data of new studies from different countries and the more reliable results provided by systematic reviews and meta-analyzes where these data are pooled and analyzed replaced this information. In this article, general information is summarized about incubation period of SARS-CoV-2 infections, infectious period, transmission modes (nosocomial, household, and social transmission), reservoir animals, the role of asymptomatic individuals in transmission, and seasonal characteristics of these infections. In addition, the main epidemiological parameters of the epidemic such as reproductive number (R0), secondary attack rate, number of cases and mortality rates by country were examined. Data presented by the COVID-19 outbreak indicate that SARS-CoV-2 infections have higher infectivity compared to previous coronavirus infections (SARS and MERS), while have lower virulence. The available data show that the R0 value (depending on regions and periods), which is one of the basic epidemiological parameters, tends to stabilize between 2 and 3, the contamination begins 1-2 days before the symptoms appear and the incubation period is on average 5 days (1-14 days) in SARS-CoV-2 infections. R0 number is estimated as 1.56 in Turkey by the Ministry of Health on May 13, 2020 (press release). In the first 5 months of the epidemic (as of May 29), while the total number of cases in more than 50 countries exceeded 10,000, the total number of cases worldwide reached 6 million, and almost half of these cases ended (closed). While the worldwide mortality rate is around 6.1% (including cases of active infection), this rate is approximately 12% in the 3 million closed cases. In this outbreak, case numbers and mortality rates differ significantly by country. In general, the regions with the highest number of cases according to country population were Qatar, Luxembourg, Bahrain, Spain, Kuwait, Singapore, United States, Iceland, Ireland, and Belgium (in general, these countries have high per capita national income or intensive international trade activities and air travel). SARS infections are progressing with higher mortality rates than the rest of the world in European countries (such as Belgium, France, Italy, Spain, UK, Netherlands, and Sweden) having better healthcare systems than many countries, but facing unexpected patient density due to high rates of population at risk for severe infection. However, in some countries such as Brazil, Peru, Chile, Russia, Mexico, India and Bangladesh, where the number of cases remained low from the onset of the outbreak until recently, there has been a rapid increase in the number of cases in recent weeks. New increases that may occur in these countries or in different countries are likely to change statistics on the outbreak. In this article, a brief review of the main epidemiological parameters monitored at the end of the first 5 months of the outbreak is presented.

COVID-19 Salgınında Beşinci Ay Sonunda Temel Epidemiyolojik Parametreler
Files (712.7 kB)
Name Size
7.JMVI-2020-1.1;67-80.pdf
md5:fd5760235bce687ac77d665c8d6a5de1
712.7 kB Download
  • 1. Huang C, Wang Y, Li X, Ren L, Zhao J5, Hu Y, et al. Clinical features of patients infected with 2019 novel coronavirus in Wuhan, China. Lancet 2020; 395(10223): 497-506.

  • 2. Leung K, Wu JT, Liu D, Leung GM. First-wave COVID-19 transmissibility and severity in China outside Hubei after control measures, and second-wave scenario planning: a modelling impact assessment. Lancet 2020; 395(10233): 1382‐93.

  • 3. Anadolu Agency, Ankara, Turkey. Chinese coronavirus may spread to more countries. Available at: https://www.aa.com.tr/en/asia-pacific/chinese-coronavirus-may-spread-to-more-countries/1710460 [Accessed January 22, 2020].

  • 4. Wang D, Hu B, Hu C, Zhu F, Liu X, Zhang J, et al. Clinical characteristics of 138 hospitalized patients with 2019 novel coronavirus-infected pneumonia in Wuhan, China. JAMA 2020; e201585.

  • 5. Guan WJ, Ni ZY, Hu Y, Liang WH, Ou CQ, He JX, et al. Clinical Characteristics of Coronavirus Disease 2019 in China. N Engl J Med 2020; 382(18): 1708‐20.

  • 6. Chen N, Zhou M, Dong X, Qu J, Gong F, Han Y, et al. Epidemiological and clinical characteristics of 99 cases of 2019 novel coronavirus pneumonia in Wuhan, China: a descriptive study. Lancet 2020; 395(10223): 507-13.

  • 7. Guo YR, Cao QD, Hong ZS, Tan YY, Chen SD, Jin HJ, et al. The origin, transmission and clinical therapies on coronavirus disease 2019 (COVID-19) outbreak - an update on the status. Mil Med Res 2020; 7(1): 11.

  • 8. Xia W, Shao J, Guo Y, Peng X, Li Z, Hu D. Clinical and CT features in pediatric patients with COVID-19 infection: Different points from adults. Pediatr Pulmonol 2020; 55(5): 1169‐74.

