Lethal and sublethal effects of pesticides used in Brazilian citrus groves on Panonychus citri (Acari: Tetranychidae) / Efeitos letais e subletais de agrotóxicos utilizados em citros sobre o ácaro Panonychus citri (Acari: Tetranychidae)

Pesticides have been blamed as the principal factor responsible for biological disequilibrium favoring the population increase of Panonychus citri (McGregor) in Brazilian citrus groves. In order to generate subsidies for the integrated management of this pest, we evaluated the lethal and sublethal effects of pesticides used in citrus on P. citri. We tested 18 pesticides by evaluating mortality of adult female, egg viability and adult avoidance. For imidacloprid, pyriproxyfen, dimethoate, deltamethrin, lambda-cyhalothrin and lime sulfur, the principal insecticides used in Brazilian orchards, the oviposition behavior and the incidence of adult females on discontinuous pesticide residues were evaluated. The pesticides which caused adult P. citri mortality were: abamectin (94%), dimethoate (86%), lime sulfur (69%), fenpropathrin (44%), diafenthiuron (25%) and lambda-cyhalothrin (23%). The pesticides affecting egg viability were: fenpropathrin (53%), dimethoate (30%) and lime sulfur (22%). Fenpropathrin, lambda-cyhalothrin and lime sulfur caused repellent effects of 55, 45 and 22%, respectively. P. citri preferred areas untreated with deltamethrin, lambda-cyhalothrin and lime sulfur for oviposition and permanence, but the species could not distinguish areas treated with imidacloprid, pyriproxyfen and dimethoate. The insecticides abamectin, dimethoate and diafenthiuron affected survival and did not cause changes in P. citri behavior. These pesticides should be used mainly in periods P. citri occurs. On the other hand, fenpropathrin, lambda-cyhalothrin, lime sulfur and deltamethrin affect dispersal behavior, oviposition and P. citri incidence and their use should be avoided.(AU)

O intenso uso de pesticidas na citricultura tem sido apontado como o principal fator responsável por desequilíbrios biológicos, favorecendo o aumento populacional de Panonychus citri (McGregor) na citricultura brasileira. Para gerar subsídios ao manejo integrado dessa praga, avaliaram-se os efeitos letais e subletais de agrotóxicos utilizados em citros sobre P. citri. Avaliaram-se 18 agrotóxicos na mortalidade de fêmeas adultas, viabilidade de ovos e repelência de P. citri. Foram também avaliados o comportamento de oviposição e a incidência de P. citri em superfícies com áreas tratadas e não tratadas com imidacloprid, piriproxifem, dimetoato, deltametrina, lambda-cialotrina e calda sulfocálcica, por serem os principais inseticidas utilizados nos pomares brasileiros. Os pesticidas que causaram mortalidade em adultos de P. citri foram abamectina (94%), dimetoato (86%), calda sulfocálcica (69%), fempropatrina (44%), diafentiurom (25%) e lambda-cialotrina (23%). Os pesticidas que afetaram a viabilidade de ovos foram fempropatrina (53%), dimetoato (30%) e calda sulfocálcica (22%). Quanto aos efeitos subletais, fempropatrina, lambda-cialotrina e calda sulfocálcica ocasionaram repelências de 55, 45 e 22%, respectivamente. P. citri preferiu áreas não tratadas com deltametrina, lambda-cialotrina e calda sulfocálcica para oviposição e permanência. Em contraste, P. citri não foi capaz de distinguir superfícies tratadas com imidacloprid, piriproxifem e dimetoato. Os inseticidas abamectina, dimetoato e diafentiurom afetaram a sobrevivência e não causaram mudanças no comportamento de P. citri, podendo ser utilizados principalmente em períodos que P. citri ocorre. Em contrapartida, fempropatrina, lambda-cialotrina, calda sulfocálcica e deltametrina afetaram o comportamento de dispersão e oviposição de P. citri e deveriam ser evitados.(AU)

Prevalence of asthma and atopy in children living in rural areas of Cheju island for an interval of three years / 천식및알레르기

