Fixed-point Monitoring of Vaccine Immune Effects on Severe Animal Diseases in Livestock and Poultry Breeding Fields

In order to reveal the immune antibody levels and immune effect of livestock and poultry in the locality,we performed antibody surveillance on severe animal diseases in 17 livestock and poultry fields in six administrative districts of Wuhan City. The results showed that the vaccines had a good protective efficacy on highly pathogenic avian influenza( HPAI) and Newcastle disease( ND) in Wuhan City. The whole antibody levels kept above the ministerial standard( 】 70%).However,the vaccine immunity of porcine reproductive and respiratory syndrome( PRRS),swine fever( SF) and foot and mouth disease( FMD) was still poorly protective. The data indicated that the vaccines are protecting the severe animal diseases well,but there are still some potential security holes in some administrative districts.

Relationship between nutritional therapy and beneficial bacteria ratio in severe disease

Objective:To evaluate relationship between changes in the beneficial bacteria in intensive care unit(ICU)patients and nutritional therapy type.Methods:Ten patients aged≥18 years admitted to the ICU between January and December 2020,were included.Good enteral nutrition was defined as early achievement of target calorie intake through enteral feeding.The ratio of beneficial bacteria at the first and second bowel movements after each patient’s admission was calculated and the patients were classified into the increase or decrease group.Among all patients,five each were in the increase and decrease groups.We investigated patient background,changes in sequential organ failure assessment(SOFA)and acute physiology and chronic health evaluation(APACHE)Ⅱscores,nutritional doses or methods,and clinical outcomes.Results:No relationship was found between changes in the ratio of beneficial bacteria and changes in SOFA/APACHEⅡscores at the time of admission.The rate of good enteral nutrition was significantly higher in the increase group than in the decrease group(4/5 vs.0/5,P=0.01).Conclusions:An increase in beneficial bacteria may be significantly related to the early establishment of enteral nutrition.In the future,accumulating cases may make it possible to establish a new nutritional strategy for critically ill patients from an intestinal microbiota perspective.

Cardiovascular Cast Model Fabrication and Casting Effectiveness Evaluation in Fetus with Severe Congenital Heart Disease or Normal Heart

To investigate the application and effectiveness of vascular corrosion technique in preparing fetal cardiovascular cast models, 10 normal fetal heart specimens with other congenital disease（control group） and 18 specimens with severe congenital heart disease（case group） from induced abortions were enrolled in this study from March 2013 to June 2015 in our hospital. Cast models were prepared by injecting casting material into vascular lumen to demonstrate real geometries of fetal cardiovascular system. Casting effectiveness was analyzed in terms of local anatomic structures and different anatomical levels（including overall level, atrioventricular and great vascular system, left-sided and right-sided heart）, as well as different trimesters of pregnancy. In our study, all specimens were successfully casted. Casting effectiveness analysis of local anatomic structures showed a mean score from 1.90±1.45 to 3.60±0.52, without significant differences between case and control groups in most local anatomic structures except left ventricle, which had a higher score in control group（P=0.027）. Inter-group comparison of casting effectiveness in different anatomical levels showed no significant differences between the two groups. Intra-group comparison also revealed undifferentiated casting effectiveness between atrioventricular and great vascular system, or left-sided and right-sided heart in corresponding group. Third-trimester group had a significantly higher perfusion score in great vascular system than second-trimester group（P=0.046）, while the other anatomical levels displayed no such difference. Vascular corrosion technique can be successfully used in fabrication of fetal cardiovascular cast model. It is also a reliable method to demonstrate three-dimensional anatomy of severe congenital heart disease and normal heart in fetus.

Typology of the Main Fungal Diseases Affecting Winter Wheat in the Grand Duchy of Luxembourg

Over the 2003-2009 period, field campaigns were carried out in order to identify the main fungal diseases of winter wheat （Triticum aestivum） in the Grand-Duchy of Luxembourg. Four fungal diseases （septoria leaf blotch （SLB）, wheat leaf rust （WLR）, wheat powdery mildew （WPM） and fusarium head blight （FHB）） were observed and a regional-based typology was established according to their severity and prevalence. In the Gutland （South）, SLB severity was strong （about 51% on average） and higher than the severity （about 16%） prevailing in the Oesling （North）. Similar typology was observed with the WLR： high severity in the Gutland （66% and 57% for the years 2003 and 2007, respectively） and low severity （〈 1%） in the Oesling. The FHB was also present in the Eastern part of the Gutland, with a prevalence and severity significantly higher （P = 0.049 and P = 0.012, respectively, Tukey＇s test） compared with their values in the Oesling. On the other hand, the WPM severity was high in the Oesling （15% to 40%） while less than 1% in the Gutland. Such a study is important for the spatial mapping of wheat fungal diseases risk based on agroclimatic parameters and for defining optimal frequencies and dates of chemical treatments.

