Insecticide Resistance in Vectors of Medically Important Parasitic Infections

Insecticide resistance is a major threat to vector control programmes as insecticides still remain the most effective method to control the vector-borne diseases. For effective management of insecticide resistance, a knowledge of the insecticides used along with their mode of action is a prerequisite to optimize their use. Nowadays, different detection methods, viz., phenotypic, genotypic and proteomic assays are used for assessment of insecticide resistance in vectors. An understanding of the phenotypic and genotypic variations present in the vectors help in implementation of these techniques to evaluate the usefulness of insecticides in an area and to determine the efficacy of an ongoing vector control programmes. The understanding of different factors involved in emergence of insecticide resistance and the alternative solutions to control this problem by the use of rotational, mixture of insecticides and use of piperonyl butoxide to increase the efficacy of indoor residual spray and insecticide treated bed nets are some of the steps taken to tackle the problem of insecticide resistance in vectors

Where have all the diagnostic morphological parasitologists gone?

Advances in laboratory techniques have revolutionized parasitology diagnostics over the past several decades. Widespread implementation of rapid antigen detection tests has greatly expanded access to tests for global parasitic threats such as malaria, while next-generation amplification and sequencing methods allow for sensitive and specific detection of human and animal parasites in complex specimen matrices. Recently, the introduction of multiplex panels for human gastrointestinal infections has enhanced the identification of common intestinal protozoa in feces along with bacterial and viral pathogens. Despite the benefits provided by novel diagnostics, increased reliance on nonmicroscopy-based methods has contributed to the progressive, widespread loss of morphology expertise for parasite identification. Loss of microscopy and morphology skills has the potential to negatively impact patient care, public health, and epidemiology. Molecular- and antigen-based diagnostics are not available for all parasites and may not be suitable for all specimen types and clinical settings. Furthermore, inadequate morphology experience may lead to missed and inaccurate diagnoses and erroneous descriptions of new human parasitic diseases. This commentary highlights the need to maintain expert microscopy and morphological parasitology diagnostic skills within the medical and scientific community. We proposed that light microscopy remains an important part of training and practice in the diagnosis of parasitic diseases and that efforts should be made to train the next generation of morphological parasitologists before the requisite knowledge, skills, and capacity for this complex and important mode of diagnosis are lost. In summary, the widespread, progressive loss of morphology expertise for parasite identification negatively impacts patient care, public health, and epidemiology. © 2022 American Society for Microbiology

Mapping Concurrent Wasting and Stunting Among Children Under Five in India: A Multilevel Analysis

Objectives: The study aims to examine the coexisting forms, patterns, and predictors of concurrent wasting and stunting (WaSt) among children under five in India.Methods: We used data from the National Family Health Survey to understand the trend and association of WaSt among children under five-year-old in India. Univariate analysis and cross-tabulations were performed for WaSt cases. The association was determined using multilevel binary logistic regression and multilevel regression, and the results were provided as adjusted odds ratios (aOR) with 95% confidence intervals at the significance level of p < 0.05.Results: The prevalence of WaSt has decreased from 8.7% in 2005–06 to 5.2 percent in 2019–2020. The proportion of WaSt children grew rapidly from 6 to 18 months, peaked at 19 months (8%), then dropped after 24 months. The prevalence of concurrent wasting and stunting is higher among boys compared to girls. Compared to children of different birth orders, those in the higher birth order are 1.2 times more likely to be WaSt cases (aOR = 1.20, 95% CI = 1.09, 1.33). The education of the mother is strongly correlated with WaSt instances, and children of more educated mothers have a 47% lower chance of being WaSt cases (aOR = 0.63, 95% CI = 0.57, 0.71). Children from wealthy families are 52% less likely to be WaSt cases (aOR = 0.48, 95% CI = 0.43, 0.55).Conclusion: This study emphasizes the importance of concurrent wasting and stunting and its relationship with socioeconomic factors among children under five in India

Socio-environmental determinants of parasitic intestinal infections among children: a cross-sectional study in Nigeria