BACKGROUND: The prevalence of asthma has been increasing due to changes in lifestyles. OBJECTIVE: The aim of this study was to evaluate the prevalence of asthma and atopy for an interval of three years in children living in rural areas of Cheju island. METHODS: A total of 1,055 and 755 subjects aged 7-15 years in South Cheju County were enrolled for an interval of three years, respectively. They responded to the modified ISAAC questionnaire, and underwent allergy skin prick test with locally common aeroallergens and methacholine bronchial provocation test. Children who had asthma symptom as reported on the questionnaire and bronchial hyperresponsiveness to methacholine were diagnosed as current asthma. Atopy was defined as the positive skin responses to one or more aeroallergens. RESULTS: The prevalence of current asthma had increased from 4.4% to 7.0% during the three years, especially among children aged 13 to 15 years (3.9% vs. 7.6%), although the asthma prevalence was similar between the two intervals among children aged 7 to 12 years (5.2% vs. 6.8%). The atopy rate had significantly increased from 37.7% to 45.9% during the three years. As for common sensitizing aeroallergens, sensitization rate to citrus red mite had significantly increased among both the young and the old age groups. The sensitization rates to house dust mites, such as D. pteronyssinus and D. farinae, had increased among the old age groups, but not among the young age groups, although the sensitization rates to cockroach and Japanese cedar pollen were similar among both the young and old age groups at the two intervals. CONCLUSION: The prevalence of current asthma and atopy had increased among children living in rural areas of Cheju island during the three year interval. The sensitization to house dust mite and citrus red mite had increased during the three years, and may play an important role in the increased prevalence of current asthma.

Distinct effect of sensitization of house dust mite and citrus red mite (Panonychus citri) in the development of allergic diseases in 16-18 year old adolescents living in rural areas of Jeju island / 천식및알레르기

BACKGROUND: A recent investigation has demonstrated that citrus red mite (Panonychus citri) is the most important allergen in citrus-cultivating farmers with asthma or rhinitis. METHODS: A total of 2,005 adolescents (aged 16 to 18 years) living in rural areas were enrolled in this study. Each subject was evaluated by a questionnaire developed by the International Study of Allergy and Asthma in Childhood(ISSAC), and a skin prick test with 11 common inhalant allergens including citrus red mite. RESULTS: Prevalence of recent wheezing, recent rhinoconjunctivitis symptoms and eczema was 13.0%, 13.6% and 9.9%, respectively. On skin prick test, the most common sensitizing allergen was citrus red mite (20.6%), followed by Dermatophagoides pteronyssinus (18.5%), Dermato-phagoides farinae (14.6%) and cockroach (9.8). The prevalence of eczema was higher in those with sensitization to CRM than in those without sensitization to any allergens(p 0.05). On the contrary, the sensitization to house dust mites were significantly associated with the prevalence of asthma and allergic rhinitis. CONCLUSION: Citrus red mite was the most common sensitizing allergen in 16-18 year-old adolescents living in rural areas with citrus farms and sensitization to CRM was significantly associated with the prevalence of atopic dermatitis.

A Prospective Study of Asthma Prevalence and Atopy Rate in Children Living in Rural Area of Cheju Island for 3 Years / 소아알레르기및호흡기학회지

PURPOSE: Asthma has been increasing due to changes in life style and indoor environments. Manifestations of asthma and atopy varies according to age. The purpose of this study was to elucidate the changing prevalence of asthma and atopy in children living in rural area of Cheju island via three year prospective study. METHODS: A total of 314 subjects aged from 7 to 12 years was followed up for three years. They responded a ISAAC questionnare, underwent allergy skin prick test with common aeroallergens and methacholine bronchial provocation test. Children with asthma symptoms on a questionnaire and positive methacholine bronchial provocation test were diagnosed as bronchial asthma. Skin prick test was regarded as positive when the size of wheal caused by allergens was same or larger than that caused by histamine. RESULTS: The prevalence of bronchial asthma has a tendency to increase from 4.1 % to 7.3% three years later(P=0.08). The atopy rate has significantly increased from 34.1% to 49.2% in both girls and boys(P<0.001), from 35.0% to 46.9% in girls(P< 0.05), and from 33.3% to 51.3% in boys(P<0.05). The positive skin responses to Dermatophagoides pteronyssinus, D. farinae(P=0.36), Japanese cedar and cockroach were not changed between the three years. However, the postive skin reponse to citrus red mite was significantly increased three years later(from 10.7% to 31.1%, P<0.001). CONCLUSION: The asthma prevalence has a tendency to increase in children living in rural area with citrus farms. The atopy rate has been also increasing in the rural children. These phenomena may be explained by the fact that sensitization to citrus red mite has been increasing when they are getting older.

