Analysis of pathogen detection results of upper respiratory tract specimens from fever clinic patients

Objective: To explore the pathogen composition and distribution characteristics of pathogens in respiratory samples from patients with fever of unknown origin. Methods: A total of 96 respiratory samples of patients with unknown cause fever with respiratory symptoms were collected from four hospitals above grade II in Shijiazhuang area (Hebei Provincial Hospital of Traditional Chinese Medicine, Luancheng District People's Hospital, Luquan District People's Hospital, Shenze County Hospital) from January to April 2020, and multiplex-fluorescent polymerase chain reaction(PCR)was used to detect influenza A virus, influenza B virus, enterovirus, parainfluenza virus I/II/III/IV, respiratory adenovirus, human metapneumovirus, respiratory syncytial virus, human rhinovirus, human bocavirus, COVID-19, Mycoplasma pneumoniae, Chlamydia pneumoniae, Legionella pneumophila, Pseudomonas aeruginosa, Streptococcus pneumoniae, Klebsiella pneumoniae, Group A streptococcus, Haemophilus influenzae, Staphylococcus aureus nucleic acid detection, the results were analyzed for chi-square. Results: A total of 8 pathogens were detected in the upper respiratory tract samples of 96 fever patients, including 1 kind of virus, 6 kinds of bacterias, and Mycoplasma pneumoniae. There were 12 viruses including influenza virus and parainfluenza virus, Legionella pneumophila and Chlamydia pneumoniae were not detected. The pathogen detection rates in descending order were Streptococcus pneumoniae (58/96, 60.42%), Haemophilus influenzae(38/96, 39.58%), Klebsiella pneumoniae (14/96, 14.58%), Staphylococcus aureus (10/96, 10.42%), Mycoplasma pneumoniae (8/96, 8.33%), Pseudomonas aeruginosa (6/96, 6.25%), Group A streptococcus (4/96, 4.17%) and human rhinovirus (2/96, 2.08%). The proportions of single-pathogen infection and multi-pathogen mixed infection in fever clinic patients were similar, 41.67% (40/96) and 45.83% (44/96), respectively, and 12.50% (12/96)of the cases had no pathogens detected. The infection rate of Mycoplasma pneumoniae in female patients with fever (21.43%) was higher than that in male patients with fever (2.94%) (P < 0.05). There was no statistical difference between the distribution of of other pathogens and gender and age(P > 0.05). Conclusions: The upper respiratory tract pathogens were mainly bacterial infections, and occasional human rhinovirus and Mycoplasma pneumonia infections. In clinical diagnosis and treatment, comprehensive consideration should be given to the pathogen detection.

Recent progresses in rapid detection of novel coronavirus SARS-CoV-2

The global pandemic coronavirus pneumonia (COVID-19), the disease infected by the new coronavirus (SARS-CoV-2), is extremely contagious. It is mainly spread among people through respiratory droplets, aerosols, direct or indirect contact, fecal-oral transmission, and cold chain transportation. Especially, patients who are in the incubation period or have no obvious symptoms already have the ability to infect others. SARS-C0V-2 is a positive-sense single-stranded RNA virus, with a single linear RNA segment. Each SARS-CoV-2 virion is 60-140 mm in diameter. Like other coronaviruses, SARS-CoV-2 has four structural proteins, known as the spike (S), envelope(E), membrane (M), and nucleocapsid (N) proteins. To date, a variety of detection methods for the SARS-CoV-2 have been developed based on the virus structural basis and 'etiological characteristics, which would provide an effective guarantee for the diagnosis of COVID-19 patients and the control of the epidemic. In order to help for the early diagnosis and prevention of COVID-19, the pathogenic characteristics and recent progresses of detection base on nucleic acid, immunology and biosensors of the SARS-CoV-2 are reviewed in this paper.

Silent superbug killers in a river near you how factory farms contaminate public water courses on three continents

Water downstream from factory farms harbours an invisible threat to people's health which could eclipse the COVID-19 crisis. The threat? Antibiotic Resistance Genes (ARGs) which are driving antimicrobial resistance the world's superbug crisis - projected to kill up to 10 million people annually by 2050. This publication reports the presence of ARGs in animal waste discharged from industrial farms into public waterways or onto soil (or crops) in four countries. Gauge community impact and sentiment regarding the issue was also highlighted. The water and sediment from public water courses connected to effluent discharges from 6-10 pig farms were tested in each of four countries (Canada, Spain, Thailand and the USA).