  • 9. Dong Y, Mo X, Hu Y, Qi X, Jiang F, Jiang Z et al. Epidemiology of COVID-19 Among Children in China. Pediatrics 2020; e20200702. [Epub ahead of print].

  • 10. Choi SH, Kim HW, Kang JM, Kim DH, Cho EY. Epidemiology and clinical features of coronavirus disease 2019 in children. Clin Exp Pediatr 2020; 63(4): 125‐32.

  • 11. World Health Organization (WHO), Geneva, Switzerland. WHO Coronavirus Disease (COVID-19) Dashboard. Available at: https://covid19.who.int/ [Accessed May 29, 2020].

  • 12. Worldometer, Dadax Limited, Delaware, USA. COVID-19 Coronavirus Pandemic. Available at: https://www.worldometers.info/coronavirus/#countries [Accessed May 5, 2020].

  • 13. Centers for Disease Control and Prevention (CDC), Atlanta, Georgia, USA. Coronavirus Disease 2019 (COVID-19), World Map. Available at: https://www.cdc.gov/coronavirus/2019-ncov/global-covid-19/world-map.html [Accessed May 29, 2020].

  • 14. Wang Y, Wang Q, Wang K, Song C, Guo Z, Hu W. A Case of COVID-19 with Ultra-Long Incubation Period. Infect Control Hosp Epidemiol 2020;1‐7. [Epub ahead of print].

  • 15. Li Q, Guan X, Wu P, Wang X, Zhou L, Tong Y, et al. Early Transmission Dynamics in Wuhan, China, of Novel Coronavirus-Infected Pneumonia. N Engl J Med 2020; 382(13): 1199‐1207.

  • 16. Bar-On YM, Flamholz A, Phillips R, Milo R. SARS-CoV-2 (COVID-19) by the numbers. Elife 2020; 9. pii: e57309.

  • 17. Bai Y, Yao L, Wei T, Tian F, Jin DY, Chen L, et al. Presumed asymptomatic carrier transmission of COVID-19. JAMA 2020; 323(14): 1406-7.

  • 18. Lauer SA, Grantz KH, Bi Q, Jones FK, Zheng Q, Meredith HR, et al. The Incubation Period of Coronavirus Disease 2019 (COVID-19) From Publicly Reported Confirmed Cases: Estimation and Application. Ann Intern Med 2020; 172(9): 577‐82.

  • 19. Linton NM, Kobayashi T, Yang Y, Hayashi K, Akhmetzhanov AR, Jung SM, et al. Incubation Period and Other Epidemiological Characteristics of 2019 Novel Coronavirus Infections with Right Truncation: A Statistical Analysis of Publicly Available Case Data. J Clin Med 2020; 9(2): 538.

  • 20. Ji LN, Chao S, Wang YJ, Li XJ, Mu XD, Lin MG, et al. Clinical features of pediatric patients with COVID-19: a report of two family cluster cases. World J Pediatr 2020; 1‐4. [Epub ahead of print].

  • 21. National Centre for Infectious Diseases and Academy of Medicine, Singapore. Position Statement on Period of Infectivity to Inform Strategies for De-Isolation for Covid-19 Patients, 23 May 2020. Available at: https://www.ams.edu.sg/view-pdf.aspx?file=media%5c5556_fi_331.pdf&ofile=Period+of+Infectivity+Position+Statement+(final)+23-5-20+(logos).pdf [Accessed May 26, 2020].

  • 22. Cai J, Xu J, Lin D, Yang Z, Xu L, Qu Z, et al. A Case Series of children with 2019 novel coronavirus infection: clinical and epidemiological features. Clin Infect Dis 2020; ciaa198.

  • 23. Backer JA, Klinkenberg D, Wallinga J. Incubation period of 2019 novel coronavirus (2019-nCoV) infections among travellers from Wuhan, China, 20-28 January 2020. Euro Surveill 2020; 25(5): 2000062.

  • 24. Zhao S, Lin Q, Ran J, Musa SS, Yang G, Wang W, et al. Preliminary estimation of the basic reproduction number of novel coronavirus (2019-nCoV) in China, from 2019 to 2020: A data-driven analysis in the early phase of the outbreak. Int J Infect Dis 2020; 92: 214-7.

  • 25. Ridenhour B, Kowalik JM, Shay DK. Unraveling R0: considerations for public health applications. Am J Public Health 2014; 104(2): e32‐e41.

  • 26. Guerra FM, Bolotin S, Lim G, Heffernan J, Deeks SL, Li Y, et al. The basic reproduction number (R0) of measles: a systematic review. Lancet Infect Dis 2017; 17(12): e420‐e428.

  • 27. Chowell G, Castillo-Chavez C, Fenimore PW, Kribs-Zaleta CM, Arriola L, Hyman JM. Model parameters and outbreak control for SARS. Emerg Infect Dis 2004; 10(7): 1258‐63.

