Chitosan stabilized platinum nanoparticles: In vitro and in vivo screening for analgesic and anti-inflammatory applications

In this interdisciplinary research work, the chitosan stabilized platinum nanoparticles are synthesized through the wet chemical method, and the structural, surface morphological, and optical characterizations are done using X-ray crystallography, Raman spectroscopy, transmission electron microscopy, etc. The samples were tested in in vitro trials namely egg albumin denaturation assay and DPPH radical scavenging assays and showed significantly lower effective concentrations (EC50) such as 5.44 μg/ml and 8.068 μg/ml respectively. The in vitro experiments were followed by in vivo animal model for analgesic and anti-inflammatory behaviour at two doses of 25 mg/kg and 50 mg/kg utilizing the hot plate method and the carrageenan-induced paw edema model respectively. The in vivo hot plate model for analgesic effect demonstrated that the chitosan stabilized platinum nanoparticles perform exceptionally well and show >90 % analgesia (p < 0.01) by extending the reaction time in the hot plate method-indicating better analgesia. Carrageenan-induced paw edema model demonstrated the exceptional anti-inflammatory ability of chitosan-stabilized platinum nanoparticles. Despite being given at a comparatively lower dosage, chitosan stabilized platinum nanoparticles showed a considerable decrease in paw volume (40-45 % edema inhibition) by the third hour of the anti-inflammatory experimentation (p < 0.01) outperforming the standard drug aspirin given at 100 mg/kg.

Genetic diversity of Plasmodium falciparum and Plasmodium vivax field isolates from the Nowshera district of Pakistan

BACKGROUND

The genetic diversity of malaria parasites contributes to their ability to adapt to environmental changes, develop drug resistance and circumvent the host immune system. This study aimed to analyse the genetic diversity of the Pfmsp1 and Pfmsp2 genes in Plasmodium falciparum and the Pvmsp-3α gene in Plasmodium vivax isolates from District Nowshera in Pakistan.

METHODS

Blood samples from 124 consenting patients with uncomplicated malaria presenting to different hospitals from the Nowshera district were collected between March and August 2019, representing 28 P. falciparum and 96 P. vivax isolates. The genomic DNA extracted from the isolates were subjected to nested PCR and allele-specific analysis. Pvmsp-3α amplified fragments were further treated with restriction fragment length polymorphism (RFLP)-based Hha1 restriction enzyme.

RESULTS

Of the analyzed P. falciparum, 21 distinct alleles were detected, including 14 alleles for Pfmsp-1 and 7 alleles for Pfmsp-2. The sub-allelic families MAD20 (50%) of Pfmsp-1and FC27 (75%) of Pfmsp-2 were predominant. The multiplicity of infection (MOI) was calculated as 1.4 and 1.2 for Pfmsp-1 and Pfmsp-2, respectively, with an overall mean MOI of 1.34. In P. vivax, 4 allelic variants, Pvmsp-3α types A, B, C and D, were detected, while RFLP digestion of amplicons, detected 9 sub-allelic variants (A1-A4, B1, B2, C1, C2 and D1) at the Pvmsp-3α locus.

CONCLUSION

This first ever report of molecular characterization of P. falciparum and P. vivax genotypes from District Nowshera, Pakistan reveals moderate to high allelic diversity in parasite population from District Nowshera, Pakistan.

Current vaccines, experimental immunization trials, and new perspectives to control selected vector borne blood parasites of veterinary importance

Parasite infections transmitted by vectors such as ticks and blood-sucking arthropods pose a significant threat to both human and animal health worldwide and have a substantial economic impact, particularly in the context of worsening environmental conditions. These infections can manifest in a variety of symptoms, including fever, anemia, jaundice, enlarged spleen, neurological disorders, and lymphatic issues, and can have varying mortality rates. In this review, we will focus on the current state of available vaccines, vaccine research approaches, and trials for diseases caused by vector-borne blood parasites, such as Babesia, Theileria, Anaplasma, and Trypanosoma, in farm animals. Control measures for these infections primarily rely on vector control, parasiticidal drug treatments, and vaccinations for disease prevention. However, many of these approaches have limitations, such as environmental concerns associated with the use of parasiticides, acaricides, and insecticides. Additionally, while some vaccines for blood parasites are already available, they still have several drawbacks, including practicality issues, unsuitability in non-endemic areas, and concerns about spreading other infectious agents, particularly in the case of live vaccines. This article highlights recent efforts to develop vaccines for controlling blood parasites in animals. The focus is on vaccine development approaches that show promise, including those based on recombinant antigens, vectored vaccines, and live attenuated or genetically modified parasites. Despite intensive research, developing effective subunit vaccines against blood stage parasites remains a challenge. By learning from previous vaccine development efforts and using emerging technologies to define immune mechanisms of protection, appropriate adjuvants, and protective antigens, we can expand our toolkit for controlling these burdensome diseases.

Correction: Asad et al. Anti-Inflammatory, Antipyretic, and Analgesic Potential of Chitin and Chitosan Derived from Cockroaches (Periplaneta americana) and Termites. J. Funct. Biomater. 2024, 15, 80

In the original publication [...].

Nanomaterials as a Potential Target for Infectious Parasitic Agents

Despite the technological advancement in the era of personalized medicine and therapeutics development, infectious parasitic causative agents remain one of the most challenging areas of research and development. The disadvantages of conventional parasitic prevention and control are the emergence of multiple drug resistance as well as the non-specific targeting of intracellular parasites, which results in high dose concentration needs and subsequently intolerable cytotoxicity. Nanotechnology has attracted extensive interest to reduce medication therapy adverse effects including poor bioavailability and drug selectivity. Numerous nanomaterials-based delivery systems have previously been shown in animal models to be effective in the treatment of various parasitic infections. This review discusses a variety of nanomaterials-based antiparasitic procedures and techniques as well as the processes that allow them to be targeted to different parasitic infections. This review focuses on the key prerequisites for creating novel nanotechnology-based carriers as a potential option in parasite management, specifically in the context of human-related pathogenic parasitic agents.