An outbreak of school influenza complicated with Mycoplasma pneumoniae infection

Objective: To describe the clinical features, causal agent and transmission mode of a fever outbreak in a school in Shanghai. Methods: Field epidemiological approaches including case definition development, searching for contacts, distribution of diseases description, environmental sampling and laboratory testing. Results: A total of 16 influenza-like cases were included, all concentrated in the one class of grade two, including 15 students and 1 teacher. Among student cases, the incidence rate was 36.59%(15/41), the average age was 7.4 years, the incidence rate was 36.84%(7/19) for boys, 36.36%(8/22) for girls. The clinical course was 5-15 days, with the median of 9 days, and 18.75%(3/16) of the cases stayed studying while sick. The nasopharyngeal swab specimens in 16 cases all tested positive for influenza B, of which 11 tested positive for mycoplasma pneumoniae and 1 case also tested positive for coronavirus OC43. Body temperature, number of mononuclear cells, and treatment time of patients infected with Influenza B and mycoplasma pneumoniae were higher than those of patients infected with influenza B alone(P < 0.05). The outbreak lasted for 12 days, all sick students were treated and discharged from hospital, with no severe cases or death, and the outbreak was effectively controlled. Conclusion: This campus cluster outbreak caused by influenza B and mycoplasma pneumoniae. Patients with influenza B with mycoplasma pneumoniae have severe symptoms and a long course of illness, suggesting the importance of early management of the epidemic.

Risky business: how Peru's wildlife markets are putting animals and people at risk

This publication presents Peru's illegal wildlife trade activity before and after Covid-19 pandemic which creates a perfect conditions for zoonotic emerging infectious diseases such as SARS-CoV-2 to emerge and spread among animals and people, thus recommendations to prevent this scenario are highlighted.

Multi-country outbreak of severe acute hepatitis of unknown origin in children, 2022.

AIM: To describe epidemiological characteristics of multi-country outbreak of severe acute hepatitis of unknown origin in children in 2022. METHODS: A descriptive epidemiological study design was used. The review based on the available information concerning this multi-country outbreak aims to summarise the current knowledge about the severe acute hepatitis of unknown origin in children, highlights the suggested working hypotheses, introduces some of the potential explanations for its occurrence and reports on public health measures undertaken to control the disease. RESULTS: Since the first 10 cases of severe acute hepatitis of unknown origin in children in the United Kingdom on 5 April 2022, and up until the 29 August 2022, more than 1000 probable cases have been reported in 35 countries in the world. Up to today, 22 children died in this multi-country outbreak. Despite the numerous theories that have been suggested on the possible underlying causes of the outbreak, an association with hepatitis A-E viruses has been excluded. Adenovirus serotype 41 has been detected in numerous cases, which makes it the most likely underlying cause of the disease. CONCLUSION: Efficient surveillance and comprehension advancements of the epidemiology of this disease are especially important for effective prevention and outbreak response.

Recent progresses in rapid detection of novel coronavirus SARS-CoV-2

The global pandemic coronavirus pneumonia (COVID-19), the disease infected by the new coronavirus (SARS-CoV-2), is extremely contagious. It is mainly spread among people through respiratory droplets, aerosols, direct or indirect contact, fecal-oral transmission, and cold chain transportation. Especially, patients who are in the incubation period or have no obvious symptoms already have the ability to infect others. SARS-C0V-2 is a positive-sense single-stranded RNA virus, with a single linear RNA segment. Each SARS-CoV-2 virion is 60-140 mm in diameter. Like other coronaviruses, SARS-CoV-2 has four structural proteins, known as the spike (S), envelope(E), membrane (M), and nucleocapsid (N) proteins. To date, a variety of detection methods for the SARS-CoV-2 have been developed based on the virus structural basis and 'etiological characteristics, which would provide an effective guarantee for the diagnosis of COVID-19 patients and the control of the epidemic. In order to help for the early diagnosis and prevention of COVID-19, the pathogenic characteristics and recent progresses of detection base on nucleic acid, immunology and biosensors of the SARS-CoV-2 are reviewed in this paper.

Changing spatiotemporal patterns for hepatitis of unspecified aetiology in China, 2004-2021: a population-based surveillance study.

