Outbreak Of Human Infection Research Articles

Assessment of bacterial and parasitic contamination of fruits gathered from specific local markets in Addis Ababa, Ethiopia

BackgroundAround the world, food-borne illnesses are still a frequent and significant hazard to public health. Human infection outbreaks brought on by eating raw fruits have happened more frequently. Fruits have been connected in recent years to a number of outbreaks of food-borne illness around the globe, including in Ethiopia.ObjectiveTo assess bacterial and parasitic contamination of fruits gathered from specific local markets in Addis Ababa, Ethiopia.MethodsA cross-sectional study was carried out using fruits gathered from Addis Ababa local marketplaces. Convenient sampling were applied. With the assumption that each vendor provided 30 samples, a total of 120 fruit samples were gathered. Fruit samples were gathered in a plastic bag that had been sanitized and then brought to the lab for bacterial and parasitological investigation. All of the samples were checked for intestinal parasites and bacterial contamination. SPSS software version 25 was used to analyze the data. The Pearson's Chi-square test was used to assess categorical variables. The student's t-test was utilized to compare continuous variables, which were represented as the mean ± standard deviation. Using both univariate and multivariate analysis, odds ratios (OR) with 95% confidence intervals (CI) were computed. Statistical significance was defined as a P < 0.05.ResultsThere was a 100 (83.3%) level of bacterial contamination. While Salmonella and Shigella species were not recovered, S. aureus isolates 16 (13.3%) were the most common bacterial contamination, followed by E. coli isolates 8 (6.7%). The samples of bananas, mangos, papayas, and avocados from all four sites had total coliform (TCC) bacteria ranging from 2.1 × 103 to 3.2 × 104, 8.3x 102 to 1.8x 105CFU/g, 1.6x 102 to 3.7 x 104, and 1.2x 102 to 3.8 x 104 CFU/g, in that order. No parasites were found in this investigation.Conclusion and recommendationIt is usually recommended that customers in this research region wash and handle infected fruits properly to prevent bacterial illnesses. In addition, fruit dealers should have their bacterial contaminations routinely inspected. Large-scale research is advised to support this discovery.

Detection and molecular characterization of West Nile virus in Culex pipiens mosquitoes in Central Macedonia, Greece, 2019–2021

Since 2010 when West Nile virus (WNV) emerged in Greece, it causes seasonal outbreaks of human infections almost every year. During May-October of 2019–2021 a total number of 51,504 Culex pipiens mosquitoes were trapped in all seven regional units of Central Macedonia in northern Greece. They were grouped into 1099 pools and tested for WNV. The virus was detected in 5% of the mosquito pools (1.5%, 3.6% and 9.6% pools in 2019, 2020, and 2021, respectively), with significant rate differences among the regional units and years. The highest maximum likelihood estimation for WNV infection rates calculated per 1000 mosquitoes for 2019 and 2020 were 1.89 and 3.84 in Serres, and 7.08 for 2021 in Pella regional unit. Sixteen whole genome sequences were taken by applying a recently described PCR-based next generation sequencing protocol. Phylogenetic analysis showed that the sequences belonged to the Central European clade of WNV lineage 2, and that a virus strain introduced in Greece in 2019 continued to circulate and spread further during 2020–2021. The data are useful for public health and mosquito control programs' operational scheduling, while the whole genome sequences are an added value for molecular epidemiology and evolutionary studies.

