what is the malaria symptoms all about?

Malaria is a mosquito-borne infectious disease affecting humans and other animals caused by parasitic protozoans (a group of single-celled microorganisms) belonging to the Plasmodium type.Malaria causes symptoms that typically include fever,fatigue, vomiting, and headaches. In severe cases it can cause yellow skin, seizures, coma, or death.Symptoms usually begin ten to fifteen days after being bitten. If not properly treated, people may have recurrences of the disease months later.In those who have recently survived an infection, reinfection usually causes milder symptoms. This partial resistancedisappears over months to years if the person has no continuing exposure to malaria.

The disease is most commonly transmitted by an infected female Anopheles mosquito. The mosquito bite introduces theparasites from the mosquito’s saliva into a person’s blood.The parasites travel to the liver where they mature andreproduce. Five species of Plasmodium can infect and be spread by humans. Most deaths are caused by P. falciparumbecause P. vivax, P. ovale, and P. malariae generally cause a milder form of malaria. The species P. knowlesi rarely causes disease in humans.Malaria is typically diagnosed by the microscopic examination of blood using blood films, or with antigen-based rapid diagnostic tests. Methods that use the polymerase chain reaction to detect the parasite’s DNA have been developed, but are not widely used in areas where malaria is common due to their cost and complexity.

The risk of disease can be reduced by preventing mosquito bites through the use of mosquito nets and insect repellents, or with mosquito control measures such as spraying insecticides and draining standing water.Several medications are available to prevent malaria in travellers to areas where the disease is common. Occasional doses of the combination medicationsulfadoxine/pyrimethamine are recommended in infants and after the first trimester of pregnancy in areas with high rates of malaria. Despite a need, no effective vaccine exists, although efforts to develop one are ongoing. The recommended treatment for malaria is a combination of antimalarial medications that includes an artemisinin. The second medication may be either mefloquine, lumefantrine, or sulfadoxine/pyrimethamine.Quinine along with doxycycline may be used if an artemisinin is not available. It is recommended that in areas where the disease is common, malaria is confirmed if possible before treatment is started due to concerns of increasing drug resistance. Resistance among the parasites has developed to several antimalarial medications; for example, chloroquine-resistant P. falciparum has spread to most malarial areas, and resistance to artemisinin has become a problem in some parts of Southeast Asia.

The disease is widespread in the tropical and subtropical regions that exist in a broad band around the equator.This includes much of Sub-Saharan Africa, Asia, and Latin America. In 2015, there were 214 million cases of malaria worldwide resulting in an estimated 438,000 deaths, 90% of which occurred in Africa. Rates of disease have decreased from 2000 to 2015 by 37%, but increased from 2014 during which there were 198 million cases.Malaria is commonly associated with poverty and has a major negative effect on economic development. In Africa, it is estimated to result in losses of US$12 billion a year due to increased healthcare costs, lost ability to work, and negative effects on tourism.

Owing to the non-specific nature of the presentation of symptoms, diagnosis of malaria in non-endemic areas requires a high degree of suspicion, which might be elicited by any of the following: recent travel history, enlarged spleen, fever, low number of platelets in the blood, and higher-than-normal levels of bilirubin in the blood combined with a normal level of white blood cells.

Malaria is usually confirmed by the microscopic examination of blood films or by antigen-based rapid diagnostic tests (RDT). In some areas, RDTs need to be able to distinguish whether the malaria symptoms are caused by Plasmodium falciparum or by other species of parasites since treatment strategies could differ for non-P. falciparum infections.Microscopy is the most commonly used method to detect the malarial parasite—about 165 million blood films were examined for malaria in 2010.Despite its widespread usage, diagnosis by microscopy suffers from two main drawbacks: many settings (especially rural) are not equipped to perform the test, and the accuracy of the results depends on both the skill of the person examining the blood film and the levels of the parasite in the blood. The sensitivity of blood films ranges from 75–90% in optimum conditions, to as low as 50%. Commercially available RDTs are often more accurate than blood films at predicting the presence of malaria parasites, but they are widely variable in diagnostic sensitivity and specificity depending on manufacturer, and are unable to tell how many parasites are present.

In regions where laboratory tests are readily available, malaria should be suspected, and tested for, in any unwell person who has been in an area where malaria is endemic. In areas that cannot afford laboratory diagnostic tests, it has become common to use only a history of fever as the indication to treat for malaria—thus the common teaching “fever equals malaria unless proven otherwise”. A drawback of this practice is overdiagnosis of malaria and mismanagement of non-malarial fever, which wastes limited resources, erodes confidence in the health care system, and contributes to drug resistance.Although polymerase chain reaction-based tests have been developed, they are not widely used in areas where malaria is common as of 2012, due to their complexity.

Classification

Malaria is classified into either “severe” or “uncomplicated” by the World Health Organization (WHO). It is deemed severe when any of the following criteria are present, otherwise it is considered uncomplicated.

1. Decreased consciousness
2. Significant weakness such that the person is unable to walk
3. Inability to feed
4. Two or more convulsions
5. Low blood pressure (less than 70 mmHg in adults and 50 mmHg in children)
6. Breathing problems
7. Circulatory shock
8. kidney in the urine
9. Bleeding problems, or hemoglobin less than 50 g/L (5 g/dL
10. glucose less than 2.2 mmol/L (40 mg/dL)
11.   or levels of greater than 5 mmol/L
12. A parasite level in the blood of greater than 100,000 per  in low-intensity transmission areas, or 250,000 per ul in high-intensity transmission areas

Cerebral malaria is defined as a severe P. falciparum-malaria presenting with neurological symptoms, including coma , or with a coma that lasts longer than 30 minutes after a seizure.

Various types of malaria have been called by the names below: