Malaria - Symptoms, Causes and Treatment

The disease is prevalent in subtropical and tropical countries like India, Vietnam, and Africa, where mosquito control is a big challenge. Once the infected mosquito bites the host human or animal, it injects the parasite into the host’s bloodstream. The parasite travels to the host’s liver, which becomes its breeding ground, where it matures. And gradually the body starts showing malaria symptoms. You can detect malaria through a simple blood test, which is essential to deciding the course of treatment. Recovery might be slow, and quarantine is advised. 

Signs and Symptoms of Malaria

The signs and symptoms of malaria may vary from animals to humans. In humans, too, it varies in severity from young to old. The manifestation of malaria may occur within 610 to 15 days of exposure and sometimes as late as six months. The most common malaria symptoms include:

• Fever
• Shivering or chills
• A constant uneasy feeling
• Diarrhoea
• Headaches
• Rapid heart rate
• Increased breathing
• Underlying fatigue
• Muscle pain
• Joint pain
• Nausea and vomiting
• Pain in the abdomen
• Dry cough

Malaria may manifest in some adults through intense bouts of chills and fevers, which may last for a few minutes or hours. This is quickly followed by extreme sweating when the fever subsides. In medical terms, this is a classic malaria symptom, also known as paroxysm. Such cyclic manifestation may not be seen in all patients. In children, the symptoms are mostly restricted to high fever, dry caught, diarrhoea, and vomiting. 

Initial Signs of Malaria

In the early days of exposure, you may feel that the signs and symptoms of malaria are similar to other conditions like a viral infection, gastroenteritis, or sepsis. The symptoms may include:

• Headache
• High fever
• Joint pain
• Vomiting
• Hemolytic anaemia
• Jaundice
• Blood in the urine
• Convulsions

Types of Malaria and their Symptoms

According to the World Health Organisation (WHO), you can classify malaria as severe or uncomplicated. It is declared severe if one or more of the following malaria symptoms appear:

• Inability to eat
• Very low blood pressure (<70 in adults and <50 in children)
• Decreased consciousness
• Difficulty in breathing
• Pulmonary oedema
• Haemoglobin <50g/L
• Circulatory shock
• Lactate levels >5 mmol/L
• Parasite level in the blood >100K/μL

In extremely severe cases, the patient may present neurological symptoms, including coma. Such cases are called cerebral malaria.

Causes of Malaria

Malaria is caused by a single-celled parasite of the plasmodium group. As discussed, the parasite is injected through a mosquito bite in humans and animals. The following steps explain the cycle of parasite transmission that causes malaria.

1. The female Anopheles mosquito bites an infected host and becomes infected with the parasite.
2. This mosquito then bites another host, transmitting the parasite into the host’s body.
3. The parasite enters the bloodstream and travels to the liver, which becomes its breeding ground to mature and reproduce for about a year.
4. Once the parasites mature, they leave the liver and attack the red blood cells.
5. Once in the red blood cells, the parasite begins to affect the host’s immunity, which manifests the signs and symptoms of malaria. 
6. The entire cycle is repeated if an uninfected mosquito bites this infected person at this juncture. 

Other Ways of Malaria Transmission

There are a few other ways in which you can contract malaria. The infection can be transmitted:

• From a pregnant mother to an unborn child
• Through blood transfusions
• Sharing used needles

Living or visiting an area or region where the disease is prevalent also increases your chances of contracting malaria. The most popular regions in the world that are notoriously famous for the prevalence of malaria are:

• Southeast Asia
• South Asia
• Pacific Islands
• Central America
• Northern South America
• Sub-Saharan Africa

While there are preventive measures in place that the local governments ensure, the inherent climate is a potent factor in the spread of the disease. Those who are at a greater risk of contracting malaria are:

• Infants
• Young children
• Older adults
• Pregnant women
• People travelling from areas with no prevalence of malaria

Recurrent Malaria

Malaria symptoms can come back even after a prolonged period of non-recurrence. Based on the cause, recurrent malaria may be classified into three types.

