Clinical and epidemiological structure of imported infectious diseases in Moscow

The expansion of international tourism and increasing migration have led to a higher risk of the emergence and spread of various infectious diseases, including those that are not endemic to Russia. Therefore, studying the characteristics of infectious diseases in children and adults returning from international travel is of considerable importance.

Objective. To analyze the clinical and epidemiological characteristics of imported infectious diseases in children and adults after international travel.

Materials and Methods. We conducted a single-center retrospective cohort study at Infectious Clinical Hospital No. 1 of the Moscow Department of Health. Medical records of 2005 adults and 501 children who developed illness during or after international travel and were admitted to the hospital’s isolation ward after returning from abroad between 2009 and 2019 were retrospectively reviewed. Statistical analysis was performed using IBM SPSS Statistics version 26.0.

Results. The age of the study participants ranged from 1 month to 86 years. Among hospitalized patients, children 1–3 years accounted for the largest proportion (41.9 %). Children were hospitalized more frequently during the summer (176 cases, 35.1 %; p<0.001) and autumn (139 (27,7; 23,6-31,6), p<0,05), whereas adults were more commonly hospitalized in the winter (496 cases, 24.7 %; p<0.001) and in the spring (526 (26,2; 24,5–28,1), p<0,05). In the epidemiological history, travel to the Republic of Türkiye was most common among children (17.0 %), while travel to the Kingdom of Thailand predominated among adults (24.9 %). Compared with adults, children were more frequently diagnosed with enterovirus infection (37.0 % vs 19.2 %, p<0.001) among infections with a fecal-oral transmission route, and pertussis (1.5 % vs 0.1 %, p<0.05) among infections with an airborne transmission route. Among children, dengue fever was the most frequently diagnosed vector-borne infection (88.9 %).

Conclusion. We identified the epidemiological characteristics and etiological structure of imported infectious diseases and demonstrated seasonal, geographic, and nosological differences in infectious diseases among children compared with adults after international travel.

1. World Tourism Organization, International Tourism Highlights, 2023 Edition — The impact of COVID-19 on tourism (2020–2022). 2023. UNWTO, Madrid, DOI: 10.18111/9789284424986.

2. GeoSentinel. Official website. https://geosentinel.org/ Ссылка активна на 30.06.2026.

3. ISTM. Official website. https://www.istm.org/ Ссылка активна на 30.06.2026).

4. Hamer D.H., Rizwan A., Freedman D.O., Kozarsky P., Libman M. GeoSentinel: past, present and future. J Travel Med. 2020; 27(8):t aaa219. DOI: 10.1093/jtm/taaa219.

5. Osman S., Preet R. Dengue, chikungunya and Zika in GeoSentinel surveillance of international travellers: a literature review from 1995 to 2020. J Travel Med. 2020; 27(8): taaa222. DOI: 10.1093/jtm/taaa222.

6. Turizm v Rossii. Statisticheskie dannye. (in Russ.). https://ps.rosstat.gov.ru/tourism/Ссылка активна на 30.06.2026.

7. On the state of the sanitary and epidemiological well-being of the population in the Russian Federation in 2024: State report. Moscow: Federal Service for Surveillance on Consumer Rights Protection and Human Well-being.. 2025; 424 (in Russ.).

8. Zvereva N.N., Pylaeva E.Yu., Erovichenkov A.A., Sayfullin M.A., Elagina T.N., Tovstik V.A. et al. Awareness of Russian tourists traveling to tropical and equatorial countries about the prevention of infectious diseases during travel. Detskie Infektsii = Children’s Infections.2023; 22(1):19-26. (in Russ.) DOI: 10.22627/2072-8107-2023-22-1-19-26

9. Weinberg M., Hickey P.W. Traveling Safely with Infants and Children. In: Centers for Disease Control and Prevention. CDC Yellow Book: Health Information for International Travel. Atlanta: U.S. Department of Health and Human Services, Public Health Service; 2025. URL: https://www.cdc.gov/yellow-book/hcp/family-travel/traveling-safely-with-infants-and-children.html/Ссылка активна на 30.06.2026.