Human Polymorphonuclear Cells Support Zika Virus to Cross Endothelial Monolayer and Access Bloodstream

The rapid spread of new outbreaks of human infection caused by Zika virus (ZIKV) has raised many global concerns since 2016. Despite the increasing knowledge of this virus, data on the pathogenesis of ZIKV are still missing. In particular, it is still unknown how the virus crosses the endothelial monolayer and gets access to the bloodstream. In the present work, we used human umbilical vein endothelial cells (HUVECs) as a model to study ZIKV infection in vitro. We demonstrated that HUVECs are an optimal reservoir for viral replication, as they were able to sustain ZIKV infection up to two weeks, without showing a cytopathic effect. In order to evaluate the integrity of endothelial monolayer, immunofluorescence was performed on mock-infected or ZIKV-infected cells ± peripheral blood mononuclear cells (PBMCs) or polymorphonuclear cells (PMN), 48 h p.i., by using an anti-VE-Cadherin antibody, a major adherence protein that maintains the integrity of intercellular junctions. In addition to infection, we noted that the presence of some components of the immune system, such as PMNs, played an important role in altering the endothelial monolayer in cell junctions, suggesting that presence at the site of infection probably promotes the spread of ZIKV in vivo in the bloodstream.

Human antibody recognition of H7N9 influenza virus HA following natural infection.

Avian H7N9 influenza viruses cause sporadic outbreaks of human infections and threaten to cause a major pandemic. The breadth of B cell responses to natural infection and the dominant antigenic sites recognized during first exposure to H7 HA following infection are incompletely understood. Here, we studied the B cell response to H7 HA of 2 individuals who had recovered from natural H7N9 virus infection. We used competition binding, hydrogen-deuterium mass spectrometry, and single-particle negative stain electron microscopy to identify the patterns of molecular recognition of the antibody responses to H7 HA. We found that circulating H7-reactive B cells recognized a diverse antigenic landscape on the HA molecule, including HA head domain epitopes in antigenic sites A and B and in the trimer interface-II region and epitopes in the stem region. Most H7 antibodies exhibited little heterosubtypic breadth, but many recognized a wide diversity of unrelated H7 strains. We tested the antibodies for functional activity and identified clones with diverse patterns of inhibition, including neutralizing, hemagglutination- or egress-inhibiting, or HA trimer–disrupting activities. Thus, the human B cell response to primary H7 natural infection is diverse, highly functional, and broad for recognition of diverse H7 strains.

Mammals Preferred: Reassortment of Batai and Bunyamwera orthobunyavirus Occurs in Mammalian but Not Insect Cells.

Reassortment is a viral genome-segment recomposition known for many viruses, including the orthobunyaviruses. The co-infection of a host cell with two viruses of the same serogroup, such as the Bunyamwera orthobunyavirus and the Batai orthobunyavirus, can give rise to novel viruses. One example is the Ngari virus, which has caused major outbreaks of human infections in Central Africa. This study aimed to investigate the potential for reassortment of Bunyamwera orthobunyavirus and the Batai orthobunyavirus during co-infection studies and the replication properties of the reassortants in different mammalian and insect cell lines. In the co-infection studies, a Ngari-like virus reassortant and a novel reassortant virus, the Batunya virus, arose in BHK-21 cells (Mesocricetus auratus). In contrast, no reassortment was observed in the examined insect cells from Aedes aegypti (Aag2) and Aedes albopictus (U4.4 and C6/36). The growth kinetic experiments show that both reassortants are replicated to higher titers in some mammalian cell lines than the parental viruses but show impaired growth in insect cell lines.

Common Themes in Zoonotic Spillover and Disease Emergence: Lessons Learned from Bat- and Rodent-Borne RNA Viruses.

Rodents (order Rodentia), followed by bats (order Chiroptera), comprise the largest percentage of living mammals on earth. Thus, it is not surprising that these two orders account for many of the reservoirs of the zoonotic RNA viruses discovered to date. The spillover of these viruses from wildlife to human do not typically result in pandemics but rather geographically confined outbreaks of human infection and disease. While limited geographically, these viruses cause thousands of cases of human disease each year. In this review, we focus on three questions regarding zoonotic viruses that originate in bats and rodents. First, what biological strategies have evolved that allow RNA viruses to reside in bats and rodents? Second, what are the environmental and ecological causes that drive viral spillover? Third, how does virus spillover occur from bats and rodents to humans?