Objectives: As global efforts continue toward the target of eliminating viral hepatitis by 2030, the emergence of acute hepatitis of unspecified aetiology (HUA) remains a concern. This study assesses the overall trends and changes in spatiotemporal patterns in HUA in China from 2004 to 2021. Methods: We extracted the incidence and mortality rates of HUA from the Public Health Data Center, the official website of the National Health Commission of the People's Republic of China, and the National Notifiable Infectious Disease Surveillance System from 2004 to 2021. We used R software, ArcGIS, Moran's statistical analysis, and joinpoint regression to examine the spatiotemporal patterns and annual percentage change in incidence and mortality of the HUA across China. Results: From 2004 to 2021, a total of 707,559 cases of HUA have been diagnosed, including 636 deaths. The proportion of HUA in viral hepatitis gradually decreased from 7.55% in 2004 to 0.72% in 2021. The annual incidence of HUA decreased sharply from 6.6957 per 100,000 population in 2004 to 0.6302 per 100,000 population in 2021, with an average annual percentage change (APC) reduction of -13.1% (p < 0.001). The same result was seen in the mortality (APC, -22.14%, from 0.0089/100,000 in 2004 to 0.0002/100,000 in 2021, p < 0.001). All Chinese provinces saw a decline in incidence and mortality. Longitudinal analysis identified the age distribution in the incidence and mortality of HUA did not change and was highest in persons aged 15-59 years, accounting for 70% of all reported cases. During the COVID-19 pandemic, no significant increase was seen in pediatric HUA cases in China. Conclusion: China is experiencing an unprecedented decline in HUA, with the lowest incidence and mortality for 18 years. However, it is still important to sensitively monitor the overall trends of HUA and further improve HUA public health policy and practice in China.

Coinfection in the cases of feline panleukopenia: a literature review

Coinfection caused by bacteria, parasites, or viruses complicates almost all feline panleukopenia virus (FPV) infections. Pathogens that colonize the gastrointestinal tract, Clostridium perfingens, Clostridium piliforme, Cryptosporidium spp, Giardia spp, Tritrichomonas fetus, canine parvovirus type 2,Salmonella sp., feline coronavirus, feline bocavirus, and feline astrovirus were isolated in the presence of FPV infection. Complex mechanisms between viruses, bacteria, protozoa, and hosts contribute to the pathogenesis and severity of coinfection. Prompt and accurate diagnosis, vaccination precautions, and appropriate treatment play important roles in reducing morbidity and mortality. This article outlines the etiology, pathogenesis, diagnosis, prevention, and treatment that can help veterinarians and pet owners improve their knowledge of managing the diseases.

Focus on laryngeal disease in the cat

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Identification of priority pathogens for aetiological diagnosis in adults with community-acquired pneumonia in China: a multicentre prospective study.

BACKGROUND: Community-acquired pneumonia (CAP) is a major public health challenge worldwide. However, the aetiological and disease severity-related pathogens associated with CAP in adults in China are not well established based on the detection of both viral and bacterial agents. METHODS: A multicentre, prospective study was conducted involving 10 hospitals located in nine geographical regions in China from 2014 to 2019. Sputum or bronchoalveolar lavage fluid (BALF) samples were collected from each recruited CAP patient. Multiplex real-time PCR and bacteria culture methods were used to detect respiratory pathogens. The association between detected pathogens and CAP severity was evaluated. RESULTS: Among the 3,403 recruited eligible patients, 462 (13.58%) had severe CAP, and the in-hospital mortality rate was 1.94% (66/3,403). At least one pathogen was detected in 2,054 (60.36%) patients, with two or more pathogens were co-detected in 725 patients. The ten major pathogens detected were Mycoplasma pneumoniae (11.05%), Haemophilus influenzae (10.67%), Klebsiella pneumoniae (10.43%), influenza A virus (9.49%), human rhinovirus (9.02%), Streptococcus pneumoniae (7.43%), Staphylococcus aureus (4.50%), adenovirus (2.94%), respiratory syncytial viruses (2.35%), and Legionella pneumophila (1.03%), which accounted for 76.06-92.52% of all positive detection results across sampling sites. Klebsiella pneumoniae (p < 0.001) and influenza viruses (p = 0.005) were more frequently detected in older patients, whereas Mycoplasma pneumoniae was more frequently detected in younger patients (p < 0.001). Infections with Klebsiella pneumoniae, Staphylococcus aureus, influenza viruses and respiratory syncytial viruses were risk factors for severe CAP. CONCLUSIONS: The major respiratory pathogens causing CAP in adults in China were different from those in USA and European countries, which were consistent across different geographical regions over study years. Given the detection rate of pathogens and their association with severe CAP, we propose to include the ten major pathogens as priorities for clinical pathogen screening in China.

