Highly sensitive extraction-free saliva-based molecular assay for rapid diagnosis of SARS-CoV-2.

The COVID-19 pandemic highlighted the necessity of fast, sensitive, and efficient methods to test large populations for respiratory viruses. The "gold standard" molecular assays for detecting respiratory viruses, such as quantitative polymerase chain reaction (qPCR) and reverse transcription qPCR (RT-qPCR), rely on invasive swab samples and require time-consuming and labor-intensive extraction processes. Moreover, the turnaround time for RT-qPCR-based assays is too lengthy for rapid screening. Extraction-free saliva-based methods provide a non-invasive sampling process with a fast turnaround time and are suitable for high-throughput applications. However, when used with a standard RT-qPCR system, the absence of extraction significantly reduces the assays' sensitivity. Here, using a novel optical modulation biosensing (OMB) platform, we developed a rapid and highly sensitive extraction-free saliva-based molecular assay. We blindly tested 364 paired nasopharyngeal swabs and saliva samples from suspected SARS-CoV-2 cases in Israel. Compared with the gold standard swab-based RT-qPCR assay, the sensitivity of the extraction-free saliva-based OMB assay is 90.7%, much higher than the sensitivity of extraction-free saliva-based RT-qPCR assay (77.8%) with similar specificity (95.3% and 97.6%, respectively). Moreover, out of 12 samples identified by the OMB-based assay as positive, 8 samples were collected from hospitalized patients in a COVID-19 ward and were verified to be SARS-CoV-2-positive upon admission, indicating that the actual clinical sensitivity and specificity of the OMB assay are higher. Considering its user-friendly saliva-based protocol, short and cost-effective extraction-free process, and high clinical accuracy, the OMB-based molecular assay is very suitable for high-throughput testing of large populations for respiratory viruses. IMPORTANCE: Three years after the SARS-CoV-2 outbreak, there are no molecular tests that combine low-cost and straightforward sample preparation, effective sample handling, minimal reagent and disposable requirements, high sensitivity, and high throughput required for mass screening. Existing rapid molecular techniques typically sacrifice certain requirements to meet others. Yet, localized outbreaks of novel viral diseases happen daily in different parts of the world. In this context, respiratory diseases are of specific importance, as they are frequently airborne and highly contagious, with the potential for a rapid global spread. The widely accepted opinion is that another pandemic is just a question of time. To ensure that the containment efforts for the upcoming "disease X" are successful, introducing rapid, high-throughput, and highly sensitive diagnostic methods for detecting and identifying pathogens is critical. A few months into the pandemic, saliva was suggested as a diagnostic matrix for SARS-CoV-2 detection. The collection of saliva does not require swabs and is minimally invasive. In particular, extraction-free saliva-based assays require fewer reagents and disposables, and therefore are faster and cheaper, offering an appealing alternative for low-income countries. Unfortunately, current extraction-free saliva-based detection methods, such as direct RT-qPCR or isothermal amplification, have either low sensitivity or low throughput. Therefore, we believe that the presented highly sensitive ht-OMBi platform and the extraction-free saliva-based molecular assay can become an essential tool in the infectious disease monitoring toolbox.

Comparison of Intralesional Sodium Stibogluconate versus Intralesional Meglumine Antimoniate for the Treatment of Leishmania major Cutaneous Leishmaniasis.

Israel is endemic for Old-World cutaneous leishmaniasis. The most common species is Leishmania major. However, the available treatment options are limited. This study's objective was to compare the authors' experience with different antimony intralesional treatments of Leishmania major cutaneous leishmaniasis. A retrospective evaluation was undertaken for cases of Leishmania major cutaneous leishmaniasis treated by pentavalent antimony in a university-affiliated medical centre in Israel. The previous treatment of intralesional sodium stibogluconate (Pentostam®) was compared with the current treatment of meglumine antimoniate (Glucantime®). One hundred cases of cutaneous leishmaniasis were treated during the study period, of whom 33 were treated with intralesional sodium stibogluconate and 67 were treated with intralesional meglumine antimoniate. The patients were 78 males and 22 females, mean age 24 (range 10-67) and there was a total of 354 skin lesions. Within 3 months from treatment, 91% (30/33) of the intralesional sodium stibogluconate group and 88% (59/67) of the intralesional meglumine antimoniate group had complete healing of the cutaneous lesions after an average of 3 treatment cycles (non-statistically significant). In conclusion, the 2 different medications have the same efficacy and safety for treating cutaneous leishmaniasis. Pentavalent antimoniate intralesional infiltration treatment is safe, effective, and well tolerated with minimal side effects for Old-World cutaneous leishmaniasis.