Distinct Allelic Diversity of Plasmodium vivax Merozoite Surface Protein 3-Alpha (PvMSP-3α) Gene in Thailand Using PCR-RFLP

Considering the importance of merozoite surface proteins (MSPs) as vaccine candidates, this study was conducted to investigate the polymorphism and genetic diversity of Plasmodium vivax merozoite surface protein 3-alpha (PvMSP-3α) in Thailand. To analyze genetic diversity, 118 blood samples containing P. vivax were collected from four malaria-endemic areas in western and southern Thailand. The DNA was extracted and amplified for the PvMSP-3α gene using nested PCR. The PCR products were genotyped by PCR-RFLP with Hha I and Alu I restriction enzymes. The combination patterns of Hha I and Alu I RFLP were used to identify allelic variants. Genetic evaluation and phylogenic analysis were performed on 13 sequences, including 10 sequences from our study and 3 sequences from GenBank. The results revealed three major types of PvMSP-3α, 91.5% allelic type A (∼1.8 kb), 5.1% allelic type B (∼1.5 kb), and 3.4% allelic type C (∼1.2 kb), were detected based on PCR product size with different frequencies. Among all PvMSP-3α, 19 allelic subtypes with Hha I RFLP patterns were distinguished and 6 allelic subtypes with Alu I RFLP patterns were identified. Of these samples, 73 (61%) and 42 (35.6%) samples were defined as monoallelic subtype infection by Hha I and Alu I PCR-RFLP, respectively, whereas 77 (65.3%) samples were determined to be mixed-allelic subtype infection by the combination patterns of Hha I and Alu I RFLP. These results strongly indicate that PvMSP-3α gene is highly polymorphic, particularly in blood samples collected from the Thai-Myanmar border area (the western part of Thailand). The combination patterns of Hha I and Alu I RFLP of the PvMSP-3α gene could be considered for use as molecular epidemiologic markers for genotyping P. vivax isolates in Thailand.

Epidemiology of Cryptosporidium Infection in Romania: A Review

Since 1983, when the first report of a human Cryptosporidium spp. infection was published in Romania, and until now, many studies on cryptosporidiosis have been published in our country, but most of them are in the Romanian language and in national journals less accessible to international scientific databases. Although the infection was first recognized as a problem in children or immunocompromised people or more of a problem in low-income or underdeveloped global countries, we have shown in this review that it can also occur in people with normal immunological function and that the epidemiology of our country can provide a theoretical basis for the formulation of a Cryptosporidium spp. prevention strategy. In addition, 9.1% of healthy children and 73% of immunocompromised children were observed to have Cryptosporidium spp. infections. Higher rates have also been reported in immunocompromised adults (1.8-50%). Analyzing the prevalence of Cryptosporidium spp. infection in animals, we found values of 28.52% in cattle, 18% in buffalo calves, between 27.8 and 60.4% in pigs, 52.7% in dogs, and 29.4% in cats. Furthermore, in Romania, the burden of cryptosporidiosis, including acute infections and long-term sequelae, is currently unknown.

Treatment of Urticaria caused by severe cryptosporidiosis in a 17-month-old child - a case report

BACKGROUND

Cryptosporidium is an intracellular protozoan that causes gastrointestinal symptoms in humans and animals. In immunocompromised patients and children under 5 years of age, the infection is severe and can be life-threatening due to severe diarrhea.

CASE PRESENTATION

We report a case of urticaria associated with Cryptosporidium in a 17-month-old female Iranian child. The patient had moderate diarrhea (> 3 loose, watery stools but not more than 10 diarrhea stools in a day), weight loss, and acute urticarial (rash clears completely within 6 weeks). Since the child's father worked in livestock farming, the parasite may have been transferred from the cow or calve to the house and the child. Several Cryptosporidium oocysts were detected in the modified acid-fast staining of the child's stool sample. The patient was successfully treated with nitazoxanide (100 mg twice daily) and became negative for parasites three days after treatment and one week after discharge from the hospital. The child was observed to produce < 3 loose stools in the previous 24 h after 1-week post-treatment and after 6 months of follow-up.

CONCLUSION

A number of parasites are associated with urticaria, but to our knowledge, there is no information on Cryptosporidium-induced urticaria. Therefore, our result may be evidence for the role of this parasite in the development of urticaria if other causes such as food allergies, autoimmune diseases and etc. don't role in urticaria.

Molecular epidemiology of Cryptosporidium species in Kpong and its environs, Ghana

BACKGROUND

Cryptosporidium is a ubiquitous enteric protozoan pathogen infecting humans, domestic animals, and wildlife worldwide. It is a waterborne pathogen with recognized zoonotic potential and a definite cause of diarrhea and nutritional disorders in institutional and community settings. One challenge facing the world's supply of clean drinking water is contamination from feces and soil. It has been established that small quantities of oocysts, the infective stage, can cause human disease. Also, their resistance to chlorination and other water treatment procedures has been demonstrated. Kpong, a community in the Lower Manya Krobo Municipality of the Eastern Region of Ghana, is one of the primary sources of water supply to Accra, the capital city of Ghana. Being able to determine the effectiveness of water treatment processes and identifying sources of contamination of this pathogen in our water bodies is thus of public health importance. The study aimed to conduct molecular epidemiology of Cryptosporidium spp. in the Lower Manya Krobo Municipality.

METHODOLOGY/PRINCIPAL FINDINGS

A total of 230 samples, 180 fecal samples from cattle and 50 water samples (tap water and well water) were collected from the following communities: Kpong, Akwernor, Ablotsi, Nuaso, and Atua, all in the Lower Manya Krobo Municipality. Samples were screened for Cryptosporidium by microscopy and PCR. The 18S rRNA gene was amplified by nested polymerase chain reaction (PCR), and the final product was sequenced. The prevalence of Cryptosporidium from the fecal samples was estimated as 10% (18/180) by microscopy, while all 50 water samples were negative. However, PCR gave the prevalence of Cryptosporidium as 47.8% (86/180) for fecal samples and 20% (10/50) for water samples. Based on the 18S rRNA gene, three sequenced samples showed high homology to C. parvum species. The phylogenetic analysis confirmed this as these sequences clustered with C. parvum sequences from other countries.