Concern over global outbreak of acute severe hepatitis of unknown etiology in children

Acute severe hepatitis in children of unknown cause is a childhood liver disease of unknown etiology that emerged suddenly during the global pandemic of coronavirus disease 2019. Since it was reported in early April 2022, it has involved more than 20 countries around the world with about 450 cases, mainly in Europe and North America, and no similar case has been reported in China. The disease occurs mostly in children under 5 years of age and is characterized mainly by liver disease manifestations such as jaundice and elevated transaminases, with rare respiratory symptoms;a few cases develop into liver failure and need liver transplantation, and most cases have a good prognosis. The disease is currently considered to be caused by infection, but the exact pathogen remains unclear. Adenovirus is detected in blood in many cases, so the possibility of infection caused by adenovirus should be considered;and factors such as lack of trained immunity and persistent inflammatory in children with COVID-19 should also be considered. The disease is no evidence of interpersonal transmission, infectivity is low, but the possibility of a pandemic outbreak in countries with a high prevalence of COVID-2019 needs to be guarded against;hand hygiene and respiratory protection may reduce the risk of morbidity. This article provides an overview of the epidemiological and clinical features of the disease and analyzes its nature, etiology and transmission risk in order to provide updated awareness of its clinical diagnosis and treatment.

Evaluation and analysis of rates of bacterial co-infections and antimicrobial usage in COVID-19 patients: a retrospective cohort analysis

Background: The coronavirus disease 2019 (COVID- 19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread over the world. Although there are minimal microbiological and antibiotic data on COVID-19, bacterial co-infections have been related to poor outcomes in respiratory viralinfections. Adequate antibiotic use in conformity withantibiotic stewardship (ABS) recommendations is necessary during the pandemic. Material and procedure: We conducted a retrospective single-center cohort analysis of 140 adulthospitalised patients (ages 17-99) with confirmed COVID-19 who were admitted between February 16, 2021, and April 22, 2021, and who were discharged onMay 6, 2021. From 140 COVID-19 participants, the following clinical data was gathered: Men made up 63.5 percent of the participants, with a median age of 63.5 years (range 17-99). Results: According to local ABS recommendations, the most commonly administered antibiotic regimen was ampicillin/sulbactam (41.5 percent) with a median length of 6 (range 1-13) days. Urine antigen testing for Legionella pneumophila and Streptococcus peumoniaewas negative in all of the patients. In critically ill patients hospitalised to intensive care units (n = 50), co-infections with Enterobacterales (34.0%) and Aspergillus fumigatus (18.0%) were discovered. Blood cultures obtained at admission had a diagnostic yield of 4.2 percent. Conclusion: While bacterial and fungal co-infections are rare in COVID-19 patients, they are widespread in critically ill individuals. More investigation into the impact of antimicrobial therapy on therapeutic success in COVID-19 patients is essential to prevent antibiotic abuse. COVID-19 management might be improved with the aid of ABS standards. It's also necessary to look at the microbiological patterns of infectious consequences in COVID-19 individuals who are severely unwell.

Prospect of Vaccinia virus vector vaccine for wildlife

Against a pandemic of emerged infectious disease, COVID-19, new generation vaccines based on nucleic acids or recombinant viruses, which had not been used as vaccines in humans, have been inoculated and shown to be successful. They are, however, heat-labile and need a cold-chain including deep-freezers for storage and transportation. Vaccinia virus (VAC) vector vaccine (VACV) is a pioneer of new generation of vaccines constructed by using molecular biological technology. VACV, which has contributed to eradication of smallpox, has excellent characteristics of vaccinia virus such as a high heat-stability and long-lasting immunological effects. It is possible to distinguish the immunological responses of vaccination from those of natural infections. We started our developmental researches 35 years ago, using attenuated VAC strains established in Japan. In this article, we first describe the early researches of VACVs;development of two VACVs for Bovine leukemia virus and Rinderpest morbillivirus antigens and their protective immunity in large mammals, sheep and cows. Second, application of VACV is described;Rabies-VACV, which has already been licensed, used in the field in Europe and USA, and resulted in a prominent decrease of rabies. Then, current status of VACV research is described;non-replicating VACVs in mammalian cells have been developed as new-generation and ultimately-safe vaccines. We discuss the possibility of future application of VACV for wildlife.