Utilization of edge-to-edge valve plastic technique to correct severe tricuspid regurgitation in patients with congenital heart disease

Objective Tricuspid regurgitation is often associated in patients with congenital heart disease. Significant morbidity and mortality are related to tricuspid valve replacement. Tricuspid valve plasty is still a preferred choice. This report deals with our surgical experience in using edge-to-edge valve plasty technique to correct severe

Perianal Crohn’s disease:Still more questions than answers

In this editorial we comment on the article by Pacheco et al published in a recent issue of the World Journal of Gastroenterology.We focus specifically on the burden of illness associated with perianal fistulizing Crohn’s disease(PFCD)and the diagnostic and therapeutic challenges in the management of this condition.Evol-ving evidence has shifted the diagnostic framework for PFCD from anatomical classification systems,to one that is more nuanced and patient-focused to drive ongoing decision making.This editorial aims to reflect on these aspects to help clinicians face the challenge of PFCD in day-to-day clinical practice.

Impact of interleukin 6 levels on acute lung injury risk and disease severity in critically ill sepsis patients

BACKGROUND Sepsis is a life-threatening condition characterized by a dysregulation of the host response to infection that can lead to acute lung injury(ALI)and multiple organ dysfunction syndrome(MODS).Interleukin 6(IL-6)is a pro-inflammatory cytokine that plays a crucial role in the pathogenesis of sepsis and its complications.AIM To investigate the relationship among plasma IL-6 levels,risk of ALI,and disease severity in critically ill patients with sepsis.METHODS This prospective and observational study was conducted in the intensive care unit of a tertiary care hospital between January 2021 and December 2022.A total of 83 septic patients were enrolled.Plasma IL-6 levels were measured upon admission using an enzyme-linked immunosorbent assay.The development of ALI and MODS was monitored during hospitalization.Disease severity was evaluated by Acute Physiology and Chronic Health Evaluation II(APACHE II)and Sequential Organ Failure Assessment(SOFA)scores.RESULTS Among the 83 patients with sepsis,38(45.8%)developed ALI and 29(34.9%)developed MODS.Plasma IL-6 levels were significantly higher in patients who developed ALI than in those without ALI(median:125.6 pg/mL vs 48.3 pg/mL;P<0.001).Similarly,patients with MODS had higher IL-6 levels than those without MODS(median:142.9 pg/mL vs 58.7 pg/mL;P<0.001).Plasma IL-6 levels were strongly and positively correlated with APACHE II(r=0.72;P<0.001)and SOFA scores(r=0.68;P<0.001).CONCLUSIONElevated plasma IL-6 levels in critically ill patients with sepsis were associated with an increased risk of ALI andMODS.Higher IL-6 levels were correlated with greater disease severity,as reflected by higher APACHE II andSOFA scores.These findings suggest that IL-6 may serve as a biomarker for predicting the development of ALI anddisease severity in patients with sepsis.

Systemic immune-inflammation index combined with pediatric appendicitis score in assessing the severity and prognosis for paediatric appendicitis

BACKGROUND Pediatric appendicitis is a common cause of abdominal pain in children and is recognized as a significant surgical emergency.A prompt and accurate diagnosis is essential to prevent complications such as perforation and peritonitis.AIM To investigate the predictive value of the systemic immune-inflammation index(SII)combined with the pediatric appendicitis score(PAS)for the assessment of disease severity and surgical outcomes in children aged 5 years and older with appendicitis.METHODS Clinical data of 104 children diagnosed with acute appendicitis were analyzed.The participants were categorized into the acute appendicitis group and chronic appendicitis group based on disease presentation and further stratified into the good prognosis group and poor prognosis group based on prognosis.The SII and PAS were measured,and a joint model using the combined SII and PAS was constructed to predict disease severity and surgical outcomes.RESULTS Significant differences were observed in the SII and PAS parameters between the acute appendicitis group and chronic appendicitis group.Correlation analysis showed associations among the SII,PAS,and disease severity,with the combined SII and PAS model demonstrating significant predictive value for assessing disease severity[aera under the curve(AUC)=0.914]and predicting surgical outcomes(AUC=0.857)in children aged 5 years and older with appendicitis.CONCLUSION The study findings support the potential of integrating the SII with the PAS for assessing disease severity and predicting surgical outcomes in pediatric appendicitis,indicating the clinical utility of the combined SII and PAS model in guiding clinical decision-making and optimizing surgical management strategies for pediatric patients with appendicitis.