Association between HLA-DRB1 alleles and the sensitization to citrus red mite (Panonychus citri) / 천식및알레르기

BACKGROUND: Recent investigations have demonstrated that citrus red mite (Panonychus citri, CRM) is an important allergen in the development of asthma in the rural population. The aim of this study was to investigate whether susceptibility or resistance to IgE responses to CRM was associated with HLA-DRB1 alleles. MATERIAL AND METHODS: Blood samples were obtained from two groups of unrelated Korean adolescents: 298 CRM-sensitive subjects and 99 age-matched non-atopic healthy controls. Sensitization to CRM was evaluated using skin-prick responses and serum specific IgE levels. Genotyping of HLA-DRB1 alleles was carried out using PCR-based methods. RESULTS: The frequency of DRB1*07 was significantly higher in the IgE responders to CRM (15.1%) than in the controls (3.0%), but the frequency of the other alleles was the same between the two groups. CONCLUSIONS: HLA-DRB1*07 was significantly associated with sensitization to CRM, and may be a risk factor for the sensitization to this allergen.

Risk factors for the sensitization to citrus red mite (Panonychus citri) in adolescents living in rural areas of Cheju island / 천식및알레르기

INTRODUCTION: Recent investigations have demonstrated that citrus red mite is a common sensitizing allergen in children and adults living in rural areas of Cheju island. OBJECTIVE: The aims of this study were to evaluate the sensitization rate to the citrus red mite and to determine the risk factors for this sensitization in adolescents living in rural areas of Cheju island. SUBJECTS AND METHODS: A total of 3,395 adolescents (from ages 13 to 15 years old) living in rural areas of Cheju island were enrolled in this study. Each subject was evaluated by a modified ISAAC questionnaire, and a skin prick test with 11 common inhalant allergens including citrus red mite. RESULTS: On skin prick test the most common sensitizing allergen was D. pteronyssinus (27.9%), followed by D. farinae (23.9%), citrus red mite (18.3%), and cockroach (16.7%). Sensitization rate to citrus red mite was higher in those living near citrus orchards than in those living far from the orchards, and higher in those visiting citrus orchards more frequently than in those visiting less frequently. CONCLUSION: Citrus red mite is a common sensitizing allergen in adolescents living in rural areas of Cheju island. The sensitization rate to citrus red mite may be partially determined by environ- mental exposure.

Specific IgG1 and IgG4 antibodies to citrus red mite in citrus farmers: a study of their relationship to respiratory symptoms