Background: Intestinal parasitic infections are a major public health problem among school-aged children, especially those residing in rural areas. These infections predispose the children to several other health problems. This study assesses intestinal parasitic infections among school children in a rural area in Nigeria and their socioenvironmental determinants. Methods: This cross-sectional study included 250 primary school-age children from three randomly selected schools in Elemere, a poor rural area in Kwara State, Nigeria. A semi-structured questionnaire was used to record the socio-demographic data, and stool samples were microscopically examined for intestinal parasites. Results: The overall prevalence of intestinal parasites was 23.6% (59/250). Of the infected children, the most common parasite was Ascaris lumbricoides 50.8% (30/59), followed by Giardia lamblia 28.8% (17/59), Entamoeba spp.16.9% (10/59) and Dipylidium caninum in 3.4% (2/59). Rural domicile was associated with parasitic infections (P= 0.036) compared to a semi-urban or urban residence. Compared to younger age groups, children in the higher age groups had 64% (95% confidence interval,0.15–0.90;P= 0.03) lesser parasitic infections. Conclusion: Intestinal parasitic infections are common in school children in the studied area, and may be associated with unclean water sources, poor hygiene, and economic conditions. General health education should emphasize cleanliness, personal hygiene and sanitation to prevent and control parasitic intestinal infections among schoolchildren in these communities

Shigellosis: Epidemiology in India

Shigellosis is one of the major causes of diarrhoea in India. The accurate estimates of morbidity and mortality due to shigellosis are lacking, though it is endemic in the country and has been reported to cause many outbreaks. The limited information available indicates Shigella to be an important food- borne pathogen in India. S. flexneri is the most common species, S. sonnei and non-agglutinable Shigellae seem to be steadily surfacing, while S. dysenteriae has temporarily disappeared from the northern and eastern regions. Antibiotic-resistant strains of different Shigella species and serotypes have emerged all over the world. Especially important is the global emergence of multidrug resistant Shigellae, notably the increasing resistance to third generation cephalosporins and fluoroquinolones, and also azithromycin. This calls for a continuous and strong surveillance of antibiotic resistance across the country for periodic updation of the local antibiograms. The prevention of shigellosis is desirable as it will substantially reduce the morbidity associated with diarrhoea in the country. Public health measures like provision of safe water and adequate sanitation are of immense importance to reduce the burden of shigellosis, however, the provision of resources to develop such an infrastructure in India is a complex issue and will take time to resolve. Thus, the scientific thrust should be focused towards development of a safe and affordable multivalent vaccine. this review is focused upon the epidemiology, disease burden and the therapeutic challenges of shigellosis in Indian perspective

Rapid identification of medically important mosquitoes by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

Abstract Background Accurate and rapid identification of dipteran vectors is integral for entomological surveys and is a vital component of control programs for mosquito-borne diseases. Conventionally, morphological features are used for mosquito identification, which suffer from biological and geographical variations and lack of standardization. We used matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) for protein profiling of mosquito species from North India with the aim of creating a MALDI-TOF MS database and evaluating it. Methods Mosquito larvae were collected from different rural and urban areas and reared to adult stages. The adult mosquitoes of four medically important genera, Anopheles, Aedes, Culex and Armigerus, were morphologically identified to the species level and confirmed by ITS2-specific PCR sequencing. The cephalothoraces of the adult specimens were subjected to MALDI-TOF analysis and the signature peak spectra were selected for creation of database, which was then evaluated to identify 60 blinded mosquito specimens. Results Reproducible MALDI-TOF MS spectra spanning over 2–14 kDa m/z range were produced for nine mosquito species: Anopheles (An. stephensi, An. culicifacies and An. annularis); Aedes (Ae. aegypti and Ae. albopictus); Culex (Cx. quinquefasciatus, Cx. vishnui and Cx. tritaenorhynchus); and Armigerus (Ar. subalbatus). Genus- and species-specific peaks were identified to create the database and a score of > 1.8 was used to denote reliable identification. The average numbers of peaks obtained were 55–60 for Anopheles, 80–100 for Aedes, 30–60 for Culex and 45–50 peaks for Armigeres species. Of the 60 coded samples, 58 (96.67%) were correctly identified by MALDI-TOF MS with a score > 1.8, while there were two unreliable identifications (both Cx. quinquefasciatus with scores < 1.8). Conclusions MALDI-TOF MS appears to be a pragmatic technique for accurate and rapid identification of mosquito species. The database needs to be expanded to include species from different geographical regions and also different life-cycle stages to fully harness the technique for entomological surveillance programs

