Malaria is a life-threatening disease caused by parasites that are transmitted to people through the bites of infected female Anopheles mosquitoes. It is preventable and curable. There are 5 parasite species that cause malaria in humans, and 2 of these species – Plasmodium falciparum and Plasmodium vivax – pose the greatest threat.
As per World Health Organisation, WHO, nearly half of the world’s population was at risk of malaria in 2022. While sub-Saharan Africa carries a disproportionately high share of the global malaria burden, the WHO regions of South-East Asia, Eastern Mediterranean, Western Pacific, and the Americas also report significant numbers of cases and deaths.
How does one ‘catch’ Malaria?
Malaria mostly spreads to people through the bites of some infected female Anopheles mosquitoes. Blood transfusion and contaminated needles may also transmit malaria. The first symptoms may be mild, similar to many febrile illnesses, and difficulty to recognize as malaria. Left untreated, P. falciparum malaria can progress to severe illness and death within 24 hours.
The infection is caused by a parasite and does not spread from person to person. Symptoms can be mild or life-threatening. Mild symptoms are fever, chills and headache. Severe symptoms include fatigue, confusion, seizures, and difficulty breathing. Infants, children under 5 years, pregnant women, travellers and people with HIV or AIDS are at higher risk of severe infection.
Malaria can be prevented by avoiding mosquito bites and with medicines. Treatments can stop mild cases from getting worse.
Scientists recently have developed a new vaccination strategy for malaria, which is boosting immunity through bites from mosquitoes carrying a genetically engineered version of the parasite that causes malaria. In a trial, the new approach reduced participants’ susceptibility to malaria, potentially paving the way for more effective ways to stop the disease.
The study published in ‘The New England Journal of Medicine’ recently, exposed participants to bites from mosquitoes that had a modified version of the Plasmodium falciparum parasite, which causes malaria. In humans, the parasites travel to the liver and then infect red blood cells. The parasites were engineered to stop developing shortly after delivery into a human. Nearly 90% of participants exposed to the modified parasites avoided contracting the disease after being bitten by malaria mosquitoes.
Julius Hafalla, an immunologist at the London School of Hygiene & Tropical Medicine, said, “These findings represent a significant step forward in malaria vaccine development. The ongoing global malaria burden makes the development of more effective vaccines a critical priority.”
Symptoms: Symptoms usually appear 10–15 days after the bite of an infected mosquito. Early symptoms include fever, headache, and chills. Severe symptoms include fatigue, confusion, seizures, and difficulty breathing.
Transmission: Malaria is spread by the bite of infected female Anopheles mosquitoes. It can also be transmitted through blood transfusions and contaminated needles.
Diagnosis: A doctor can suspect malaria based on your travel history, symptoms, and physical exam. To confirm, they may order laboratory tests to see if the parasite is in your blood.
Treatment: Malaria is treatable, and starting treatment as soon as possible can often prevent severe illness and death. Chloroquine is often used as an anti-malarial medicine, but there are also treatments for chloroquine-resistant infections.
Vaccines for Malaria:
So far, there are two approved malaria vaccines. Both aim to provide long-term immunity by producing antibodies that block malaria parasites from infecting liver cells, as well as targeting breakthrough infections. However, the vaccines are only about 75% effective, and require booster shots. Hence, immunologists are continuing to explore alternative strategies to battle the disease.
One of those approaches is using genetically modified parasites. The research team had previously conducted a trial to examine the effectiveness of a modified malaria parasite, called GA1, designed to stop developing about 24 hours after infection in humans. But the GA1 parasite protected only a few participants against malaria, leading the team to engineer a second parasite, GA2. GA2 is designed to stop developing about six days post-infection, during the crucial period where the parasites replicate in human liver cells.
The researchers tested whether exposure to GA1 or GA2 could help humans develop immunity to malaria. They exposed participants to bites from 50 mosquitoes; 10 participants received bites from mosquitoes infected with GA1 parasites, and 10 were bitten by those with GA2 parasites. Three weeks later, they exposed participants to malaria-carrying mosquitoes. Just before exposure to these mosquitoes, both sets of participants had higher levels of antibodies than before. One of eight (13%) participants bitten by GA1 parasites didn’t contract malaria compared with 89% in the GA2 group. Other than the itching associated with mosquito bites, side effects were limited.
The researchers are now keen to replicate their results in a larger trial.
Study reveals how mosquitoes possess bizarre sense of smell
This post was originally published on here