CONCLUSION/SIGNIFICANCE

Cryptosporidium parvum was identified as the persistent species in the study communities. This outcome supports the evidence that domesticated animals serve as potential reservoirs of zoonotic transmission of cryptosporidiosis. The persistence of cryptosporidiosis in cattle indicates its presence in the human population. In addition, the presence of Cryptosporidium parvum in the wells makes it alarming and necessary to consider a holistic approach such as One Health Strategies to identify and control cases in humans.

Impact of enteropathogens on faltering growth in a resource-limited setting

Introduction

Environmental enteropathy is an important contributor to childhood malnutrition in the developing world. Chronic exposure to fecal pathogens leads to alteration in intestinal structure and function, resulting in impaired gut immune function, malabsorption, and growth faltering leading to environmental enteropathy.

Methods

A community-based intervention study was carried out on children till 24 months of age in Matiari district, Pakistan. Blood and fecal specimens were collected from the enrolled children aged 3-6 and 9 months. A real-time PCR-based TaqMan array card (TAC) was used to detect enteropathogens.

Results

Giardia, Campylobacter spp., enteroaggregative Escherichia coli (EAEC), Enteropathogenic Escherichia coli (EPEC), Enterotoxigenic Escherichia coli (ETEC), and Cryptosporidium spp. were the most prevailing enteropathogens in terms of overall positivity at both time points. Detection of protozoa at enrollment and 9 months was negatively correlated with rate of change in height-for-age Z (ΔHAZ) scores during the first and second years of life. A positive association was found between Giardia, fecal lipocalin (LCN), and alpha 1-Acid Glycoprotein (AGP), while Campylobacter spp. showed positive associations with neopterin (NEO) and myeloperoxidase (MPO).

Conclusion

Protozoal colonization is associated with a decline in linear growth velocity during the first 2 years of life in children living in Environmental enteric dysfunction (EED) endemic settings. Mechanistic studies exploring the role of cumulative microbial colonization, their adaptations to undernutrition, and their influence on gut homeostasis are required to understand symptomatic enteropathogen-induced growth faltering.

Molecular evaluation of Cryptosporidium spp. among breeding calves of Lorestan province Western Iran

BACKGROUND

Cryptosporidium spp. are opportunistic intestinal protozoans with global distribution and are of great importance as zoonotic protozoans are common to humans and domestic animals, including cattle and calves. Identification and detection of parasite species using precise methods including molecular methods can be an effective step in treating and controlling parasites.

OBJECTIVES

This study aimed to investigate the prevalence of Cryptosporidium among breeding calves of Khorramabad city, Lorestan province, Western Iran, using PCR.

METHODS

The faecal samples were taken from 181 healthy and diarrhoeal calves and after the Ziehl Neelsen Acid-fast staining and microscopic evaluation, the genomic DNA was extracted for molecular evaluations. To detect Cryptosporidium species, specific primers targeting the SAM-1 gene of Cryptosporidium and a commercial master mix were used for PCR.

RESULTS

Out of 181 faecal samples of breeding calves in Khorramabad city, 9 samples (5%) were positive for Cryptosporidium spp. using the PCR method. Statistical analysis of the data showed that there was no significant statistical relationship between Cryptosporidium infection of the calves and variables of age, breed, type of water consumption, clinical signs of diarrhoea, and sampling location, while parasite infection had a significant relationship with calf gender so that all Cryptosporidium positive samples were from male calves (p ≤ 0.05).

CONCLUSIONS

Considering the presence of Cryptosporidium infection, the region's traditional grazing system, and the close relationship between livestock and humans, there is a possibility of human infection in the region. So preventive measures such as periodic animal testing with sensitive and accurate diagnostic techniques including PCR, pharmacological treatment of livestock, water hygiene and the use of industrial grazing instead of traditional grazing to improve the hygiene of food consumed by livestock are recommended.

Knowledge, attitudes, and practices regarding Crimean-Congo hemorrhagic fever among general people: A cross-sectional study in Pakistan

Background

Crimean-Congo hemorrhagic fever (CCHF) continues to pose a serious threat to the fragile healthcare system of Pakistan with a continuous increase of morbidity and mortality. The present study aimed to assess the knowledge, attitudes, and practices regarding CCHF among general people who resided in Pakistan.

Methods

An online cross-sectional survey design was applied, and a convenience sampling technique was used to recruit 1039 adult people from Pakistan. Data were collected from September 08 to October 12, 2021. The questionnaire consisted of a total of 32 questions in four parts assessing socio-demographics, as well as knowledge, attitudes, and practices regarding CCHF. All statistical analyses were performed using the Statistical Package for the Social Sciences (SPSS), and logistic regression analyses were performed to determine the factors associated with good knowledge, positive attitudes, and good practices.

Results

Alarmingly, 51.5% of participants heard about CCHF infection before administering the survey. Among these, 20.2%, 33.3%, and 48.2% of the study participants had demonstrated good knowledge, positive attitudes, and good practices, respectively. Binary logistic regression analysis revealed that education and income status had a significant impact on knowledge and attitudes (p<0.05). Similarly, the mean attitude scores differed significantly by age, education, and income status (p<0.05).

Conclusions

The findings reflected inadequate levels of knowledge, attitudes, and practices regarding CCHF among general people in Pakistan which may regard as lower than expected. As CCHF is a highly contagious disease, it’s urgent to initiate a comprehensive approach to handle the situation before it spreads further in Pakistan.

Dynamical behaviours and stability analysis of a generalized fractional model with a real case study

Introduction

Mathematical modelling is a rapidly expanding field that offers new and interesting opportunities for both mathematicians and biologists. Concerning COVID-19, this powerful tool may help humans to prevent the spread of this disease, which has affected the livelihood of all people badly.

