High-resolution melting analysis identifies reservoir hosts of zoonotic Leishmania parasites in Tunisia

Background Leishmaniasis is endemic in Tunisia and presents with different clinical forms, caused by the species Leishmania infantum, Leishmania major, and Leishmania tropica. The life cycle of Leishmania is complex and involves several phlebotomine sand fly vectors and mammalian reservoir hosts. The aim of this work is the development and evaluation of a high-resolution melting PCR (PCR-HRM) tool to detect and identify Leishmania parasites in wild and domestic hosts, constituting confirmed (dogs and Meriones rodents) or potential (hedgehogs) reservoirs in Tunisia. Methods Using in vitro-cultured Leishmania isolates, PCR-HRM reactions were developed targeting the 7SL RNA and HSP70 genes. Animals were captured or sampled in El Kef Governorate, North West Tunisia. DNA was extracted from the liver, spleen, kidney, and heart from hedgehogs (Atelerix algirus) (n = 3) and rodents (Meriones shawi) (n = 7) and from whole blood of dogs (n = 12) that did not present any symptoms of canine leishmaniasis. In total, 52 DNA samples were processed by PCR-HRM using both pairs of primers. Results The results showed melting curves enabling discrimination of the three Leishmania species present in Tunisia, and were further confirmed by Sanger sequencing. Application of PCR-HRM assays on reservoir host samples showed that overall among the examined samples, 45 were positive, while seven were negative, with no Leishmania infection. Meriones shawi were found infected with L. major, while dogs were infected with L. infantum. However, co-infections with L. major/L. infantum species were detected in four Meriones specimens and in all tested hedgehogs. In addition, multiple infections with the three Leishmania species were found in one hedgehog specimen. Sequence analyses of PCR-HRM products corroborated the Leishmania species found in analyzed samples. Conclusions The results of PCR-HRM assays applied to field specimens further support the possibility of hedgehogs as reservoir hosts of Leishmania. In addition, we showed their usefulness in the diagnosis of canine leishmaniasis, specifically in asymptomatic dogs, which will ensure a better evaluation of infection extent, thus improving elaboration of control programs. This PCR-HRM method is a robust and reliable tool for molecular detection and identification of Leishmania and can be easily implemented in epidemiological surveys in endemic regions. Graphical Abstract

Evaluation of in-house ELISA and 11 commercial ELISA kits in the serological diagnosis of COVID-19

Introduction: ELISA-Immunoassays can complement the molecular diagnostic methods, and can be one of the important tools of sero-surveillance and vaccine evaluation. The aim of the presented study was to develop in-house ELISA and evaluate 11 commercial ELISA tests for detection of anti-SARS-CoV-2 antibodies in serum samples collected from COVID patients. Methods: In total, 237 serum samples obtained from 165 people with COVID-19 with RT-PCR confirmed SARS-CoV-2 virus infection were used for the study. The specificity of the developed in-house ELISA kit was tested using 170 serum samples obtained from patients with various bacterial and viral infections. The study used an in-house ELISA and 11 commercial ELISA kits developed by various manufacturers. Results: The presented study showed high sensitivity (81.0%) and specificity (97.2%) of the developed in-house kit in relation to the RT-PCR method. The sensitivity of the inhouse test significantly increased (98.1%) when only convalescents - persons at least 3 weeks after COVID-19 were examined. Commercial ELISA kits most frequently detected IgG antibodies (from 44.9% to 89.4%), especially in samples obtained later in the disease, and the least frequent detection of IgM antibodies (from 4.2% to 42.4%). Conclusions: All the presented ELISA kits may be used in serodiagnosis of COVID-19 however the detection of antibodies in individual tests differed quite significantly and was dependent on the period of the disease, on the class of immunoglobulins and the type of antigen used. The sensitivity of serological tests in the IgG class is clearly higher when examining samples obtained at least 2-3 weeks from the onset of clinical symptoms. Searching for IgA antibodies may be useful mainly in the early phase of the disease while IgM antibodies does not provide significant additional information. In the case of asymptomatic or mild infection, the level of antibodies is low which may be the cause problems with the correct interpretation of epidemiological surveys