Fumbling out the effective pathways to apply the wildlife and forest analytic toolkit in the Mekong region: looking at data and analysis perspectives

The Wildlife and Forest Analytic Toolkit, introduced by the International Consortium on Combating Wildlife Crime (ICCWC), is designed to increase the effectiveness of measures combating wildlife and forest crimes (WAFCs). Greater Mekong Subregion (GMS) countries have applied this toolkit as one of their priority actions after recognizing concerns about the biodiversity system and conservational zone through several illegal wildlife trade (IWT) activities. Although the toolkit has realized its fundamental objectives to readjust legal frameworks, enhance enforcement involvement, and improve their judicial and prosecutorial operations, the last components of data and analysis have not yet been implemented. This leads to slow updates of both trends and patterns concerning WAFCs that raise questions about the real levels of exploitation in the region. Using gray literature with published materials, combined with the IWT's database in the CITES system, this study examines why the data and analysis component of the Toolkit created obstacles in the GMS countries. Findings point to there being at least four main challenges to implementing data and analysis as the toolkit has recommended in the region: (1) availability and reliability of data;(2) data collection;(3) data resources (internal vs. external level);and (4) analytic research and its related monitors. Some practical recommendations call for further discussions. Meanwhile, updated information and specific data relating to zoonotic disease transmission are timely, considering the coronavirus pandemic.

Possession of exotic animals and zoonotic diseases: an approach from the Mexican context

The possession of exotic animals as pets is a social practice that has become more visible in Mexico in recent years, so it is interesting to understand its environmental and social implications and those related to human health. The present study aims to identify the main species of exotic animals kept as pets and the zoonotic diseases reported in these species. We analyzed official figures of seizures of exotic fauna in Mexico and reviewed specialized literature on zoonotic diseases documented in Mexico in these species. We identified zoonoses in species of fauna that can be acquired legally and illegally in the country, reported in environments in which animals coexist with other species and are in direct contact with people, which represents an important factor in the spread and propensity of this type of disease. We conclude that the sanitary regulation of wildlife markets, the monitoring and studying microorganisms associated with wildlife are valuable strategies to prevent the emergence of zoonoses.

Acute severe non-A-E-hepatitis of unknown origin in children - A 30-year retrospective observational study from north-west Germany.

BACKGROUND & AIMS: The etiology of the current acute severe non-A-E hepatitis epidemic in children remains unclear. We aimed to describe the occurrence and outcomes of acute severe hepatitis in pediatric patients in North-West Germany over a period of more than 30 years and in the context of the current epidemic. METHODS: We analyzed all cases of acute severe hepatitis in childhood, as defined by the World Health Organization, at Hannover Medical School from 1990 and at the University Hospital of Essen from 2009 to 16 May 2022. We separated cases into a historic cohort (1990-2018) and a COVID-19 era cohort (2019-2022). RESULTS: After application of exclusion criteria, 107 patients with acute severe hepatitis were identified (2.32 cases/center/year). Annual incidence per center rose significantly from 2.2 (historic cohort until 2018) to 4.25/center/year (from 2019, p = 0.002). Of all cases, 75.7% presented with jaundice, while 53.3% had clinical signs of infection. Two cases of adenovirus were proven (2004/2016), other pathogens detected were HHV-6 (4), CMV, HSV, EBV(3). Sixty-nine patients (64.5%) met the criteria of pediatric acute liver failure, with 44 requiring liver transplantation. In the current cohort, patients with infection, gastrointestinal symptoms and higher alanine aminotransferase had a better chance of transplant-free survival, whereas hepatic encephalopathy, higher international normalized ratio and bilirubin predicted a poor outcome. Twenty-five patients developed hepatitis-associated aplastic anemia and 19 patients (17.8%) died. CONCLUSIONS: Acute non-A-E-hepatitis in children is a rare but severe entity, often leading to acute liver failure. Clinical presentation in our current cohort resembles 2022 NAEH cases, with improved outcomes compared to historic controls. The rising incidence of NAEH in our centers since 2019, in the absence of adenoviral infection, indicates other potential triggers of similar NAEH cases. IMPACT AND IMPLICATIONS: As the current epidemic of severe acute non-A-E-hepatitis cases in children highlights our limited understanding in the field, we aim to describe current cases, characterizing the presentation over time, and defining similarities and discrepancies before and during the COVID-19 pandemic. Our data show a rising incidence of non-A-E-hepatitis cases since the beginning of the COVID-19 pandemic. These cases were not associated with adenoviral infections, suggesting that the recently described accumulation of adenovirus infections in relationship to hepatitis is a new trigger for a known phenomenon, rather than a new disease entity. Therefore, the role of protective isolation and subsequent lack of contact with trivial infections in children during the pandemic should be the subject of further examinations. We expect our data to contribute to a better understanding of severe acute hepatitis in childhood, increased vigilance for this potentially lethal disease beyond the current epidemic, and ultimately improved clinical diagnosis and care.