Enumeration of Escherichia coli and determination of Salmonella spp. and verotoxigenic Escherichia coli in shellfish (Mytilus galloprovincialis and Ruditapes decussatus) harvested in Sardinia, Italy.

The aim of the present study was to evaluate the occurrence of Salmonella spp., Verotoxigenic E. Coli (VTEC) and enumerate E. coli in shellfish (Mytilus galloprovincialis and Ruditapes decussatus) collected before and after depuration from two class B harvesting areas located in Sardinia (Italy). All the samples were analyzed for Salmonella spp. detection according to European Commission Regulation (EC) 2073/2005 and examined using the five tube Most-Probable-Number (MPN) method for enumeration of E. coli in accordance with the European Union reference method ISO 16649-3:2015. E. coli VTEC was investigated following a direct multiplex Polymerase Chain Reaction (PCR) screening test. The enumeration of E. coli met the European law limit for Class A areas of 230 MPN/100g. The averaged enumeration of E. coli in samples of M. galloprovincialis and R. decussatus collected at the harvesting time was 39 and 37 MPN/100 g respectively. The average contamination levels in samples collected after purification were 58 MPN/100g (M. galloprovincialis) and 32 MPN/100 g (R. decussatus). E. coli VTEC was not detected, on the contrary, Salmonella ser. Typhimurium was detected in one sample of M. galloprovincialis and in one sample of R. decussatus collected at the harvesting time. No significant associations were observed between E. coli levels in shellfish and environmental parameters of water or with the detection of Salmonella ser. Typhimurium in M. galloprovincialis and R. decussatus samples. Nevertheless, the occurrence of Salmonella ser. Typhimurium, involved in human infection outbreaks, should be considered a potential risk for consumers.

Trichinellosis in Slovakia - epidemiological situation in humans and animals (2009-2018).

Trichinella spp. are zoonotic parasitic nematodes with almost worldwide distribution. The infection can be transmitted through the foodborne route and can cause serious health problems in infected human patients. It is also an economically important issue due to the high financial cost connected with prevention of the disease. The study aimed to discover trends in the epidemiological situation in people and animals in Slovakia in 2009-2018. Data on human trichinellosis originated from the Public Health Authority of the Slovak Republic, and data on Trichinella infection in animals from the State Veterinary and Food Administration of the Slovak Republic. A seroepidemiological study on 655 voluntary respondents was performed. Altogether, 29 human cases were reported between 2009-2018, with a maximum of 13 cases in 2011. Males were affected more often (19 cases) than females (10 cases); the average age of patients was 45.1 years. Antibodies to Trichinellawere detected in two sera (0.3%): in a serum from one hunter and one veterinarian. In the monitored period, the average prevalence of Trichinella infection was 9.6% in 2,295 red foxes, and 0.04% in 165,643 wild boars. Three (1.7%) of 178 surveyed brown bears were positive. Within the compulsory monitoring of trichinellosis in domestic pigs, none from a total of 1,632,688 pigs were positive. The presence of three species, Trichinellabritovi, T. spiralis and T. pseudospiralis, was documented, with T. britovi representing 93.9% of identified isolates. The study indicates that the prevalence of Trichinella infection has not changed considerably with time in Slovakia, and the risk of human infection outbreaks is connected mainly with the consumption of wild boar meat.

Cellular Organelles Reorganization During Zika Virus Infection of Human Cells.