Clinical Characteristics and Outcomes Among Travelers With Severe Dengue : A GeoSentinel Analysis.

BACKGROUND: Dengue virus is a flavivirus transmitted by Aedes mosquitoes and is an important cause of illness worldwide. Data on the severity of travel-associated dengue illness are limited. OBJECTIVE: To describe the epidemiology, clinical characteristics, and outcomes among international travelers with severe dengue or dengue with warning signs as defined by the 2009 World Health Organization classification (that is, complicated dengue). DESIGN: Retrospective chart review and analysis of travelers with complicated dengue reported to GeoSentinel from January 2007 through July 2022. SETTING: 20 of 71 international GeoSentinel sites. PATIENTS: Returning travelers with complicated dengue. MEASUREMENTS: Routinely collected surveillance data plus chart review with abstraction of clinical information using predefined grading criteria to characterize the manifestations of complicated dengue. RESULTS: Of 5958 patients with dengue, 95 (2%) had complicated dengue. Eighty-six (91%) patients had a supplemental questionnaire completed. Eighty-five of 86 (99%) patients had warning signs, and 27 (31%) were classified as severe. Median age was 34 years (range, 8 to 91 years); 48 (56%) were female. Patients acquired dengue most frequently in the Caribbean (n = 27 [31%]) and Southeast Asia (n = 21 [24%]). Frequent reasons for travel were tourism (46%) and visiting friends and relatives (32%). Twenty-one of 84 (25%) patients had comorbidities. Seventy-eight (91%) patients were hospitalized. One patient died of nondengue-related illnesses. Common laboratory findings and signs were thrombocytopenia (78%), elevated aminotransferase (62%), bleeding (52%), and plasma leakage (20%). Among severe cases, ophthalmologic pathology (n = 3), severe liver disease (n = 3), myocarditis (n = 2), and neurologic symptoms (n = 2) were reported. Of 44 patients with serologic data, 32 confirmed cases were classified as primary dengue (IgM+/IgG-) and 12 as secondary (IgM-/IgG+) dengue. LIMITATIONS: Data for some variables could not be retrieved by chart review for some patients. The generalizability of our observations may be limited. CONCLUSION: Complicated dengue is relatively rare in travelers. Clinicians should monitor patients with dengue closely for warning signs that may indicate progression to severe disease. Risk factors for developing complications of dengue in travelers need further prospective study. PRIMARY FUNDING SOURCE: Centers for Disease Control and Prevention, International Society of Travel Medicine, Public Health Agency of Canada, and GeoSentinel Foundation.

Cutaneous Leishmaniasis Caused by Leishmania infantum, Israel, 2018-2021.

Cutaneous leishmaniasis (CL) is endemic to Israel. Previously, CL caused by Leishmania infantum had been reported in Israel only once (in 2016). We report 8 L. infantum CL cases; 7 occurred during 2020-2021. None of the patients had systemic disease. L. infantum CL may be an emerging infection in Israel.

Zika virus infection in European travellers returning from Thailand in 2022: A GeoSentinel case series.

Zika virus is a mosquito-borne flavivirus which caused major epidemics in the Pacific and the Americas between 2013 and 2015. International travellers have previously acted as a sentinel population for Zika virus transmission in endemic areas, where local transmission may be incompletely captured by local surveillance systems. We report five recent European travellers returning from Thailand with Zika virus infection, highlighting the risk of ongoing endemic transmission in this popular tourist destination.