Acute severe hepatitis outbreak in children: A perfect storm. What do we know, and what questions remain?

During the first half of 2022, the World Health Organization reported an outbreak of acute severe hepatitis of unknown aetiology (AS-Hep-UA) in children, following initial alerts from the United Kingdom (UK) where a cluster of cases was first observed in previously well children aged <6 years. Sporadic cases were then reported across Europe and worldwide, although in most countries incidence did not increase above the expected baseline. There were no consistent epidemiological links between cases, and microbiological investigations ruled out known infectious causes of hepatitis. In this review, we explore the evidence for the role of viral infection, superimposed on a specific host genetic background, as a trigger for liver pathology. This hypothesis is based on a high prevalence of Human Adenovirus (HAdV) 41F in affected children, together with metagenomic evidence of adeno-associated virus (Adeno-associated viruses)-2, which is a putative trigger for an immune-mediated liver injury. Roles for superantigen-mediated pathology have also been explored, with a focus on the potential contribution of SARS-CoV-2 infection. Affected children also had a high frequency of the MHC allele HLA-DRB1*04:01, supporting an immunological predisposition, and may have been vulnerable to viral coinfections due to disruption in normal patterns of exposure and immunity as a result of population lockdowns during the COVID-19 pandemic. We discuss areas of ongoing uncertainty, and highlight the need for ongoing scrutiny to inform clinical and public health interventions for this outbreak and for others that may evolve in future.

Detection of human adenovirus F41 in wastewater and its relationship to clinical cases of acute hepatitis of unknown aetiology

As of 8 July 2022, the World Health Organization (WHO) have reported 1010 probable cases of acute hepatitis of unknown aetiology in children worldwide, including approximately 250 cases in the United Kingdom (UK). Clinical presentations have often been severe, with liver transplantation a frequent clinical outcome. Human adenovirus F41 (HAdV-F41) has been detected in most children with acute hepatitis, but its role in the pathogenesis of this infection has yet to be established. Wastewater-based epidemiology (WBE) has become a well-established tool for monitoring the community spread of SARS-CoV-2, as well as other pathogens and chemicals. In this study, we adopted a WBE approach to monitoring levels of HAdV-F40/41 in wastewater before and during an acute hepatitis outbreak in Northern Ireland. We report increasing detection of HAdV-F40/41 in wastewater, concomitant with increasing numbers of clinical cases. Amplicon whole genome sequencing further classified the wastewater-derived HAdV as belonging to the F41 genotype which in turn was homologous to clinically derived sequences. We propose that WBE has the potential to inform community surveillance of HAdV-F41 and can further contribute to the ongoing global discussion supporting HAdV-F41 involvement in acute hepatitis cases. © 2022 The Authors

The similarities and differences between SARS-CoV-2 and Human immunodeficiency virus

Both coronavirus disease 2019(COVID-19) and acquired immune deficiency syndrome(AIDS) are known as category B infectious diseases, which were caused respectively by SARS-CoV-2 and human immunodeficiency virus(HIV). Although HIV infection is not a risk factor for COVID-19, latest clinical studies have shown that HIV-positive COVID-19 patients experience longer disease course and are more likely to have severe COVID-19 compared with HIV-negative COVID-19 patients, especially those with low CD4+ T cells count or with no antiretroviral therapy(ART).In this review, we aim to compare the etiological and pathogenetic differences between COVID-19 and AIDS, and to elucidate the immunological and virologic characteristics of HIV-positive COVID-19 patients, which helps for a better understanding of SARS-CoV-2 and HIV co-infections.