Prof. Khitam Muhsen

Professor, Department of Epidemiology and Preventive Medicine, School of Public Health, Tel Aviv University

Prof. Muhsen started her career as a pediatric and public health nurse in Arab villages in Northern Israel. In 2005, she completed her Master's degree in Epidemiology and Preventive Medicine (with distinction) and in 2011, she completed her Ph.D. degree (Mentor Prof. Daniel Cohen). Prof. Muhsen completed a 2-year (2011-2013) postdoctoral fellowship at the Center for Vaccine Development at the University of Maryland School of Medicine (MD, USA) under the mentorship of Prof. Myron M. Levine.

Prof. Muhsen joined the School of Public Health in October 2013 as a Senior Lecturer and established her research group and laboratory. In 2018, she received tenure and was promoted to Associate Professor. In 2023, she was promoted to Full Professor.

As of September 2023, Prof. Khitam Muhsen was appointed as the Head of the Department of Epidemiology and Preventive Medicine at the School of Public Health, Tel Aviv University.

• Epidemiology of infectious disease
• Helicobacter pylori, enteric infections, the gut microbiome and their role in health and disease
• Sero-epidemiological studies
• Health disparities
• Antibiotic resistance
• Vaccine epidemiology

My main research fields is the epidemiology of infectious disease, including the assessment of disease burden, risk factors and populations' exposure to various pathogens, utilization sero-epidemiological tools.

Helicobacter pylori infection is acquired during early childhood. It causes chronic gastritis, which mostly remains asymptomatic; however in a small portion of the infected people H. pylori causes peptic ulcers and gastric cancer. Our current research focuses on the role of H. pylori in extragastric diseases such as iron deficiency anemia, cognitive function, and diabetes mellitus. The epidemiology of enteric infections in various populations consists of an additional main research area in our group. Nowadays, we also assess the role of the gut microbiome in children's health and development, including cardiometabolic health and the role of nutrition and lifestyle in these associations.

Our research involves population-based studies in which we integrate various epidemiological and biostatistical methods, as well as biological markers assessed by immunological, microbiological and molecular tools.

During the COVID-19 pandemic, Prof. Muhsen led several epidemiological studies in the Israeli population to assess the acquisition and transmission of the infection in populations at risk, as well as the effectiveness of COVID-19 vaccines in real-life and COVID-19 vaccine hesitancy.

Click here for a complete list of Prof. Muhsen's Peer-Reviewed Articles.

Selected Publications (More recent to less recent):

1. Mari A, Na'amnih W, Ghantous L, Ahmad HS, Khoury T, Muhsen K. Quality of life and severity of symptoms among patients with various degrees of reflux esophagitis: a prospective study. Sci Rep. 2023;13(1):13970. doi: 10.1038/s41598-023-41332-w. PMID: 37634042.

2. Lapidot Y, Maya M, Reshef L, Cohen D, Ornoy A, Gophna U, Muhsen K. Relationships of the gut microbiome with cognitive development among healthy school-age children. Front Pediatr. 2023;11:1198792. doi:10.3389/fped.2023.1198792. PMID: 37274812.

3. Cohen D, Izak M, Stoyanov E, Mandelboim M, Perlman S, Amir Y, Goren S, Bialik A, Kliker L, Atari N, Yshai R, Zaide Y, Marcus H, Madar-Balakirski N, Israely T, Paran N, Zimhony O, Shinar E, Maor Y, Muhsen K. Predictors of reinfection with pre-Omicron and Omicron variants of concern among individuals who recovered from COVID-19 in the first year of the pandemic. Int J Infect Dis. 2023;132:72-79. doi: 10.1016/j.ijid.2023.04.395. PMID:37072052.

4. Donkor ES, Muhsen K, Johnson SAM, Kotey FCN, Dayie NTKD, Tetteh-Quarcoo PB, Tette EMA, Osei MM, Egyir B, Nii-Trebi NI, Owusu-Okyere G, Owusu-Ofori A, Amir Y, Perlman S, Lopes PH, Mfodwo A, Gordon NC, Gresham L, Smolinski M, Cohen D. Multicenter surveillance of antimicrobial resistance among Gram-negative bacteria isolated from bloodstream infections in Ghana. Antibiotics (Basel). 2023;12(2):255. doi: 10.3390/antibiotics12020255. PMID: 36830166.

