Zoonoses and Geomedical Factors
Jul Låg in Geomedicine, 2017
Trypanomosiasis is any disease caused by a trypanosome. Many of these diseases are zoonoses. They are transmitted by different arthropods. According to Greenham,1 trypanosomiasis affected 10 million people, and has dogs, pigs, cattle, game animals, and many rodents as reservoir hosts. Chagas disease in South America is produced by a trypanosome whose target organ is the heart in man, while the different trypanosoma of the brucei group in Africa have as their main target organ the central nervous system of man. In Africa, the main transmitters of the diseases are different tse-tse flies (Glossina), horseflies, (Tabanidae), stomoxys, and some mosquitoes may to some extent be transmitters. In Africa, some large breeding places of the tse-tse fly have been cleared of bush and dusted with pesticides. But the fight has been hampered by the emergence of insecticide-resistant flies. At the same time, ecological problems have resulted from the use of insecticides. It is important to remove bushes and trees near the living places of man to keep the tse-tse flies away. In tropical America, trypanomiasis is mainly transmitted by assasin bugs (Triotoma infestans). The elimination of the Chagas is a matter of personal and public hygiene and housing. The economic and social improvement of common man is perhaps most important for a solution of the Chagas problem.
Suramin
M. Lindsay Grayson, Sara E. Cosgrove, Suzanne M. Crowe, M. Lindsay Grayson, William Hope, James S. McCarthy, John Mills, Johan W. Mouton, David L. Paterson in Kucers’ The Use of Antibiotics, 2017
Two subspecies of flagellated protozoa in the Trypanosomatidae family cause distinct subtypes of clinical disease (Bruckner and Labarca, 2007). West African (Gambian) trypanosomiasis is caused by Trypanosoma brucei gambiense and occurs in West and Central Africa. East African (Rhodesian) trypanosomiasis is caused by T. b. rhodesiense. Both infections are transmitted by the bite of an infected Glossina spp. (tsetse fly), and are endemic only in areas where these are found. Each subspecies has a particular relationship with certain Glossina biogroups, resulting in the distinct geographical distribution of these infections across Africa. T. b. gambiense predominantly infects humans, with only few animals infected in endemic areas, whereas T. b. rhodesiense is a zoonosis and has extensive animal reservoirs. Humans are thought to be infected when other hosts are not available as a food source or when their occupation brings them in close contact with Glossina flies; for example, farmers, firewood collectors, and game wardens (Burri and Brun, 2009).
Whose Knowledge Matters?
Kevin Bardosh in One Health, 2016
Despite the donors pulling out, there have been a few other funding options that have emerged recently, such as the Pan African Tsetse and Trypanosomiasis Eradication Campaign (PATTEC) established in 2000. African heads of state agreed to a continent-wide campaign coordinated by the African Union, funded within Africa, and mobilized with local resources. This follows the ‘Zambian narrative’ as the plan was renegotiated with regional governments to eliminate the vector from the southern tsetse belt: ‘Botswana has provided staff, expertise … Namibia has used [a] specialist airfield for aerial spraying, Zambia and Angola have [given] … US$8.5 million of funding’ (Senior, 2009). Aerial spraying and localized use of insecticides has eradicated the tsetse fly that carries Trypanosoma brucei gambiense and Trypanosoma brucei rhodesiense from 36,000 km2 across Botswana, Namibia, Angola and Zambia. However, there seems to be latent politics at play within PATTEC itself. One interviewee attended a PATTEC meeting, which he described as being ‘all over the place’ regarding control measures. In Zambia and Zimbabwe, PATTEC seems to be concentrating on the use of what is often considered a controversial control modality: the Sterile Insect Technique (SIT) (see Scoones, this book). But Zambia is struggling to fund this – several interviewees commented that there are lots of ideas without any funds attached.