Malaria among Croatian seafarers between 2004 and 2014: evaluation of chemoprophylaxis use and occupational disease reporting

In Croatia, malaria was eradicated in 1964 and has since been imported, ten cases a year in average, mostly by Croatian migrant workers, seafarers in particular. About 80 % of registered cases were infected in Africa and the main reason for infection was negligence in the use of chemoprophylaxis. The aim of the study was to establish the incidence of malaria among Croatian seafarers from 2004 to 2014, how many of them took chemoprophylaxis properly, and whether malaria was acknowledged as occupational disease. To get our answers we analysed epidemiological surveys of the Croatian Institute of Public Health completed by patients and reviewed epidemiological bulletins and the national Register of Occupational Diseases. Over the investigated period, a total of 102 people fell ill with malaria, of whom 25 were seafarers. Seventeen did not take chemoprophylaxis at all and eight took them without following instructions. In addition, none of them had malaria recognised as occupational disease under Croatian law, nor is there any information that they exercised their rights in any other way. All this clearly points out that seafarers and their employers need to be informed much better about the benefits of preventive measures and their labour rights.

Association between food insecurity and major depressive episodes amid Covid-19 pandemic: results of four consecutive epidemiological surveys from southern Brazil

Objective: To assess the association between household food insecurity (FI) and major depressive episodes (MDE) amid Covid-19 pandemic in Brazil. Design: Cross-sectional study carried out with data from four consecutive population-based studies. Setting: The study was conducted between May and June 2020, in Bagé, a Brazilian southern city. Household FI was measured using the short-form version of the Brazilian Food Insecurity Scale. Utilizing the Patient Health Questionnaire-9, we used two different approaches to define MDE: the cut-off point of ≥9 and the diagnostic criteria proposed by the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV-R). Association between FI and MDE was analysed using crude and adjusted Poisson regression models. Participants: 1550 adults (≥20 years old). Results: The prevalence of household FI was 29.4% (95%C.I 25.0; 34.4). MDE prevalence varied from 4.4% (95%C.I. 3.1 to 6.0), when we used the DSM-IV-R criteria to define this condition, to 9.6% (95%C.I 7.3; 12.5) of the sample, when we used the cut-off point of ≥9 as definition. Prevalence of MDE was more than two times higher in those individuals living with FI, independent of the criteria adopted to define the outcome. Adjustment for potential confounders did not change the association’s magnitude. Conclusion: Household FI has been positively associated with MDE amid Covid-19 pandemic, independent of sociodemographic characteristics of participants. Actions are needed to warrant basic living conditions to avoid food insecurity and hunger and its consequences for the Brazilian population, especially those consequences linked to mental health disorders.

A Severe Gastroenteritis Outbreak of Salmonella enterica Serovar Enteritidis Linked to Contaminated Egg Fried Rice, China, 2021

