Malária: Plasmodium sp. + DICAS PARA SUA PROVA PRÁTICA | Parte 1| PARASITOLOGIA #3

Summary

This video provides a comprehensive overview of malaria, explaining its global impact, historical origins, and transmission cycle. The disease, caused by the *Plasmodium* parasite and transmitted by *Anopheles* mosquitoes, has been responsible for millions of infections and deaths worldwide. The video explores the life cycle of the parasite, including its various stages in humans and mosquitoes, and the role of different species in causing malaria. It also discusses malaria's prevalence in tropical regions like Africa and South America, highlighting key factors like climate, human activity, and mosquito biology that influence transmission and prevention.

Takeaways

• 😀 Malaria is a major global health concern, with 445,000 deaths worldwide in 2016 and 216 million infections.
• 😀 Malaria has been present for over 3,000 years, with early records found in ancient Chinese and Mesopotamian texts.
• 😀 The parasite responsible for malaria is *Plasmodium*, which exists in several species that can infect humans, with *Plasmodium falciparum*, *Plasmodium vivax*, and *Plasmodium malariae* being the most notable.
• 😀 The Anopheles mosquito is the primary vector for transmitting malaria, and only 17% of the 400 species within this genus can transmit the parasite.
• 😀 Humans serve as intermediate hosts in the malaria life cycle, with Anopheles mosquitoes acting as definitive hosts where the parasite undergoes sexual reproduction.
• 😀 Malaria transmission is highest in tropical and subtropical regions, with the majority of cases occurring in Africa, and smaller percentages in Asia, Central America, and South America.
• 😀 In Brazil, malaria is primarily concentrated in the Amazon region, affecting nine states, particularly the Amazon, Acre, and Amapá states.
• 😀 Malaria transmission is influenced by environmental factors, with the rainy season promoting the spread of Anopheles mosquitoes as they breed in stagnant, clean water.
• 😀 The malaria parasite enters the human body via mosquito bites and initially targets the liver before infecting red blood cells, leading to symptoms like fever and chills.
• 😀 The *Plasmodium* parasite has a unique feature where it can form dormant liver stages known as hypnozoites, which can reactivate and cause relapses of malaria in certain species like *Plasmodium vivax* and *Plasmodium ovale*.
• 😀 Malaria can also be transmitted through blood transfusions, needle-sharing, and congenitally from mother to child, bypassing the typical mosquito transmission cycle.

Q & A

What is malaria, and how many people are infected worldwide each year?

Malaria is a deadly disease caused by the Plasmodium parasite, transmitted by Anopheles mosquitoes. In 2016, there were 445,000 deaths and around 216 million people infected worldwide.

How has the number of malaria infections changed over time?

Malaria has decreased over time, with efforts from the World Health Organization (WHO) and other organizations aiming to reduce infection rates. The goal is to eradicate malaria in some regions by 2030.

When were the first records of malaria, and what evidence points to its early existence?

The earliest records of malaria date back over 3,000 years, found in ancient Chinese scriptures and Mesopotamian tablets. These records indicate symptoms resembling malaria, such as intermittent fevers, though the cause was unknown at the time.

Who discovered the Plasmodium parasite, and when was it identified?

The Plasmodium parasite, which causes malaria, was discovered in 1880 by the French doctor Alphonse Laveran.

What are the four main species of Plasmodium that cause malaria in humans?

The four main species of Plasmodium that cause malaria in humans are *Plasmodium falciparum*, *Plasmodium vivax*, *Plasmodium malariae*, and *Plasmodium ovale*.

How does the *Anopheles* mosquito transmit malaria?

The *Anopheles* mosquito transmits malaria by injecting the sporozoite form of the Plasmodium parasite into the human bloodstream when it bites. The sporozoites then travel to the liver, where they mature and reproduce.

What happens during the liver stage of the malaria parasite lifecycle?

During the liver stage, the Plasmodium parasite invades liver cells (hepatocytes) and reproduces asexually. This reproduction results in the formation of merozoites, which are released back into the bloodstream to invade red blood cells.

What is the role of red blood cells in the transmission of malaria?

Red blood cells play a key role in malaria transmission. The merozoites released from the liver invade red blood cells, where they reproduce and cause the cells to burst, leading to symptoms like fever and anemia.

Why do some people experience relapses of malaria even after treatment?

Some species of Plasmodium, such as *Plasmodium vivax* and *Plasmodium ovale*, can form dormant forms called hypnozoites in the liver. These dormant parasites can reactivate after a period of time, leading to relapses of the disease.

How can malaria be transmitted aside from mosquito bites?

Malaria can also be transmitted through other means, such as blood transfusions, sharing needles, and from mother to child (congenital transmission). These alternative transmission routes bypass the usual mosquito cycle.