Context- Recently World health organization (WHO) released World Malaria report 2019.

Findings

• Globally, there were 228 million cases of malaria in 2018, down from 251 million cases in 2010. More than 85% of the global malaria deaths in 2018 were concentrated in the 20 countries of WHO’s African region and India. Compared to 2017, India reported 2.6 million fewer cases in 2018. This makes India the country with the largest absolute reductions among the countries that share 85% of the malaria burden
• Seven states account for about 90% of the burden of malaria cases in India, according to the World Malaria Report 2019 released by the World Health Organization (WHO) on Wednesday. These are Uttar Pradesh, Jharkhand, Chhattisgarh, West Bengal, Gujarat, Odisha and Madhya Pradesh.
• Nigeria had the highest burden of all malaria cases, at 24%. However, incidence of P vivax malaria (the second most common form of the disease) was the highest in India, which accounts for 47% of all cases in 2018,
• WHO region-wise, the highest estimated cases of all malaria forms were in Africa, at 93% of the cases (213 million), followed by South-East Asia (7.9 million), East Mediterranean (4.9), Western Pacific (1.98) and the Americas (9.29).

About Malaria

• Malaria is caused by Plasmodium parasites. The parasites are spread to people through the bites of infected female Anopheles mosquitoes, called "malaria vectors." There are 5 parasite species that cause malaria in humans, and 2 of these species – P. falciparum and P. vivax – pose the greatest threat.
• In 2017, P. falciparum accounted for 99.7% of estimated malaria cases in the WHO African Region, as well as in the majority of cases in the WHO regions of South-East Asia (62.8%), the Eastern Mediterranean (69%) and the Western Pacific (71.9%).
• P. vivax is the predominant parasite in the WHO Region of the Americas, representing 74.1% of malaria cases.

Symptoms

• The first symptoms – fever, headache, and chills – may be mild and difficult to recognize as malaria. If not treated within 24 hours, P. falciparum malaria can progress to severe illness, often leading to death.
• Children with severe malaria frequently develop one or more of the following symptoms: severe anaemia, respiratory distress in relation to metabolic acidosis, or cerebral malaria. In adults, multi-organ failure is also frequent.

Transmission

• In most cases, malaria is transmitted through the bites of female Anopheles mosquitoes. There are more than 400 different species of Anopheles mosquito; around 30 are malaria vectors of major importance.
• All of the important vector species bite between dusk and dawn. The intensity of transmission depends on factors related to the parasite, the vector, the human host, and the environment.
• Anopheles mosquitoes lay their eggs in water, which hatch into larvae, eventually emerging as adult mosquitoes. The female mosquitoes seek a blood meal to nurture their eggs. Each species of Anopheles mosquito has its own preferred aquatic habitat; for example, some prefer small, shallow collections of fresh water, such as puddles and hoof prints, which are abundant during the rainy season in tropical countries.
• Transmission is more intense in places where the mosquito lifespan is longer (so that the parasite has time to complete its development inside the mosquito) and where it prefers to bite humans rather than other animals. The long lifespan and strong human-biting habit of the African vector species is the main reason why approximately 90% of the world's malaria cases are in Africa.
• Transmission also depends on climatic conditions that may affect the number and survival of mosquitoes, such as rainfall patterns, temperature and humidity.
• For this reason, most malaria deaths in Africa occur in young children, whereas in areas with less transmission and low immunity, all age groups are at risk.

Prevention

• WHO recommends protection for all people at risk of malaria with effective malaria vector control. Two forms of vector control – insecticide-treated mosquito nets and indoor residual spraying – are effective in a wide range of circumstances.

Diagnosis and treatment

• Early diagnosis and treatment of malaria reduces disease and prevents deaths. It also contributes to reducing malaria transmission.
• The best available treatment, particularly for P. falciparum malaria, is artemisinin-based combination therapy (ACT)

Antimalarial drug resistance

• Resistance to antimalarial medicines is a recurring problem. Resistance of P. falciparum malaria parasites to previous generations of medicines, such as chloroquine and sulfadoxine-pyrimethamine (SP), became widespread in the 1950s and 1960s, undermining malaria control efforts and reversing gains in child survival.

Vaccines against malaria

• RTS,S/AS01 (RTS,S) is the first and, to date, the only vaccine to show partial protection against malaria in young children. It acts against P. falciparum, the most deadly malaria parasite globally and the most prevalent in Africa.

WHO Global Technical Strategy for Malaria 2016-2030 

• The WHO Global Technical Strategy for Malaria 2016-2030 – adopted by the World Health Assembly in May 2015 – provides a technical framework for all malaria-endemic countries. It is intended to guide and support regional and country programmes as they work towards malaria control and elimination.

The Strategy sets ambitious but achievable global targets, including:

• Reducing malaria case incidence by at least 90% by 2030.
• Reducing malaria mortality rates by at least 90% by 2030.
• Eliminating malaria in at least 35 countries by 2030.
• Preventing a resurgence of malaria in all countries that are malaria-free.