What Are the Different Types of Tropical Diseases?

various parasitic diseases.

Tropical disease

- Tropical Diseases-Types

various parasitic diseases.

Leprosy.

Opportunistic infection in patients with low immune function.

Rare and rare infectious diseases.

Some newly discovered infectious diseases.

- Tropical Diseases-Treatment

Researchers announced on Monday that they have demonstrated in a mouse test that a vaccine extracted from the sandfly's saliva is effective in preventing a lethal tropical disease, affecting millions of people in developing countries Fatal tropical disease. A research team led by Jose Ribeiro from the National Institute of Allergy and Infectious Diseases (NIAID) has experimented with sand fly saliva to create a vaccine against Leishmaniasis. The disease is transmitted by blood-sucking mosquitoes. It is a common disease in many tropical and desert areas, so scientists have been trying to develop an effective vaccine to prevent the disease.

Leishmaniasis is a general term for a series of diseases. Leishmania are different types of single-cell parasites that cause nasal, throat, and oral erosive infections, painful skin lesions, and deadly parasites of internal organs.

It is estimated that approximately 12 million people worldwide have the disease, mainly in Central and South America, Africa and the Middle East. Mice were injected with the Leishmania vaccine mixed with the saliva of the sand fly, and it was found that the immunized mice had much less symptoms of Leishmania infection than those without immunization.

Researchers published an article in this year's Journal of Experimental Medicine pointed out that the skin lesions of the immunized mice were smaller and the infection improved after 6 weeks. The ulcerative lesions on the skin of non-immunized mice are large and parasites cannot be eradicated. NIAID director Anthony Fauci said that with saliva, we could also develop vaccines to prevent other diseases caused by mosquito bites. Ribeiro and colleagues isolated a protein from the saliva of sand flies that stimulated the mice's own immune response. They studied the genes encoding this protein to develop related vaccines.

Ribeiro said: Different types of sand flies carry their unique salivary proteins and spread different types of Leishmania. If the anti-sialoprotein vaccine is equally effective in humans, they will study the parasites in different areas separately. Ribeiro's next work is to test the Leishmaniasis vaccine in dogs and monkeys.

Information on tropical diseases

What are neglected tropical diseases?

Neglected tropical diseases * Infectious diseases that are prevalent in hot and humid climates in poor areas, especially in the tropics. Most of them are parasitic diseases transmitted by insects such as mosquitoes, black flies, white maggots, tsetse flies, hunting flies, and house flies, as well as snails. The source of some diseases is contaminated water and worm-grown soil. Environmental pollution has worsened the transmission chain, and poor living and sanitary conditions in turn have exacerbated environmental pollution. Once widespread, these diseases were now concentrated in extreme poverty. In other parts of the world, they have gradually disappeared as living and sanitary conditions improved.

The neglected tropical diseases are not listed here one by one, and there are differences among different regions and countries. The diseases that WHO is currently focusing on are: "measured diseases" that can be treated with treatment tools, including soil-borne helminth infections, lymphatic filariasis, onchocerciasis, schistosomiasis, corn fields Naronic nematode disease, zoonotic helminthiasis, dengue / dengue hemorrhagic fever, rabies, IELTS; "lack of measures" that need to be treated for specific diseases, they are Leishmaniasis, African human trypanosomiasis, America Trypanosomiasis and Buruli ulcer.

Why tropical diseases classify them

The organization classifies neglected tropical diseases for two reasons. First of all, all of these diseases, although their etiology and physiological effects vary, cause severe disability and life-long inconvenience. Secondly, these diseases are inextricably linked to poverty, and their geographical areas affected overlap. Concentrated endemic areas often lack safe drinking water or personal hygiene due to lack of water, poor environmental sanitation, poor housing, and mosquitoes that spread disease.

In addition, because many people suffer from many of these diseases at the same time, treating these diseases as a group is important for control planning.

Impact of neglected tropical diseases

Disease permanently affects human potential, making it difficult for more than a billion poor people to escape poverty. They also impose extremely heavy economic burdens on endemic countries.

Some of these diseases have greatly affected the economic productivity of young adults. Some diseases impede the development and intellectual development of children. All of these diseases afflict patients and often cause social stigma and discrimination. Most diseases cause blindness or disability, causing damage to the appearance or disability. They have a latent latency period, and patients often become ill and severely damaged after many years of almost unconscious infection, which misses the opportunity for treatment. During this period, the parasites multiply and flow through the body and accumulate in the tissues, internal organs, eyes or lymphatic system when mature. Some parasites damage the skin and subcutaneous tissue. If it is not detected and treated in time, it can cause irreversible damage. Other neglected tropical diseases can be fatal in weeks or months when they are advanced.

Tropical disease severity

One-sixth of the population, or one billion people, is infected with one or more of these diseases. These diseases have not been addressed in national health programmes. These diseases are mainly concentrated in low-income countries in Africa and Latin America, where up to five to seven diseases may be prevalent in large areas of these countries. These diseases have also cost heavily in parts of Asia and the Middle East, but with fewer overlaps.

Examples of tropical diseases

Since the written record, most of these diseases have caused serious disaster to human beings. Since the biblical era, historical records are full of descriptions of the pain, disability, and shame caused by some diseases such as leprosy. Other diseases, such as African sleeping sickness, are notorious and have had extremely serious clinical consequences. After the patient's brain is attacked by a parasite, if the diagnosis and treatment are not timely, the mortality rate reaches 100%. Some diseases, although less well-known, have equally serious consequences. Onchocerciasis and trachoma can be blind. Buruli ulcers and some forms of Leishmaniasis damage soft tissues and can invade bones. American trypanosomiasis and other forms of leishmaniasis severely damage the internal organs. Guinea nematode disease causes severe pain, leaving the patient bedridden for months. Lymphatic filariasis causes disability, and the patient has severely enlarged limbs and external organs. Schistosomiasis and soil-derived helminthiasis cause severe anemia, cause malnutrition, and affect children's development and growth.