Objectives

The main objective of this research is to explore an efficient mathematical model for the investigation of COVID-19 dynamics in a generalized fractional framework.

Methods

The new model in this paper is formulated in the Caputo sense, employs a nonlinear time-varying transmission rate, and consists of ten population classes including susceptible, infected, diagnosed, ailing, recognized, infected real, threatened, diagnosed recovered, healed, and extinct people. The existence of a unique solution is explored for the new model, and the associated dynamical behaviours are discussed in terms of equilibrium points, invariant region, local and global stability, and basic reproduction number. To implement the proposed model numerically, an efficient approximation scheme is employed by the combination of Laplace transform and a successive substitution approach; besides, the corresponding convergence analysis is also investigated.

Results

Numerical simulations are reported for various fractional orders, and simulation results are compared with a real case of COVID-19 pandemic in Italy. By using these comparisons between the simulated and measured data, we find the best value of the fractional order with minimum absolute and relative errors. Also, the impact of different parameters on the spread of viral infection is analyzed and studied.

Conclusion

According to the comparative results with real data, we justify the use of fractional concepts in the mathematical modelling, for the new non-integer formalism simulates the reality more precisely than the classical framework.

Mathematical Modeling Investigation of Violence and Racism Coexistence as a Contagious Disease Dynamics in a Community

Recently, violence, racism, and their coexistence have been very common issues in most nations in the world. In this newly social science discipline mathematical modelling approach study, we developed and examined a new violence and racism coexistence mathematical model with eight distinct classes of human population (susceptible, violence infected, negotiated, racist, violence-racism coinfected, recuperated against violence, recuperated against racism, and recuperated against the coinfection). The model takes into account the possible controlling strategies of violence-racism coinfection. All the submodels and the violence-racism coexistence model equilibrium points are calculated, and their stabilities are analyzed. The model threshold values are derived. As a result of the model qualitative analysis, the violence-racism coinfection spreads under control if the corresponding basic reproduction number is less than unity, and it propagates through the community if this number exceeds unity. Moreover, the sensitivity analysis of the parameter values of the full model is illustrated. We have applied MATLAB ode45 solver to illustrate the numerical results of the model. Finally, from qualitative analysis and numerical solutions, we obtain relevant and consistent results.

Assessing the potential impact of COVID-19 Omicron variant: Insight through a fractional piecewise model

We consider a new mathematical model for the COVID-19 disease with Omicron variant mutation. We formulate in details the modeling of the problem with omicron variant in classical differential equations. We use the definition of the Atangana-Baleanu derivative and obtain the extended fractional version of the omicron model. We study mathematical results for the fractional model and show the local asymptotical stability of the model for infection-free case ifR 0 < 1 . We show the global asymptotically stable of the model for the disease free case whenR 0 ≤ 1 . We show the existence and uniqueness of solution of the fractional model. We further extend the fractional order model into piecewise differential equation system and give a numerical algorithm for their numerical simulation. We consider the real cases of COVID-19 in South Africa of the third wave March 2021-Sep 2021 and estimate the model parameters and getR 0 ≈ 1 . 4004 . The real parameters values are used to show the graphical results for the fractional and piecewise model.

Intestinal Parasitic Infections Among Pediatric Patients in a Metropolitan City of Bangladesh With Emphasis on Cryptosporidiosis

Introduction Gastrointestinal parasitic infections are one of the global health concerns in developing countries like Bangladesh. Among them, Cryptosporidium spp. plays an essential role in causing diarrhea, malnutrition, and poor cognitive function, especially in children. This study was conducted to identify the frequency of Cryptosporidium cases and other parasitic agents.  Methods A cross-sectional observational study was conducted among 219 hospitalized children with diarrhea. The conventional microscopic technique was applied for parasitic detection. Particular staining (modified Ziehl-Neelsen) procedure was performed to identify oocysts of Cryptosporidium spp. A polymerase chain reaction (PCR) was performed to determine the SSU rRNA and gp60 gene of Cryptosporidium.  Results Cysts of Giardia duodenalis (2.3%), ova of Ascaris lumbricoides (1.4%,), Trichuris trichiura (0.5%), and both A. lumbricoides and T. trichiura (0.9%) were identified in samples through wet mount preparation. The distribution of Cryptosporidium spp. as detected by the staining method and nested PCR was 1.4% and 4.1%, respectively.  Conclusion Factors independently associated with Cryptosporidium infection are unsafe water, lack of regular hand washing, and insufficiency of exclusive breastfeeding. This study reports, presumably for the first time, the detection of Cryptosporidium oocysts in Chattogram metropolitan city of Bangladesh.

Cryptosporidium and colorectal cancer: a review of epidemiology and possible association

Cryptosporidiosis is an important protozoan disease with serious public health implications. The contribution of Cryptosporidium to colorectal cancer is still vaguely studied, but little evidence from experimental and epidemiological studies has suggested a possible association. This review discusses the epidemiology of cryptosporidiosis and colorectal cancer and attempts to unravel the possible link between the two diseases using epidemiological, pathological, molecular, and immunological evidence. The review stressed the need to undertake more studies in this relatively neglected field.

Global Analysis and Optimal Control Model of COVID-19

COVID-19 remains the concern of the globe as governments struggle to defeat the pandemic. Understanding the dynamics of the epidemic is as important as detecting and treatment of infected individuals. Mathematical models play a crucial role in exploring the dynamics of the outbreak by deducing strategies paramount for curtailing the disease. The research extensively studies the SEQIAHR compartmental model of COVID-19 to provide insight into the dynamics of the disease by underlying tailored strategies designed to minimize the pandemic. We first studied the noncontrol model's dynamic behaviour by calculating the reproduction number and examining the two nonnegative equilibria' existence. The model utilizes the Castillo-Chavez method and Lyapunov function to investigate the global stability of the disease at the disease-free and endemic equilibrium. Sensitivity analysis was carried on to determine the impact of some parameters on R₀. We further examined the COVID model to determine the type of bifurcation that it exhibits. To help contain the spread of the disease, we formulated a new SEQIAHR compartmental optimal control model with time-dependent controls: personal protection and vaccination of the susceptible individuals. We solved it by utilizing Pontryagin's maximum principle after studying the dynamical behaviour of the noncontrol model. We solved the model numerically by considering different simulation controls' pairing and examined their effectiveness.