Salmonella contamination of eggs and egg shells has been identified as a public health problem worldwide. Here, we reported an outbreak of severe gastrointestinal symptoms caused by Salmonella enterica serovar Enteritidis (S. enteritidis) in China. We evaluated the outbreak by using epidemiological surveys, routine laboratory testing methods, and whole genome sequencing (WGS). This outbreak occurred in a canteen in Beijing, during March 9–11, 2021, 225 of the 324 diners who have eaten at the canteen showed gastrointestinal symptoms. The outbreak had characteristical epidemiological and clinical features. It caused a very high attack rate (69.4%) in a short incubation time. All patients developed diarrhea and high fever, accompanied by abdominal pain (62.3%), nausea (50.4%), and vomiting (62.7%). The average frequency of diarrhea was 12.4 times/day, and the highest frequency of diarrhea was as high as 50 times/day. The average fever temperature was 39.4°C, and the highest fever temperature was 42°C. Twenty strains of S. enteritidis were recovered, including 19 from the patients samples, and one from remained egg fried rice. Antibiotic susceptibility test showed that the 20 outbreak strains all had the same resistance pattern. PFGE results demonstrated that all 20 strains bore completely identical bands. Phylogenetic analysis based on WGS revealed that all 20 outbreak strains were tightly clustered together. So the pathogenic source of this food poisoning incident may was contaminated egg fried rice. Resistance gene analysis showed that the outbreak strains are all multi-drug resistant strains. Virulence gene analysis indicated that these outbreak strains carried a large number of virulence genes, including 2 types of Salmonella pathogenicity islands (SPI-1 and SPI-2). Other important virulence genes were also carried by the outbreak strains, such as pefABCD, rck and shdA. And the shdA gene was not in other strains located in the same evolutionary branch as the outbreak strain. We speculated that this is a significant reason for the serious symptoms of gastroenteritis in this outbreak. This outbreak caused by S. enteritidis suggested government should strengthen monitoring of the prevalence of outbreak clone strains, and take measures to mitigate the public health threat posed by contaminated eggs.

Validation of self-reported oral health among Indonesian adolescents

Background and aim With the recognition of health as a subjective state, self-reported oral health has been applied in many epidemiological studies. However, the validity of self-reports may vary across different age groups and socio-cultural backgrounds and by using different tools. This study aimed to assess the validity of self-reported oral health of 15-year-old Indonesian adolescents. Materials and methods This study used data from the Indonesian National Oral Health Survey, a part of the Indonesian Basic Health Survey 2018. The study included 572 15-year-old Indonesian adolescents. We compared the presence of clinically assessed dental caries, tooth loss, and fillings following the World Health Organization Basic Health Survey method and questionnaire-based self-reported oral conditions using McNemar test. The sensitivity (Sn), specificity (Sp), and likelihood ratios (LRs) of self-reports were calculated using clinical assessment as the reference standard. The overall accuracy of self-reports in identifying the clinical condition was assessed using the area under the curve (AUC) of a receiver operating characteristic curve. Results Self-reports significantly underestimated the clinical presence of caries (39.3% and 67.1%) and overestimated the clinical presence of tooth loss (9.3% and 4.2%) and filling (4.7% and 2.4%, p < 0.05). All self-reported conditions had higher Sp (at least 70.3%) than Sn (max 54.2%) and the AUC for all self-reported conditions were < 0.7. Self-reporting the presence of fillings had the highest LR+ = 11. Conclusions Self-reporting oral health in Indonesian adolescents had low accuracy. Further studies of other methods of self-reporting are needed before they can be used to assess adolescents’ oral health in epidemiological surveys.

Identification of the Unique Clinical and Genetic Features of Chinese Lung Cancer Patients With EGFR Germline Mutations in a Large-Scale Retrospective Study

BackgroundEpidemiological surveys have suggested that lung cancer has inherited susceptibility and shows familial aggregation. However, the distribution and prevalence of epidermal growth factor receptor (EGFR) germline variants and their roles in lung cancer genetic predisposition in Chinese population remain to be elucidated.MethodsIn this study, EGFR germline and somatic variants were retrospectively reviewed from the next-generation sequencing results of 31,906 patients with lung cancer. Clinical information was also collected for patients with confirmed EGFR germline mutations.ResultsA total of 22 germline EGFR variants were identified in 64 patients with lung cancer, accounting for 0.2% of the total cases studied. Five patients were diagnosed as multiple primary carcinomas. Family history was documented in 31.3% (20/64) of patients, 55% of which were diagnosed as lung cancer. G863D was the most frequent EGFR germline mutation, followed by P848L, D1014N, and K757R. Somatic EGFR-sensitive mutations were identified in 51.6% of patients with germline EGFR mutations. The proportion of L858R mutation, exon 19 deletion, and rare sensitive mutation was 50%, 17.6%, and 32.4%, respectively. D1014N and T790M mutations were common in young patients. The family members of patients with P848L, R776H, V769M, and V774M mutations were more commonly diagnosed with cancers. A total of 19 patients were confirmed to have received EGFR tyrosine kinase inhibitors (TKIs), but the response to EGFR-TKIs differed among patients with different EGFR mutations.ConclusionChinese patients with lung cancer harbored unique and dispersive EGFR germline mutations and showed unique clinical and genetic characteristics, with varied response patterns to EGFR-TKI treatment.