Citrus red mite (CRM) is known as the most common sensitizing allergen in subjects with asthma and rhinitis working on citrus farms. The aim of this study is to evaluate the role of specific IgG1 (slgG1) and specific IgG4 (slgG4) to CRM in citrus farmers. Questionnaire survey and skin prick test including CRM antigen was done by 136 workers. Specific IgE (slgE), slgG1 and slgG4 to CRM were detected by enzyme-linked immunosorbent assay (ELISA). CRM-sensitive-asthma was diagnosed upon presence of asthmatic symptoms by questionnaire, airway hyperresponsiveness to methacholine and slgE to CRM. CRM-sensitive rhinitis was diagnosed upon presence of rhinitis symptoms and slgE to CRM. Eleven (8.1+ACU-) had CRM-sensitive asthma and 25 (18.4+ACU-) had CRM-sensitive rhinitis. Significant association was noted between presence of asthmatic symptoms and slgE or slgG4 (p+ADw-0.05, respectively), while no significant association was noted in slgG1 (p+AD4-0.05). Significant association was noted in the prevalence between slgG4 and slgE (p+ADw-0.05), while no significant association was noted between slgG1 and slgG4 or slgE (p+ADw-0.05, respectively). There was a significant correlation between slgE and slgG4 level (r+AD0-0.39, p+ADw-0.05). These findings suggest that the presence of slgG1 to CRM is response to CRM exposure, and further studies will be needed to evaluate the role of slgG4.Citrus red mite (CRM) is known as the most common sensitizing allergen in subjects with asthma and rhinitis working on citrus farms. The aim of this study is to evaluate the role of specific IgG1 (slgG1) and specific IgG4 (slgG4) to CRM in citrus farmers. Questionnaire survey and skin prick test including CRM antigen was done by 136 workers. Specific IgE (slgE), slgG1 and slgG4 to CRM were detected by enzyme-linked immunosorbent assay (ELISA). CRM-sensitive-asthma was diagnosed upon presence of asthmatic symptoms by questionnaire, airway hyperresponsiveness to methacholine and slgE to CRM. CRM-sensitive rhinitis was diagnosed upon presence of rhinitis symptoms and slgE to CRM. Eleven (8.1+ACU-) had CRM-sensitive asthma and 25 (18.4+ACU-) had CRM-sensitive rhinitis. Significant association was noted between presence of asthmatic symptoms and slgE or slgG4 (p+ADw-0.05, respectively), while no significant association was noted in slgG1 (p+AD4-0.05). Significant association was noted in the prevalence between slgG4 and slgE (p+ADw-0.05), while no significant association was noted between slgG1 and slgG4 or slgE (p+ADw-0.05, respectively). There was a significant correlation between slgE and slgG4 level (r+AD0-0.39, p+ADw-0.05). These findings suggest that the presence of slgG1 to CRM is response to CRM exposure, and further studies will be needed to evaluate the role of slgG4.

Specific IgG1 and IgG4 antibodies to citrus red mite in citrus farmers: a study of their relationship to respiratory symptoms

Citrus red mite (CRM) is known as the most common sensitizing allergen in subjects with asthma and rhinitis working on citrus farms. The aim of this study is to evaluate the role of specific IgG1 (slgG1) and specific IgG4 (slgG4) to CRM in citrus farmers. Questionnaire survey and skin prick test including CRM antigen was done by 136 workers. Specific IgE (slgE), slgG1 and slgG4 to CRM were detected by enzyme-linked immunosorbent assay (ELISA). CRM-sensitive-asthma was diagnosed upon presence of asthmatic symptoms by questionnaire, airway hyperresponsiveness to methacholine and slgE to CRM. CRM-sensitive rhinitis was diagnosed upon presence of rhinitis symptoms and slgE to CRM. Eleven (8.1+ACU-) had CRM-sensitive asthma and 25 (18.4+ACU-) had CRM-sensitive rhinitis. Significant association was noted between presence of asthmatic symptoms and slgE or slgG4 (p+ADw-0.05, respectively), while no significant association was noted in slgG1 (p+AD4-0.05). Significant association was noted in the prevalence between slgG4 and slgE (p+ADw-0.05), while no significant association was noted between slgG1 and slgG4 or slgE (p+ADw-0.05, respectively). There was a significant correlation between slgE and slgG4 level (r+AD0-0.39, p+ADw-0.05). These findings suggest that the presence of slgG1 to CRM is response to CRM exposure, and further studies will be needed to evaluate the role of slgG4.Citrus red mite (CRM) is known as the most common sensitizing allergen in subjects with asthma and rhinitis working on citrus farms. The aim of this study is to evaluate the role of specific IgG1 (slgG1) and specific IgG4 (slgG4) to CRM in citrus farmers. Questionnaire survey and skin prick test including CRM antigen was done by 136 workers. Specific IgE (slgE), slgG1 and slgG4 to CRM were detected by enzyme-linked immunosorbent assay (ELISA). CRM-sensitive-asthma was diagnosed upon presence of asthmatic symptoms by questionnaire, airway hyperresponsiveness to methacholine and slgE to CRM. CRM-sensitive rhinitis was diagnosed upon presence of rhinitis symptoms and slgE to CRM. Eleven (8.1+ACU-) had CRM-sensitive asthma and 25 (18.4+ACU-) had CRM-sensitive rhinitis. Significant association was noted between presence of asthmatic symptoms and slgE or slgG4 (p+ADw-0.05, respectively), while no significant association was noted in slgG1 (p+AD4-0.05). Significant association was noted in the prevalence between slgG4 and slgE (p+ADw-0.05), while no significant association was noted between slgG1 and slgG4 or slgE (p+ADw-0.05, respectively). There was a significant correlation between slgE and slgG4 level (r+AD0-0.39, p+ADw-0.05). These findings suggest that the presence of slgG1 to CRM is response to CRM exposure, and further studies will be needed to evaluate the role of slgG4.