[POST-ARTEMISININ DELAYED HEMOLYSIS AFTER TREATMENT OF MALARIA].

INTRODUCTION: Falciparum malaria is highly endemic in sub-Saharan Africa. The disease is caused by the intra-cellular parasite Plasmodium within erythrocytes. The recommended treatment is artemisinin-based combination which is efficient and safe. In some patients, artemisinin can cause hemolysis weeks after treatment, presenting with severe anemia. Most of the published cases were following intravenous treatment. We present a case of a falciparum malaria patient with hemolysis and severe anemia two weeks after oral treatment with artemisinin-based combination therapy.

Exportation of Monkeypox Virus From the African Continent.

BACKGROUND: The largest West African monkeypox outbreak began September 2017, in Nigeria. Four individuals traveling from Nigeria to the United Kingdom (n = 2), Israel (n = 1), and Singapore (n = 1) became the first human monkeypox cases exported from Africa, and a related nosocomial transmission event in the United Kingdom became the first confirmed human-to-human monkeypox transmission event outside of Africa. METHODS: Epidemiological and molecular data for exported and Nigerian cases were analyzed jointly to better understand the exportations in the temporal and geographic context of the outbreak. RESULTS: Isolates from all travelers and a Bayelsa case shared a most recent common ancestor and traveled to Bayelsa, Delta, or Rivers states. Genetic variation for this cluster was lower than would be expected from a random sampling of genomes from this outbreak, but data did not support direct links between travelers. CONCLUSIONS: Monophyly of exportation cases and the Bayelsa sample, along with the intermediate levels of genetic variation, suggest a small pool of related isolates is the likely source for the exported infections. This may be the result of the level of genetic variation present in monkeypox isolates circulating within the contiguous region of Bayelsa, Delta, and Rivers states, or another more restricted, yet unidentified source pool.

Existence of immunological memory response in true sero-negative individuals post COVID-19 molecular diagnosis.

Approximately 1-8% of individuals do not develop antibodies following SARS-CoV-2 infection (sero-negatives). One BNT162b2 dose resulted in potent humoral response in 14 sero-negatives and 15 sero-positives, significantly higher than the response of 15 naïve-individuals, to two doses suggesting that COVID-19 provoked a memory response in individuals without detectable antibodies.

Schistosomal extracellular vesicle-enclosed miRNAs modulate host T helper cell differentiation.

During the chronic stage of Schistosoma infection, the female lays fertile eggs, triggering a strong anti-parasitic type 2 helper T-cell (Th2) immune response. It is unclear how this Th2 response gradually declines even though the worms live for years and continue to produce eggs. Here, we show that Schistosoma mansoni downregulates Th2 differentiation in an antigen-presenting cell-independent manner, by modulating the Th2-specific transcriptional program. Adult schistosomes secrete miRNA-harboring extracellular vesicles that are internalized by Th cells in vitro. Schistosomal miRNAs are found also in T helper cells isolated from Peyer's patches and mesenteric lymph nodes of infected mice. In T helper cells, the schistosomal miR-10 targets MAP3K7 and consequently downmodulates NF-κB activity, a critical transcription factor for Th2 differentiation and function. Our results explain, at least partially, how schistosomes tune down the Th2 response, and provide further insight into the reciprocal geographic distribution between high prevalence of parasitic infections and immune disorders such as allergy. Furthermore, this worm-host crosstalk mechanism can be harnessed to develop diagnostic and therapeutic approaches for human schistosomiasis and Th2-associated diseases.

Efficacy of Systemic Treatment for Leishmania tropica Cutaneous Leishmaniasis.