Raw meat based diet (RMBD) for household pets as potential door opener to parasitic load of domestic and urban environment. Revival of understated zoonotic hazards? A review

RMBD (acronym of Raw Meat Based Diet) and BARF diets (acronym for Biologically Appropriate Raw Food or Bones and Raw Food) account dietary regimens based on raw ingredients (including raw meat), popular in pet feeding. Animal tissues and organs as well as other uncooked ingredients are more and more popularly used by pet owners to feed household pets. However, the increased risk of exposure to microbiological and parasitic agents poses the question as to whether such diets may be recommendable to be handled and offered to domestic cats and dogs co-living in domestic and urban environment. Above all, the threat of human and animal infections by parasites from raw meat fed to pets is not sufficiently explored and tracked, meanwhile deserving particular surveillance, instead. At this regard, raw meat feeding to pets may represent a route of exposure to the increased risk of environmental load. In fact, some parasites typically found in rural environment can be given the chance to complete their life-cycle, for the closeness between definitive and intermediate hosts. This is of particular concern, as potentially infected pets serving as definitive hosts can become a continuous source of environmental diffusion of parasites, both at domestic and urban level. The handling of raw meat requires adequate knowledge and awareness of the hygienic principles to prevent the onset of disorders related to both manipulation by pet owners and uncooked food consumption by the pet. This review aimed to shed a comprehensive overview of the hygienic aspects related to raw pet feeding, as to handling of raw meat in domestic environment, with special emphasis on parasitic agents and related zoonotic hazards.

An Update on Zoonotic Cryptosporidium Species and Genotypes in Humans

The enteric parasite, Cryptosporidium is a major cause of diarrhoeal illness in humans and animals worldwide. No effective therapeutics or vaccines are available and therefore control is dependent on understanding transmission dynamics. The development of molecular detection and typing tools has resulted in the identification of a large number of cryptic species and genotypes and facilitated our understanding of their potential for zoonotic transmission. Of the 44 recognised Cryptosporidium species and >120 genotypes, 19 species, and four genotypes have been reported in humans with C. hominis, C. parvum, C. meleagridis, C. canis and C. felis being the most prevalent. The development of typing tools that are still lacking some zoonotic species and genotypes and more extensive molecular epidemiological studies in countries where the potential for transmission is highest are required to further our understanding of this important zoonotic pathogen. Similarly, whole-genome sequencing (WGS) and amplicon next-generation sequencing (NGS) are important for more accurately tracking transmission and understanding the mechanisms behind host specificity.

Modeling and dynamic analysis of novel coronavirus pneumonia (COVID-19) in China

Although novel coronavirus pneumonia (COVID-19) was widely spread in mainland China in early 2020, it was soon controlled. To study the impact of government interventions on the spread of disease during epidemics, a differential equation system is established to simulate the process of virus propagation in this paper. We first analyze its basic properties, basic reproduction number R 0 and existence of equilibria. Then we prove that the disease-free equilibrium (DFE) is Globally Asymptotically Stable when R 0 is less than 1. Through the analysis of the daily epidemic data from January 10, 2020 to March 11, 2020, combined with the implementation of the national epidemic policy, we divide the whole process into three stages: the first stage (natural state), the second stage (isolation state), the third stage (isolation, detection and treatment). By using the weighted nonlinear least square method to fit the data of three stages, the parameters are obtained, and three basic reproduction numbers are calculated, which are:R 01 = 2.6735 ,R 02 = 0.85077 ,R 03 = 0.18249 . Sensitivity analysis of threshold parameters and corresponding graphical results were also performed to examine the relative importance of various model parameters to the spread and prevalence of COVID-19. Finally, we simulate the trend of three stages and verify the theory of Global Asymptotic Stability of DFE. The conclusion of this paper proves theoretically that the Chinese government's epidemic prevention measures are effective in the fight against the spread of COVID-19. This study can not only provide a reference for research methods to simulate COVID-19 transmission in other countries or regions, but also provide recommendations on COVID-19 prevention measures for them.

HLA class I and II associations with common enteric pathogens in the first year of life

BACKGROUND

genetic susceptibility to infection is mediated by numerous host factors, including the highly diverse, classical human leukocyte antigen (HLA) genes, which are critical genetic determinants of immunity. We systematically evaluated the effect of HLA alleles and haplotypes on susceptibility to 12 common enteric infections in children during the first year of life in an urban slum of Dhaka, Bangladesh.

METHODS

a birth cohort of 601 Bangladeshi infants was prospectively monitored for diarrhoeal disease. Each diarrhoeal stool sample was analyzed for enteric pathogens by multiplex TaqMan Array Card (TAC). High resolution genotyping of HLA class I (A and B) and II (DRB1, DQA1, and DQB1) genes was performed by next-generation sequencing. We compared the frequency of HLA alleles and haplotypes between infected and uninfected children.

FINDINGS

we identified six individual allele associations and one five-locus haplotype association. One allele was associated with protection: A*24:02 - EAEC. Five alleles were associated with increased risk: A*24:17 - typical EPEC, B*15:01 - astrovirus, B*38:02 - astrovirus, B*38:02 - Cryptosporidium and DQA1*01:01 - Cryptosporidium. A single five-locus haplotype was associated with protection: A*11:01~B*15:02~DRB1*12:02~DQA1*06:01~DQB1*03:01- adenovirus 40/41.

INTERPRETATION

our findings suggest a role for HLA in susceptibility to early enteric infection for five pathogens. Understanding the genetic contribution of HLA in susceptibility has important implications in vaccine design and understanding regional differences in incidence of enteric infection.

FUNDING

this research was supported by the National Institute of Health (NIH) and the Bill and Melinda Gates Foundation.