  • 28. Kucharski AJ, Althaus CL. The role of superspreading in Middle East respiratory syndrome coronavirus (MERS-CoV) transmission [published correction appears in Euro Surveill 2015; 20(32). pii: 21207]. Euro Surveill 2015; 20(25): 14‐8.

  • 29. Liu Y, Gayle AA, Wilder-Smith A, Rocklöv J. The reproductive number of COVID-19 is higher compared to SARS coronavirus. J Travel Med 2020; 27(2): taaa021.

  • 30. Riou J, Althaus CL. Pattern of early human-to-human transmission of Wuhan 2019 novel coronavirus (2019-nCoV), December 2019 to January 2020 [published correction appears in Euro Surveill 2020; 25(4): pii=2000058.

  • 31. Çiftçi E, Arga G. Çocuklarda COVID-19 (Bölüm 17). In: COVID-19, Memikoğlu O, Volkan Genç (eds). 2020, Ankara Üniversitesi Basımevi, Beşevler, Ankara. pp: 127-35.

  • 32. Jing QL, Liu MJ, Yuan J, Zhang ZB, Zhang AR, Dean NE, et al. Household Secondary Attack Rate of COVID-19 and Associated Determinants. medRxiv 2020.04.11.20056010.

  • 33. Anadolu Agency, Ankara, Turkey. Bakan Koca: Şu anki şartlarda salgın kontrol altında. Available at: https://www.aa.com.tr/tr/koronavirus/bakan-koca-su-anki-sartlarda-salgin-kontrol-altinda/1839636 [Accessed May 13, 2020].

  • 34. Liu Y, Eggo RM, Kucharski AJ. Secondary attack rate and superspreading events for SARS-CoV-2. Lancet 2020; 395(10227): e47.

  • 35. Wu J, Huang Y, Tu C, Bi C, Chen Z, Luo L, et al. Household Transmission of SARS-CoV-2, Zhuhai, China, 2020. Clin Infect Dis 2020. pii: ciaa557. [Epub ahead of print].

  • 36. Fiebelkorn AP, Goodson JL. Measles (rubeola). In: Brunette GW (ed), CDC Health Information for International Travel 2014: The Yellow Book. 2014, Oxford University Press, New York. pp:249-52.

  • 37. World Health Organization (WHO), Geneva, Switzerland. New influenza A (H1N1) virus: global epidemiological situation, June 2009. Available at: https://www.who.int/wer/2009/wer8425.pdf?ua=1 [Accessed April 26, 2020].

  • 38. Drosten C, Meyer B, Müller MA, Corman VM, Al-Masri M, Hossain R, et al. Transmission of MERS-coronavirus in household contacts. N Engl J Med 2014; 371(9): 828‐35.

  • 39. Van Kerkhove MD, Alaswad S, Assiri A, Perera R APM, Peiris M, El Bushra HE, et al. Transmissibility of MERS-CoV Infection in Closed Setting, Riyadh, Saudi Arabia, 2015. Emerg Infect Dis. 2019; 25(10): 1802‐9.

  • 40. Society of Pediatrics, Chinese Medical Association; Editorial Board, Chinese Journal of Pediatrics. Recommendations for the diagnosis, prevention and control of the 2019 novel coronavirus infection in children (first interim edition). Zhonghua Er Ke Za Zhi 2020; 58(3): 169-74.

  • 41. Zimmermann P, Curtis N. COVID-19 in Children, Pregnancy and Neonates: A Review of Epidemiologic and Clinical Features. Pediatr Infect Dis J 2020; 39(6): 469-77.

  • 42. Novel Coronavirus Pneumonia Emergency Response Epidemiology Team. The epidemiological characteristics of an outbreak of 2019 novel coronavirus diseases (COVID-19) in China [Chinese Center for Disease Control and Prevention]. Zhonghua Liu Xing Bing Xue Za Zhi 2020; 41: 145-51.

  • 43. Kim SE, Jeong HS, Yu Y, Shin SU, Kim S, Oh TH, et al. Viral kinetics of SARS-CoV-2 in asymptomatic carriers and presymptomatic patients. Int J Infect Dis 2020. pii: S1201-9712(20)30299-X.

  • 44. Casey M, Griffin J, McAloon CG, Byrne AW, Madden JM, McEvoy D, et al. Estimating pre-symptomatic transmission of COVID19: a secondary analysis using published data. MedRxiv 2020.

  • 45. de Wit E, van Doremalen N, Falzarano D, Munster VJ. Nat Rev Microbiol 2016; 14(8): 523-34.

