Route Of Infection Research Articles

An Overview of Chikungunya Disease, Origins, Symptoms, Transmission, Route of Infection, Diagnosis, and Treatment

Chikungunya is a disease caused by the Chikungunya virus (CHIKV), an alphavirus transmitted by a mosquito. This disease has spread to different countries around the world with many outbreaks occurring. Even though CHIKV had already been a mystery since its isolation in 1952, the article provides an overview of the disease’s prevalence, historical background, clinical signs, methods of transmission, laboratory diagnosis, and remedies utilized.

Occurrence and Distribution of Root-Knot Nematodes in Kiwifruit Orchard

The study was conducted to investigate the infestation and distribution of plant-parasitic nematodes on kiwi orchards in Korea. Plant parasitic nematodes genus and densities were investigated at a total of 102 sites in Jeollanam-do, Gyeongsangnam-do, and Jeju-do, which are the main production areas of domestic kiwi orchards. Plant parasitic nematodes detected were of 9 genera, including root-knot nematodes (Meloidogyne spp.), spiral nematodes (Helicotylenchus spp.), and needle nematodes (Paratylenchus spp.), and 56% of the 102 plantations were infected with root-knot nematodes. Root-knot nematodes were found to be the most important plant parasitic nematode in domestic kiwi orchards. The average density of root-knot nematodes is 97 per 300 cm<sup>3</sup> soil, and there is concern about the kiwi yield reduction. As a result of identifying the root-knot nematode species: M. arenaria, M. hapla, M. incognita, and M. javanica. Among them, M. arenaria is the most dominant. As the plant parasitic nematode infection route in fruit trees is often spread through the transplantation of infected seedlings, attention should be paid to the production of nematode-free plants during the production and supply of kiwifruit plants.

The Importance of Animal Models in Biomedical Research: Current Insights and Applications

Animal research is considered a key element in advance of biomedical science. Although its use is controversial and raises ethical challenges, the contribution of animal models in medicine is essential for understanding the physiopathology and novel treatment alternatives for several animal and human diseases. Current pandemics' pathology, such as the 2019 Coronavirus disease, has been studied in primate, rodent, and porcine models to recognize infection routes and develop therapeutic protocols. Worldwide issues such as diabetes, obesity, neurological disorders, pain, rehabilitation medicine, and surgical techniques require studying the process in different animal species before testing them on humans. Due to their relevance, this article aims to discuss the importance of animal models in diverse lines of biomedical research by analyzing the contributions of the various species utilized in science over the past five years about key topics concerning human and animal health.

Gonorrhoea in Poland in 2019-2020.

The aim was the assessment of the epidemiological situation of gonorrhoea in Poland in 2019 and 2020. Case-based data on gonorrhoea from surveillance were used (to calculate the rate, data from the Statistics Poland on the number of population was used), which were compared with data from previous years. Data on patients treated in dermatology-venereology clinics in 2019-2020 were taken from the Statistical Bulletins of the Ministry of Health. The surveillance definition is: a confirmed case (means meeting the laboratory criteria), probable case (clinical criteria and an epidemiological link - contact with a confirmed case of gonorrhoea) and a possible case (the doctor diagnosed gonorrhoea). Year 2019 was the one with the highest number of reported gonorrhoea cases over the 2014-2020 period - 522 cases and 1.37/100,000 population. In 2020, there was a decrease in cases by 47.13% (246 cases and 0.64/100,000 inhabitants). Delays in reporting were identified - between the diagnosis and the first notification for 2019 and 2020, on average, intervened 36 and 52 days, respectively. On the other hand, in dermatologyvenereology clinics, the number of people treated for gonorrhoea did not change - 448 in 2019 and 442 in 2020. 1) The COVID-19 pandemic has deepened the problems of reporting good quality gonorrhoea data in epidemiological surveillance - the planning of appropriate preventive measures in central/local health policies is not possible. Improving surveillance and reporting of complete data on gonorrhoea cases is essential for reliable evaluation of the epidemiological situation. 2) Extensive prophylactic measures should be implemented (including for those under 18 years of age), targeting the source of and to cross routes of infection, including the promotion of safer sexual behaviors and informing the sexual partner.