Epidemiology of Cryptosporidium Infections among People Living with HIV/AIDS in Nigeria: Results of Systematic Review and Meta-analysis

PURPOSE

Cryptosporidium is implicated in diarrhea epidemics in many parts of the world and is said to be the most common protozoan cause of diarrhea among people living with HIV/AIDS (PLWHA) globally. To provide data on the burden of Cryptosporidium infections among Nigerians living with HIV/AIDS, we reported the prevalence, geographic distribution and Cryptosporidium species diversity among this population in Nigeria.

METHODS

We used the PRISMA guidelines to perform a systematic review and meta-analysis of articles published between January 1, 1995 and April 21, 2020. Pooled estimate (PE), heterogeneity, quality of each study and publication bias were determined using the random-effects model, Cochran's Q test, the 9 point Joanna Briggs Institute Critical Appraisal Instrument and the Egger's regression asymmetry test, respectively.

RESULTS

Forty-six articles reported 2612 positive cases of Cryptosporidium infections from 12,756 PLWHA examined in 20 Nigerian States and the Federal Capital Territory. Overall pooled estimate was 14.5% (95% CI 10.4-19.9) with a range of 0.3% (95% CI 0.0-1.8) to 43.7% (95% CI 35.6-52.3) across sub-groups, with the PEs in relation to CD4⁺ T cell count, species and age showing significant variations at p < 0.05. Cryptosporidium hominis was the most prevalent (3.5%, 95% CI 2.3-5.2) of the six Cryptosporidium species reported in Nigeria.

CONCLUSION

Cryptosporidium infections are moderately prevalent among PLWHA in Nigeria with the highest regional prevalence in the north-east. In addition to personal hygienic practices, the inclusion of Cryptosporidium screening as part of HIV/AIDS clinics in Nigeria will reduce the burden of the parasite among PLWHA in Nigeria.

Molecular Epidemiology of Human Cryptosporidiosis in Low- and Middle-Income Countries

Cryptosporidiosis is one of the most important causes of moderate to severe diarrhea and diarrhea-related mortality in children under 2 years of age in low- and middle-income countries. In recent decades, genotyping and subtyping tools have been used in epidemiological studies of human cryptosporidiosis. Results of these studies suggest that higher genetic diversity of Cryptosporidium spp. is present in humans in these countries at both species and subtype levels and that anthroponotic transmission plays a major role in human cryptosporidiosis. Cryptosporidium hominis is the most common Cryptosporidium species in humans in almost all the low- and middle-income countries examined, with five subtype families (namely, Ia, Ib, Id, Ie, and If) being commonly found in most regions. In addition, most Cryptosporidium parvum infections in these areas are caused by the anthroponotic IIc subtype family rather than the zoonotic IIa subtype family. There is geographic segregation in Cryptosporidium hominis subtypes, as revealed by multilocus subtyping. Concurrent and sequential infections with different Cryptosporidium species and subtypes are common, as immunity against reinfection and cross protection against different Cryptosporidium species are partial. Differences in clinical presentations have been observed among Cryptosporidium species and C. hominis subtypes. These observations suggest that WASH (water, sanitation, and hygiene)-based interventions should be implemented to prevent and control human cryptosporidiosis in low- and middle-income countries.

An SIER model to estimate optimal transmission rate and initial parameters of COVD-19 dynamic in Sri Lanka

COVID-19 global outbreak has been significantly damaging the human well-being, life style of people and the global economy. It is clear that the entire world is moving into a dangerous phase of this epidemic at the moment. With absence of a preventive vaccine, the governments across world implement, monitor and manage various public health and social distancing measures to control the spread of this extremely contagious disease and it is found that most of these responses have been critical results of numerous mathematical and decision support models. In this study, SEIR compartment structure is used to model the COVID-19 transmission in Sri Lanka. Reported cases data during the first 80 days of the outbreak is used to model the time dependent transmission rate of the disease. Optimal transmission rates and initial size of the exposed and infected sizes of the populations are then estimated matching between clinically identified cases to model based simulated outcomes.

A probable means to an end: exploring P131 pharmacophoric scaffold to identify potential inhibitors of Cryptosporidium parvum inosine monophosphate dehydrogenase

Compound P131 has been established to inhibit Cryptosporidium parvum's inosine monophosphate dehydrogenase (CpIMPDH). Its inhibitory activity supersedes that of paromomycin, which is extensively used in treating cryptosporidiosis. Through the per-residue energy decomposition approach, crucial moieties of P131 were identified and subsequently adopted to create a pharmacophore model for virtual screening in the ZINC database. This search generated eight ADMET-compliant hits that were examined thoroughly to fit into the active site of CpIMPDH via molecular docking. Three compounds ZINC46542062, ZINC58646829, and ZINC89780094, with favorable docking scores of - 8.3 kcal/mol, - 8.2 kcal/mol, and - 7.5 kcal/mol, were selected. The potential inhibitory mechanism of these compounds was probed using molecular dynamics simulation and Molecular Mechanics Generalized Poisson Boltzmann Surface Area (MM/PBSA) analyses. Results revealed that one of the hits (ZINC46542062) exhibited a lower binding free energy of - 39.52 kcal/mol than P131, which had - 34.6 kcal/mol. Conformational perturbation induced by the binding of the identified hits to CpIMPDH was similar to P131, suggesting a similarity in inhibitory mechanisms. Also, in silico investigation of the properties of the hit compounds implied superior physicochemical properties with regards to their synthetic accessibility, lipophilicity, and number of hydrogen bond donors and acceptors in comparison with P131. ZINC46542062 was identified as a promising hit compound with the highest binding affinity to the target protein and favorable physicochemical and pharmacokinetic properties relative to P131. The identified compounds can serve as a basis for conducting further experimental investigations toward the development of anticryptosporidials, which can overcome the challenges of existing therapeutic options. Graphical abstract P131 and the identified compounds docked in the NAD⁺ binding site of Cryptosporidium parvum IMPDH.

