Influenza A H1N1 virus in Indian pigs & its genetic relatedness with pandemic human influenza A 2009 H1N1.

Background & objectives: With the emergence of a new reassortant influenza A H1N1 virus that caused the 2009 pandemic it was felt necessary that pigs should be closely monitored for early detection of any influenza virus infection. Therefore, we investigated disease outbreaks with clinical history suggestive for swine influenza reported to our laboratory by owners of affected pig farms in Uttar Pradesh. Methods: Detection of swine influenza A virus (SIV) was attempted by isolation in embryonated chicken eggs. Presence of virus was detected by haemagglutination (HA) test and RT-PCR for amplification of different gene segments, cloning and sequencing. BLAST analysis of sequence data, phylogenetic analysis and mutation analysis based on HA, NA and matrix genes was done. Results: SIV could be isolated from one farm and all eight gene segments amplified by RT-PCR. BLAST analysis of partial nucleotide sequences and phylogenetic analysis using nucleotide sequence of HA (601 nt), NA (671 nt) and M (1031 nt) genes indicated close genetic relationship of the Indian swine isolate (A/Sw/UP-India-IVRI01/2009) with human pandemic 2009 (H1N1). The HA gene showed close relationship with the viruses of “North American Swine” lineage, whereas the NA and M genes clustered with the viruses of “Eurasian Swine” lineage, indicating a novel HA-NA reassortant. The remaining of 5 genes (NP, PA, PB1, PB2 and NS) belonged to “North American Swine” lineage. Interpretation & conclusions: This is perhaps the first report describing swine influenza among Indian pigs caused by an influenza A H1N1 virus sharing close homology with the human pandemic (H1N1) 2009 virus. Further reassortment with circulating influenza viruses must be closely monitored.

Polycythemia vera presenting with bilateral papilledema: a rare case report.

A 45-year-old male patient presented with gradual onset of headache, vomiting and blurring of vision of 28 days duration. Ophthalmological examination revealed normal anterior segment and pupillary reflex. No abnormality was detected in the vitreous. Optic disc showed features of advanced papilledema with normal macula and retinal periphery in both eyes. Visual acuity was 20/200 in the right eye and counting fingers close range in the left eye. Non-contrast computed tomography of brain was normal and magnetic resonance imaging showed sagittal sinus thrombosis without any evidence of venous infarction or intracranial mass. Routine hematological investigations revealed increased hemoglobin level, packed cell volume and leucocytosis. Further investigation revealed increased Vitamin B12 and decreased serum erythropoietin. A diagnosis of polycythemia vera was made from the above findings. This case is being presented for the rarity of association of polycythemia vera with bilateral advanced papilledema due to sagittal sinus thrombosis.