Introduction
When birds get malaria, it is called “avian malaria.” It is often known as “bird malaria” and is similar to human malaria. The causative organism of this malaria is Plasmodium protozoa, members of the Haemosporida group. Avian malaria is a contagious illness and known for decimating native bird populations on the Hawaiian islands.
Hawaiian honeycreeper populations have been destroyed by avian malaria. The parasite that causes malaria is transmitted to birds by the bite of non-native mosquitoes, where it can proliferate in the blood and organs and cause severe anemia. Hawaiian honeycreepers did not develop the immune systems necessary to combat the unusual disease since they were on isolated islands. Over two-thirds of Hawaiian honeycreepers are now extinct due to this outbreak, and many species experience mortality rates of more than 90 percent.
Where Did Avian Malaria Come From?
This illness first occurred in Hawaii, and native honeycreepers are extremely vulnerable. Avian malaria has aided in the decrease and extinction of Hawaiian forest birds. Scientists from the USGS (United States Geological Survey) are looking into the effects of climate change and elevation on the dynamics of this disease.
How Does Avian Malaria Spread?
Avian malaria is transmitted through infected mosquito bites. Since the 1940s, avian malaria has become more widespread worldwide, especially in Africa and Europe, two of the main routes for bird migration. The disease has also been found in species that were previously believed to be outside the geographic range of Plasmodium, including the Galapagos penguin (S. mendiculus), house sparrows (Passer domesticus), great tits (Parus major), and blackcaps (Sylvia atricapilla). Although the causes of the expansion of avian malaria are unknown, habitat loss and climate change have been linked. These variables are likely to affect and maybe widen the distribution of parasites or parasite-carrying mosquitoes.
What Is the Difference Between Avian Malaria and West Nile Virus?
The mosquito-borne diseases, West Nile virus (WNV) and avian malaria parasites of the genus Plasmodium, which can cause serious disease and illness in people and birds, respectively, are both present throughout southern Europe in endemic form. The female mosquitoes that carry the West Nile virus bite humans and transmit the disease. The signs are mild and disappear after a few days.
The primary difference between the West Nile virus and malaria is that the former is a single-stranded RNA (ribonucleic acid) virus that causes West Nile fever. At the same time, the latter is a mosquito-borne disease brought on by Plasmodium parasites.
Are Humans Affected by Avian Malaria?
No. Despite belonging to the same family of protozoa as those that cause malaria in humans, Plasmodium relictum cannot spread the illness to humans. In contrast, Anopheles mosquitoes, the only species that transmit human malaria, do not harbor Plasmodium relictum. Therefore, the two protozoa never ever come into contact.
How Did Avian Malaria Affect the Lifespan of Birds?
Birds can contract avian malaria. The birds lose red blood cells if the parasite burden is too high (anemia). Loss of red blood cells can cause deteriorating health and possibly death because they are essential for carrying oxygen throughout the body.
Apart from this, studies have revealed that avian malaria can affect the length of telomeres, which are the end part of chromosomes. This infectious disease has an adverse effect by shortening the telomeres of the birds. They shield DNA (deoxyribonucleic acid) from harm, and their length can estimate the lifespan. Longer telomeres indicate a longer life. The fact that the shortened telomeres do not just harm the bird that contracted malaria is even more concerning, the researchers found. Malaria-infected female birds can still give birth to healthy chicks. Still, they can also pass on a genetic propensity for shorter telomeres to their offspring, effectively leading to new generations of birds with shorter life spans.
How Can Avian Malaria Be Prevented?
The primary goals of management efforts for avian malaria have been to reduce the number of Plasmodium-carrying mosquitoes, such as by removing breeding sites for them where standing water collects, as well as to identify methods to promote the emergence of genetic resistance in susceptible species. Some populations of the amakihi bird that live at lower elevations have spontaneously evolved resistance (Hemignathus virens; a type of Hawaiian honeycreeper).
Quick Facts About Avian Malaria
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It is comparable to human malaria in that it is brought on by single-celled protozoans of the genus Plasmodium and spread by the bite of mosquitoes carrying the infection.
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Along with plasmodium, Haemoproteus protozoans are occasionally thought to cause avian malaria.
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Only Anopheles mosquitoes carry the human disease, whereas mosquitoes from numerous species, including Culex and Aedes, carry avian malaria.
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Globally, a vast variety of birds, including ducks, falcons, pigeons, and penguins, are susceptible to avian malaria. However, it appears that perching birds, such as songbirds, are more vulnerable.
Is Avian Malaria Expanding to Other Regions?
Yes, the range of mosquitoes that transmit avian malaria is constantly growing as a result of rising temperatures. The disease had spread all the way to Alaska, where it had never been present before, and this information was reported in a study conducted in 2012. Such species there are more susceptible because they have not evolved any immunity. The population of birds could be drastically impacted if this tendency persists.
Conclusion:
The first incidence of avian malaria was reported in Hawaii island. There were no mosquitoes on the Hawaii islands before people came. But by the middle of the 1800s, mosquitoes had unintentionally spread throughout the archipelago and were well-established. The southern house mosquito, Culex quinquefasciatus, poses the worst risk to Hawaiian birds of all species. It was first observed in 1826 and is the main carrier of avian malaria and avian pox. It is also thought to be responsible for the decline and eventual extinction of many native forest species. Till now, this infectious disease has affected many birds of different species in various regions. Additionally, it has emerged as an outbreak in many countries. The best way to manage this infectious disease is through its prevention which can be done through mosquito control measures.