Insights from respiratory virus co-infections

Respiratory viral co-infections present significant challenges in clinical settings due to their impact on disease severity and patient outcomes.Current diagnostic methods often miss these co-infections,complicating the epidemiology and management of these cases.Research,primarily conducted in vitro and in vivo,suggests that co-infections can lead to more severe illnesses,increased hospitalization rates,and greater healthcare utilization,especially in high-risk groups such as children,the elderly,and immunocompromised individuals.Common coinfection patterns,risk factors,and their impact on disease dynamics highlight the need for advanced diagnostic techniques and tailored therapeutic strategies.Understanding the virological interactions and immune response modulation during co-infections is crucial for developing effective public health interventions and improving patient outcomes.Future research should focus on the molecular mechanisms of co-infection and the development of specific therapies to mitigate the adverse effects of these complex infections.

APACHE system is better than Ranson system in the prediction of severity of acute pancreatitis

BACKGROUND: It has been suggested that addition of obesity score to the APACHE-Ⅱ system can lead to more accurate prediction of severity of acute pancreatitis. However there is scanty information on the usefulness of the combined APACHE-O scoring system in Asian patients. This study aimed to compare the accuracy of Ranson, APACHE-Ⅱ and APACHE-O systems in assessing severity of acute pancreatitis in a local Chinese population. METHODS: One hundred and one consecutive patients with acute pancreatitis were prospectively studied. Body mass index (BMI) was measured on admission. Ranson score, APACHE-Ⅱ and APACHE-O scores were recorded on admission and at 48 hours. By adopting the cut-off levels and definitions advocated in the Atlanta consensus for severe disease, the diagnostic accuracy of the three scoring systems was compared by the area under the curve (AUC) under the receiver operator characteristic curve. RESULTS: Of the 101 patients, 12 (11.9%) patients suffered from severe pancreatitis. Obesity was uncommon and only two patients (2.0%) had BMI >30. Eighty-two (81.2%) patients were normal weight (BMI≤25) whereas 17 (16.8%) were overweight ( BMI 25-30 ). Overweight or obesity (BMI >25) was not associated with severe pancreatitis (P= 0.40). The AUC for admission scores of Ranson, APACHE-Ⅱ, and APACHE-O systems was 0. 549, 0. 904 and 0. 904, respectively. The AUC for 48-hour scores of Ranson, APACHE-Ⅱ and APACHE-O systems was 0.808, 0.955 and 0.951, respectively. CONCLUSIONS: The APACHE-Ⅱ scoring system is more accurate than the Ranson scoring system of the prediction of severity in acute pancreatitis. Addition of obesity score does not significantly improve the predictive accuracy of the APACHE-Ⅱ system in our local population with a low prevalence of obesity.

Coagulopathy and the prognostic potential of D-dimer in hyperlipidemia-induced acute pancreatitis

BACKGROUND： Coagulopathy and its association with disease severity in hyperlipidemia （HL）- and non-hyperlipidemia （NHL）-induced acute pancreatitis （AP） are not dear. The present study was to evaluate the relationship between coagulation homeostasis and AP.

Circulating miR-125a but not miR-125b is decreased in active disease status and negatively correlates with disease severity as well as inflammatory cytokines in patients with Crohn's disease