Zika virus (ZIKV) is an enveloped positive stranded RNA virus belonging to the genus Flavivirus in the family Flaviviridae that emerged in recent decades causing pandemic outbreaks of human infections occasionally associated with severe neurological disorders in adults and newborns. The intracellular steps of flavivirus multiplication are associated to cellular membranes and their bound organelles leading to an extensive host cell reorganization. Importantly, the association of organelle dysfunction with diseases caused by several human viruses has been widely reported in recent studies. With the aim to increase the knowledge about the impact of ZIKV infection on the host cell functions, the present study was focused on the evaluation of the reorganization of three cell components, promyelocytic leukemia nuclear bodies (PML-NBs), mitochondria, and lipid droplets (LDs). Relevant human cell lines including neural progenitor cells (NPCs), hepatic Huh-7, and retinal pigment epithelial (RPE) cells were infected with the Argentina INEVH116141 ZIKV strain and the organelle alterations were studied by using fluorescent cell imaging analysis. Our results have shown that these three organelles are targeted and structurally modified during ZIKV infection. Considering the nuclear reorganization, the analysis by confocal microscopy of infected cells showed a significantly reduced number of PML-NBs in comparison to uninfected cells. Moreover, a mitochondrial morphodynamic perturbation with an increased fragmentation and the loss of mitochondrial membrane potential was observed in ZIKV infected RPE cells. Regarding lipid structures, a decrease in the number and volume of LDs was observed in ZIKV infected cells. Given the involvement of these organelles in host defense processes, the reported perturbations may be related to enhanced virus replication through protection from innate immunity. The understanding of the cellular remodeling will enable the design of new host-targeted antiviral strategies.

Outbreak of human infections with uncommon Salmonella serotypes linked to pet bearded dragons, 2012-2014.

Reptiles are one of the fastest growing sectors in the United States pet industry. Reptile-associated salmonellosis (RAS) continues to be an important public health problem, especially among children. We investigated an outbreak of human Salmonella infections resulting from serotypes Cotham and Kisarawe, predominately occurring among children. An outbreak of illnesses was identified in persons with exposure to pet bearded dragon lizards. Human and animal health officials, in cooperation with the pet industry, conducted epidemiologic, traceback and laboratory investigations. Onsite sampling was conducted at two US breeding facilities, one foreign breeding facility, and a large pet retail chain. A total of 166 patients in 36 states were identified with illness onset dates from 02/2012-06/2014. The median patient age was 3years (range, <1-79years), 57% were aged ≤5years, and 37% were aged ≤1year. Forty-four patients (37%) were hospitalized, predominantly children. Sampling at breeding facilities and a national pet store chain resulted in isolation of outbreak serotypes at each facility; isolation proportions ranged from 2%-24% of samples collected at each facility.Epidemiologic, microbiologic and traceback evidence linked an outbreak of uncommon Salmonella serotypes to contact with pet bearded dragons. The high proportion of infants involved in this outbreak highlights the need to educate owners about the risk of RAS in children and the potential for household contamination by pet reptiles or their habitats. Strategies should be developed to improve breeding practices, biosecurity and monitoring protocols to reduce Salmonella in the pet reptile trade.

Human infection caused by Streptococcus suis serotype 2 in China: report of two cases and epidemic distribution based on sequence type

BackgroundStreptococcus suis is a zoonotic pathogen that causes serious systemic infections in pigs and occupation-related infections in humans who contact with pigs or pork products. In China, it has caused two outbreaks of human infection and surveillance for S.suis has been ongoing since last time.Case presentationTwo cases of meningitis and sepsis caused by S. suis were reported in this study. Both patients work in relation to the pork trade, a risk factor for S. suis infection. The outcome was favorable after a prolonged ceftriaxone therapy but one patient was left with mild hearing loss. Two isolates were identified as sequencing type (ST) 7, S. suis serotype 2 (SS2), which is one the most prevalent and cause two outbreaks in China. Whole-genome sequencing (WGS) revealed that a high degree identity was noted in the genome organizations and sequences between two sporadic ST7 SS2 isolates in this study and representative epidemic virulent isolates. Major differences among them are two sporadic ST7 SS2 isolates lacked a virulence factor called agglutinin receptor and an 89 K pathogenicity island (PAI), which plays important role in the pathogenesis of streptococcal toxic shock syndrome (STSS). A summary about STs of human infection with S. suis in China was completed. The result showed ST1 and ST7 were still the major STs and several novel STs were successfully discovered in different provinces.ConclusionsOur results enhanced the understanding of the ability to cause life-threatening infections in humans and the distribution and evolution of the S. suis in China.

