Control And Care of Malaria to Adults

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• Key facts

  • 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.
  • In 2017, there were an estimated 219 million cases of malaria in 87 countries.
  • The estimated number of malaria deaths stood at 435 000 in 2017.
  • The WHO African Region carries a disproportionately high share of the global malaria burden. In 2017, the region was home to 92% of malaria cases and 93% of malaria deaths.
  • Total funding for malaria control and elimination reached an estimated US$ 3.1 billion in 2017. Contributions from governments of endemic countries amounted to US$ 900 million, representing 28% of total funding.
  
  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 of malaria

Malaria is an acute febrile illness. In a non-immune individual, symptoms usually appear 10–15 days after the infective mosquito bite. 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. In malaria endemic areas, people may develop partial immunity, allowing asymptomatic infections to occur.

Who is at risk?

In 2017, nearly half of the world's population was at risk of malaria. Most malaria cases and deaths occur in sub-Saharan Africa. However, the WHO regions of South-East Asia, Eastern Mediterranean, Western Pacific, and the Americas are also at risk. In 2017, 87 countries and areas had ongoing malaria transmission.
Some population groups are at considerably higher risk of contracting malaria, and developing severe disease, than others. These include infants, children under 5 years of age, pregnant women and patients with HIV/AIDS, as well as non-immune migrants, mobile populations and travellers. National malaria control programmes need to take special measures to protect these population groups from malaria infection, taking into consideration their specific circumstances.

Disease burden

According to the latest World malaria report, released in November 2018, there were 219 million cases of malaria in 2017, up from 217 million cases in 2016. The estimated number of malaria deaths stood at 435 000 in 2017, a similar number to the previous year.
The WHO African Region continues to carry a disproportionately high share of the global malaria burden. In 2017, the region was home to 92% of malaria cases and 93% of malaria deaths.
In 2017, 5 countries accounted for nearly half of all malaria cases worldwide: Nigeria (25%), the Democratic Republic of the Congo (11%), Mozambique (5%), India (4%) and Uganda (4%).
Children under 5 years of age are the most vulnerable group affected by malaria; in 2017, they accounted for 61% (266 000) of all malaria deaths worldwide.

Transmission of malaria

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. In many places, transmission is seasonal, with the peak during and just after the rainy season. Malaria epidemics can occur when climate and other conditions suddenly favour transmission in areas where people have little or no immunity to malaria. They can also occur when people with low immunity move into areas with intense malaria transmission, for instance to find work, or as refugees.
Human immunity is another important factor, especially among adults in areas of moderate or intense transmission conditions. Partial immunity is developed over years of exposure, and while it never provides complete protection, it does reduce the risk that malaria infection will cause severe disease. 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.

          Predisposing Factors for Malaria

• The predisposing factors for malaria infection include:

             o A decreased immunity of the population
             o Children who are under-five years
               Children are more prone to get malaria infection
             o Impaired immunity due to other illnesses
             o Pregnant women
             o Women are at increased risks of acquiring malaria to their unborn babies    
            o Poor nutritional status
            o Travellers coming from areas with no malaria to malaria endemic area
            o People with poor socioeconomic status
            o This is due to poor feeding and therefore malnutrition
            o Ignorance        
            o Sleeping without LLIN (long lasting Impregnated Nets)
            o Living in an environment with stagnant water
  
      Transmission of Malaria

•  Malaria is transmitted by the female anopheles mosquito which requires human blood for the development of its eggs.
•  When a female mosquito bites a human being it injects malaria parasites which is present in its saliva
• The parasites are then taken to the liver where they grow and after a time become released to the general circulation
• When in the general circulation the parasites invade the red blood cells where they multiply
• The parasite is released from the red blood cells as male and female gametocytes which are later taken by the female anopheles mosquito when sucking blood.
•  These are again taken to the salivary glands where they grow.
•  When the mosquito bites another human being, the parasites are injected into the blood and the transmission continues. 

    Signs and Symptoms of Malaria

•  Patients with malaria will present with the following symptoms and signs:

                o Headache
                o Fever
                o Generalized body weakness
                o Joint pain
                o Sometimes vomiting and diarrhoea
                o Loss of appetite.

•  This can be manifested by reluctance/refusal to feed in children

                     o Change in the colour of the mucous membrane from pink to white

•  If the patient will not receive early and adequate treatment may present with the following symptoms and signs:

                    o Change in behaviour ( confusion
                    o Extreme body weakness
                    o Difficulty in breathing
                    o Convulsion
                    o Loss of consciousness
                    o Vomiting everything

     Preventive measures of malaria

•   Malaria can be prevented by providing health education to the community insisting on:

                o Making the surroundings clean to reduce mosquitoes breed.
                o Filling or drying stagnant water reservoir
                o Clearing bushes
                o Wear long sleeved clothes to protect the body from mosquito bites.
                o Using long lasting impregnated nets (LLINs)
                o Reminding all pregnant mother to use SP prophylaxis
                o Using insect repellents
                o Killing adult mosquito by indoor residual house spraying
                o Killing larvae with larvicides
                o Improving malaria case management
                o Taking all patient with sign and symptoms of malaria to the Health facility for test and management
                o Patients compliance to treatment regimen (completing the doze as directed by the healthcare provider)

        Summary

•   Malaria is caused by an organism called Plasmodium which is transmitted to humans by a female Anopheles mosquito.

•  The predisposing factors for malaria include infants and under-fives, pregnant women and travellers coming from areas with no malaria to malaria endemic areas.

•  Preventive measures include creation of community awareness, bite prevention, chemoprophylaxis and improve malaria case management.