AIMS OF THE STUDY: The aims of this review were to assess the scale of the global trade in F. cirrhosa, and to synthesise studies of the impacts of wild harvest on F. cirrhosa populations and on the extent of emerging cultivation initiatives as an alternative to wild harvest.
METHODS: Firstly, we reviewed published information on studies on impacts of wild F. cirrhosa harvest from across the geographic range of this species. Secondly, global trade data for F. cirrhosa were analysed.
RESULTS: The principal demand for F. cirrhosa bulbs is in China, where hundreds of different companies produce Fritillaria preparations. Trade data also show that in 2013, China exported over 44 tonnes of F. cirrhosa bulbs to Taiwan and 26.7 tonnes to the Republic of Korea. Extensive commercial use and limited wild stocks result in a high price (2000 - 3800 CNY per kg (around US$ 303 -560 per kg in 2017)) for F. cirrhosa bulbs. Prices of cultivated Fritillaria bulbs are much lower (600-680 CNY per kg in 2017) than wild harvested bulbs. But due to very specific growth requirements of F. cirrhosa, cultivation is not yet able to meet total demand. The consequence is continued exploitation of wild stocks. At the same time, however, an increasing proportion of the demand is met by cultivation of alternative Fritillaria species that are easier to grow than F. cirrhosa. The air-dry mass of F. cirrhosa bulbs varies between 0.0917 and 0.1116 g per bulb. This represents 8960 - 10,900 bulbs/kg or 8.9 - 10.9 million bulbs per tonne. Current demand therefore represents billions of bulbs per year.
CONCLUSIONS: Demand for F. cirrhosa bulbs, particularly from China, makes this species one of the most intensively harvested alpine Himalayan medicinal bulbs. Although F. cirrhosa is listed as a Class III protected species in China, billions of these tiny, wild harvested bulbs are sold per year. Due to demand exceeding supply, the price of F. cirrhosa bulbs has increased dramatically. Between 2002 and 2017, for example, the price of wild harvested F. cirrhosa bulbs increased over nine-fold, from the equivalent of US$60 in 2002 to US$560 per kg in 2017. To date, cultivation has been unable to meet the entire market demand for F. cirrhosa bulbs, although other Fritillaria species are successfully cultivated on a larger scale.
METHODS: From June 2013 through May 2014, diarrheal stool samples were collected at one national referral hospital in Thimphu, two regional referral hospitals in the eastern and central regions, and one general hospital in the western region of Bhutan. NoV was detected by reverse transcription-polymerase chain reaction (RT-PCR), by amplifying the capsid gene. The RT-PCR results were confirmed by nucleotide sequencing of the amplicons.
RESULTS: The proportion of NoV-positive stool samples was 23.6% (147/623), of which 76.9% were NoV GII and the remainders were NoV GI. The median age of infected children was 15.5 months, with a fairly balanced female: male ratio. NoV GII was most prevalent in the colder months (late November-mid April) and NoV GI had the highest prevalence in the summer (mid April-late September). Nucleotide sequencing was successful in 99 samples of GII strains. The most common genotypes were GII.3 (42.6%), GII.4 Sydney 2012 (15.8%), and GII.4 unassigned (11.9%). No GII.21 was found in any child in the present study. Phylogenetic analysis showed that GII.3 strains in the present study belonged to an independent cluster in lineage B. These strains shared an ancestor with those from different countries and Bhutanese strains circulating during 2010.
CONCLUSION: NoV remains an important cause of diarrhea among Bhutanese children. Genotype GII.3 from a single ancestor strain has spread, replacing the previously circulating GII.21. Current NoV genotypes are similar to the strains circulating worldwide but are primarily related to those in neighboring countries. NoV GII is prevalent during the cold season, while GI is prevalent during the summer. To develop a NoV infection control policy, further studies are needed.