5. Shitrit P, Chowers MY, Muhsen K. The development and validation of screening tools for semi-automated surveillance of surgical site infection following various surgeries. Front Med (Lausanne). 2023;10:1023385. doi:10.3389/fmed.2023.1023385. PMID: 36778736.

6. Kassem E, Na'amnih W, Shapira M, Ornoy A, Muhsen K. Comparison between school-age children with and without obesity in nutritional and inflammation biomarkers. J Clin Med. 2022;11(23):6973. doi: 10.3390/jcm11236973. PMID:36498548.

7. Na'amnih W, Akawi A, Abu-Moch A, Cohen R, Dror G, Kassem E, Muhsen K, Ornoy A. Associations of early-life exposures and socioeconomic status with cognitive development at preadolescence. Pediatr Neonatol. 2023;64(2):192-200. doi: 10.1016/j.pedneo.2022.06.015. PMID: 36357285.

8. Israel Y, Muhsen K, Rokney A, Adler A. Epidemiological and clinical characteristics of non-typhoidal Salmonella bloodstream infections in central Israel: A Case-Control Study. Microorganisms. 2022;10(10):1942.doi: 10.3390/microorganisms10101942. PMID: 36296218.

9. Cohen D, Ashkenazi S, Schneerson R, Farzam N, Bialik A, Meron-Sudai S, Asato V, Goren S, Baran TZ, Muhsen K, Gilbert PB, MacLennan CA. Threshold protective levels of serum IgG to Shigella lipopolysaccharide: re-analysis of Shigella vaccine trials data. Clin Microbiol Infect. 2023;29(3):366-371. doi:10.1016/j.cmi.2022.10.011. PMID: 36243351.

10. Muhsen K, Maimon N, Mizrahi AY, Varticovschi B, Bodenheimer O, Cohen D, Dagan R. Association of BNT162b2 vaccine third dose receipt with incidence of SARS-CoV-2 infection, COVID-19-related hospitalization, and death among residents of long-term care facilities, August to October 2021. JAMA Netw Open. 2022;5(7):e2219940. doi: 10.1001/jamanetworkopen.2022.19940. PMID:35796153.

11. Muhsen K, Maimon N, Mizrahi AY, Boltyansky B, Bodenheimer O, Diamant ZH, Gaon L, Cohen D, Dagan R. Association of receipt of the fourth BNT162b2 dose with Omicron infection and COVID-19 hospitalizations among residents of long-term care facilities. JAMA Intern Med. 2022;182(8):859-867 doi:10.1001/jamainternmed.2022.2658. PMID: 35737368.

12. Mari A, Na'amnih W, Gahshan A, Ahmad HS, Khoury T, Muhsen K. Comparison in adherence to treatment between patients with mild-moderate and severe reflux esophagitis: A Prospective Study. J Clin Med. 2022;11(11):3196. doi:10.3390/jcm11113196. PMID: 35683583.

13. Gazit S, Shlezinger R, Perez G, Lotan R, Peretz A, Ben-Tov A, Herzel E, Alapi H, Cohen D, Muhsen K, Chodick G, Patalon T. Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) naturally acquired immunity versus vaccine-induced immunity, reinfections versus breakthrough infections: a retrospective cohort study. Clin Infect Dis. 2022;75(1):e545-e551. doi:10.1093/cid/ciac262. PMID: 35380632.

14. Lapidot Y, Reshef L, Maya M, Cohen D, Gophna U, Muhsen K. Socioeconomic disparities and household crowding in association with the fecal microbiome of school-age children. NPJ Biofilms Microbiomes. 2022;8(1):10. doi:10.1038/s41522-022-00271-6. PMID: 35241676.

15. Gazit S, Shlezinger R, Perez G, Lotan R, Peretz A, Ben-Tov A, Herzel E, Alapi H, Cohen D, Muhsen K, Chodick G, Patalon T. The incidence of SARS-CoV-2 reinfection in persons with naturally acquired immunity with and without subsequent receipt of a single dose of BNT162b2 vaccine : a retrospective cohort study. Ann Intern Med. 2022;175(5):674-681. doi: 10.7326/M21-4130. PMID: 35157493.