10. Weinberg M., Mitchell T. Travel Vaccine Recommendations for Infants and Children. In: Centers for Disease Control and Prevention. CDC Yellow Book: Health Information for International Travel. 2026 ed. Atlanta: U.S. Department of Health and Human Services, Public Health Service; 2025. https://www.cdc.gov/yellow-book/hcp/family-travel/travelvaccine-recommendations-for-infants-and-children.html/ Ссылка активна на 30.06.2026.

11. Prikaz Departamenta zdravoohraneniya goroda Moskvy ot 19 sentyabrya 2017 g. № 675 “Ob obespechenii meropriyatij po preduprezhdeniyu zanosa i rasprostraneniya infekcionnyh (parazitarnyh) boleznej, trebuyushchih provedeniya meropriyatij po sanitarnoj ohrane territorii goroda Moskvy”(in Russ.). https://base.garant.ru/49611834/ Ссылка активна на 30.06.2026

12. Prikaz Departamenta zdravoohraneniya goroda Moskvy ot 13 fevralya 2015 g. № 97 «Ob obespechenii meropriyatij po preduprezhdeniyu zanosa i rasprostraneniya infekcionnyh (parazitarnyh) boleznej, trebuyushchih provedeniya meropriyatij po sanitarnoj ohrane territorii goroda Moskvy»(in Russ.). https://base.garant.ru/70974480/ Ссылка активна на 30.06.2026

13. Prikaz Departamenta zdravoohraneniya goroda Moskvy ot 18.10.2010 № 1850 «Ob obespechenii meropriyatij po preduprezhdeniyu zanosa i rasprostraneniya infekcionnyh (parazitarnyh) boleznej, trebuyushchih provedeniya meropriyatij po sanitarnoj ohrane territorii goroda Moskvy» (in Russ.). https://base.garant.ru/396132/Ссылка активна на 30.06.2026

14. Erovichenkov A.A., Zvereva N.N., Sayfullin M.A. Okolot N.V. Prevention of Imported Infectious Diseases in Travelers. Epidemiology and Vaccinal Prevention. 2018; 17(5): 89–95 (in Russ.) DOI: 10.31631/2073-3046-2018-17-5-89-95

15. Zvereva N.N., Saifullin M.A., Sayfullin R.F., Erovichenkov A.A., Bazarova M.V., Pshenichnaya N.Yu. Epidemiological and etiological features of travel-related febrile illnesses in hospitalized Russian children and adults: A single-centre, retrospective analysis in Moscow. Travel Medicine and Infectious Disease. 2020; 34: 101447. DOI: 10.1016/j.tmaid.2019.07.003.

16. Sayfullin M.A., Zvereva N.N., Pylaeva E.Yu., Smetanina S.V., Larichev V.Ph., Karan L.S., et al. Chikungunya fever in a child after visiting Thailand. Pediatria n.a. G.N. Speransky. 2020; 99 (6): 271–275 (in Russ.).

17. Saifullin M.A., Kelly E.I., Bazarova M.V., Larichev V.F., Karan L.S., Akinshina Yu.A. et al. Dengue fever fatal case Epidemiologiya i Infektsionnye Bolezni. 2015; 20(2): 49–51 (in Russ.). DOI: https://doi.org/10.17816/EID40879.

18. Sayfullin M.A., Karan’ L.S., Zvereva N.N., Bazarova M.V. Imported tick-borne rickettsioses in Moscow in 2005–2016. Infectious Diseases: News, Opinions, Training. 2017;(2):67–72 (in Russ.).

19. Petrova I.S., Muravev O.B., Kuzmenko T.N., Sayfullin M.A., Boytsov P.V., Larichev V.F., et al. The case of imported Japanese encephalitis (JE) in a Russian traveler (2014). Epidemiologiya i Infektsionnye Bolezni. 2014; 19 (4): 60–62 (in Russ.).

20. Elliott K.C., Mattapallil J.J. Zika Virus-A Reemerging Neurotropic Arbovirus Associated with Adverse Pregnancy Outcomes and Neuropathogenesis. Pathogens. 2024; 13(2): 177. DOI: 10.3390/pathogens13020177.