Frequency of Cryptosporidiosis in Children having Persistent Diarrhea

Objective:

Globally childhood diarrheal diseases continue to be the second leading cause of death. Cryptosporidium spp are important intestinal parasites that cause diarrhea in humans and animals particularly in developing countries. This investigation was carried out to find out the frequency of cryptosporidiosis in children presenting with persistent diarrhea.

Methods:

Two hundred stool samples were collected in this descriptive cross-sectional study conducted at Microbiology Department, Combined Military Hospital, Lahore Pakistan between the months of July to Dec 2014. Children aged five years to 12 years who presented with persistent diarrhea were included in the study. Stool specimens were processed using the modified acid-fast staining method, and microscopically examined for Cryptosporidium infection.

Results:

The average age of study participants was 7.95 with a standard deviation of 2.21 years. Among the participants 66% were males whereas 34% were females. Twenty eight percent had presence of oocysts in stool samples.

Conclusions:

The frequency of Cryptosporidiosis among children with persistent diarrhea was 28%. This high frequency indicates that this population is uniquely susceptible to infection. It also highlights the need for education about hygiene, accurate diagnosis, and treatment of Cryptosporidiosis. There is also a need for additional studies regarding the occurrence of this pathogen.

Sustainable Management of the Red Palm Weevil: The Nexus between Farmers’ Adoption of Integrated Pest Management and Their Knowledge of Symptoms

The red palm weevil (RPW) (Rhynchophorus ferruginous) is one of the most serious pest insects threatening the sustainability of the date palm sector (Phoenix dactylifera L.). Nevertheless, a gap exists in the body of knowledge regarding patterns in farmers’ adoption of integrated pest management (IPM) for RPW control and how their knowledge of RPW symptomology influences IPM adoption. Data were collected using structured questionnaires from 183 palm growers in Al-Ahsa Governorate, Saudi Arabia. The results indicate that most farmers had insufficient knowledge to visually diagnose RPW symptoms and damage. Farmers moderately adopted preventive measures recommended for protection from RPW infestation. Only 13.11% of the farmers exhibited a high rate of adoption of pest management practices for RPW control and eradication. The findings revealed a strong positive association (0.8, p < 0.01) between the knowledge level regarding symptoms and IPM adoption level, whereby the respondents with more knowledge of RPW symptoms showed a higher level of adoption in all IPM categories. This study contributes to the development of our understanding of the social behaviors and risks associated with RPW. This might enhance the quality of awareness campaigns and extension programs and assist in developing a visual inspection protocol for RPW infestation for farmers.

Optimization of the Controls against the Spread of Zika Virus in Populations

In this paper, we study and explore two control strategies to decrease the spread of Zika virus in the human and mosquito populations. The control strategies that we consider in this study are awareness and spraying campaigns. We solve several optimal control problems relying on a mathematical epidemic model of Zika that considers both human and mosquito populations. The first control strategy is broad and includes using information campaigns, encouraging people to use bednetting, wear long-sleeve shirts, or similar protection actions. The second control is more specific and relies on spraying insecticides. The control system relies on a Zika mathematical model with control functions. To develop the optimal control problem, we use Pontryagins’ maximum principle, which is numerically solved as a boundary value problem. For the mathematical model of the Zika epidemic, we use parameter values extracted from real data from an outbreak in Colombia. We study the effect of the costs related to the controls and infected populations. These costs are important in real life since they can change the outcomes and recommendations for health authorities dramatically. Finally, we explore different options regarding which control measures are more cost-efficient for society.

Modelling the dynamics of Pine Wilt Disease with asymptomatic carriers and optimal control

Pine wilt disease is a lethal tree disease caused by nematodes carried by pine sawyer beetles. Once affected, the trees are destroyed within a few months, resulting in significant environmental and economic losses. The role of asymptomatic carrier trees in the disease dynamics remains unclear. We developed a mathematical model to investigate the effect of asymptomatic carriers on the long-term outcome of the disease. We performed a stability and sensitivity analysis to identify key parameters and used optimal control to examine several intervention options. Our model shows that, with the application of suitable controls, the disease can be eliminated in the vector population and all tree populations except for asymptomatic carriers. Of the possible controls (tree injection, elimination of infected trees, insecticide spraying), we determined that elimination of infected trees is crucial. However, if the costs of insecticide spraying increase, it can be supplemented (although not replaced entirely) by tree injection, so long as some spraying is still undertaken.

A biological mathematical model of vector-host disease with saturated treatment function and optimal control strategies

The aims of this paper to explore the dynamics of the vector-host disease with saturated treatment function. Initially, we formulate the model by considering three different classes for human and two for the vector population. The use of the treatment function in the model and their brief analysis for the case of disease-free and endemic case are briefly shown. We show that the basic reproduction number (< or >) than unity, the disease-free and endemic cases are stable locally and globally. Further, we apply the optimal control technique by choosing four control variables in order to maximize the population of susceptible and recovered human and to minimize the population of infected humans and vector. We discuss the results in details of the optimal controls model and show their existence. Furthermore, we solve the optimality system numerically in connection with the system of no control and the optimal control characterization together with adjoint system, and consider a set of different controls to simulate the models. The considerable best possible strategy that can best minimize the infection in human infected individuals is the use of all controls simultaneously. Finally, we conclude that the work with effective control strategies.

Histopathological studies of red palm weevil Rhynchophorus ferrugineus, (Olivier) larvae and adults to evaluate certain nano pesticides

Rhynchophorus ferrugineus (RPW) (Olivier) (Coleoptera: Curculionidae) is one of the most destructive pest of palm according to dozens of literature, a lot of effort have been made since three decades up to date to solve this problem, one of newest solution raised is using nano pesticides. Imidacloprid and Chloropyrophos and their nano form were tested against 10 days-old larvae and newly emerged adults of the red palm weevil. The pesticides had toxicological and pathological effects on Rh. ferrugineus larvae and adults. The toxicity effect of nano chloropyrophos was more than others. The damage included vaculation of cytoplasm, analyzes and destroyed nuclei of the epithelial cells. The larvae were more sensitive in the total damages in comparison with adults. This investigation is the first record to the histopathological effects of nano pesticides.