A vigorous study of fractional order mathematical model for SARS-CoV-2 epidemic with Mittag-Leffler kernel

SARS-CoV-2 and its variants have been investigated using a variety of mathematical models. In contrast to multi-strain models, SARS-CoV-2 models exhibit a memory effect that is often overlooked and more realistic. Atangana-Baleanu’s fractional-order operator is discussed in this manuscript for the analysis of the transmission dynamics of SARS-CoV-2. We investigated the transmission mechanism of the SARS-CoV-2 virus using the non-local Atangana-Baleanu fractional-order approach taking into account the different phases of infection and transmission routes. Using conventional ordinary derivative operators, our first step will be to develop a model for the proposed study. As part of the extension, we will incorporate fractional order derivatives into the model where the used operator is the fractional order operator of order Ψ1. Additionally, some basic aspects of the proposed model are examined in addition to calculating the reproduction number and determining the possible equilibrium. Stability analysis of the model is conducted to determine the necessary equilibrium conditions as they are also required in developing a numerical setup. Utilizing the theory of nonlinear functional analysis, for the model, Ulam-Hyers’ stability is established. We present a numerical scheme based on Newton’s polynomial in order to set up an iterative algorithm for the proposed ABC system. The application of this scheme to a variety of values of Φ1 indicates that there is a relationship between infection dynamics and the derivative’s order. We present further simulations which demonstrate the importance and cruciality of different parameters, as well as their effect on the dynamics and administer the disease. Furthermore, this study will provide a better understanding of the mechanisms underlying contagious diseases, thus supporting the development of policies to control them.

Elevated Temperature, Nitrate and Diesel Oil Enhance the Distribution of the Opportunistic Pathogens Scedosporium spp.

Scedosporium infections mainly occur after aspiration of contaminated water or inoculation with polluted environmental materials. Scedosporium spp. have been isolated from anthropogenic environments frequently. To understand their propagation and routes of infection, possible reservoirs of Scedosporium spp. should be explored. In this study, the impact of temperature, diesel and nitrate on Scedosporium populations in soil is described. Soil was treated with diesel and KNO3 and incubated for nine weeks at 18 and 25 °C. Isolation of Scedosporium strains was done using SceSel+. For the identification of 600 isolated strains, RFLP and rDNA sequencing were used. Scedosporium apiospermum, S. aurantiacum, S. boydii and S. dehoogii were isolated at the beginning and/or the end of incubation. Temperature alone had a minor effect on the Scedosporium population. The combination of 25 °C and nitrate resulted in higher Scedosporium numbers. Treatment with 10 g diesel/kg soil and incubation at 25 °C resulted in even higher abundance, and favored S. apiospermum and S. dehoogii. The results of this study show that diesel-polluted soils favor dispersal of Scedosporium strains, especially S. apiospermum and S. dehoogii. Higher temperature force the effect of supplementations.

Clinical Course and Severity of COVID-19 in 940 Infants with and without Comorbidities Hospitalized in 2020 and 2021: The Results of the National Multicenter Database SARSTer-PED.

