Emergence of dengue virus type-3 in northern India.

During the last few decades dengue has reemerged in several parts of Southeast Asia, including India. A major outbreak of dengue infection occurred in northern India during October to December 2003. To determine the etiology, we carried out serological, virological and molecular investigations of this outbreak. A total of 76 dengue suspected patient blood samples were collected from Gwalior, Madhya Pradesh and Delhi, India. Serological investigations carried out using an in-house Dipstick ELISA protocol revealed the presence of anti-dengue antibodies in 53 patients. Twelve of them (22%) had a positive IgM response, indicative of primary infection, and 22 of them (42%) revealed only IgG antibodies, indicative of secondary infection. RT-PCR analysis employing dengue group specific amplimer revealed the presence of dengue specific RNA in four acute phase samples. These four RT-PCR positive samples were further processed for virus isolation in C6/36 cells and suckling mice, yielding four dengue virus isolates. The Nested PCR analysis employing serotype specific amplimer revealed the presence of dengue-3 specific 389 bp amplicon. This study confirmed the reemergence of dengue virus type-3 in a dominant form in India after a gap of nine years. Earlier, dengue virus type-2 was implicated as the etiology of a major dengue epidemic in Delhi in 1996 and Gwalior in 2001. The implication of dengue type-3 as etiology of a DHF epidemic in neighboring Sri Lanka and Bangladesh recently confirms the reemergence of dengue type-3 as the dominant form on the Indian subcontinent.

Transbronchial needle aspiration in undiagnosed radiographic shadows.

Background: Transbronchial needle aspiration (TBNA) is diagnostic in benign and malignant pulmonary lesions. The technique of TBNA has made mediastinal and hilar nodes accessible. In addition to its usefulness in central airway lesions, TBNA has been found to increase the diagnostic yield in peripheral lesions also. Aim: To evaluate the role of transbronchial needle aspiration (TBNA) in cases of unconfirmed radiographic shadows. Material and Methods: A detailed clinical history was recorded in all the 54 patients, who presented with an unconfirmed radiographic shadow. Thereafter, fibreoptic specimens of bronchial aspirate and TBNA were collected, and subjected to Ziehl-Neelsen staining, Graim’s staining, fungal smear, culture for pyogenic organisms and acid fast bacilli and cytological examination by H & E stain and Papanicolaou staining.Bronchial biopsy was collected in cases wherever feasible and specimens were paraffin embedded cut into 3-5 mm thickness and stained with H & E stain. Results: Out of 54, 48.1% were diagnosed to be having bronchogenic carcinoma, 20.4% each pneumonia and tuberculosis, while one patient had primary fungal infection (Candida abbicaus). The overall diagnostic yield was highest with TBNA (85.2%) followed by transbronchial biopsy (48.2%) and bronchial aspiration (42.7%) cases. Conclusion: TBNA offers an unique opportunity to make a pathological diagnosis at the time of bronchoscopy. It is equally effective in diagnosing various infective conditions like pneumonia and tuberculosis.