On this blog post we will uncover a series of diseases that plague countries located close to the equator, we have faced this terrible diseases while on our mission trips to Latin America, although they may not be as common as say, High Blood pressure, Diabetes or even Asthma, but Neglected Tropical Diseases (as the WHO classifies them), can be just as life-threatening, and disfiguring as any other disease you may have heard of.
We will mainly discuss a series of Parasites, Viruses, and Bacteria that fall into this category, including endemic diseases of the countries we usually visit.
This category includes all of the tropical soil worms, including Ascaris, Hookworm, and Trichuris trichiura (Whipworm), that may parasitize human beings and other organisms. These kinds of helminths develop in the environment without the participation of intermediate hosts.
Helminths for whose completion of development change of host is necessary. The typical example of this is a bull Tapeworm. Its adult form parasitizes in a human body, larvae — at cattle. Sometimes the additional host is necessary for full development of a worm of with a change of three hosts the wide Tapeworm reaches its mature adult state, which in turn causes the symptoms.
Malaria is a widespread disease in the geographical areas where it is endemic, and its transmission is through a vector. There are plans for its control and prevention from the most primary aspect of its dissemination, the reproduction of infected mosquitoes.
Definition: an acute or chronic disease caused by the presence of sporozoan parasites of the genus Plasmodium in the red blood cells, transmitted from an infected to an uninfected individual by the bite of anopheline mosquitoes. It’s characterized by periodic attacks of chills and fever that coincide with mass destruction of blood cells and the release of toxic substances by the parasite at the end of each reproductive cycle.
(“Malaria.” Merriam-Webster.com. Merriam-Webster, n.d. Web. 9 Feb. 2018.)
Symptoms: Chills, High Fever, Diaphoresis, Headaches, and Vomiting.
Spreading of the disease: Through an infected mosquito. All case of suspected malaria should have a parasitological test (microscopy or Rapid diagnostic test (RDT)) to confirm the diagnosis.
The term leishmaniasis encompasses multiple clinical syndromes, several of which are described here—the cutaneous, mucosal, and visceral forms, which result from infection of macrophages in the dermis
Definition: a tropical and subtropical disease caused by Leishmania and transmitted by the bite of sandflies. It affects either the skin or the internal organs.
Symptoms: Cutaneous leishmaniasis is the most common form of the disease. It usually produces ulcers on the exposed parts of the body, such as the face, arms, and legs. There may be a large number of lesions – sometimes up to 200 – which can cause severe disability.
Spreading of the disease: through an infected mosquito.
The Bancroftian Filariasis
This filariasis affects the lymphatic system and can produce abnormal hypertrophy of some parts of the body, causing pain, severe disability, and social stigma.
Definition: Any of numerous slender filamentous nematodes (Wuchereria, Onchocerca, and related nematodes genus) that as adults are parasites in the blood or tissues of mammals and as larvae usually develop in biting insects.
Symptoms: Filarial infection can cause a variety of clinical manifestations, including lymphoedema of the limbs, genital disease (hydrocele, chylocele, and swelling of the scrotum and penis) and recurrent acute attacks, which are extremely painful and are accompanied by fever. The vast majority of infected people are asymptomatic, but virtually all of them have subclinical lymphatic damage, and as many as 40% have kidney damage, with proteinuria and haematuria.
Spreading of the disease: The disease is caused by three species of thread-like nematode worms, known as filariae – Wuchereria bancrofti, Brugia malayi and Brugia timori. Male larvae are about 3–4 centimeters in length, and female worms 8–10 centimeters. The male and female worms together form “nests” in the human lymphatic system, the network of nodes and vessels that maintain the delicate fluid balance between blood and body tissues.
There is two presentations of this disease, benign and hemorrhagic form.
Definition: An acute infectious disease caused by a flavivirus (species Dengue virus of the genus Flavivirus), transmitted by Aedes mosquitoes, and characterized by headache, severe joint pain, and rash— also called breakbone fever, dengue fever “Dengue.”
Merriam-Webster.com. Merriam-Webster, n.d. Web. 13 Feb. 2018.
Symptoms: Fever, Joint Pain, Asthenia, Rash, Hemorrhages.
Spreading of the disease: Dengue fever is transmitted by the bite of an Aedes mosquito infected with a dengue virus. The mosquito becomes infected when it bites a person with dengue virus in their blood. It can’t be spread directly from one person to another person.
Bacillary and dysenteric diarrhea are common.
Definition: Diarrhoea is defined as the passage of three or more loose or liquid stools per day (or more frequent enactment than is typical for the individual). Frequent passing of formed stools is not diarrhea, nor is the passing of loose, “pasty” stools by breastfed babies.
Symptoms: Diarrhoea is usually a symptom of an infection in the intestinal tract, which can be caused by a variety of bacterial, viral and parasitic organisms. The virus is spread through contaminated food or drinking-water, or from person-to-person as a result of poor hygiene.
The spread of the disease:
- Malnutrition: Children who die from diarrhea often suffer from underlying malnutrition, which makes them more vulnerable to diarrhea. Each diarrhoeal episode, in turn, makes their malnutrition even worse.
- Source: Water contaminated with human feces, for example, from sewage, septic tanks, and latrines, is of particular concern.
- Other causes: Diarrhoeal disease can also spread from person-to-person, aggravated by poor personal hygiene.
The parasites that cause schistosomiasis live in certain types of freshwater snails. The infectious form of the parasite, known as Cercariae, emerge from the snail, hence contaminating water. You can become infected when your skin comes in contact with contaminated freshwater.
Definition: Infestation with or disease caused by schistosomes; specifically: a severe endemic illness of humans in Africa and parts of Asia and South America that are contracted when Cercariae released into fresh waters (such as rivers). That happens by a snail intermediate host penetrate the skin, and that is marked primarily by blood loss and tissue damage — called also snail fever.
Symptoms: Although a few patients may have minor skin irritation when the cercariae enter the skin, most people do not develop symptoms until the eggs develop (about one to two months after initial skin penetration). Then, fever, chills, cough, and muscle aches can begin within one to two months of infection. However, most people have no symptoms at this early phase of the disease. Fever, Abdominal pain (liver/spleen area), Bloody diarrhea or blood in the stools, Cough, Malaise, Headache, Rash and Body Aches
Spreading of the disease: Causal agents of the disease are blood flukes (schistosomes). Their eggs leave the human body in urine (in urinary schistosomiasis) or feces (in intestinal schistosomiasis), hatch in water and liberate larvae (miracidia) that penetrate freshwater snail hosts. After several weeks of growth and multiplication, cercariae emerge from the snails and penetrate human skin during contaminative water contact (wading, swimming, washing). Cercariae transform and subsequently migrate through the lungs to the liver where they mature into adult worms. These adult worms move to the veins of the abdominal cavity or of the urinary tract. Most of the eggs produced are trapped in the tissues, but a proportion escapes through the bowel or urinary bladder.