Tamar Grossman

Dr. Tamar Grossman

orcid

Research Focus & Metrics

Academic Career Length

14Years (2013-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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22 August 2023 in Journal of Travel Medicine
Verified
Journal Article
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TGTamar Grossman
Tamar Grossman
JVJulia Vainer
Julia Vainer
YPYael Paran
Yael Paran
LSLiora Studentsky
Liora Studentsky
UMUri Manor
Uri Manor
ESEli Schwartz
Eli Schwartz
Artemisinin-based combination therapies (ACTs) are recommended as first-line treatment against uncomplicated P. falciparum infection. Emergence of mutations in the PfKelch13 propeller domain has resulted in resistance to artemisinin in Southeast Asia. Mutations in Pfcoronin propeller domain confer reduced artemisinin susceptibility in vitro to an African Plasmodium strain, but their role in clinical resistance has not been established. We conducted a retrospective observational study of Israeli travellers returning from Sub-Saharan Africa with P. falciparum malaria, including patients with artemether-lumefantrine failure. Blood samples from all malaria-positive returning travellers are delivered to the national Parasitology Reference Laboratory along with personal information. Confirmation of malaria, species identification and comparative parasite-load analysis were performed using real-time PCR. DNA extractions from stored leftover samples were analysed for the presence of mutations in the Pfkelch13 (PF3D7_1343700) and Pfcoronin (PF3D7_1251200) genes. Age, weight, initial parasitemia level and Pfcoronin status were compared in patients who failed treatment versus responders. During 2009–2020, 338 patients had P. falciparum malaria acquired in Africa. Of those, 15 (24–69 years old, 14 males) failed treatment with artemether-lumefantrine. Four were still parasitemic at the end of treatment and 11 had malaria recrudescence. Treatment failure rates were 0% during 2009–2012, 9.1% during 2013–2016 and 17.4% during 2017–2020. In all patients the Pfkelch13 propeller domain had wild-type sequence. We did find the P76S mutation in the propeller domain of Pfcoronin in 4/15 (28.6%) of the treatment-failure cases compared to only 3/56 (5.5%) in the successfully treated patients (p = 0.027). The emergence of artemether-lumefantrine treatment failure was not associated with mutations in Pfkelch13. However, P76S mutation in the Pfcoronin gene was more frequently present in the treatment-failure group and merits further investigation. The increase of malaria incidence in Sub-Saharan-Africa partly attributed to the COVID-19 pandemic might also reflect a wider spread of ACT resistance.

3 July 2019 in The American Journal of Tropical Medicine and Hygiene
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Journal Article
Closed access
ESEfrat Golan Shaposhnik
Efrat Golan Shaposhnik
SASaid Abozaid
Said Abozaid
TGTamar Grossman
Tamar Grossman
EMEsther Marva
Esther Marva
AOAvi On
Avi On
Avi PeretzAvi Peretz
Avi Peretz
Cryptosporidium is a parasite that causes watery diarrhea among both children and adults. However, because many physicians do not routinely ask for Cryptosporidium diagnostic test, cryptosporidiosis prevalence is likely underestimated. The current study investigated the prevalence of cryptosporidiosis among children admitted to the hospital with gastrointestinal symptoms. Stool sample was collected from each child and subjected to routine microbiological culture. Cryptosporidium presence was tested by three different methods: real-time PCR (RT-PCR), quick antigen, and microscopic examination with acid-fast staining. Each positive specimen was further tested with BioFire FilmArray Multiplex PCR (bioMérieux SA, Marcy-l'Etoile, France) to determine that Cryptosporidium is the only pathogen in the sample. Demographic and epidemiological data were collected from the patients’ medical records. Of 291 patient stool samples, nine were positive for Cryptosporidium hominis or Cryptosporidium parvum. The average age of the nine Cryptosporidium-positive cases was 2.3 years, lower than the average age of the study population (4.2 years). Of the positive cases, 66.7% were Arabs and 33.3% were Jews. The main complaint of children with Cryptosporidium was diarrhea. Regarding the laboratory methods for Cryptosporidium identification, of the positive samples, 100% (9/9) were identified by RT-PCR, 88% (8/9) were positive by antigen test, and only 67% (6/9) were positive by microscopic examination with acid-fast staining. Because of the low incidence of Cryptosporidium among patients in our facility, the prevalence of cryptosporidiosis still cannot be established. Nevertheless, among the other pathogens found in stool samples, Cryptosporidium is the second leading cause of hospitalization due to gastrointestinal disease in children in our area.

