Salil Kumar Gupta

Incrimination of Blomia tropicalis as a Potent Allergen in House Dust and its Role in Allergic Asthma in Kolkata Metropolis, India

BackgroundTheincreasing trend in allergic diseases has become obvious in the present day, especially in developing countries like India, because of many factors such as change in ambient air quality, increased air pollution, metamorphic change in living habits and lifestyle, and climate [1]. Mites present in house dust represent a major source of allergens, resulting in different allergic manifestations all over the world, and hypersensitivity to these dust mites may play a pivotal role in pathogenesis of several allergic complaints including bronchial asthma. The present study evaluated the sensitization toward house dust and house dust mites among patients residing in Kolkata metropolis, India, who are suffering from allergic asthma.MethodsThe skin prick test was performed on a total of 1079 patients (585 males and 494 females) between the age group 5-50 years and 50 healthy controls using a variety of 16 common aero-allergenic extracts including 4 allergens of interest, viz. Dermatophagoides pteronyssinus, Dermatophagoides farinae, and Blomia tropicalis and total house dust allergens. Total serum IgE level was measured by using the EIA technique and specific IgE levels against aforesaid allergens were detected with the Pharmacia ImmunoCAP 100 System. The influence of age and sex, if any, on allergen sensitivity was also investigated. All statistical analyses were performed using SPSS 10.0 for Windows and Zar [2].ResultsThe responses among patients with asthma to house dust and house dust mite allergen tests were as follows: house dust (96.22%), D. pteronyssinus (75.06%), B. tropicalis (72%), and D. farinae (63.72%). The frequency of positive skin response was found to be independent of age and sex. The total serum IgE levels in patients varied between 7.3 and 4040 IU/ml (mean 369 ± 26.51 IU/ml). Specific IgE antibody test proved that 83% patients showed sensitivity toward at least 1 of the allergens tested.DiscussionThe results indicate that patients are highly sensitive to house dust and 3 other allergenic mites, namely, D. pteronyssinus, D. farinae, and B. tropicalis, as evidenced by the skin prick test, quantification of total serum IgE, and detection of allergen-specific IgE antibodies among patients of Kolkata. Although mites belonging to the genus Dermatophagoides have already been incriminated as a major source of allergen in house dust in India, this is the first time the role of B. tropicalis mites causing allergic asthma has been reported from an Indian population. Thus, the importance of B. tropicalis mite as an aetiopathological agent in causing various allergic manifestations among the Kolkata population should not be undermined and the allergen should be included in routine allergy testing.

Description of two new species of mites of the family laelapidae (Acari: Mesostigmata) from rat burrow in West Bengal, India

Two new species of laelapid mites, Hypoaspis reticulatus and Pseudolaelaps splendens collected from rat burrow in West Bengal, India are described and illustrated.

Description of two new species of dust mites from Kolkata, India

Two new species belonging to the genera Tarsonemus Koch (Fam: Tarsonemidae) and Raphignathus Koch (Fam: Raphignathidae), collected from house dust of Kolkata metropolis are described here.

Seasonal Variations in Synanthropic Mite Community of Calcutta, India

Synanthropic acarine populations, especially house dust mites are considered as a major source of allergen responsible for different allergic manifestations. Considering the manifold importance of synanthropic mites, knowledge on the seasonal population structure of this mite fauna is of primary importance for the better understanding of the disease prevalence and pathogenesis. However, very little is known on the seasonal population structure of this ecologically well defined group of mites in Indian context. In the present communication, ecological observations on the seasonal population structure of this group of mites were made with special reference to house dust mites which forms a major component of synanthropic mite community. To fulfill the objective, bedroom floor dust were collected and processed from 60 selected houses in and around Kolkata metropolitan areas during four distinct seasons (winter, spring, summer and autumn) for two consecutive years. Floor dust were collected by sweeping the floor and brought to the laboratory in polythene packet for further analysis. On analyzing the season-wise data, it was noted that the average number of total mite was highest in summer and lowest in spring; Pyroglyphids were highest in summer and lowest in winter; Glycyphagids were highest in autumn and lowest in spring. The study indicates that a temperature of 25–30°C and relative humidity between 65 and 75% were optimum for the successful growth and multiplication of these mites.