In the present article, while referring to different types of medicinal leeches and their importance, the history of world leech therapy with its inconsistency are discussed. The application of medicinal leeches reached its peak in the nineteenth century, and consequently led to the extinction of their populations in many Western countries, and then there was a drop of leech therapy. By isolating Hirudin from salivary glands, leech saliva complex compounds were again significantly welcomed in the treatment of cardiovascular diseases, organ transplantation and plastic surgery. In Iran, medicinal leeches have been used for treatment of different diseases by well-known Ancient Scientists such as Avicina, Razi, Jorjani and Aghili Alavi Shirazi. Medicinal leeches were approved as a traditional product by the Food and Drug Administration of the Ministry of Health and Medical Education of Iran, and the instructions for its use were approved in 2019 in the National Committee of Medicinal Leeches. Some activities carried out at the University of Tehran about the medicinal leeches include: organizing two International Conference and startup weekend on Medicinal Leeches, offering 15 national and international training workshops on reproduction and breeding of medicinal leeches, the first training workshop for technical officers, establishing a protected area for medicinal leeches, pursuing the establishment of a National Committee and constituted the first automated center for reproduction and breeding of medicinal leeches. Currently, leech industry is facing many issues, including the illegal import of leeches from abroad, lack of control on leech overfishing from the natural habitats, which led to the extinction of medicinal leeches, as well as the supplying the medical and health centers with infected leeches, feeding reared leeches with contaminated blood, no-insurance coverages of leech treatment, and medicinal leech farms. The above problems should be solved with special attention and advanced management.

Leeches have been used to complement medical therapies for many years, however there is little data on the microorganisms they may harbor as part of their flora. The study aims were to (1) identify the presence of bacteria and (2) the presence of Hepatitis B and C viruses (HBV and HCV) in medicinal leeches using traditional bacteriological assays, Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) and Quantitative real-time PCR (RT-qPCR). Samples obtained from the body surface, intestine and jaws from 10 Hirudo verbana leeches were aseptically cultured using traditional microbiological assays. Bacterial isolates were identified using the MALDI-TOF technique and the presence of HBV and HCV was analyzed using RT-qPCR. The primary bacterium isolated from the sampled leeches were Aeromonas veronii (A. veronii) which was isolated from the jaws, gut and body surface of all leeches. Other bacteria isolated at a lower frequency from various parts were Chryseobacterium gleum, Ochrobactrum anthropi, Moraxella osloensis, Microbacterium oxydans, Kytococcus sedentarius, Rhizobium radiobacter, Staphylococcus hominis, Citrobacter and Bacillus. No anaerobic bacteria or hepatitis viruses were detected. Interestingly, some of the bacterial species identified in this study have been implicated in hospital acquired infections and are of particular risk to immunocompromised patients. The recovery of potential human pathogens from within medicinal leeches is a public health concern and consequently their use should be restricted and avoided in susceptible individuals or a prophylactic treatment should be applied.

The aim of this study was to determine the hemocyte type of medicinal leeches, Hirudo sulukii and H. verbana. It was also determined the fractions of hemolymph proteins in these leech species. According to the analyses, four types of hemocyte (prohemocyte, plasmatocyte, granulocyte, and eleocyte) were detected in two species. The prohemocytes have large nuclei, and their cytoplasm occupies a small area. The plasmotocytes are the most abundant hemocyte type. They are polymorphic cells and are found together as aggregations. The granulocytes are generally rounded in shape and typically have large granules in their cytoplasm. The eleocytes are the least found cells in hemolymph and have few granules in their cytoplasm. The areas of hemocyte types did not differ between the two species. Using polyacrilamid disc gel electrophoresis, it was determined that the hemolymph proteins of H. verbana were separated into 11 fractions or fraction groups. On the other hand, they were separated into 10 fractions or fraction groups in H. sulukii. In addition to qualitative differences, there were important quantitative differences between electropherograms of the two leech species. Therefore, these findings made a contribution to studies considering Hirudo sulukii as a new species different from Hirudo verbana.

Priapism is well-defined by persistent, painful penile erection which happens without sexual stimulation. Currently, the hirudotherapy is practiced to treat venous congestion and subsequent compartment syndrome. Here we will report acase of a male with priapism treated by leeches. The case was a 26 yr old young single male referred to the Razi Hospital Emergency Department, Guilan University of Medical Sciences, Rasht, Iran due to long-time spontaneous erections.The patient had no history of mental disorders, trauma or sickle cell anemia. we insert two leeches in each side of penile shaft for two hours, after a one hour break we insert do in same manner for another cycle. At follow-up twodays later he had significantly decreased pain, though still had cavernosal swelling and tenderness to palpation. Thepatient was subsequently discharged after three days of admission. The pain and perineal swelling completely resolvedover the course of one month. In this case, chronology indicates that leech therapy was possibly treatment option forpriapism. This procedure seems to be non-invasive treatment strategy worth to discussing in such patients.

Leech therapy was popular for many centuries. While many research studies have supported the medical use of Hirudo medicinalis, other species have not received that much attention. Due to the large demand and lack of supply, more research is needed to justify the medical use of other species. Ibn al Quff provided general guidelines on differentiating between the beneficial and toxic types of leeches.In his manuscript al-Oomdaa fi Senaatal-Jeraaha, Ibn al Quff described the uses, as well as different types, of leeches. A copy of the manuscript was obtained from King Abdulaziz Public Library in Riyadh, Saudi Arabia (Arabic). I studied the manuscript and translated it to English.Medical literaturehas proven that many leeches can be used with some efficacy. Ibn al Quff provided descriptions of the beneficial and toxic types of leeches.Additional beneficial species of leeches that can be used in medicine have been described in the literature. Ibn al Quff described and differentiated the beneficial and harmful types available during his time. Additional scientific research is necessary to classify these leeches.

This study aimed to identify the most suitable species of Iranian medical leeches for aquaculture through a comparative study of growth, survival and reproduction of Hirudo medicinalis and Hirudo orientalis, which are native to the southern shores of the Caspian Sea and do not have sufficient information about their biology. Medicinalis growth was significantly faster (p<0. 05) until the fifth month, then growth increased in favor of Orientalis. Fertility was diagnosed in almost all adults with Medicinalis (96%) and Orientalis (98%). Survival in Orientalis was higher during growth and reproduction. Fertility and cocooning in Orientalis took longer. There were fewer cocoons with smaller sizes and more babies per cocoon in the Orientalis species. Medicinalis likewise had more cocoons with larger sizes and fewer babies per cocoon. Overall, the findings of this study indicate that Orientalis reaches adult size relatively early, continues to reproduce in more unfavorable environmental and breeding conditions, and shows high fertility performance, thus making it a better option for breeding medicinal leeches in leech breeding centers.

Leeches as one of the most important components of the aquatic ecosystem has gained so much attention. Due to their parasitism, they are commercially considered as dangerous factor in fishery and biologically as potential indexes for chemical pollutant in aquatic ecosystems. So their identification and population dynamics in different aquatic habitats would be valuable. Species diversity of fresh water leeches in three rivers in east of Tehran province, Lar, Jajrood and Hablehrood rivers, were studies through 6 months in 2015. During the sampling procedure from 10 station in 3 rivers, two species, Placobdella costata and Erpobdella octaculata were collected which the latter was more frequent in all the sampling points. Study on population dynamics of Erpobdella octaculata showed no significant difference among different sampling points; however, population in different sampling months showed significant difference and the most collected samples belonged to May; it was assumed that the highest population in May would be due to the higher population of their host Ephemeroptera, favorite temperature of water and low level of chemical pollutants.