  • 46. Zhou Q, Gao Y, Wang H, Liu R, Du P, Wang X, et al. Nosocomial Infections Among Patients with COVID-19, SARS and MERS: A Rapid Review and Meta-Analysis. medRxiv 2020.04.14.20065730.

  • 47. Wang J, Feng H, Zhang S, Ni Z, Ni L, Chen Y, et al. SARS-CoV-2 RNA detection of hospital isolation wards hygiene monitoring during the Coronavirus Disease 2019 outbreak in a Chinese hospital. Int J Infect Dis 2020; 94: 103-6.

  • 48. Liu Y, Ning Z, Chen Y, Guo M, Liu Y, Gali NK, et al. Aerodynamic analysis of SARS-CoV-2 in two Wuhan hospitals. Nature 2020. [Epub ahead of print].

  • 49. Zhou P, Yang XL, Wang XG, Hu B, Zhang L, Zhang W, et al. A pneumonia outbreak associated with a new coronavirus of probable bat origin. Nature 2020; 579(7798): 270-3.

  • 50. World Health Organization (WHO), Geneva, Switzerland. Summary of probable SARS cases with onset of illness from November 1, 2002 to July 31, 2003. Available at: https://www.who.int/csr/sars/country/table2004_04_21/en/ [Accessed April 18, 2020].

  • 51. World Health Organization (WHO), Geneva, Switzerland. Middle East respiratory syndrome coronavirus (MERS-CoV). Available at: http://applications.emro.who.int/docs/EMRPUB-CSR-241-2019-EN.pdf?ua=1&ua=1&ua=1 [Accessed April 26, 2020].

  • 52. Gollakner R, Capua I. Is COVID-19 the first pandemic that evolves into a panzootic?. Vet Ital 2020; 56(1): 7‐8.

  • 53. Halfmann PJ, Hatta M, Chiba S, Chiba S, Maemura T, Fan S, et al. Transmission of SARS-CoV-2 in Domestic Cats. N Engl J Med 2020; [Epub ahead of print].

  • 54. Leroy EM, Ar Gouilh M, Brugère-Picoux J. The risk of SARS-CoV-2 transmission to pets and other wild and domestic animals strongly mandates a one-health strategy to control the COVID-19 pandemic. One Health 2020; 100133. [Epub ahead of print].

  • 55. Shi J, Wen Z, Zhong G, Yang H, Wang C, Huang B, et al. Susceptibility of ferrets, cats, dogs, and other domesticated animals to SARS-coronavirus 2. Science 2020; eabb7015.

  • 56. Zhang Q, Zhang H, Huang K, Yang Y, Hui X, Gao J, et al. SARS-CoV-2 neutralizing serum antibodies in cats: a serological investigation. bioRxiv 2020.04.01.021196.

  • 57. Gryseels S, De Bruyn L, Gyselings R, Calvignac-Spencer S, Leendertz F, Leirs H. Risk of Human-to-Wildlife Transmission of SARS-CoV-2. Preprints 2020, 2020050141.

  • 58. Kim YI, Kim SG, Kim SM, Kim EH, Park SJ, Yu KM, et al. Infection and Rapid Transmission of SARS-CoV-2 in Ferrets. Cell Host Microbe 2020; 27(5): 704‐9.e2.

  • 59. Wan Y, Shang J, Graham R, Baric RS, Li F. Receptor Recognition by the Novel Coronavirus from Wuhan: an Analysis Based on Decade-Long Structural Studies of SARS Coronavirus. J Virol 2020; 94(7): e00127-20.

  • 60. Dowell SF, Ho MS. Seasonality of infectious diseases and severe acute respiratory syndrome-what we don't know can hurt us. Lancet Infect Dis 2004; 4(11): 704‐8.

  • 61. Monto AS, DeJonge P, Callear AP, Bazzi LA, Capriola S, Malosh RE, et al. Coronavirus occurrence and transmission over 8 years in the HIVE cohort of households in Michigan. J Infect Dis 2020; jiaa161. [Epub ahead of print].

  • 62. International Committee on Taxonomy of Viruses, Washington, DC. ICTV reports; Coronaviridae. Available at: https://talk.ictvonline.org/ictv-reports/ictv_9th_report/positive-sense-rna-viruses-2011/w/posrna_viruses/222/coronaviridae [Accessed March 30, 2020].

  • 63. Gaunt ER, Hardie A, Claas EC, Simmonds P, Templeton KE. Epidemiology and clinical presentations of the four human coronaviruses 229E, HKU1, NL63, and OC43 detected over 3 years using a novel multiplex real-time PCR method. J Clin Microbiol 2010; 48(8):2940-7.

43
51
views
downloads
Views 43
Downloads 51
Data volume 36.3 MB
Unique views 39
Unique downloads 48

Share

Cite as