Neglected Tropical Diseases and Helminthic Infections Flashcards
What are neglected tropical diseases?
- Disease preventable and treatable
- Affect poor, vulnerable populations living in hard to reach places
The world wide the top 5 neglected tropical diseases are?
- Lymphatic filariasis
- Onchocerciasis
- Schistosomiasis
- Soil-transmitted helminths
- Trachoma
Lymphatic filariasis
Lymphatic filariasis, considered globally as a neglected tropical disease (NTD), is a parasitic disease caused by microscopic, thread-like worms. The adult worms only live in the human lymph system. The lymph system maintains the body’s fluid balance and fights infections.
Parent Disease: Parasitic disease
Vector: Mosquitoes
Onchocerciasis
Onchocerciasis, also known as river blindness, is a disease caused by infection with the parasitic worm Onchocerca volvulus. Symptoms include severe itching, bumps under the skin, and blindness. It is the second-most common cause of blindness due to infection, after trachoma.
Causes: Onchocerca volvulus spread by a black fly
Symptoms: Itching, bumps under the skin, blin…
Other names: River blindness, Robles disease
Specialty: Infectious disease
Schistosomiasis
Schistosomiasis, also known as bilharzia, is a disease caused by parasitic worms. Although the worms that cause schistosomiasis are not found in the United States, people are infected worldwide. In terms of impact this disease is second only to malaria as the most devastating parasitic disease.
Soil-transmitted helminths
Soil-transmitted helminths refer to the intestinal worms infecting humans that are transmitted through contaminated soil (“helminth” means parasitic worm): Ascaris lumbricoides (sometimes called just “Ascaris“), whipworm (Trichuris trichiura), and hookworm (Anclostoma duodenale and Necator americanus).
Trachoma
Trachoma is a disease of the eye caused by infection with the bacterium Chlamydia trachomatis. Blindness from trachoma is irreversible. It is a public health problem in 44 countries, and is responsible for the blindness or visual impairment of about 1.9 million people.09 May 2021
Causes: Chlamydia trachomatis
Diseases or conditions caused: Blindness
The burden of Neglected tropical disease.
> 1.5-billion people (24% of the world’s population)
40% live in Africa
> 7 countries have been validated as having eliminated one of the five diseases
2 are from Africa (Morocco [trachoma, 2016] and Togo [lymphatic filariasis, 2017]
WHO strategies recommended to address neglected tropical diseases
Community-based surveys for mapping or monitoring and evaluation purposes are core activities of NTD programmes
- Preventive chemotherapy
- Individual care management
- Vector control
- Veterinary public health
- Water, sanitation and hygiene
Considerations during the covid-19 pandemic
> Temporary suspension of community-based surveys, mass treatment and active case finding
> Community-based vector control and veterinary public health interventions should continue with strict precautions
:hand hygiene, respiratory etiquette, physical distancing
Treatment targets for neglected tropical diseases
- 65% and above for lymphatic filariasis and Onchocerciasis
- 75% and above for Schistosomiasis in school-aged children
- 75% and above for soil-transmitted helminths in school-age and pre-school children
- 80% and above for trachoma
In South Africa, the most common NTDs are?
In SA, the most common NTDs include infection with the soil-transmitted helminths - Ascaris lumbricoides, Trichuris trichiura, Necator americanus, Enterobius vermicularis - and the less prevalent but common Strongyloides and Taenia spp. and Schistosoma haematobium and S. mansoni.
Soil-transmitted helminths and
Schistosomiasis
What is a helminth?
- derived from the Greek helmins :“parasitic worm”
- Exist as free-living organisms or as parasites of plant or animal hosts
- Nemathelminthes: e.g. nematodes (roundworms)
- Platyhelminthes e.g. cestodes (tapeworms) and trematodes (flukes)
Helminthic parasites?
Helminthic parasites are multicellular worms
Complex life cycles with stages of development outside the human host
Soil-transmitted helminths
> Roundworm (Ascaris lumbricoides)
Whipworm (Trichuris trichiura)
Hookworm (Anclostoma duodenale and Necator americanus)