Tag: parasite

KALA AZAR (visceral leishmaniasis)

BY DAKSHITA NAITHANI

INTRODUCTION

After moving to internal organs such as the liver, spleen, and bone marrow, a parasite causes illness. If not treated, it nearly invariably leads to death.

People get this condition by sandfly bites, which contracted the parasite after consuming the blood of a parasite-infected person. There are more than 20 distinct Leishmania parasites that cause the illness around the globe, and 90 different sandfly species that carry the infection.

However, in India, there is just one parasitic species, Leishmania donovani, and only one sandfly species, Phlebotomus argentipes, that spreads the illness.

Visceral leishmaniasis, commonly known as kala-azar, is marked by recurrent bouts of fever, significant weight loss, spleen and liver enlargement, and anaemia (which may be serious).

In underdeveloped nations, if the illness is not treated, the mortality rate can reach 100% in as little as two years.

SYMPTOMS

When people develop visceral leishmaniasis, the most typical symptoms are

 FEVER

 ENLARGEMENT OF SPLEEN AND LIVER

Misdiagnosis is critical, because kala-azar has a near-100 percent death rate if not treated properly. It does not always leave its hosts unmarked, even after restoration. A secondary form of the illness called post kala-azar dermal leishmaniasis, or PKDL, may develop after effective treatment—usually a few months after kala-azar, but as long as many years with the Indian strain. This illness begins with tiny, measles-like skin lesions on the face that grow in size and spread throughout the body.

In individuals who have recovered from the illness , it is characterised by a hypopigmented macular, maculopapular, and nodular rash and  generally emerges 6 months to a year or more after the disease appears to be cured, although it can happen sooner or even simultaneously.

It is thought to have a crucial role in the disease’s maintenance and transmission, notably by functioning as a parasite reservoir. The lesions may eventually consolidate into disfiguring, bloated formations that resemble leprosy, causing blindness in certain cases if they extend to the eyes.

The visceral type of Leishmania is caused by two different species of Leishmania. L. donovani is the species found in East Africa and the Indian subcontinent, whereas L. infantum, also known as L. chagasi, is found in Europe, North Africa, and Latin America.

LIFE CYCLE

 Life cycle is completed in two hosts: humans and sandflies. The adult female sandfly feeds at night and is a bloodsucker. When a Leishmania-infected person is bitten by a fly, the parasite is consumed along with the blood.

The protozoan is an amastigote, which is spherical, non-motile, and just 3–7 micrometres in diameter. The amastigotes inside the sandfly’s stomach soon change into the promastigotes, which are elongated and motile forms. It is spindle-shaped and thrice the size of the amastigote, and has a single flagellum that allows it to move. They live extra cellularly in the alimentary canal reproducing asexually and migrating to the proximal end of the gut where they become ready for a transmission.

The promastigotes are introduced after being released locally at the biting site as the fly bites. Promastigotes infect macrophages once inside the human host. They revert to their tiny amastigote form inside the cells.

In macrophage cells, amastigotes reproduce. They tear down their host cell by sheer mass pressure after repeated replication, although there is also new hypothesis that they are able to exit the cell via activating the macrophage’s exocytosis response.

The protozoans in the daughter cells then move to new hosts in fresh cells or through the circulation. The infection progresses and affects the spleen and liver in particular. Sandflies eat the liberated amastigotes in peripheral tissues, which starts a new phase.

TREATMENT

The traditional treatment is with

  • Sodium stibogluconate 
  • Meglumine antimoniate

Resilience is increasingly prevalent in India, with resistance rates as high as 60% in some regions of Bihar. Amphotericin B in its many liposomal formulations is now the treatment of choice for visceral leishmaniasis acquired in India. The first oral therapy for this illness was miltefosine. Miltefosine had a cure rate of 95% in Phase III clinical studies.

The medicine is typically well tolerated compared to other medications. Gastrointestinal disruption on the first or second day of therapy (a 28-day course of treatment) is the most common adverse effect, but it has no influence on effectiveness. Miltefosine is a medication of choice since it is accessible as an oral formulation, which eliminates the cost and inconvenience of hospitalisation and allows for outpatient delivery of the drug.