Cryptosporidiosis among Hemodialysis Patients in Jordan: First Preliminary Screening Surveillance

Few studies have reported the incidence of cryptosporidiosis among hemodialysis patients worldwide. Currently many molecular and immunological assays have been developed for the sensitive diagnosis of cryptosporidiosis, but still, the microscopic detection of the parasitic infective stage (oocysts) in stool specimens using modified acid stain is regarded as a reliable sensitive technique which is widely used in many clinical labs. In the present study, a total of 133 stool samples were collected from hemodialysis patients and were screened for Cryptosporidium oocyst using formalin-ether concentration and modified acid-fast staining technique. Clinical and demographic data were also collected and analyzed. Cryptosporidium oocysts were recovered in 15/133 (11%) of the investigated hemodialysis patients. The age of patients ranged from 25 to 80 years (mean: 57.84 ± 12.22). Most of the Cryptosporidium-positive cases were recovered from males (73.7%) residing in rural villages in Irbid city (86.6%). The most repeatedly reported symptoms in the Cryptosporidium-positive patients were gastrointestinal symptoms, including diarrhea (15%), nausea (24%), abdominal pain (23%) and bloating (17%), in addition to general fatigue (32%) and weight loss (19%). No statistically significant associations for certain clinical symptoms or risk factors were found. The present study is the first preliminary study in Jordan that provided a brief screening for the incidence of cryptosporidiosis among hemodialysis patients.

Spatio-temporal numerical modeling of reaction-diffusion measles epidemic system

In this work, we investigate the numerical solution of the susceptible exposed infected and recovered measles epidemic model. We also evaluate the numerical stability and the bifurcation value of the transmission parameter from susceptibility to a disease of the proposed epidemic model. The proposed method is a chaos free finite difference scheme, which also preserves the positivity of the solution of the given epidemic model.

Prevalence and risk factors associated with cryptosporidiosis among children within the ages 0-5 years attending the Limbe regional hospital, southwest region, Cameroon

Background

Cryptosporidiosis is a pathological condition caused by infection with coccidian protozoan parasites Cryptosporidium. Cryptosporidium is one of the most common causes of childhood diarrhea in developing countries. So far, no data has been published on its prevalence among children with diarrhea in Cameroon. This study was therefore, designed to assess the prevalence and risk factors associated with Cryptosporidiosis among children within the ages 0–5 years suffering from diarrhea and being attended to at the Limbe Regional Hospital.

Methods

The study was a hospital based analytical cross-sectional study involving children within the ages 0–5 years (n = 112) hospitalized or consulted in the pediatric departments of the hospital between April 2018 and May 2018. Stool specimens were processed using the modified acid-fast staining method, and microscopically examined for Cryptosporidium infection.

Results

A total of 112 participants were recruited out of which 67 presented with diarrhea. A high prevalence 9/67 (13.40%) of Cryptosporidium was noticed in children with diarrhea than children without diarrhea 1/45 (2.2%). There was a significant relationship (p = 0.041) between prevalence of Cryptosporidium and the presence of diarrhea in children within the ages 0–5 years in the Limbe Regional Hospital. It was realized that children from parents with primary level of education, children whose parents did not respect exclusive breastfeeding and those whose parents were giving them pipe borne water for drinking recorded a higher prevalence.

Conclusions

This study revealed an overall prevalence of 8.9% for Cryptosporidium among children of ages 0–5 years that attended the Limbe Regional Hospital. The prevalence among children that presented with diarrhea was 13.4%. The study clearly demonstrated that Cryptosporidium is an important protozoal etiologic agent for children with diarrhea in Limbe.

Electronic supplementary material

The online version of this article (10.1186/s12889-019-7484-8) contains supplementary material, which is available to authorized users.

Optimal control for a fractional tuberculosis infection model including the impact of diabetes and resistant strains

The objective of this paper is to study the optimal control problem for the fractional tuberculosis (TB) infection model including the impact of diabetes and resistant strains. The governed model consists of 14 fractional-order (FO) equations. Four control variables are presented to minimize the cost of interventions. The fractional derivative is defined in the Atangana-Baleanu-Caputo (ABC) sense. New numerical schemes for simulating a FO optimal system with Mittag-Leffler kernels are presented. These schemes are based on the fundamental theorem of fractional calculus and Lagrange polynomial interpolation. We introduce a simple modification of the step size in the two-step Lagrange polynomial interpolation to obtain stability in a larger region. Moreover, necessary and sufficient conditions for the control problem are considered. Some numerical simulations are given to validate the theoretical results.

Modeling the interactions among phythopatogens and phyllosphere microorganisms for the biological disease control of Olea europaea L

In this paper we formulate a model for assessing the interaction between the phytopathogen Spilocaea oleaginea and the phyllosphere microorganisms that are present in the olive tree leaves. The model describes the evolution in time of the foliage of the olive tree and the two different microorganisms, the phytopathogen fungi, that negatively affect the plant causing spots in the leaves, and the beneficial phyllosphere microorganisms, that help in keeping in check the invasion of the former. The system possesses five equilibria that are suitably analysed for feasibility and stability. The model shows interesting features: a bistable behavior, exhibited by three different pairs of equilibria. The separatrix surface of the basins of attraction of one such pair is computed. This allows the possible assessment of human intervention for control of the disease. Persistent oscillations via Hopf bifurcation are also discovered.

A theoretical model for Zika virus transmission

In this paper, we present and analyze an SEIR Zika epidemic model. Firstly, we investigate the model with constant controls. The steady states of the model is found to be locally and globally asymptotically stable. Thereafter, we incorporate time dependent controls into the model in order to investigate the optimal effects of bednets, treatments of infective and spray of insecticides on the disease spread. Furthermore, we used Pontryagin’s Maximum Principle to determine the necessary conditions for effective control of the disease. Also, the numerical results were presented.