AIM To determine the association of circulating mi R-125 a/b expression with the risk and disease severity of Crohn's disease(CD), and with inflammatory cytokines.METHODS Plasma samples were collected from patients with active CD(A-CD), or CD in remission(R-CD) and from healthy controls(HCs). The levels of the inflammatory cytokines interleukin-17(IL-17), tumour necrosis factor-α(TNF-α), and interferon-γ(IFN-γ) were measured by enzyme-linked immunosorbent assay. The expression of mi R-125 a/b was assessed by quantitative polymerase chain reaction(q PCR).RESULTS Twenty-nine A-CD patients, 37 R-CD patients, and 37 HCs were included in the study. Plasma mi R-125 a expression was decreased in A-CD patients comparedwith that in R-CD patients(P < 0.001) and HCs(P < 0.001). mi R-125 a expression levels enabled the differentiation of A-CD from R-CD patients [area under curve(AUC) = 0.854] and from HCs(AUC = 0.780), whereas mi R-125 b expression did not. mi R-125 a was negatively correlated with C-reaction protein(CRP)(P = 0.017), erythrocyte sedimentation rate(ESR)(P = 0.026), Crohn's disease activity index(CDAI)(P = 0.003), IL-17(P = 0.015), and TNF-α(P = 0.004) in A-CD patients. Furthermore, mi R-125 a was negatively associated with CRP(P = 0.038) and CDAI(P = 0.021) in R-CD patients. Regarding mi R-125 b, no association with CRP, CDAI, IL-17, TNF-α, or IFN-γ was found in A-CD or in R-CD patients. mi R-125 a levels gradually increased in A-CD patients who achieved clinical remission(P = 0.009) after 3-mo treatment, whereas they remained unchanged among patients who failed to achieve remission. No changes in mi R-125 b expression were detected in remission or non-remission patients after treatment. CONCLUSION Circulating mi R-125 a but not mi R-125 b is decreased in patients with active disease status and negatively correlates with disease severity and inflammatory cytokines in patients with CD.

Early diagnosis and prediction of severity in acute pancreatitis using the urine trypsinogen-2 dipstick test:A prospective study

AIM： To evaluate the use of the trypsinogen-2 dipstick （Actim Pancreatitis） test for early diagnosis and prediction of severity in acute pancreatitis （AP）. METHODS： Ninety-two patients with AP were included in this study. The control group was 25 patients who had acute abdominal pain from non-pancreatic causes. Urine trypsinogen-2 dipstick test （UTDT） and conventional diagnostic tests were performed in all patients. Patients were divided by the Atlanta classification into two groups as having mild or severe pancreatitis. RESULTS： UTDT was positive in 87 （94.6%） of the AP patients and in two （8%） controls （P 〈 0.05）. Positive UTDT was found in 61 （92.4%） of 66 （71.7%） patients with mild pancreatitis and in all （100%） of the 26 （28.3%） with severe pancreatitis （P 〉 0.05）. UTDT positivity lasted longer in severe pancreatitis compared with that in mild pancreatitis （6.2 ＋ 2.5 d vs 2.0 ＋ 1.43 d, P 〈 0.05）. The sensitivity, specificity, positive predictive value, negative predictive value （NPV）, positive likelihood ratio （PLR） and negative likelihood ratio （NLR） of UTDT were 91%, 72%, 96.6%, 70.4%, 3.4 and 0.1, respectively. CONCLUSION： UTDT is a simple, rapid and reliable method for use on admission. It has high specificity and low NLR for early diagnosis and prediction of severity in AP. However, its relatively low NPV does not allow trypsinogen-2 dipstick test to be a stand-alone tool for diagnosis of acute pancreatitis; the use of other conventional diagnostic tools remains a requirement.

Ehealth:Low FODMAP diet vs Lactobacillus rhamnosus GG in irritable bowel syndrome

AIM: To investigate the effects of a low fermentable, oligosaccharides, disaccharides, monosaccharides and polyols diet (LFD) and the probiotic Lactobacillus rhamnosus GG (LGG) in irritable bowel syndrome (IBS).

Precore/core region mutations of hepatitis B virus related to clinical severity

Despite the availability of an effective vaccine, hepatitis B virus (HBV) infection remains a major health problem, with more than 350 million chronically infected people worldwide and over 1 million annual deaths due to cirrhosis and liver cancer. HBV mutations are primarily generated due both to a lack of proofreading capacity by HBV polymerase and to host immune pressure, which is a very important factor for predicting disease progression and therapeutic outcomes. Several types of HBV precore/core (preC/C) mutations have been described to date. The host immune response against T cells drives mutation in the preC/C region. Specifically, preC/C mutations in the MHC class II restricted region are more common than in other regions and are significantly related to hepatocellular carcinoma. Certain mutations, including preC G1896A, are also significantly related to HBeAg-negative chronic infection. This review article mainly focuses on the HBV preC/C mutations that are related to disease severity and on the HBeAg serostatus of chronically infected patients.