This study aimed to analyze the differences in severity and clinical characteristics of COVID-19 in infants hospitalized in Poland in 2021, when the dominance of variants of concern (VOCs) alpha and delta was reported, compared to 2020, when original (wild) SARS-CoV-2 was dominant (III-IV vs. I-II waves of the pandemic, respectively). In addition, the influence of the presence of comorbidities on the clinical course of COVID-19 in infants was studied. This multicenter study, based on the pediatric part of the national SARSTer database (SARSTer-PED), included 940 infants with COVID-19 diagnosed between March 1, 2020, and December 31, 2021, from 13 Polish inpatient centers. An electronic questionnaire, which addressed epidemiological and clinical data, was used. The number of hospitalized infants was significantly higher in 2021 than in 2020 (651 vs. 289, respectively). The analysis showed similar lengths of infant hospitalization in 2020 and 2021, but significantly more children were hospitalized for more than 7 days in 2020 (p < 0.009). In both analyzed periods, the most common route of infection for infants was household contact. There was an increase in the percentage of comorbidities, especially prematurity, in children hospitalized in 2021 compared to 2020. Among the clinical manifestations, fever was predominant among children hospitalized in 2021 and 2020. Cough, runny nose, and loss of appetite were significantly more frequently observed in 2021 (p < 0.0001). Severe and critical conditions were significantly more common among children with comorbidities. More infants were hospitalized during the period of VOCs dominance, especially the delta variant, compared to the period of wild strain dominance, even though indications for hospitalization did not include asymptomatic patients during that period. The course of COVID-19 was mostly mild, characterized mainly by fever and respiratory symptoms. Comorbidities, particularly from the cardiovascular system and prematurity, were associated with a more severe course of the disease in infants.

Evaluation of repRNA vaccine for induction and in utero transfer of maternal antibodies in a pregnant rabbit model

Mother-to-child transmission is a major route for infections in newborns. Vaccination in mothers to leverage the maternal immune system is a promising approach to vertically transfer protective immunity. During infectious disease outbreaks, such as the 2016 Zika virus (ZIKV) outbreak, rapid availability of vaccines can prove critical in reducing widespread disease burden. The recent successes of mRNA vaccines support their evaluation in pregnant animal models to justify their use in neonatal settings. Here we evaluated immunogenicity of self-amplifying replicon (repRNA) vaccines, delivered with our clinical-stage LION nanoparticle formulation, in pregnant rabbits using ZIKV and HIV-1 as model disease targets. We showed that LION/repRNA vaccines induced robust antigen-specific antibody responses in adult pregnant rabbits that passively transferred to newborn kits in utero. Using a matrixed study design, we further elucidate the effect of vaccination in kits on the presence of pre-existing maternal antibodies. Our findings showed that timing of maternal vaccination is critical in maximizing in utero antibody transfer, and subsequent vaccination in newbornsmaintained elevated antibody levels compared with no vaccination. Overall, our results support further development of the LION/repRNA vaccine platform for maternal and neonatal settings.

Occurrence of brown root rot in Ocean Expo Park, Okinawa, Japan: Infection route and preventive control measures

AbstractOcean Expo Park, established in 1976 on subtropical Okinawa Island, Japan, has approximately 8000 planted or naturally grown trees in an area of 77.2 ha. Windfall of these trees occurs mainly due to typhoons; wood chips made from the trunks and roots of windfall trees are commonly used as mulching material throughout the park areas, despite possible infection by pathogenic fungi such as Phellinus noxius, the pathogen causing brown root rot. P. noxius is distributed in tropical and subtropical areas worldwide and has a broad host range. The fungus can infect host plants with mycelia via root‐to‐root contact or with basidiospores. Here, we report the current status of tree damage caused by brown root rot in the park and infer the infection routes of P. noxius based on microsatellite markers. Among a total of 294 trees surveyed in the park, P. noxius was isolated from 13 trees of five species. P. noxius was observed more frequently on Ficus microcarpa than on other tree species. Ficus superba var. japonica was identified as a new host species, and Bombax ceiba was first recorded as a host plant of P. noxius in Japan. Among the 13 P. noxius isolates from the diseased trees, 2 isolates from adjacent diseased trees were considered to be of the same genet, while the other 11 isolates were different genets, indicating that infection by basidiospores occurred frequently among trees in the entire park, although spread via root systems also occurred between at least two adjacent trees. An identical genet was not detected at distant locations, which suggests that the disease does not spread via chips. However, mulching with chips can lead to wood decay due to decaying fungi other than P. noxius. Therefore, in accordance with the precautionary principle, the park currently prohibits the chipping and mulching of windfall or damaged trees and is considering disposal methods such as burning.