Noroviruses in shellfish: Challenges and facts

Noroviruses are among the most common causes of foodborne outbreaks of human infection. Study of the noroviruses has been difficult due to the lack of a cell culture system, so molecular techniques became the gold standard. Recently though, a cell culture system has been developed and will aid in the acquisition of new knowledge related to human noroviruses.

First outbreak of human infection with avian influenza A(H7N9) virus in Guangxi, China, 2016 to 2017.

First outbreak of human infection with avian influenza A(H7N9) virus in Guangxi, China, 2016 to 2017.

Green Technology: Bacteria-Based Approach Could Lead to Unsuspected Microbe⁻Plant⁻Animal Interactions.

The recent and massive revival of green strategies to control plant diseases, mainly as a consequence of the Integrated Pest Management (IPM) rules issued in 2009 by the European Community and the increased consumer awareness of organic products, poses new challenges for human health and food security that need to be addressed in the near future. One of the most important green technologies is biocontrol. This approach is based on living organisms and how these biocontrol agents (BCAs) directly or indirectly interact as a community to control plant pathogens and pest. Although most BCAs have been isolated from plant microbiomes, they share some genomic features, virulence factors, and trans-kingdom infection abilities with human pathogenic microorganisms, thus, their potential impact on human health should be addressed. This evidence, in combination with the outbreaks of human infections associated with consumption of raw fruits and vegetables, opens new questions regarding the role of plants in the human pathogen infection cycle. Moreover, whether BCAs could alter the endophytic bacterial community, thereby leading to the development of new potential human pathogens, is still unclear. In this review, all these issues are debated, highlighting that the research on BCAs and their formulation should include these possible long-lasting consequences of their massive spread in the environment.

Recent Proceedings on Prevalence and Pathogenesis of Streptococcus suis.

Streptococcus suis (S. suis) is an important zoonotic pathogen that causes huge economic losses in the pig industry, as well as severe illness and even death in humans. The outbreak of human infection of S. suis in China in 2005 led to significant human morbidity and death, prompting an increase in global studies of S. suis. In recent years, important advances have been made regarding the etiology, genomics, excavation of virulence genes, and vaccine research in S. suis. A number of countries and regions have identified their predominantly serotypes. The development of genome sequencing technology has laid an important foundation for the study of pathogenic mechanisms. For example, 89K PAI was found in representative virulence strains in China, and several studies have been carried out to confirm multiple genes which carries are closely related to virulence. Also, the functions of some regulatory genes represented by the two-component signal transduction system have been analyzed. The development of inactivated vaccines, natural avirulent vaccines, gene-deletion attenuated vaccines, subunit vaccines, and glycoconjugate vaccines have greatly contributed to the prevention and control of the disease in the future. This article aims to summarize the research progress to provide directions for future research and the prevention of S. suis.

Chiroptera as a Potential Reservoir of Dangerous for Humans Viruses in the Territory of the Republic of Guinea. Part 2

Among the viruses transmitted by Chiroptera, filoviruses, lissaviruses, henipaviruses, and coronaviruses pose the major threat to humans. The featured review is devoted to the analysis of the results of studies on the role of African Chiropterans in the circulation sustenance of the viruses. Chronology of investigations on the search of natural reservoir of Filoviruses and the evidence of Chiroptera participation in their circulation are described in the paper. Presented are summarized data on the involvement of chiropterans in the circulation of lissaviruses on the African continent. Given is the information concerning the role of African species of Chiroptera in the circulation of henipaviruses - dangerous for humans viruses of Paramyxoviridae family, associated with chiropterans of South-Eastern Asia. Considered is the possibility of SARS and MERS-like coronaviruses circulation in the populations of certain species of African Chiroptera. Engagement of the Chiroptera from Guinean Republic in maintenance of circulation of the mentioned above viruses in potential natural foci in the territory of the country and possibility of occurrence of dangerous human infection outbreaks is also assessed. The necessity for further investigation of the role of Chiroptera as carriers of the stated viruses to clarify the current epidemiological and epizootiological situation on the viral pathogens in the Republic of Guinea is substantiated.