Prevalence of allergic rhinitis and its causative allergens in people in rural area of Cheju IsIand / 천식및알레르기

OBJECTIVE: Cross-sectional survey was performed to evaluate prevalence of allergic rhinitis and its causative allergens in people in rural area of Cheju Isl~and. Subject and METHOD: A total of 1,236 people with 1,055 children and 181 adults in rural area of Cheju Island were enrolled in this study. In children, 544 were males and 511 were females, and their mean age was 12.3(ranging from 7 to 16) years. In adults, 78 were males and 103 were females, and their mean age was 50.1 (ratging from 18 to 87) years. Evaluations included a questionnaire survey, and skin prick test with extracts of Japanese cedar (Cryptomera japonica, J cedar) pollen and citrus red mite (Panonychus citri, CRM) as well as eleven common inhalant allergens. RESULTS: Prevalence of chronic nasal symptoms was 40.6% (429/1,055) in children, and 45.8 % (83/181) in adults. Prevalence of allergic rhinitis based on positive nasal symptoms on the questionnaire and positive skin response to one or more of the 13 inhalant allergens were 15.4 % (159/1.035) in children, and 19.3% (35/181) in adults. Of 1,035 children, skin-test response was positive in 37.6%, and common sensitizing allergens in order of decreasing frequency were Dermatophagoides pteronpssinus (DP) (26.6%), D. farinae (DF)(22.6%), CRM(14.2%), cockroach(11.3%) and J cedar(9.7%). Of 181 adults, skin-test response was positive in 25.9%, and t,he most common sensitizing allergen was CRM(16.5%), followed by cockroach(11.0%), DP(9. 9%), DF(9.4%), and J cedar(6.6%). Of 159 children with allergic rhinitis, the common sensitizing allergens in order of deereasing frequency were DP(79.2%), DF(67.3%), CRM(35.8%), J cedar(32.7%), and cockroach(27.0%). Of 35 adults with allergic rhinitis, the most common sensitizing allergen was CRM(68.6%), followed by DP(40%), DF(34.3%), cockroach(34.3%), and J cedar(28.9%). CONCLUSION: Allergic rhinitis is a very common disease with a prevalence of 15.4% in children and 19.3% in adults in rural area of Cheju island, and common sensitizing allergens include house dust mite, citrus red mite, cockroach, and Japanese cedar pollen.

Antigenic distribution of HLA - DRB1 locus in citrus red mite ( Panonychus citri ) - sensitive asthma / 천식및알레르기

BACKGROUND: Specific IgE responses to allergens provide useful models for evaluating the genetic factors that control human immune responses. HLA class II gene products are involved in the antigen presentation of exogenous antigens. OBJECTIVE: The aim of this study was to evaluate whether susceptibility or resistance to asthma induced by the citrus red mite (Panonychus citri, CRM) was associated with HLA class II gene-encoded antigens. METHODS: Peripheral venous blood samples were collected from two groups of unrelated Korean adults. Ninety-one patients with citrus red mite-induced asthma and 98 exposed, healthy control subjects. The second exon of the HLA-DRB1 genes was selectively amplified by the polymerase chain reaction method. HLA typing was carried out using PCR-sequence specific oligonucleotide probes(PCR-SSOP). RESULTS: The frequency of HLA-DR7 was significantly higher among the CRM-sensitive asthmatics than among the controls (17.6% vs 4.1%, RR=3.92, p=0.01). Conversely, the frequency of HLA-DR4 was significantly lower among the CRM-sensitive asthmatics than among the controls(19.8% vs 40.8%, RR=0.36, p=0.01). No significant difference was found in the distributions of the other HLA-DRB1 gene-encoded antigens between the two groups. CONCLUSION: HLA-DRB1 genes may be involved in the development of citrus red mite-induced asthma. In addition, HLA-DR7 may increase, and DR4 decrease, the risk of developing asthma in exposed individuals.