Lophomonas as a respiratory pathogen—jumping the gun

Human infections with the protozoan Lophomonas have been increasingly reported in the medical literature over the past three decades. Initial reports were based on microscopic identification of the purported pathogen in respiratory specimens. Later, a polymerase chain reaction (PCR) was developed to detect Lophomonas blattarum, following which there has been a significant increase in reports. In this minireview, we thoroughly examine the published reports of Lophomonas infection to evaluate its potential role as a human pathogen. We examined the published images and videos of purported Lophomonas, compared its morphology and motility characteristics with host bronchial ciliated epithelial cells and true L. blattarum derived from cockroaches, analyzed the published PCR that is being used for its diagnosis, and reviewed the clinical data of patients reported in the English and Chinese literature. From our analysis, we conclude that the images and videos from human specimens do not represent true Lophomonas and are predominantly misidentified ciliated epithelial cells. Additionally, we note that there is insufficient clinical evidence to attribute the cases to Lophomonas infection, as the clinical manifestations are non-specific, possibly caused by other infections and comorbidities, and there is no associated tissue pathology attributable to Lophomonas. Finally, our analysis reveals that the published PCR is not specific to Lophomonas and can amplify DNA from commensal trichomonads. Based on this thorough review, we emphasize the need for rigorous scientific scrutiny before a microorganism is acknowledged as a novel human pathogen and discuss the potential harms of misdiagnoses for patient care and scientific literature. Copyright © 2023 American Society for Microbiology. All Rights Reserved

Allele Frequency of ABO Blood Group Antigen and the Risk of Esophageal Cancer

Background. ABO blood group and risk of squamous cell carcinoma of esophagus have been reported by many studies, but there is no discipline that had provided association with the genotype and gene frequency by population statics. Methods. We conducted a case-control study on 480 patients with squamous cell carcinoma of the esophagus and 480 noncancer patients. ABO blood group was determined by presence of antigen with the help of monoclonal antibody. Chi-square test and odds ratio (OR) with 95% confidence intervals (CIs) were calculated by statistical methods, and gene frequencies were calculated by Hardy-Weinberg model. Results. We observed significant associations between ABO genotype and squamous cell carcinoma of esophagus. OR (95% CIs) was 1.69 (1.31–2.19) for presence of B antigen allele relative to its absence (P<0.0001); in female subgroup OR (95% CIs) observed at 1.84 (1.27–2.65) was statistically significant (P=0.001). SCC of esophagus shows significant difference in comparison to general population; blood group B is found to be higher in incidence (P=0.0001). Increased risk of cancer was observed with absence of Rh antigen (P=0.0001). Relatively increased gene frequency of q[B] allele is observed more significantly in female cancer patients (P=0.003). Conclusion. Statistically significant association between squamous cell carcinoma of the esophagus and ABO and Rh genotype is identified by this study. Sex and anatomical site of cancer also present with statistically significant relative association. However, larger randomised trials are required to establish the hypothesis

Additional file 1: of Rapid identification of medically important mosquitoes by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

Figure S1. MALDI-TOF MS spectra of three representative specimens of An. stephensi. Figure S2. MALDI-TOF MS spectra of three representative specimens of An. culicifacies. Figure S3. MALDI-TOF MS spectra of three representative specimens of An. annularis. Figure S4. MALDI-TOF MS spectra of three representative specimens of Ae. aegypti. Figure S5. MALDI-TOF MS spectra of three representative specimens of Ae. albopictus. Figure S6. MALDI-TOF MS spectra of three representative specimens of Cx. tritaenorhynchus. Figure S7. MALDI-TOF MS spectra of three representative specimens of Cx. vishnui. Figure S8. MALDI-TOF MS spectra of three representative specimens of Cx. quinquefasciatus. Figure S9. MALDI-TOF MS spectra of three representative specimens of Ar. subalbatus. (PDF 2050 kb