Endosymbiont-containing germarium transcriptional survey in a cereal weevil depicts downregulation of immune effectors at the onset of sexual maturity.

Insects often establish long-term relationships with intracellular symbiotic bacteria, i.e., endosymbionts, that provide them with essential nutrients such as amino acids and vitamins. Endosymbionts are typically confined within specialized host cells called bacteriocytes that may form an organ, the bacteriome. Compartmentalization within host cells is paramount for protecting the endosymbionts and also avoiding chronic activation of the host immune system. In the cereal weevil Sitophilus oryzae, bacteriomes are present as a single organ at the larval foregut-midgut junction, and in adults, at the apex of midgut mesenteric caeca and at the apex of the four ovarioles. While the adult midgut endosymbionts experience a drastic proliferation during early adulthood followed by complete elimination through apoptosis and autophagy, ovarian endosymbionts are maintained throughout the weevil lifetime by unknown mechanisms. Bacteria present in ovarian bacteriomes are thought to be involved in the maternal transmission of endosymbionts through infection of the female germline, but the exact mode of transmission is not fully understood. Here, we show that endosymbionts are able to colonize the germarium in one-week-old females, pinpointing a potential infection route of oocytes. To identify potential immune regulators of ovarian endosymbionts, we have analyzed the transcriptomes of the ovarian bacteriomes through young adult development, from one-day-old adults to sexually mature ones. In contrast with midgut bacteriomes, immune effectors are downregulated in ovarian bacteriomes at the onset of sexual maturation. We hypothesize that relaxation of endosymbiont control by antimicrobial peptides might allow bacterial migration and potential oocyte infection, ensuring endosymbiont transmission.

Migrating Anatidae as Sources of Environmental Contamination with Zoonotic Giardia, Cryptosporidium, Cyclospora and Microsporidia.

Giardia, Cryptosporidium, Cyclospora, and microsporidia are gastrointestinal pathogens that can cause various disease symptoms in both animals and humans. Numerous studies worldwide have confirmed the presence of these eukaryotic pathogens in nesting and migrating wild geese, ducks, and swans. Migration spreads these zoonotic enteric pathogens to distant locations, which could have public health implications. Soils and water bodies (lakes, ponds, rivers and wetlands) in urban and suburban areas have been shown to be vulnerable to contamination by waterfowl droppings. This review addresses the epidemiology of these enteric pathogens in wild migratory bird species (Anatidae) and some consequences of their spread in the environment. To date, both zoonotic pathogens and genotypes restricted to avian hosts have been found in faecal samples from 21 anatid species worldwide. One of the routes of infection for these zoonotic gastrointestinal micropathogens is the indirect route. For example, shared water bodies (e.g., for drinking or recreational purposes) previously contaminated by birds during the migratory season may facilitate infections of humans through water. However, it is unclear how much wild waterfowl contribute to the transmission of giardiasis, cryptosporidiosis, cyclosporosis, and microsporidiosis in many regions through contaminated environmental sources. Comprehensive epidemiological surveillance based on molecular data on gastrointestinal pathogens is crucial to take measures to control infections in the future.

Safety of Antiretroviral Therapy in the Treatment of HIV/AIDS in Children: Systematic Review and Meta-analysis.

The safety of using different antiretroviral therapies (ART) in pediatric HIV/AIDS patients is not well-established. Therefore, this study aimed to assess the safety of ART in children. A systematic review of randomized clinical trials (RCTs) was conducted to assess the safety of ART used by pediatric patients living with HIV/AIDS. The electronic search was conducted in PubMed and Scopus, in addition to a manual search. Studies were included if they assessed the safety of ART compared to placebo or another ART. Direct and indirect meta-analyses were conducted regarding safety outcomes. The systematic review included 21 RCTs. The studies included more than 5500 participants, and age ranged from 3 months to 18 years. The drugs evaluated were nucleoside reverse transcriptase inhibitors (NRTI); non-NRTI; and protease inhibitors. The predominant route of infection was vertical. Direct meta-analyses were performed for the outcomes sleep disorders, hepatobiliary disorders, respiratory disorders, hypertransaminasemia, neutropenia, hospitalization, and death. For these outcomes, no statistically significant differences were found. Indirect meta-analyses were performed for the outcomes anemia, gastrointestinal disorders, liver disorders, severe adverse events (AE), AE that led to changes in treatment, fever, and skin manifestations. However, no statistically significant differences were found for these outcomes. In this study, non-significant differences were detected in the safety of different ART used in pediatric individuals. The choice of appropriate therapy should be based on its efficacy and the individual characteristics of each patient.