A Review of the South African National Oral Health Policy

Advocacy for oral health promotion, prevention and treatment of oral diseases is founded on a comprehensive oral health policy that is integrated into the South African National Health Policy. The policy is intended to be a roadmap in the pursuit of achieving optimum oral health for the South African population. To review the National Oral Health Policy of SA (NOHPSA) in terms of context, strengths, weaknesses, implementation and monitoring regarding the oral health status of the SouthAfrican population.Results Promotive and preventive services lack detail on activities to achieve goals. The objectives, although very well defined, cannot be measured and there is no way of knowing whether they have been achieved. It was evident that the policy needs to be reviewed and updated in accordance to recent survey data, population growth and the profile (number and types) of health service providers. The prospect of updating the policy relies on the availability of current epidemiological surveys, which are not available, the most recent survey was conducted in 2002. The policy lacks a monitoring and evaluation plan. This is critical not only for the assessment of actualisation of aims and objectives, but for the sustainability of intended interventions.

Worldwide prevalence of suicidal ideation and suicide plan among people with schizophrenia: a meta-analysis and systematic review of epidemiological surveys

Schizophrenia is a severe psychiatric disorder with high premature mortality rates. This is a meta-analysis and systematic review of the prevalence of suicidal ideation (SI) and suicide plan (SP) among people with schizophrenia. PubMed, Web of Science, Embase, and PsycINFO were systematically searched from their respective inception to October 10, 2020. Data on prevalence of SI and/or SP were synthesized using the random effects model. Twenty-six studies covering 5079 people with schizophrenia were included for meta-analysis. The lifetime and point prevalence of SI were 34.5% (95% CI: 28.2−40.9%), and 29.9% (95% CI: 24.2−35.6%), respectively. The lifetime prevalence of SP was 44.3% and the point prevalence of SP ranged between 6.4 and 13%. Subgroup and meta-regression analyses revealed that source of patients, survey countries, and sample size were significantly associated with the point prevalence of SI, while male proportion and quality assessment scores were significantly associated with the lifetime and point prevalence of SI. Survey time and mean age were significantly associated with lifetime prevalence of SI. Both SI and SP are common in people living with schizophrenia, especially in males and inpatients. Routine screening and effective interventions for SI and SP should be implemented in this population.

Abundance and Stability as Common Properties of Allergens

There have been many attempts to identify common biophysical properties which differentiate allergens from their non-immunogenic counterparts. This review will focus on recent studies which examine two such factors: abundance and stability. Anecdotal accounts have speculated that the elevated abundance of potential allergens would increase the likelihood of human exposure and thus the probability of sensitization. Similarly, the stability of potential allergens dictates its ability to remain a viable immunogen during the transfer from the source to humans. This stability could also increase the resilience of potential allergens to both gastric and endosomal degradation, further skewing the immune system toward allergy. Statistical analyses confirm both abundance and stability as common properties of allergens, while epidemiological surveys show a correlation between exposure levels (abundance) and allergic disease. Additional studies show that changes in protein stability can predictably alter gastric/endosomal processing and immunogenicity, providing a mechanistic link between stability and allergenicity. However, notable exceptions exist to both hypotheses which highlight the multifaceted nature of immunological sensitization, and further inform our understanding of some of these other factors and their contribution to allergic disease.