Possible discovery of Chinese lung fluke, Paragonimus skrjabini in Manipur, India.

To obtain more information about Paragonimus species prevalent in Manipur, India, hundreds of freshwater crabs, Potamiscus manipurensis, were captured from mountain streams in the Motbung Mountains in Senapati District, from December 1997 to January 1998. Crab extracts were prepared by digestion, differential filtration, and sedimentation. The filtered sediments were critically examined under a stereomicroscope. Isolated Paragonimus metacercariae were used for morphological study and animal experimentation. Forty-seven metacercariae were fed orally to a 3-month-old male puppy of local breed; at autopsy 155 days after inoculation, 12 adult worms were recovered; 2 were free in the thoracic cavity and 5 pairs were in lung cysts. Two adult worms were flattened and fixed in 70% ethanol and the remaining worms were put directly into 70% ethanol and preserved until July 2005. The former 2 worms were stained with borax carmine for morphological study at Sikkim Manipal Institute of Medical Sciences, Sikkim, India. Two adult worms in the latter group were sent to the National Institute of Infectious Diseases, Tokyo, Japan, for morphological identification and DNA sequencing. The morphological features of the borax carmine-stained worms were characteristic of P. skrjabini, although no genetic material for PCR amplification and sequencing could be extracted from the worm.