Written by Angela Alcaraz
Illustration by Sophia Dumlao
Published 15 February 2021
Neglected Tropical Diseases (NTD) are a group of diseases that include several parasitic, viral, and bacterial diseases  and mostly affect people who live in impoverished places. These people are often infected because they lack safe water, have poor housing conditions, and poor sanitation. Once they become infected, the NTDs can impair their physical and cognitive development, making it difficult to earn a living, and cause social stigma in infected people which, in turn, would further promote their poverty.[1,3] These diseases affect more than 1 billion people worldwide.
These NTDs, however, can be prevented and eventually eliminated,  so that no one would become infected again. The World Health Organization recommends five major interventions for NTDs. First is preventive chemotherapy wherein free and quality medicine are delivered on a large-scale and in regular intervals as a treatment to the disease. Second is providing safe drinking water, basic sanitation and hygiene, and education which helps in reducing the frequency of these NTDs.[3,4] Third would be vector control in which vectors, living organisms that carry the disease to humans, are managed in an ecologically friendly way so that the transmission of the disease can be controlled.  Fourth is veterinary public health which applies veterinary science to protect and improve human health. Lastly would be innovative and intensified case management, referring to the active surveillance and early diagnosis and treatment to at least control the disease.
In the Philippines, there are ten prevalent NTDs, but only six of those are considered to be of public health importance.
First is Lymphatic filariasis, also known as elephantiasis which is caused by parasites called nematodes or roundworms. It damages the lymphatic system and the kidneys, and in chronic conditions, causes tissue swelling or skin/tissue thickening. This disease has spread to 46 provinces in the Philippines. Fortunately, as of 2018, 40 out of those 46 provinces are declared to be free of Lymphatic filariasis.
Second is Schistosomiasis a parasitic disease caused by trematodes in the genus Schistosoma.  It is the eggs of the parasite, that leads to chronic inflammation since the eggs would get stuck in the intestines or liver. The disease is endemic to 1,608 barangays and, as of 2018, 30% have high prevalence of the disease, 26% are moderate, and 33% have low prevalence while the remaining 11% has unknown status.
Third is Soil-transmitted helminthiases (STH) that are caused by nematodes and hookworms in the Philippines. STH causes the malabsorption of nutrients and blocks the gastrointestinal tract.  All 81 provinces in the Philippines are endemic for the disease. As of 2018, 28 provinces have a prevalence of <20%, 43 are between 20% and 50%, while the remaining 11 have >50%.
Fourth is Food-borne trematodiases, or FBT, which are a group of infections caused by ingesting larvae of trematodes. Previous researches identified that various provinces in the Philippines are endemic for paragonimiasis, echinostomiasis, heterophyidiasis and fascioliasis which are specific infections of FBT, but there is not enough data on these diseases to have a full comprehension of its prevalence.
Fifth is Leprosy, a disease caused by the bacteria Mycobacterium leprae. The disease damages the skin causing skin lesions and nerve which can cause burning sensations or lessen feeling. On a national level, the Philippines has maintained the elimination level, but there are areas in the country that have high prevalence of leprosy.
Sixth is Rabies caused by the virus Lyssavirus type I and is 100% fatal once clinical symptoms appear. The disease is transmitted to humans through the bite of an infected animal, typically a dog. As the virus spreads, inflammation of the brain and spinal cord will develop until it becomes fatal. As of 2018, 6 provinces and 18 island municipalities in the Philippines have been declared rabies-free.
This progress in reducing NTD infections was all thanks to the great effort of the national programs. The National Filariasis Program helped in reducing lymphatic filariasis through Mass Drug Administration (MDA) and Morbidity Management Disability Prevention which involves alleviating suffering of those who are infected. Through MDA, vector control, and improving access to safe water and proper sanitation , the National Schistosomiasis Control and Elimination Program was able reduce Schistosomiasis in the endemic barangays. The DOH and DepEd were in partnership for the Soil Transmitted Helminthiases Control Program, promoting health education and providing deworming drugs. For FBTs, there is no program for its control and prevention since, as mentioned before, there is a lack of information about it. The National Leprosy Control Program administered multi-drug therapy for treatment and health education to lessen leprosy’s social stigma. DOH partnered with DA, DILG, DENR, and DepEd for the National Rabies Prevention and Control Program which advocates awareness of rabies and provides drugs after exposure to rabies.
Even with the efforts of these programs, NTDs have yet to be fully eliminated in the Philippines. There are many challenges that hinder us from doing that. As the country grows closer to eliminating these diseases, there is a need for new tools to effectively monitor and evaluate the NTD programs. The NTD control and elimination programs also have to compete with other health programs that have higher priority such as HIV and malaria. Even with decades of campaigning and advocating, there did not seem to have enough community awareness of NTDs. There are also socio-ecological threats such as rapid urbanization, deforestation, and conversion of agricultural lands which can influence the transmission of NTDs.