Tissue Tropism of H9N2 Low-Pathogenic Avian Influenza Virus in Broiler Chickens by Immunohistochemistry

The H9N2 subtype of low-pathogenic avian influenza viruses (LPAIV) is a widespread pathogen of poultry that can also infect humans. The characterization of viral infections is a complex process, involving clinical, pathological, and virological investigations. The aim of this study was to adapt and optimize an immunohistochemical (IHC) technique developed for LPAIVs specifically for the detection of H9N2 virus antigens in infected tissues. Twenty-one-day-old broiler chickens were inoculated with three different strains of H9N2 virus by different infection routes (i.e., intranasal-intratracheal and intravenous) or co-infected with infectious bronchitis virus (IBV) and observed for 11 days post infection. The suggested IHC protocol was modified: (i) DAB (diamino-benzidine) was substituted with AEC (3-amino-9-ethyl carbazole) as chromogen; and (ii) indirect two-step immune reactions of monoclonal primary and peroxidase-labeled anti-mouse secondary antibodies were used instead of avidin-biotin complexes. Avian influenza virus antigen appears as a red precipitate in the nuclei of affected cells but can also be identified in the cytoplasm. Mild hyperemia and congestion were observed in the trachea, air sac, and lungs of the challenged birds, and fibrinous exudate was found at the bifurcation in a few cases. Neither gross pathological nor IHC lesions were found in the control group. Using the optimized protocol and an associated scoring scheme, it was demonstrated that the H9N2 strains tested exhibited respiratory and urinary tract tropism irrespective of the route of inoculation. On day 5, viral antigen was detected in the respiratory tract and kidney in 30-50% of the samples. On day 11, no IHC signal was observed, indicating the lack of viral replication. Slight differences in viral antigen expression were found between the different H9N2 virus strains, but, in contrast to highly pathogenic avian influenza (HPAI), no viral antigen was detected in the brain and pancreas. Thus, IHC can be considered as an informative, visual addition to the toolkit for the characterization of H9N2 LPAIV infections.

Natural history of nonhuman primates after conjunctival exposure to Ebola virus

Transmission of Ebola virus (EBOV) primarily occurs via contact exposure of mucosal surfaces with infected body fluids. Historically, nonhuman primate (NHP) challenge studies have employed intramuscular (i.m.) or small particle aerosol exposure, which are largely lethal routes of infection, but mimic worst-case scenarios such as a needlestick or intentional release, respectively. When exposed by more likely routes of natural infection, limited NHP studies have shown delayed onset of disease and reduced mortality. Here, we performed a series of systematic natural history studies in cynomolgus macaques with a range of conjunctival exposure doses. Challenge with 10,000 plaque forming units (PFU) of EBOV was uniformly lethal, whereas 5/6 subjects survived lower dose challenges (100 or 500 PFU). Conjunctival challenge resulted in a protracted time-to death compared to i.m. Asymptomatic infection was observed in survivors with limited detection of EBOV replication. Inconsistent seropositivity in survivors may suggest physical or natural immunological barriers are sufficient to prevent widespread viral dissemination.

Tracing the origin of large respiratory droplets by their deposition characteristics inside the respiratory tract during speech.

Origin of differently sized respiratory droplets is fundamental for clarifying their viral loads and the sequential transmission mechanism of SARS-CoV-2 in indoor environments. Transient talking activities characterized by low (0.2 L/s), medium (0.9 L/s), and high (1.6 L/s) airflow rates of monosyllabic and successive syllabic vocalizations were investigated by computational fluid dynamics (CFD) simulations based on a real human airway model. SST k-ω model was chosen to predict the airflow field, and the discrete phase model (DPM) was used to calculate the trajectories of droplets within the respiratory tract. The results showed that flow field in the respiratory tract during speech is characterized by a significant laryngeal jet, and bronchi, larynx, and pharynx-larynx junction were main deposition sites for droplets released from the lower respiratory tract or around the vocal cords, and among which, over 90% of droplets over 5 µm released from vocal cords deposited at the larynx and pharynx-larynx junction. Generally, droplets' deposition fraction increased with their size, and the maximum size of droplets that were able to escape into external environment decreased with the airflow rate. This threshold size for droplets released from the vocal folds was 10-20 µm, while that for droplets released from the bronchi was 5-20 µm under various airflow rates. Besides, successive syllables pronounced at low airflow rates promoted the escape of small droplets, but do not significantly affect the droplet threshold diameter. This study indicates that droplets larger than 20 µm may entirely originate from the oral cavity, where viral loads are lower; it provides a reference for evaluating the relative importance of large-droplet spray and airborne transmission route of COVID-19 and other respiratory infections.

Neurologic and cutaneous infection by Clostridium piliforme in a kitten with systemic Tyzzer disease.

Tyzzer disease (TD) is a highly fatal condition of animals caused by Clostridium piliforme and characterized pathologically by enteritis, hepatitis, myocarditis, and occasionally encephalitis. Cutaneous lesions have been reported only rarely in animals with TD, and infection of the nervous system has not been described in cats, to our knowledge. We describe here neurologic and cutaneous infection by C. piliforme in a shelter kitten with systemic manifestations of TD and coinfection with feline panleukopenia virus. Systemic lesions included necrotizing typhlocolitis, hepatitis, myocarditis, and myeloencephalitis. The cutaneous lesions consisted of intraepidermal pustular dermatitis and folliculitis, with necrosis of keratinocytes and ulceration. Clostridial bacilli were identified within the cytoplasm of keratinocytes by fluorescence in situ hybridization, and a PCR assay was positive for C. piliforme. C. piliforme can infect keratinocytes leading to cutaneous lesions in cats with the location suggesting direct contact with contaminated feces as a route of infection.

The BALB/c Mouse Model for the Evaluation of Therapies to Treat Infections with Aerosolized Burkholderia pseudomallei.

Burkholderia pseudomallei, the causative agent of the disease melioidosis, has been isolated from the environment in 45 countries. The treatment of melioidosis is complex, requiring lengthy antibiotic regimens, which can result in the relapse of the disease following treatment cessation. It is important that novel therapies to treat infections with B. pseudomallei be assessed in appropriate animal models, and discussions regarding the different protocols used between laboratories are critical. A 'deep dive' was held in October 2020 focusing on the use of the BALB/c mouse model and the inhalational route of infection to evaluate new antibiotic therapies.

A highly energy-efficient magnetoelectric–photocatalytic coupling for water remediation

Contaminated water is one of the main infection routes for serious diseases, and water remediation of different environmental contaminations is an urge today. Here, we introduce a novel high-μ ribbon FeBSi–ZnO magnetoelectric (ME) nanocomposite that exhibits a magnetoelectric–photocatalytic (MEPC) coupling effect, which further enhances electrochemical activity for water remediation. Compared to the previously reported ultrasonic piezoelectric-photocatalytic technique, the proposed MEPC coupling system is 100–1200 times more energy-efficient. This energy-efficient catalysis can be attributed to the effective charge energy shifting generated by the low-power MEPC coupling system, which promotes the surface redox reaction via transferred electrons and holes and generation of the reactive oxygen species of •O−2 and •OH. It is also found that the kinetic rate of organic pollutant degradation under MEPC activity is approximately three times faster than that of a pure PC process. The degradation efficiency for indigo carmine (IC), methyl orange (MO), and rhodamine B (RB) organic pollutants is 98% (less than 60 min), 97%, and 92% within 120 min, respectively. Also, MEPC activity could conduct 99.9% reduction of E. coli bacteria within 30 min. This study, therefore, provides an original MEPC system and an effective strategy for the sustainable environmental remediation endowed with an energy-efficient and low-cost nature owing to the multiphysical field synergetic effect.

Symptoms and Prevention Measures of Erysipelas Disease in Pigs

Pig erysipelas is caused by pig erysipelas a kind of acute febrile zoonotic disease, disease quickly, pigs die within 2-4 days, route of infection with endogenous, digestive tract infection, blood sucking insects feeding, skin contact, the disease if not timely control, will threaten the healthy growth of pigs, seriously affect the farmers' actual income. Transmission and spread of erysipelas in pigs. The disease is clinically characterized by high fever and acute death, and is characterized by sow abortion, which can cause infection of pigs and all kinds of animals. After pigs infected with bacteria, various diseases can occur, and then cause pig erysipelas. To the public, the pig industry caused huge economic losses. A comprehensive understanding of erysipelas is important for the prevention and treatment of the disease. The source, route of transmission, prevalence and comprehensive control of the disease are summarized. Pig erysipelas strategy, designed to provide evidence.

KIR2DL4/HLA-G polymorphisms were associated with HCV infection susceptibility among Chinese high-risk population.

Killer-cell immunoglobulin-like receptors 2DL4 (KIR2DL4) and the human leukocyte antigen class I-G (HLA-G) display vital parts in immune responses against hepatitis C virus(HCV) infection. We select four potentially functional single nucleotide polymorphisms(SNPs) of KIR/HLA to explore the associations between KIR2DL4/HLA-G genetic variants and HCV infection results.In the present case-control study, a total of 2225 HCV-infected high-risk subjects, including 1778 paid blood donors (PBD) and 447 drug users were consecutively recruited before treatment from 2011 to 2018. KIR2DL4-rs660773, KIR2DL4-rs660437, HLA-G-rs9380142, and HLA-G-rs1707 SNPs were sorted as genotypes in the subdivided groups, involving 1095 uninfected controls subjects, 432 spontaneous HCV clearance subjects and 698 HCV persistent infection subjects. After genotyping experiments using the TaqMan-MGBassay, modified logistic regression was used to calculate the correlation among the SNPs and HCV infection. The SNPs were functionally annotated using bioinformatics analysis.Following adjusting by age, sex, alanine aminotransferase, aspartate aminotransferase, IFNL3-rs12979860, IFNL3-rs8099917, and the infection route, the logistic regression analysisdiscovered that KIR2DL4-rs660773 and HLA-G-rs9380142 were correlated with vulnerability to HCV infection (all p < 0.05). In a locus-dosage way, compared with subjects carrying the rs9380142-AA or rs660773-AA genotypes, subjects with rs9380142-AG or rs660773-AG/GG (all p < 0.05) were more vulnerable to HCV infection; the overall impact of their risk genotypes (rs9380142-AGrs660773-AG/GG) was correlated with an elevated incidence of HCV infection (ptrend < 0.001). In the Haplotype analysis, patients with haplotype AG were more likely to contract HCV compared to those with the highest common AA haplotype (p = 0.002) were higher in susceptibility to infect HCV. The SNPinfo web server estimated that rs660773 is a transcription factor binding site, whereas rs9380142 is a potential microRNA-binding site.In two Chinese high-risk population (PBD and drug uesrs), KIR2DL4 rs660773-G and HLA-G rs9380142-G alleles polymorphisms are related to HCV susceptibility. KIR2DL4/HLA-G pathway genes might affect the innate immune responses by regulating KIR2DL4/HLA-G transcription and translation play a potential role in HCV infection.