Leeches can reduce swelling in the tissues and promote healing, helping in particular to restore circulation after microsurgery to reattach body parts. Other clinical applications include varicose veins, muscle cramps, thrombophlebitis, and joint diseases such as epicondylitis and osteoarthritis.Leech secretions contain several bioactive substances with anti-inflammatory, anticoagulant and antimicrobial effects. One active component of leech saliva is a small protein, hirudin. It is widely used as an anticoagulant drug to treat blood-clotting disorders, and manufactured by recombinant DNA technology.In 2012 and 2018, Ida Schnell and colleagues trialled the use of Haemadipsa leeches to gather data on the biodiversity of their mammalian hosts in the tropical rainforest of Vietnam, where it is hard to obtain reliable data on rare and cryptic mammals. They showed that mammal mitochondrial DNA, amplified by the polymerase chain reaction, can be identified from a leechs blood meal for at least four months after feeding. They detected Annamite striped rabbit, small-toothed ferret-badger, Truong Son muntjac, and serow in this way. Water pollution
Exposure to synthetic estrogen as used in contraceptive medicines, which may enter freshwater ecosystems from municipal wastewater, can affect leeches reproductive systems. Although not as sensitive to these compounds as fish, leeches showed physiological changes after exposure, including longer sperm sacs and vaginal bulbs, and decreased epididymis weight. Notes
References
General bibliography
Ruppert, Edward E.; Fox, Richard S.; Barnes, Robert D. (2004). Invertebrate Zoology, 7th Edition. Cengage Learning. ISBN 978-81-315-0104-7. External links
 Media related to Hirudinea at Wikimedia Commons
 Data related to Hirudinea at Wikispecies
 The dictionary definition of leech at Wiktionary
IFN, Rimantadine (Flumadine), Rimantidine & .alpha.IFN, 1-Adamantan-1-ylethylamine, rimantidin, Rimantadin A, (R)-1-(Adamantan-1-yl)ethan-1-amine, 1-adamantanylethylamine, Maybridge1_002066, SCHEMBL2981, 1-tricyclo[3.3.1.1~3,7~]dec-1-ylethanamine, Oprea1_602732, SCHEMBL2619249, CHEMBL1201272, DTXSID2023561, SCHEMBL20409367, CHEBI:94440, CTK6A4437, HMS1410F13, HMS2090L19, HMS3604N13, HMS3655J05, 1-Adamantanemethylamine, ?-methyl-, ALBB-013870, BCP12269, HY-B0338, ZX-AN012619, ANW-72018, BBL013215, BDBM50216627, MFCD00869344, s1964, STK177253, (alpha-methyl-1-adamantyl)methylamine, AKOS000264537, AKOS006238592, AKOS016038537, .alpha.-Methyl-1-adamantanemethylamine, AM84461, API0024288, BBV-156986, CCG-236078, CS-2380, DB00478, FCH3207896, MCULE-9027470290, IDI1_007990, NCGC00159491-03, NCGC00159491-05, AK-58175, AS-68744, CC-34261, LS-15019, OR315791, SBI-0206810.P001, AB0012750, AX8049536, DB-042207, FT-0630403, H6325, ST45025920, SW220023-1, EN300-33990, C07236, D08483, Q421711-[(3R,5S,7s)-adamantan-1-yl]ethan-1-amine, AB00638368-09, AB00959689-03, AB01506092_02, AB01506092_03, 392R284, C-06592, BRD-A84282119-003-01-2, Z56757137, 1-(Tricyclo[3.3.1.1>3,7>]dec-1-yl)ethanamine (HCl), Tricyclo(3.3.1.1^3,7)decane-1-methanamine, .alpha.-methyl-, 1-(1-Adamantyl)ethylamine Hydrochloride;Rimantadine hydrochloride, Tricyclo(3.3.1.1(sup 3,7))decane-1-methanamine, .alpha.-methyl-, Tricyclo[3,3,1,1(3,7)]decane-1-methanamine, .alpha.-methyl-, Tricyclo(3.3.1.1^3,7)decane-1-methanamine, .alpha.-methyl- & IFN.alpha

References
External links
U.S. FDA press release announcing rimantadines approval
U.S. Center for Drug Evaluation and Research rimantadine description
U.S. NIH rimantadine description
U.S. CDC flu anti-viral treatment information