An Overview of Brutal Parasites: The Killing Machines

Apicomplexans are the members of  a large phylum Protista, most of them are parasites. The known apicomplexan parasites of humans and animals are Plasmodium and Toxoplasma, plasmodium causes malaria and toxoplasma is responsible for toxoplasmosis.

An Overview of Brutal Parasites: The Killing MachinesThey multiplication of parasite takes place in host cells and they have extracellular forms which are polarized and roving cells, known as zoites, having a submembrane & actomyosin motor. Zoites infect the host cells by a quick process which is exclusively supported by their motor.

After binding with host cell, this is dependent upon the combination of cell and zoite, there is formation of tight junction  (TJ) between apical tip of zoite and the host cell. Ultimately it leads to formation of parasitophorous vacuole. Then zoite results into multiplication and new zoites are formed and then new host cells are infected.

Malaria is the most common and fatal infection of human side in world and caused by a protozoan parasite. The 40% people of world live in those areas which are endemic to malaria. 500 million cases are reported every year and there are 1.5-2.7 million deaths due to this notorious parasite, high ratio of deaths is in children 90% of them are under 5-year age.  However, all age groups are at high risk. It has been reported that 4 species out of 100 species of plasmodium are responsible for infection in human beings. The major deaths are caused by P. falciparum. P. vivax, P. ovale and P. malariae (less severe).

Toxoplasma is a zoonotic parasite and prevalent worldwide, disease causing agent is toxoplasma gondii and was reported for first in 1930. It has been reported in many countries like in 1990s it was prevalent in European countries including France, Austria, Germany and Switzerland the seroprevalence  has been estimated from 37-58% in child bearing women and no obstetric issues were reported.

Seroprevalences were higher in countries like Latin America including Brazil, Argentina, Jamaica, Cuba and Venezuela like from 51 to 72%. In African countries like Benin, Congo, Cameron, Togo and Gabon seroprevalence  was 54-77% slightly higher than Latin America, but in Asian countries the seroprevalence is low like from 4-39%. It is because of climatic differences between these regions. But overall, we see it is higher in adult humans in the world.

Leishmaniasis is a disease of tropical and subtropical areas caused by leishmania an intracellular parasite and is transmitted to humans by the bite of a sand fly, these two spp. of flies Phlebotomus and Lutzomyia, the region where disease is prevalent are Europe, North Africa, Middle East, Asia, and part of Southern America); exceptionally, it is indicated that the transmission was by laboratory accident. In accordance to World Health Organization (WHO), leishmaniasis is among the 07 most important diseases of tropics and it is seen as serious public health threat as infection progresses the outcomes are really fatal.

Oceania is leishmania free country excluding all other countries of the world. The infection shows different degrees of severity and it depends upon the species of Leishmania involved and the immune status of patient. In Mexican territory, the most common form is the cutaneous chondral form which is also called as chiclero’s ulcer.

The distribution of leishmania is worldwide; it has been reported in 89 countries of the world. Areas endemic to this disease are Asia, Mediterranean, Africa and in America, In America, it is a jungle zoonotic. Has been reported in many countries, from the south of United States to the north of Argentina (seroprevalence has been estimated 0.17% for cutaneous leishmaniasis). 12 to 15 million people in the world are infected, and 350 million people are at risk of acquiring this disease. It has been reported that 1.5 to 2 million new cases occur every year, and it causes 70,000 deaths every year.

WHO led an effort in 2012 to report the burden and distribution of leishmania infection in 102 countries of the world to identify the cases of cutaneous and visceral leishmaniasis and the data til 2010 indicate that 90% of global cases of Visceral Leishmaniosis occurred in Bangladesh, India, Sudan, south of Sudan and Brazil, 70% of Cutaneous Leishmaniosis cases occurred in Brazil, Afghanistan, Algeria, Costa Rica, Colombia, Iran, Sudan, Ethiopia, and the Syrian Arab Republic.

There are various strategies which are being employed for control of internal and external parasites, so, there are antiparasitic drugs which have antiprotozoal, anthelminthic and acaricidal properties, and are subdivided into further categories according to their mode of action. These drugs have various properties like they are easily administered, orally active, effective in single or multiple dosages, inexpensive, wide safety margin if are being used rationally and easy excretion from host body. The drawback of these drugs is development of resistance and tolerance in host and parasite due to their blind use in animals and humans in recent decades.

Now a days, scientists are discovering new stains of these parasites every day and they were also employed in combinations so now this method of parasite control is much lesser in practice, still in but scientists are developing new drugs and strategies. But to cope these issues governments must take actions to keep people safe from such lethal scenario, because we have gone through all pros and cons of these parasites and what they do to their hosts. It’s time for genius minds to rethink and make new strategies and plans to overcome all such issues. Because we already have, and we will.

An Overview of Brutal Parasites: The Killing Machines written by Hammad Ur Rehman Bajwa1,*, Muhammad Kasib Khan1, Asad Ur Rehman Bajwa3, Muhammad Uzair Asghar1, Muhammad Rashid Khalid Bajwa2, Saad Salman Khan1

  1. Department of Parasitology,University of Agriculture, Faisalabad
  2. Department of CMS, University of Agriculture, Faisalabad
  3. Department of Mechanical Engineering, University of Management and Technology, Sialkot Campus

By Dr. Hammad Ur Rehman Bajwa

PhD Scholar, Department of Pathobiology, University of Illinois, Urnana-Champaign.