Why are they ignored?

The disease is not very eye-catching. They do not cause large-scale outbreaks, so they have not caught the attention of the public and the press. They have not spread internationally. Although they cause huge, long-term suffering, they have not killed a large number of people and have not affected rich countries. These diseases are often overlooked when setting health agendas and budgets. Limited resources are available for health investment in endemic countries. These diseases must compete for funding with more eye-catching diseases that have much higher mortality rates and attract much attention at home and abroad. The pain caused by neglected tropical diseases is largely unknown. Patients are concentrated in remote rural areas and huge slums on the outskirts of the city. They have no safe drinking water, low education, poor sanitation, poor housing, and may not have access to health care services at all. These diseases are unknown for other reasons. Patients have difficulty accessing medical services, and poor families can't afford expensive expenses. As a result, many people have been dragged to the point where their illness is so severe that they cannot be reversed. The stigma associated with maiming and defaced diseases has made patients, especially female patients, reluctant to seek medical attention. In research and development, these diseases are also ignored. There is insufficient incentive to develop new diagnostic tools, medicines and vaccines for diseases where there is a market but patients are unable to pay for their medical costs.

Common diseases of tropical diseases

In addition to soil-borne helminthiasis affecting more than 1 billion people, the six most prevalent neglected tropical diseases are:

Schistosomiasis

The number of people infected is more than 200 million. About 120 million people have symptoms and about 20 million are seriously ill.

Lymphatic filariasis

The number of people infected is about 120 million. The disease is the second leading cause of disability worldwide.

Blinding trachoma

About 80 million people are infected, 6 million of whom are blind. The disease is the leading cause of infection blindness worldwide.

Onchocerciasis

About 37 million people are infected, and the vast majority of patients are in Africa. The disease causes severe dermatitis, visual impairment or blindness, and patients' life expectancy may be reduced by up to 15 years.

American trypanosomiasis

About 13 million people are infected, mostly in Latin America. Due to factors such as immigration, blood transfusion, congenital transmission, and organ donation, the disease has emerged in areas previously thought to be free of the disease and in non-endemic countries, and control and surveillance are urgently needed.

Leishmaniasis

In 88 countries in Africa, Asia, Europe and the Americas, more than 12 million people have been infected. WHO estimates that 350 million people are under threat and that between 1.5 million and 2 million new infections occur each year. Visceral leishmaniasis, which can be fatal quickly, is the most serious form of the disease and is forming a worrying global trend.

Has tropical disease made any progress

Yes, considerable progress is being made. Many effective drugs and other interventions have been used to treat or prevent many of these diseases.

Large-scale public-private partnerships have been established to implement interventions to assist those in need. Some of these partnerships have received substantial drug donations from the pharmaceutical industry. Ambitious goals and deadlines have been identified for several of these diseases, and a number of diseases affecting public health have been determined to be eradicated or eliminated.

Some progress has been made:

The estimated number of people suffering from blinding trachoma in 1985 was 360 million, and today it has fallen to about 80 million.

Leprosy is close to being eliminated as a public health problem, with the number of cases falling from 5.2 million in 1985 to the current 213,000. More than 14.5 million patients have recovered.

Onchocerciasis is no longer a public health problem and a social and economic impact on the 10 worst affected West African countries. At least 600,000 cases of blindness have been avoided, and 25 million hectares of land can be safely cultivated and settled.

Targets for eradication of Guinea nematode disease have been identified. In 1985, there were approximately 3.5 million cases in 20 countries, and the number of cases has now fallen sharply. There are only 4,616 cases in 6 countries, of which 98% are concentrated in Ghana and Sudan.

In 2007 alone, 546 million people were treated to prevent the spread of lymphatic filariasis. Accelerated delivery of treatment services in 48 endemic countries (total 81 endemic countries). Since 2000, more than 1 billion people have been treated, the prevalence and severity of the disease have been greatly reduced, and millions of children have avoided the infection. In August 2007, China became the first country to announce the elimination of lymphatic filariasis as a public health problem. South Korea also announced the elimination of the disease in March 2008.

Prospects for the prevention or treatment of tropical diseases

In October 2006, WHO and multiple partners launched a comprehensive prevention and treatment strategy for the four most burdensome diseases, bringing new hope to millions of people affected by these diseases. The four diseases are: onchocerciasis, lymphatic filariasis, schistosomiasis, and soil-borne helminthiasis. Launched with the support of more than 25 partner organizations, the core of this new strategy is the provision of preventive chemotherapy. These four diseases can be prevented with medicines offered by the pharmaceutical industry free of charge or at a substantial discount. These drugs are effective and safe, and can be provided to all affected communities as preventive drugs without the need for costly case detection and diagnosis.

What else do tropical diseases need

To identify diseases that can be treated with preventive chemotherapy, the most needed is to expand population coverage. Although the drugs are free or inexpensive, the large number of affected people poses a considerable challenge to business and logistics, and the implementation costs are relatively high. To further complicate matters, most of the affected or at-risk populations live in the least accessible areas and often do not have access to formal health services. For the most difficult to treat diseases such as African sleeping sickness, Leishmaniasis, American trypanosomiasis, and Buruli ulcer, there must be better development of better diagnostic tools, drugs and other interventions. Incentives are needed to encourage research and development. There is also a need to develop new tools that are cheaper and suitable for field applications.