Spectroscopic Leaf Level Detection of Powdery Mildew for Winter Wheat Using Continuous Wavelet Analysis

Powdery mildew （Blumeria graminis） is one of the most destructive crop diseases infecting winter wheat plants, and has devastated millions of hectares of farmlands in China. The objective of this study is to detect the disease damage of powdery mildew on leaf level by means of the hyperspectral measurements, particularly using the continuous wavelet analysis. In May 2010, the reflectance spectra and the biochemical properties were measured for 114 leaf samples with various disease severity degrees. A hyperspectral imaging system was also employed for obtaining detailed hyperspectral information of the normal and the pustule areas within one diseased leaf. Based on these spectra data, a continuous wavelet analysis （CWA） was carried out in conjunction with a correlation analysis, which generated a so-called correlation scalogram that summarizes the correlations between disease severity and the wavelet power at different wavelengths and decomposition scales. By using a thresholding approach, seven wavelet features were isolated for developing models in determining disease severity. In addition, 22 conventional spectral features （SFs） were also tested and compared with wavelet features for their efficiency in estimating disease severity. The multivariate linear regression （MLR） analysis and the partial least square regression （PLSR） analysis were adopted as training methods in model mildew on leaf level were found to be closely related with the development. The spectral characteristics of the powdery spectral characteristics of the pustule area and the content of chlorophyll. The wavelet features performed better than the conventional SFs in capturing this spectral change. Moreover, the regression model composed by seven wavelet features outperformed （R2=0.77, relative root mean square error RRMSE=0.28） the model composed by 14 optimal conventional SFs （R2---0.69, RRMSE--0.32） in estimating the disease severity. The PLSR method yielded a higher accuracy than the MLR method. A combination of CWA and PLSR was found to be promising in providing relatively accurate estimates of disease severity of powdery mildew on leaf level.

Prognostic value of M30/M65 for outcome of hepatitis B virus-related acute-on-chronic liver failure

AIM: To determine the prognostic value of circulating indicators of cell death in acute-on-chronic liver failure (ACLF) patients with chronic hepatitis B virus (HBV) infection as the single etiology. METHODS: Full length and caspase cleaved cytokeratin 18 (detected as M65 and M30 antigens) represent circulating indicators of necrosis and apoptosis. M65 and M30 were identified by enzyme-linked immunosorbent assay in 169 subjects including healthy controls (n = 33), patients with chronic hepatitis B (CHB, n = 55) and patients with ACLF (n = 81). According to the 3-mo survival period, ACLF patients were defined as having spontaneous recovery (n = 33) and non-spontaneous recovery which included deceased patients and those who required liver transplantation (n = 48). RESULTS: Both biomarker levels significantly increased gradually as liver disease progressed (for M65: P < 0.001 for all; for M30: control vs CHB, P = 0.072; others: P < 0.001 for all). In contrast, the M30/M65 ratio was significantly higher in controls compared with CHB patients (P = 0.010) or ACLF patients (P < 0.001). In addition, the area under receiver operating characteristic curve (AUC) analysis demonstrated that both biomarkers had diagnostic value (AUC >= 0.80) in identifying ACLF from CHB patients. Interestingly, it is worth noting that the M30/M65 ratio was significantly different between spontaneous and non-spontaneous recovery in ACLF patients (P = 0.032). The prognostic value of the M30/M65 ratio was compared with the Model for End-Stage Liver Disease (MELD) and Child-Pugh scores at the 3-mo survival period, the AUC of the M30/M65 ratio was 0.66 with a sensitivity of 52.9% and the highest specificity of 92.6% (MELD:AUC = 0.71; sensitivity, 79.4%; specificity, 63.0%; Child-Pugh: AUC = 0.77; sensitivity, 61.8%; specificity, 88.9%). CONCLUSION: M65 and M30 are strongly associated with liver disease severity. The M30/M65 ratio may be a potential prognostic marker for spontaneous recovery in patients with HBV-related ACLF. (C) 2014 Baishideng Publishing Group Co., Limited. All rights reserved.

Predictors of disease severity in ulcerative colitis patients from Southwestern Ontario