The effectiveness of systemic treatment for Leishmania tropica cutaneous leishmaniasis remains unclear. The purpose of the study is to evaluate the efficacy and safety of systemic treatments for L. tropica cutaneous leishmaniasis. This retrospective study was performed in 114 patients. Systemic treatments included liposomal amphotericin B and sodium stibogluconate. All patients underwent systemic treatment for L. tropica cutaneous leishmaniasis. Favourable treatment responses were recorded in 72.5% and 70.2% of the patients in the liposomal amphotericin B and sodium stibogluconate groups, respectively; 25.3% and 46% of those in the liposomal amphotericin B and sodium stibogluconate groups respectively, experienced at least one adverse effect. Lesions in cartilaginous areas were associated with higher treatment failure. Prior topical or systemic treatment increased the chance of future systemic treatment success. Liposomal amphotericin B was associated with a shorter intravenous treatment duration and better safety profile. Thus, liposomal amphotericin B is the treatment of choice for L. tropica cutaneous leishmaniasis.

The role of mouthwash sampling in SARS-CoV-2 diagnosis.

BACKGROUND: The current practice of COVID-19 diagnosis worldwide is the use of oro-nasopharyngeal (ONP) swabs. Our study aim was to explore mouthwash (MW) as an alternative diagnostic method, in light of the disadvantages of ONP swabs. METHODS: COVID-19 outpatients molecular-confirmed by ONP swab were repeatedly examined with ONP swab and MW with normal saline (0.9%). Other types of fluids were compared to normal saline. The Cq values obtained with each method were compared. RESULTS: Among 137 pairs of ONP swabs and MW samples, 84.6% (116/137) of ONP swabs were positive by at least one of the genes (N, E, R). However MW detected 70.8% (97/137) of samples as positive, which means 83.6% (97/116) out of positive ONP swabs, missing mainly Cq value > 30. In both methods, the N gene was the most sensitive one. Therefore, MW samples targeting N gene, which was positive in 95/137 (69.3%), are comparable to ONP swabs targeting E and R genes which gave equal results-95/137 (69.3%) and 90/137 (65.7%), respectively. Comparing saline MW to distilled water gave equal results, while commercial mouth-rinsing solutions were less sensitive. CONCLUSIONS: MW with normal saline, especially when tested by N gene, can effectively detect COVID-19 patients. Furthermore, this method was not inferior when compared to R and E genes of ONP swabs, which are common targets in many laboratories around the world.

Epidemiological and Clinical Characteristics of International Travelers with Enteric Fever and Antibiotic Resistance Profiles of Their Isolates: a GeoSentinel Analysis.

Enteric fever, caused by Salmonella enterica serovar Typhi (S Typhi) and S. enterica serovar Paratyphi (S Paratyphi), is a common travel-related illness. Limited data are available on the antimicrobial resistance (AMR) patterns of these serovars among travelers. Records of travelers with a culture-confirmed diagnosis seen during or after travel from January 2007 to December 2018 were obtained from GeoSentinel. Traveler demographics and antimicrobial susceptibility data were analyzed. Isolates were classified as nonsusceptible if intermediate or resistant or as susceptible in accordance with the participating site's national guidelines. A total of 889 travelers (S Typhi infections, n = 474; S Paratyphi infections, n = 414; coinfection, n = 1) were included; 114 (13%) were children of <18 years old. Most individuals (41%) traveled to visit friends and relatives (VFRs) and acquired the infection in South Asia (71%). Child travelers with S Typhi infection were most frequently VFRs (77%). The median trip duration was 31 days (interquartile range, 18 to 61 days), and 448 of 691 travelers (65%) had no pretravel consultation. Of 143 S Typhi and 75 S Paratyphi isolates for which there were susceptibility data, nonsusceptibility to antibiotics varied (fluoroquinolones, 65% and 56%, respectively; co-trimoxazole, 13% and 0%; macrolides, 8% and 16%). Two S Typhi isolates (1.5%) from India were nonsusceptible to third-generation cephalosporins. S Typhi fluoroquinolone nonsusceptibility was highest when infection was acquired in South Asia (70 of 90 isolates; 78%) and sub-Saharan Africa (6 of 10 isolates; 60%). Enteric fever is an important travel-associated illness complicated by AMR. Our data contribute to a better understanding of region-specific AMR, helping to inform empirical treatment options. Prevention measures need to focus on high-risk travelers including VFRs and children.