Factors affecting the parasitic contamination of edible locally produced dry season leafy vegetables cultivated in south east Enugu, Nigeria

Background/Aim: Outbreaks of human infections associated with consumption of fresh fruits and vegetables have occurred with increased frequency during the past decade. This study evaluated parasitic contamination of locally produced dry season vegetables cultivated in Enugu metropolis, Enugu State, Nigeria. Materials/Method: Vegetables, water and soil samples selected from vegetable farms were investigated. A total of 160 vegetable samples, 15 soil samples and 15 water samples were investigated. The samples were washed separately in saline and the resulting solution was subjected to standard sedimentation and flotation techniques. Physiochemical analysis of soil and water samples was done using the standard DREM technique. Furthermore, the water samples were investigated for C. parvum using the modified Ziehl-Neelsen staining technique. Results: Parasitic contamination of the different vegetables were Teifeairia occidentalis 242 (18.1%), Amaranthus hybridus 193 (15.1%), Cucurbita maxima 192 (15.0%), Solanum species 191 (14.9%), Ocimum grattisimum 136 (10.6%), Solanun nigrum 114 (8.9%), Gongronema latifolium 101 (7.9%), Talinum triangulare 73 (5.7%) and Murraya koenigii 39 (3.0%).The parasites identified included; Ascaris lumbricoides , Taenia spp, Fasciola hepatica , Schistosoma spp, Trichuris spp, Enterobius vermicularis , Toxocara .spp, Giardia lamblia , Entamoeba spp and Cryptosporidium parvum . Entamoeba species was the highest contaminating parasite 529 (41.3%) while Schistosoma haematobium was the least,14 (1.1%). Physiochemical analysis revealed a strong positive correlation between parasite load in water and total suspended solutes (TSS) (r = 0.59, p = 0.021) and turbidity ( r = 0.55, p = 0.032) and also a strong positive correlation between parasite load in the soil and organic matter (OM), (r = 0.71, p = 0.003) and silt (r = 0.63, p = 0.011). Conclusion: These vegetables should be considered as potential sources of parasitic infections, especially when they are not properly cooked (the type called ‘Half Done’) or consumed raw like the local salad (abacha) because of the high risk of parasitic infections such as giardiasis, amoebiasis, enterobiasis, cyptosporidiosis, ascariasis, etc. Public enlightenment is necessary to enhance the adoption of effective food safety approaches by agronomic practices of vegetable farmers which will in turn reduce foodborne illnesses. Keywords: Parasite, contamination, vegetables, Enugu

Surveillance of Live Poultry Markets for Low Pathogenic Avian Influenza Viruses in Guangxi Province, Southern China, from 2012\u20132015

Infections with low pathogenic avian influenza viruses (LPAIVs) can be mild or asymptomatic in poultry; however, in humans, LPAIVs can cause severe infections and death, as demonstrated by the H7N9 and H10N8 human infection outbreaks in 2013 in China. In this study, we conducted an epidemiological survey of LPAIVs at live poultry markets (LPMs) in Guangxi Province, Southern China, which is near several Southeast Asian countries. From January 2012 to December 2015, we collected 3,813 swab samples from poultry at LPMs in Guangxi. Viral isolation, hemagglutination inhibition assay and viral sequencing were utilized to identify LPAIVs in the collected samples. Among the samples, 622 (16.3%) were positive for LPAIVs. Six subtypes (H1, H3, H4, H6, H9 and H11) were individually isolated and identified. Of these subtypes, H3, H6 and H9 were predominant in ducks, geese and chickens, respectively. Among the 622 positive samples, 160 (25.7%) contained more than one subtype, and H8, H10, H12, H13, and H16 were identified among them, which highlights the continuous need for enhanced surveillance of AIVs. These results provide detailed information regarding the epidemic situation of LPAIVs in the area, which can aid efforts to prevent and control AIV transmission in humans and animals.