Design, synthesis, and antiprotozoal evaluation of new 2,4-bis[(substituted-aminomethyl)phenyl]quinoline, 1,3-bis[(substituted-aminomethyl)phenyl]isoquinoline and 2,4-bis[(substituted-aminomethyl)phenyl]quinazoline derivatives
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2020
Jean Guillon, Anita Cohen, Clotilde Boudot, Alessandra Valle, Vittoria Milano, Rabindra Nath Das, Aurore Guédin, Stéphane Moreau, Luisa Ronga, Solène Savrimoutou, Maxime Demourgues, Elodie Reviriego, Sandra Rubio, Sandie Ferriez, Patrice Agnamey, Cécile Pauc, Serge Moukha, Pascale Dozolme, Sophie Da Nascimento, Pierre Laumaillé, Anne Bouchut, Nadine Azas, Jean-Louis Mergny, Catherine Mullié, Pascal Sonnet, Bertrand Courtioux
Furthermore, another neglected disease caused by Trypanosomatidae parasites of the Trypanosoma genus is the human African trypanosomiasis (HAT), or sleeping sickness, almost invariably fatal unless treated. This infection is transmitted to humans through the bite of an infected tsetse fly. Brain involvement causes various neurological disturbances, including sleep disorders, progression to coma and, ultimately, death. There are two clinical forms: the slowly progressing form (gambiense HAT), caused by infection with Trypanosoma brucei gambiense (currently 98% of cases), and the faster progressing form (rhodesiense HAT), caused by infection with Trypanosoma brucei rhodesiense. As a neglected tropical disease targeted by the WHO for elimination, a historically low number of cases (<1000) was reported in 2018. The recent approval of a new medicine (fexinidazole) for the treatment of gambiense HAT has opened new possibilities for the management of cases and thus led to recent WHO interim guidelines for this treatment27. A veterinary form of this parasitic disease exists. Named Nagana, it is caused by Trypanosoma brucei brucei which contaminates African livestock, thus having a significant economic impact.
Emerging compounds and therapeutic strategies to treat infections from Trypanosoma brucei: an overhaul of the last 5-years patents
Published in Expert Opinion on Therapeutic Patents, 2023
Francesco Melfi, Simone Carradori, Cristina Campestre, Entela Haloci, Alessandra Ammazzalorso, Rossella Grande, Ilaria D’Agostino
Neglected tropical diseases (NTDs) are a group of 20 diverse conditions that are mainly prevalent in tropical areas, where they mostly affect impoverished communities characterized by very precarious hygienic conditions. In fact, studies suggest that the epidemiology of NTDs is often related to environmental conditions. Many NTDs are vector-borne diseases, have animal reservoirs, and are associated with multi-stage life cycles. All these factors make their public health control very challenging. Human African Trypanosomiasis (HAT), also known as the sleeping sickness, is caused by microscopic parasites of the species Trypanosoma brucei. It is transmitted by the tsetse fly (Glossina species), found only in sub-Saharan Africa. Two different subspecies of the parasite cause distinct disease patterns in humans: T. brucei gambiense (Tbg) establishes the slowly progressing African trypanosomiasis in western and central Africa, while T. brucei rhodesiense (Tbr) induces the more acute African trypanosomiasis in eastern and southern Africa [1].
Metabolomic profile, anti-trypanosomal potential and molecular docking studies of Thunbergia grandifolia
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2023
Heba A. S. El-Nashar, Ahmed M. Sayed, Hany A. M. El-Sherief, Mostafa E. Rateb, Lina Akil, Ibrahim Khadra, Taghreed A. Majrashi, Sara T. Al-Rashood, Faizah A. Binjubair, Mahmoud A. El Hassab, Wagdy M. Eldehna, Usama Ramadan Abdelmohsen, Nada M. Mostafa
Trypanosomiasis or sleeping sickness is a protozoan disease that infects animals and humans transmitted by the bite of Glossina (tsetse) fly carrying Trypanosoma brucei1. Currently, trypanosomiasis affects more than 50 million cattle and 70 million people in sub-Saharan Africa2. The available current medicines record lack of efficiency, resistance, and toxicity, so there is an urgent need for the development of novel, safe, efficacious, cost-effective drugs with new mechanism of action3,4. In African countries where trypanosomiasis is prevalent, natural products (herbal extracts) have traditionally been utilised for centuries and are still extensively used to cure infections and other parasitic diseases5,6. Interestingly, about 30% of the world population has confidence in traditional therapies due to their wide availability and affordability7. Moreover, various drugs like quinine and artemisinin were established as plant-derived potential antiprotozoal agents8.
Related Knowledge Centers
- African Trypanosomiasis
- Obligate Parasite
- Abdomen
- Blood
- Arthropod Bites & Stings
- Disease Vector
- Trypanosomatida
- Animal Trypanosomiasis
- Proboscis
- Body Plan