The drawbacks include that after a decade of usage, there is evidence of decreased effectiveness. It is teratogenic and should not be used by women who are planning to have children. Sodium stibogluconate (Pentostam) and meglumine antimoniate have been used to treat kala-azar (Glucantime). Only injections can be used to deliver these medications. They are poisonous, have several adverse effects, and are administered over a 30-day period.

What are germs?

The term “germ” encompasses an army of tiny terrors, including viruses, fungi, parasites, and bacteria. These “pathogens” all have the ability to spread from victim to victim(called a host). Germs are so small you can see them only through a microscope. They look like spiky blogs, oozing spirals,hairy hotdogs, or other microscopic monsters.

Why are germs bad for us?

These microorganisms hitch a ride into our bodies on the food we eat, in the air we breathe, or through a variety of other methods. Once they have invaded our personal spaces, germs reproduce and create toxic waste, which triggers our body’s most repulsive reactions. They make us sniffle, upchuck, run to the toilet, break out in rashes and fevers, and suffer even more unpleasant symptoms.

How do we get sick from viruses?

Most viruses are frail little things ( unlike bacteria and fungi, viruses are not even alive ) that can multiply only inside a living host ( including animals, plants, and even bacteria). There they spread overwhelming and attacking the host’s immune system and causing all sorts of nasty symptoms. Colds, flus, chicken pox, immune disorders, and measles are caused by viruses. Among the worst is a Ebola, which triggers bleeding and is fatal more than half the people who catch it.

How do we get sick from fungi?

Fungi are microscopic molds, yeasts, and other plant like pathogens that thrive in wet, warm places like our armpits, our belly buttons, and the dank spaces between our toes. They feed on our respect and dead tissues and produce stinky wastes that irritate our skin.

How do we get sick from parasites?

This ghastly germ group includes itty-bitty insect larvae, amoebas, and one celled organisms called Protozoa that live in nasty food, damp soil, or dirty water. Parasites depend on a living host for their survival. They sneak into our bodies in tainted water and food, costing of all sorts of gastrointestinal gripes: diarrhoea, vomiting, upset stomachs, and worse. Malaria – common diseases that causes chills, shaking, and fevers – is spread by a parasite passed in mosquito bites. These life-sucking relationships are often the stuff of nightmares.

How do we get sick from bacteria?

Unlike viruses, bacteria are living single celled organisms that can reproduce both outside and inside the body. Like all living things, bacteria create waste -microscopic poops that can act as a poison inside the host. You can blame sore throat, ear infections and tooth-tartar buildup on bacteria. One of the most famous bacteria is Escherichia coli. This rod shaped micorbe lives deep in your intestines, the body’s busiest bacterial neighborhood. Harmful ones make you puke for days.E.coli strains produce an important vitamin. That’s right – some bacteria are actually good for you!

How many bacteria are inside our body right now?

Your body is built of trillions of itty-bitty living blobs, called cells, that work together to make you you. But for every cell you call your own, ten foreign bacteria cluster around or near it. You are a microbe metropolis! Scientists call these communities of foreign bacteria your body’s “flora”, and no two people host the same mix of microorganisms. In fact, scientists are beginning to think of your flora as just another organ.

Can we see these bacteria?

No, they are microscopic. But you can certainly smell them. Like any living thing, bacteria eat, reproduce,die, and create waste which can make your life stink – literally !(Bacteria are the source of bad breath and body odor.)

Benefits of Bacteria

Your gut reaction might be to wrinkle your nose at the thought of bacteria inside your guts, but it turns out that many so-called good bacteria are essential to your health, the survival of life on Earth, and the making of tasty foods. Behold, the benefits of a microscopic allies…

Health boosting

Your body’s microbes support your immune system, which fights sickness.

Plant feeding

Blue-green algae and other types of bacteria convert the nitrogen in the air into compounds plants can use.

Food processing

Micorbes in our innards play a huge role in the digestive process, helping us absorb nutrients and vitamins from our food.

Food making

Bacteria are a vital ingredient in the process of turning milk into yogurt and tasty cheeses. The holes in Swiss cheese are created by carbon dioxide bubbles exhaled by bacteria during the cheese making process.

Planet Cleaning

Bacteria breakdown dead animals and plants, which “decompose” into nutrients for the living.

References :

WHY?-Answers to everything, Image publications.