The invasome of Salmonella Dublin as revealed by whole genome sequencing

BackgroundSalmonella enterica serovar Dublin is a zoonotic infection that can be transmitted from cattle to humans through consumption of contaminated milk and milk products. Outbreaks of human infections by S. Dublin have been reported in several countries including high-income countries. A high proportion of S. Dublin cases in humans are associated with invasive disease and systemic illness. The genetic basis of virulence in S. Dublin is not well characterized.MethodsWhole genome sequencing was applied to a set of clinical invasive and non-invasive S. Dublin isolates from different countries in order to characterize the putative genetic determinants involved in the virulence and invasiveness of S. Dublin in humans.ResultsWe identified several virulence factors that form the bacterial invasome and may contribute to increasing bacterial virulence and pathogenicity including mainly Gifsy-2 prophage, two different type 6 secretion systems (T6SSs) harbored by Salmonella pathogenicity islands; SPI-6 and SPI-19 respectively and virulence genes; ggt and PagN. Although Vi antigen and the virulence plasmid have been reported previously to contribute to the virulence of S. Dublin we did not detect them in all invasive isolates indicating that they are not the main virulence determinants in S. Dublin.ConclusionSeveral virulence factors within the genome of S. Dublin might contribute to the ability of S. Dublin to invade humans’ blood but there were no genomic markers that differentiate invasive from non-invasive isolates suggesting that host immune response play a crucial role in the clinical outcome of S. Dublin infection.

A review of global human infection with avian influenza and epidemiological characteristics

Avian influenza virus is an influenza A virus, which generally spreads among birds, without direct infection of human. According to the pathogenicity to chicken or turkey, it is divided into high, medium and low/non pathogenic. When the virus gene recombination or mutation, it will get the ability to infect human. Additionally, avian influenza virus can also infect human directly, such as H5N1, H7N9, H5N6, H10N8 subtype. The cases of human infection with avian influenza reported frequently after the outbreak of human infection with H7N7 avian influenza in 1959, the first death case due to avian influenza virus infection causing respiratory disease was the outbreak of human infection with H5N1 in Hongkong in 1997. To date, human infection with avian influenza is a global public health problem. As avian influenza viruses perpetuated in their natural hosts, with their high genetic divergence, it would be precursor viruses even for pandemic potential. In the 20th century, four influenza pandemics were closely related to avian influenza viruses, avian is the natural host of the avian influenza virus, poultry carrying virus and dead/sick poultry infected with avian influenza virus are easier to spread virus to human, the main transmission routes are birds-human transmission (exposure to sick/dead poultry) and environment-human transmission (such as visit live poultry market). Poultries exposure and chronic medical condition are the main risk factors of human infection with avian influenza. The symptoms varies including ordinary influenza-like illness (ILI), conjunctivitis, arthritis, severe pneumonia, respiratory failure , shock and death. At present, the treatment of human infection with avian influenza includes antiviral treatment, symptomatic treatment, Chinese medicine treatment, but the most important therapy of human infection with avian influenza is the treatment of antiviral drugs (neuraminidase inhibitors), using high dose antiviral drugs in the early stage can significantly improve the survival rate. PCR and real-time PCR are the best methods for preliminary diagnosis of human infection with avian influenza. At the same time, the increase of serum antibody titer in acute stage or recovery stage can alao be confirmed. In addition, effective preventive measures (such as publicity and education, behavioral intervention and vaccination development and application) are the important means to protect human from avian influenza.