3 September 2019 in PLOS ONE
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Journal Article
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TGTamar Grossman
Tamar Grossman
SKShifra Ken-Dror
Shifra Ken-Dror
EPElsa Pavlotzky
Elsa Pavlotzky
JVJulia Vainer
Julia Vainer
YGYael Glazer
Yael Glazer
LVLea Valinsky
Lea Valinsky
Cryptosporidium is a protozoan parasite associated with gastrointestinal illness. In immune-compromised individuals, the infection may become life-threatening. Cryptosporidiosis is a mandatory-reported disease but little was known about its prevalence and associated morbidity in Israel. Currently, laboratory diagnosis is based on microscopy or copro-antigen tests and the disease is underreported. Molecular assays, which are more sensitive and specific, are now increasingly used for identification and screening. Here, the molecular epidemiology of cryptosporidiosis is explored for the first time. Samples from 33 patients infected during an outbreak of 146 laboratory confirmed cases that occurred in Haifa and Western Galilee in 2015 were genotyped, as well as samples from 36 patients sporadically infected during 2014–2018 in different regions. The results suggest that Cryptosporidium subtypes found in Israel are more similar to those reported in the neighboring countries Jordan and Egypt than in European countries. C. hominis was the predominant species in the center and the north of Israel, implicating human-to-human transmission. C. hominis IeA11G3T3 was the most prevalent subtype contributing to morbidity.

13 December 2016 in European Journal of Clinical Microbiology & Infectious Diseases
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Journal Article
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TGTamar Grossman
Tamar Grossman
ESE. Schwartz
E. Schwartz
JVJ. Vainer
J. Vainer
VAV. Agmon
V. Agmon
YGY. Glazer
Y. Glazer
EME. Marva
E. Marva

9 September 2013 in Clinical Infectious Diseases
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Journal Article
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TLTamar Lachish
Tamar Lachish
MTMoshik Tandlich
Moshik Tandlich
TGTamar Grossman
Tamar Grossman
Eli SchwartzEli Schwartz
Eli Schwartz
Travel-related schistosomiasis is usually associated with prolonged freshwater exposure. Until recently, Uganda's crater lakes were considered schistosomiasis free due to their high-altitude location. We describe an outbreak of acute schistosomiasis after a brief exposure (mean, 22 ± 9.5 minutes) to a high-altitude crater lake.

22 November 2018 in Journal of Medical Case Reports
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Journal Article
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RCRegev Cohen
Regev Cohen
TFTalya Finn
Talya Finn
FBFrida Babushkin
Frida Babushkin
MSMaurice Shapiro
Maurice Shapiro
MUMartina Uda
Martina Uda
TGTamar Grossman
Tamar Grossman
We describe a patient with Strongyloides stercoralis hyperinfection associated with Streptococcus pyogenes and with streptococcal toxic shock syndrome. To the best of our knowledge this association has not been previously described. A 78 year-old Israeli man, who was born in Iraq but lived in Israel for 66 years, presented with multi-organ failure including acute kidney and hepatic injury, coagulopathy, and lactic acidosis. He had a medical history including aortic valve replacement, diabetes mellitus, spinal stenosis, and low back pain treated with repeated local steroid injections. Blood cultures were positive for Streptococcus pyogenes and antibiotic treatment was switched to penicillin G, clindamycin, and intravenous immunoglobulins. Repeated physical examinations failed to identify the source of the bacteremia. On day 12 of hospitalization the serology results for Strongyloides stercoralis sent on admission, because of chronic eosinophilia, came back positive. A microscopic stool examination and stool polymerase chain reaction were positive for Strongyloides stercoralis. Ivermectin therapy was commenced and continued for a total of 4 weeks. He was discharged for rehabilitation after 25 days. He had no exposure to endemic countries or to immigrants. During many years he had multiple gastrointestinal symptoms, respiratory symptoms, cutaneous symptoms, chronic eosinophilia, and high immunoglobulin E levels. He underwent several operative procedures and numerous hospitalizations and medical encounters with different experts but a parasitic infection was not considered. His asymptomatic daughter was also found to be serologically positive. Strongyloides stercoralis hyperinfection associated with Streptococcus pyogenes bacteremia and toxic shock is described for the first time. The case also highlights the importance of history taking and reviewing past laboratory results, the utility of serological tests for Strongyloides stercoralis, and the importance of screening asymptomatic family members of an infected patient. Strongyloides stercoralis hyperinfection must be considered in the differential diagnosis of any patient with Streptococcus pyogenes bacteremia or toxic shock of no clear source as well as in symptomatic patients with chronic or intermittent eosinophilia, even without any epidemiological risk factors.