16. Badran Abu Zher L, Weil M, Kassem E, Elias N, Levine MM, Muhsen K. Relationship between Helicobacter pylori IgG seroprevalence and the immune response to poliovirus vaccine among school-age children from a population with near-universal immunity level. Front Med (Lausanne). 2022;8:797719. doi: 10.3389/fmed.2021.797719. PMID: 35127752.

17. Na'amnih W, Kassem E, Tannous S, Kagan V, Jbali A, Hanukayev E, Freimann S, Obolski U, Muhsen K. Incidence and risk factors of hospitalisations for respiratory syncytial virus among children aged less than 2 years. Epidemiol Infect. 2022;150:e45. doi: 10.1017/S0950268822000152. PMID: 35105415.

18. Muhsen K, Maimon N, Mizrahi A, Varticovschi B, Bodenheimer O, Gelbshtein U, Grotto I, Cohen D, Dagan R. Effects of BNT162b2 Covid-19 vaccine booster in long-term care facilities in Israel. N Engl J Med. 2022;386(4):399-401.doi: 10.1056/NEJMc2117385. PMID: 34936758.

19. Obolski U, Kassem E, Na'amnih W, Tannous S, Kagan V, Muhsen K. Unnecessary antibiotic treatment of children hospitalised with respiratory syncytial virus (RSV) bronchiolitis: risk factors and prescription patterns. J Glob Antimicrob Resist. 2021;27:303-308. doi: 10.1016/j.jgar.2021.10.015. PMID: 34718202.

20. Muhsen K, Maimon N, Mizrahi A, Bodenheimer O, Cohen D, Maimon M, Grotto I, Dagan R. Effectiveness of BNT162b2 mRNA Coronavirus Disease 2019 (COVID-19) vaccine against acquisition of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) among healthcare workers in long-term care facilities: a prospective cohort study. Clin Infect Dis. 2022;75(1):e755-e763. doi:10.1093/cid/ciab918. PMID: 34698808.

21. Lapidot Y, Reshef L, Cohen D, Muhsen K. Helicobacter pylori and the intestinal microbiome among healthy school-age children. Helicobacter. 2021;26(6):e12854. doi: 10.1111/hel.12854. PMID: 34617641.

22. Mevorach D, Anis E, Cedar N, Bromberg M, Haas EJ, Nadir E, Olsha-Castell S, Arad D, Hasin T, Levi N, Asleh R, Amir O, Meir K, Cohen D, Dichtiar R, Novick D, Hershkovitz Y, Dagan R, Leitersdorf I, Ben-Ami R, Miskin I, Saliba W, Muhsen K, Levi Y, Green MS, Keinan-Boker L, Alroy-Preis S. Myocarditis after BNT162b2 mRNA Vaccine against Covid-19 in Israel. N Engl J Med. 2021;385(23):2140-2149. doi: 10.1056/NEJMoa2109730. PMID: 34614328.

23. Lapidot Y, Reshef L, Goldsmith R, Na'amnih W, Kassem E, Ornoy A, Gophna U, Muhsen K. The associations between diet and socioeconomic disparities and the intestinal microbiome in preadolescence. Nutrients. 2021;13(8):2645. doi: 10.3390/nu13082645. PMID: 34444813.

24. Iflah M, Kassem E, Rubinstein U, Goren S, Ephros M, Cohen D, Muhsen K. Convulsions in children hospitalized for acute gastroenteritis. Sci Rep. 2021;11(1):15874. doi: 10.1038/s41598-021-95202-4. PMID: 34354134.

25. Muhsen K, Schwaber MJ, Bishara J, Kassem E, Atamna A, Na'amnih W, Goren S, Bialik A, Mohsen J, Zaide Y, Hazan N, Ariel-Cohen O, Cohen R, Shitrit P, Marchaim D, Benenson S, Ben-David D, Rubinovitch B, Gotessman T, Nutman A, Wiener-Well Y, Maor Y, Carmeli Y, Cohen D. Sero-prevalence and sero-incidence of antibodies to SARS-CoV-2 in healthcare workers in Israel, prior to mass COVID-19 vaccination. Front Med (Lausanne). 2021;8:689994. doi:10.3389/fmed.2021.689994. PMID: 34249979.