AIM:To understand the demographic characteristics of patients in Southwestern Ontario,Canada with ulcerative colitis(UC)in order to predict disease severity. METHODS:Records from 1996 to 2001 were exam- ined to create a database of UC patients seen in the London Health Sciences Centre South Street Hospital Inflammatory Bowel Disease Clinic.To be included, patients'charts were required to have information of their disease presentation and a minimum of 5 years of follow-up.Charts were reviewed using standardized data collection forms.Disease severity was generated during the chart review process,and non-endoscopic Mayo Score criteria were collected into a composite. RESULTS:One hundred and two consecutive patients'data were entered into the database.Demographic analyses revealed that 51%of the patients were male, the mean age at diagnosis was 39 years,13.7%had a first degree relative with inflammatory bowel disease (IBD),61.8%were nonsmokers and 24.5%were ex-smokers.In 22.5%of patients the disease was limited to the rectum,in 21.6%disease was limited to the sigmoid colon,in 22.5%disease was limited to the left colon,and 32.4%of patients had pancolitis. Standard multiple regression analysis which regressed a composite of physician global assessment of disease severity,average number of bowel movements,and average amount of blood in bowel movements on year of diagnosis and age at time of diagnosis was significant,R 2=0.306,F(7,74)=4.66,P<0.01. Delay from symptoms to diagnosis of UC,gender, family history of IBD,smoking status and disease severity at the time of diagnosis didnot significantly predict the composite measure. CONCLUSION:UC severity is associated with younger age at diagnosis and year of diagnosis in a longitudinal cohort of UC patients,and may identify prognostic UC indicators.

B-type natriuretic peptide in predicting the severity of community-acquired pneumonia

BACKGROUND: Although pneumonia severity index(PSI) is widely used to evaluate the severity of community-acquired pneumonia(CAP), the calculation of PSI is very complicated. The present study aimed to evaluate the role of B-type natriuretic peptide(BNP) in predicting the severity of CAP.METHODS: For 202 patients with CAP admitted to the emergency department, BNP levels, cardiac load indexes, inf lammatory indexes including C-reactive protein(CRP), white blood cell count(WBC), and PSI were detected. The correlation between the indexes and PSI was investigated. BNP levels for survivor and non-survivor groups were compared, and a receiver operating characteristic(ROC) curve analysis was performed on the BNP levels versus PSI.RESULTS: The BNP levels increased with CAP severity(r=0.782, P<0.001). The BNP levels of the high-risk group(PSI classes IV and V) were signifi cantly higher than those of the low-risk group(PSI classes I–III)(P<0.001). The BNP levels were signifi cantly higher in the non-survivor group than in the survivor group(P<0.001). In addition, there were positive correlations between BNP levels and PSI scores(r=0.782, P<0.001). The BNP level was highly accurate in predicting the severity of CAP(AUC=0.952). The optimal cut-off point of BNP level for distinguishing high-risk patients from low-risk ones was 125.0 pg/m L, with a sensitivity of 0.891 and a specifi city of 0.946. Moreover, BNP level was accurate in predicting mortality(AUC=0.823). Its optimal cut-off point for predicting death was 299.0 pg/m L, with a sensitivity of 0.675 and a specifi city of 0.816. Its negative predictive cut-off value was 0.926, and the positive predictive cut-off value was 0.426.CONCLUSION: BNP level is positively correlated with the severity of CAP, and may be used as a biomarker for evaluating the severity of CAP.

Characterizing and Estimating Fungal Disease Severity of Rice Brown Spot with Hyperspectral Reflectance Data

Large-scale farming of agriculture crops requires real-time detection of disease for field pest management. Hyperspectral remote sensing data generally have high spectral resolution, which could be very useful for detecting disease stress in green vegetation at the leaf and canopy levels. In this study, hyperspectral reflectances of rice in the laboratory and field were measured to characterize the spectral regions and wavebands, which were the most sensitive to rice brown spot infected by Bipolaris oryzae （Helminthosporium oryzae Breda. de Hann）. Leaf reflectance increased at the ranges of 450 to 500 nm and 630 to 680 nm with the increasing percentage of infected leaf surface, and decreased at the ranges of 520 to 580 nm, 760 to 790 nm, 1550 to 1750 nm, and 2080 to 2350 nm with the increasing percentage of infected leaf surface respectively. The sensitivity analysis and derivative technique were used to select the sensitive wavebands for the detection of rice brown spot infected by B. oryzae. Ratios of rice leaf reflectance were evaluated as indicators of brown spot. R669/R746 （the reflectance at 669 nm divided by the reflectance at 746 nm, the following ratios may be deduced by analogy）, R702/R718, R692/R530, R692/R732, R535/R746, R521/R718, and R569/R718 increased significantly as the incidence of rice brown spot increased regardless of whether it＇s at the leaf or canopy level. R702/R718, R692/R530, R692/R732 were the best three ratios for estimating the disease severity of rice brown spot at the leaf and canopy levels. This result not only confirms the capability of hyperspectral remote sensing data in characterizing crop disease for precision pest management in the real world, but also testifies that the ratios of crop reflectance is a useful method to estimate crop disease severity.