To overcome these challenges, some suggestions were given such as the proposal for a new local government unit scorecard that is specific to NTDs to efficiently monitor and evaluate the program’s performance. Local sources for funding the NTD programs are being considered to bridge funding gaps. Developing and implementing pre-service NTD curricula is a way to ensure that health professionals would be more knowledgeable about NTDs. It is necessary for a paradigm shift which includes integrated approaches for better NTD management. The NTD programs of DOH must also establish meaningful and sustainable partnerships for more engagement in NTD programs. Hopefully, one day these neglected tropical diseases will be eliminated.
- Center for Disease Control and Prevention (CDC). Neglected Tropical Diseases [Internet]. [place unknown]: CDC; [date unknown] [updated 2021 Feb 18; cited 2021 Feb 22]. Available from: https://www.cdc.gov/globalhealth/ntd/
- World Health Organization (WHO). Neglected tropical diseases [Internet]. [place unknown]: WHO; 2012 Jan 17 [update date unknown; cited 2021 Feb 22]. Available from: https://www.who.int/news-room/q-a-detail/neglected-tropical-diseases
- Leonardo L, Hernandez L, Magturo TC, Palasi W, Rubite JM, de Cadiz A, et al. Current status of neglected tropical diseases (NTDs) in the Philippines. Acta Tropica [Internet]. 2020 March [cited 2021 Feb 22];203:105284. Available from: http://www.sciencedirect.com.oca.rizal.library.remotexs.co/science/article/pii/S0001706X19309015
- World Health Organizations (WHO). Neglected tropical disease [Internet]. [place unknown]: WHO; [date unknown] [updated 2021; cited 2021 Feb 22]. Available from: https://www.who.int/neglected_diseases/5_strategies/en/
- Fitzpatrick C, Nwankwo U, Lenk E, et al. An Investment Case for Ending Neglected Tropical Disease [Internet]. Washington (DC): International BAnk for Reconstruction and Development; 2017 Nov 3 [cited 2021 Feb 22]. Available from: https://www.ncbi.nlm.nih.gov/books/NBK525199/ doi: 10.1596/978-1-4648-0524-0_ch17
- World Health Organization (WHO). Lymphatic Filariasis [Internet]. [place unknown]: WHO; 2020 March 2 [update date unknown; cited 2021 Feb 24]. Available from: https://www.who.int/news-room/fact-sheets/detail/lymphatic-filariasis
- Colley DG, Bustinduy AL, Secor WE, King CH. Human schistosomiasis. Lancet [Internet]. 2014 Apr 1 [cited 2021 Feb 24];383(9936):2253-2264. Available from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4672382/ doi:10.1016/S0140-6736(13)61949-2
- Pan American Health Organization (PAHO). Soil Transmitted Helminthiasis [Internet]. [place unknown]: PAHO; [date unknown] [update date unknown; cited 2021 Feb 24]. Available from: https://www.paho.org/en/topics/soil-transmitted-helminthiasis
- World Health Organization (WHO). Foodborne trematode infections [Internet]. [place unknown]: WHO; [date unknown] [updated 2021; cited 2021 Feb 24]. Available from: https://www.who.int/foodborne_trematode_infections/infections_more/en/
- National Organization for Rare Disorders (NORD). Leprosy [Internet]. [place unknown]: WHO; 2009 [update date unknown; cited 2021 Feb 24]. Available from: https://rarediseases.org/rare-diseases/leprosy/
- World Health Organization (WHO). Rabies [Internet]. [place unknown]: WHO; 2020 April 21 [update date unknown; cited 2021 Feb 26]. Available from: https://www.who.int/news-room/fact-sheets/detail/rabies
- Department of Health (DOH). Filariasis Elimination Program [Internet]. Manila, Philippines: DOH; [date unknown] [updated 2018 Oct 26; cited 2021 Feb 26]. Available from: https://doh.gov.ph/national-filariasis-elimination-program
- Department of Health (DOH). Schistosomiasis Control Program [Internet]. Manila, Philippines: DOH; [date unknown] [updated 2018 Oct 26; cited 2021 Feb 26]. Available from: https://doh.gov.ph/schistosomiasis-control-program
- Department of Health (DOH). National Leprosy Control Program [Internet]. Manila, Philippines: DOH; [date unknown] [updated 2018 Oct 26; cited 2021 Feb 26]. Available from: https://doh.gov.ph/leprosy-control-program
Department of Health (DOH). National Rabies Prevention and Control Program [Internet]. Manila, Philippines: DOH; [date unknown] [updated 2020 Feb 14; cited 2021 Feb 26] Available from: https://doh.gov.ph/national-rabies-prevention-and-control-program