26. Muhsen K, Na'amnih W, Goldsmith R, Maya M, Zeidan N, Kassem E, Ornoy A. Associations of feeding practices in early life and dietary intake at school age with obesity in 10- to 12-year-old Arab children. Nutrients. 2021;13(6):2106. doi: 10.3390/nu13062106. PMID: 34205416.

27. Peer V, Muhsen K, Betser M, Green MS. Antibody response to pertussis vaccination in pregnant and non-pregnant women-the role of sex hormones. Vaccines (Basel). 2021;9(6):637. doi: 10.3390/vaccines9060637. PMID:34200795.

28. Haj S, Chodick G, Goren S, Na'amnih W, Shalev V, Muhsen K. Differences in glycated hemoglobin levels and cholesterol levels in individuals with diabetes according to Helicobacter pylori infection. Sci Rep. 2021;11(1):8416.doi: 10.1038/s41598-021-87808-5. PMID: 33875700.

29. Muhsen K, Sow SO, Tapia MD, Haidara FC, Reymann M, Asato V, Chen WH, Pasetti MF, Levine MM. Pre-existing Helicobacter pylori serum IgG enhances the vibriocidal antibody response to CVD 103-HgR live oral cholera vaccine in Malian adults. Sci Rep. 2020;10(1):16871. doi: 10.1038/s41598-020-71754-9. PMID: 33037244.

30. Elias N, Nasrallah E, Khoury C, Mansour B, Abu Zuher L, Asato V, Muhsen K. Associations of Helicobacter pylori seropositivity and gastric inflammation with pediatric asthma. Pediatr Pulmonol. 2020;55(9):2236-2245. doi:10.1002/ppul.24905. PMID: 32543787.

31. Na'amnih W, Ben Tov A, Bdair-Amsha A, Cohen S, Tsamir J, Chodick G, Muhsen K. Physicians' adherence to management guidelines for H. pylori infection and gastroesophageal reflux disease: a cross-sectional study. Isr J Health Policy Res. 2020;9(1):28. doi: 10.1186/s13584-020-00389-y. PMID: 32527326.

32. Muhsen K, Na'amnih W, Adler A, Carmeli Y, Cohen D. Clostridium difficile-associated disease and Helicobacter pylori seroprevalence: a case-control study. Helicobacter. 2020;25(1):e12668. doi: 10.1111/hel.12668. PMID: 31721371.

33. Muhsen K, Sinnereich R, Beer-Davidson G, Nassar H, Abu Ahmed W, Cohen D, Kark JD. Correlates of infection with <i>Helicobacter pylori positive and negative cytotoxin-associated gene A phenotypes among Arab and Jewish residents of Jerusalem. Epidemiol Infect. 2019;147:e276. doi: 10.1017/S0950268819001456. PMID: 31552815.

34. Ben Tov A, Na'amnih W, Bdair-Amsha A, Cohen S, Tzamir J, Chodick G, Muhsen K. A survey of primary-care pediatricians regarding the management of Helicobacter pylori infection and celiac disease. Isr J Health Policy Res. 2019;8(1):88. doi: 10.1186/s13584-019-0357-x. PMID: 31882019.

As a senior faculty member

• Publication Award, 2021, Faculty of Medicine, Tel Aviv University
• Dean's outstanding lecturer, 2018-2019, Faculty of Medicine, Tel Aviv University
• Tel University President Award for promoting women's education in minority groups, 2019
• Recognition award, Faradis municipal council, 2019 Women's Day
• Publication Award, 2017, Faculty of Medicine, Tel Aviv University
• Dean's outstanding teacher, 2016-2017, Faculty of Medicine, Tel Aviv University
• Dean's outstanding teacher, 2014-2015, Faculty of Medicine, Tel Aviv University 
• MAOF Award, Israel Council for Higher Education, 2013-2016 (Full-time salary support as a Senior Lecturer and a research grant)

As a post-doctoral fellow

• Rothschild post-doctoral scholarship - Yad Hanadiv Foundation, Israel

As a PhD student

• PhD Scholarship, Dan David Foundation, Israel
• PhD Scholarship for distinct Israeli Arab PhD students, Council of Higher Education and Ministry of Science, Technology and Sport, Israel