Highly Sensitive and Specific Zika Virus Serological Assays Using a Magnetic Modulation Biosensing System.

BACKGROUND: Zika virus has created global alarm because it has been associated with catastrophic fetal abnormalities, including microcephaly, spontaneous abortion, and intrauterine growth restriction. Current serological assays that detect antiviral antibodies suffer from low sensitivity and high cross-reactivity among different flaviviruses. METHODS: In this study, utilizing a novel magnetic modulation biosensing (MMB) system and the Zika nonstructural 1 protein, we show highly sensitive and specific Zika serological assays. We blindly tested 60 reverse-transcription polymerase chain reaction Zika-positive samples and healthy patients' serum samples, as well as 44 serum samples from enzyme-linked immunosorbent assay (ELISA) West Nile- and dengue-positive patients. The Zika-positive samples were collected from Israeli travelers returning from Zika-endemic areas. RESULTS: The MMB Zika assays have 88%-97% sensitivity, much higher than the current state-of-the-art EUROIMMUN ELISA assays (38%-74%). In addition, the specificity is 100%, and the cross-reactivity with West Nile and dengue viruses is minimal (0%-4%). Furthermore, the MMB assays detected Zika IgM antibodies as early as 5 days and as late as 180 days postsymptoms onset, significantly extending the number of days that the antibodies are detectable. CONCLUSIONS: The sensitivity, specificity, and simplicity of the MMB assays may significantly improve Zika diagnosis and provide accurate results for public health agencies.

Mucosal Leishmaniasis in Travelers with Leishmania braziliensis Complex Returning to Israel.

Mucosal leishmaniasis (ML) is a complication of New World cutaneous leishmaniasis (CL) caused mainly by Leishmania (Viannia) braziliensis. This retrospective study investigated all cases of ML caused by L. (V.) braziliensis in a tertiary medical center in Israel, evaluating the risk factors, clinical presentations, diagnosis, treatment, and outcome of mucosal involvement in ML caused by L. (V.) braziliensis in travelers returning to Israel. During 1993-2015, a total of 145 New World CL cases were seen in travelers returning from Bolivia; among them, 17 (11.7%) developed ML. Nasopharyngeal symptoms developed 0-3 years (median 8 months) after exposure. The only significant risk factor for developing ML was the absence of previous systemic treatment. Among untreated patients, 41% developed ML, compared with only 3% of treated patients (p = 0.005). Systemic treatment for CL seems to be a protective factor against developing ML.

Diagnosis of Imported Monkeypox, Israel, 2018.

We report a case of monkeypox in a man who returned from Nigeria to Israel in 2018. Virus was detected in pustule swabs by transmission electron microscopy and PCR and confirmed by immunofluorescence assay, tissue culture, and ELISA. The West Africa monkeypox outbreak calls for increased awareness by public health authorities worldwide.

Epidemiologic and phylogenetic analysis of the 2018 West Nile virus (WNV) outbreak in Israel demonstrates human infection of WNV lineage I.

As at 12 November 2018, an outbreak of West Nile virus (WNV) was responsible for 139 WNV infection cases in Israel. Here, we characterise the epidemiology of the outbreak and demonstrate that only WNV lineage I was circulating in mosquitoes and responsible for WNV infection in humans. This suggests that the concurrence of the outbreak in Israel with WNV outbreaks in several European countries is not due to a common, more virulent WNV genotype.

Vivax Malaria Chemoprophylaxis: The Role of Atovaquone-Proguanil Compared to Other Options.

Background: Atovaquone-proguanil is considered causal prophylaxis (inhibition of liver-stage schizonts) for Plasmodium falciparum; however, its causal prophylactic efficacy for Plasmodium vivax is not known. Travelers returning to nonendemic areas provide a unique opportunity to study P. vivax prophylaxis. Methods: In a retrospective observational study, for 11 years, Israeli rafters who had traveled to the Omo River in Ethiopia, a highly malaria-endemic area, were followed for at least 1 year after their return. Malaria prophylaxis used during this period included mefloquine, doxycycline, primaquine, and atovaquone-proguanil. Prophylaxis failure was divided into early (within a month of exposure) and late malaria. Results: Two hundred fifty-two travelers were included in the study. Sixty-two (24.6%) travelers developed malaria, 56 (91.9%) caused by P. vivax, with 54 (87.1%) cases considered as late malaria. Among travelers using atovaquone-proguanil, there were no cases of early P. falciparum or P. vivax malaria. However, 50.0% of atovaquone-proguanil users developed late vivax malaria, as did 46.5% and 43.5% of mefloquine and doxycycline users, respectively; only 2 (1.4%) primaquine users developed late malaria (P < .0001). Conclusions: Short-course atovaquone-proguanil appears to provide causal (liver schizont stage) prophylaxis for P. vivax, but is ineffective against late, hypnozoite reactivation-related attacks. These findings suggest that primaquine should be considered as the chemoprophylactic agent of choice for areas with high co-circulation of P. falciparum and P. vivax.

Region-Specific, Life-Threatening Diseases among International Travelers from Israel, 2004-2015.

We characterized posttravel hospitalizations of citizens returning to Israel by summarizing the returning traveler hospitalization dataset of the national referral Center for Travel Medicine and Tropical Diseases at Sheba Medical Center in Israel. Of 722 hospitalizations, 181 (25%) infections were life-threatening; most would have been preventable by chemoprophylaxis and pretravel vaccination.

African Histoplasmosis in HIV-Negative Patients, Kimpese, Democratic Republic of the Congo.

We describe a case series of histoplasmosis caused by Histoplasma capsulatum var. duboisii during July 2011-January 2014 in Kimpese, Democratic Republic of the Congo. Cases were confirmed by histopathology, immunohistochemistry, and reverse transcription PCR. All patients were HIV negative. Putative sources for the pathogen were cellar bats and guano fertilizer exploitation.

Area of exposure and treatment challenges of malaria in Eritrean migrants: a GeoSentinel analysis.

BACKGROUND: Recent reports highlight malaria as a frequent diagnosis in migrants who originate from Eritrea. A descriptive analysis of GeoSentinel cases of malaria in Eritrean migrants was done together with a literature review to elucidate key attributes of malaria in this group with a focus on possible areas of acquisition of malaria and treatment challenges. RESULTS: A total of 146 cases were identified from the GeoSentinel database from 1999 through September 2017, with a marked increase in 2014 and 2015. All patients originated from Eritrea and the main reporting GeoSentinel sites were in Norway, Switzerland, Sweden, Israel and Germany. The majority of patients (young adult males) were diagnosed with malaria following arrival in the host country. All patients had a possible exposure in Eritrea, but may have been exposed in documented transit countries including Ethiopia, Sudan and possibly Libya in detention centres. Most infections were due to Plasmodium vivax (84.2%), followed by Plasmodium falciparum (8.2%). Two patients were pregnant, and both had P. vivax malaria. Some 31% of the migrants reported having had malaria while in transit. The median time to onset of malaria symptoms post arrival in the host country was 39 days. Some 66% of patients were hospitalized and nine patients had severe malaria (according to WHO criteria), including five due to P. vivax. CONCLUSIONS: The 146 cases of mainly late onset, sometimes severe, P. vivax malaria in Eritrean migrants described in this multi-site, global analysis reflect the findings of single-centre analyses identified in the literature search. Host countries receiving asylum-seekers from Eritrea need to be prepared for large surges in vivax and, to a lesser extent, falciparum malaria, and need to be aware and prepared for glucose-6-phosphate dehydrogenase deficiency testing and primaquine treatment, which is difficult to procure and mainly unlicensed in Europe. There is an urgent need to explore the molecular epidemiology of P. vivax in Eritrean asylum-seekers, to investigate the area of acquisition of P. vivax along common transit routes and to determine whether there has been re-introduction of malaria in areas, such as Libya, where malaria is considered eliminated, but where capable vectors and Plasmodium co-circulate.