Types of Recurrent Malaria and their Symptoms

1. Recrudescence Malaria: Often, the parasite may survive in the blood due to ineffective or inadequate treatment. The patient may experience a long symptom-free period post the first occurrence. And the disease may still come back after a while.
2. Relapse: Sometimes, the parasites may have been effectively eliminated from the body through the proper treatment. But remnants may have survived as dormant hypnozoites in the liver cells. A relapse will typically occur within 2 weeks to 10 months 8 to 24 weeks of the first occurrence of malaria.
3. Reinfection: As the name suggests, reinfection simply means that the host gets reinfected with a new malaria parasite. This may happen even after the earlier parasite is eliminated from the body. 

Diagnosis of Malaria

The nature of malaria symptoms is non-specific. This makes it difficult for any particular test to pinpoint the result. The diagnosis is primarily based on initial signs and symptoms of malaria, which are then confirmed with the help of a parasitological test. The diagnosis is relatively more straightforward in regions where malaria is high. In fact, according to WHO protocol, any person presenting symptoms of fevers and chills will be first quarantined for malaria. Other factors that are considered for diagnosing malaria include:

• Children with any signs of anaemia - pale palms or low haemoglobin
• Pregnant women with low blood pressure

In regions with a prevalence of malaria, WHO has recommendations and guidelines for diagnosing the disease. Only those with possible exposure to malaria-prone areas or any unexplained fever need to be tested. 

Test Procedure for Detecting Malaria

A microscopic examination of blood films or an antigen-based RDT (Rapid Diagnostic Test) is the standard procedure for confirming the presence of the malaria parasite in the blood.

Microscopy is considered the gold standard test procedure for implementing this test. Here, Giemsa-stained blood is examined under a light microscope, and the presence of the parasite is confirmed or ruled out. The test is confirmed positive only when there is a minimum presence of apx. 5-10100 parasites per μL of blood. This is the minimum requirement to confirm symptomatic infection. 

This procedure is resource-intensive and requires trained personnel and a proper laboratory setup. On the other hand rapid antigen tests are easy to do

There may be places where microscopy is not the go-to for testing malaria. The resources might simply be unavailable. In such cases, a rapid antigen test may suffice to detect the presence of parasite proteins through a finger stick blood sample. At MHL through a careful selection of kits available in market both the important species of malaria are detected by this technique i.e., P. falciparum and P. vivaxThe HRP2 is the most common quick antigen test kit that is used for this kind of procedure. 

Other tests like serological tests are still used to detect the presence of antibodies against the malaria virus. But they are insufficient to diagnose signs of malaria. Other options include the relatively expensive nucleic acid amplification test. But they are not common.

Metropolis healthcare ltd. also offers cutting edge tests like comprehensive fever panel by multiplex PCR which can detect all species of malaria, salmonella (typhoid), chikungunya, dengue, leptospira, zika virus, west nile fever which may co-occur with malaria during the monsoon season. This test is done through blood sample and is of great help in diagnosing fever during monsoon season

Treatment for Malaria

You may be prescribed antimalarial medications depending on the type and severity of malaria. Common medicines are prescribed for the fever but are not enough to cure malaria. 

Treating Uncomplicated Malaria

Oral medications like artemisinin drugs are most effective for treating uncomplicated malaria. ACT or Artemisinin-Combination Therapy is the most popular way of treating this type of malaria and has proven to be 90% effective. Some deciding factors about the course of treatment for malaria include:

• Age of the patient
• Pregnancy
• Type of malaria
• Severity of the symptoms

One must consult his doctor before taking any treatment for malaria.

Common Medications for Treating Uncomplicated Malaria

Listed below are some of the most common drugs prescribed by doctors to treat malaria symptoms -

• Chloroquine Phosphate: Chloroquine was the obvious choice for treating parasites until about a few years ago. But there are increased incidences of drug resistance, because of which it is no longer the most effective.
• ACT (Artemisinin-based Combination Therapies): ACT is the most effective and popular choice for treating the malaria parasite. It is also effective against the chloroquine-resistant malaria parasite. 
• Other common medications for treating signs of malaria include Malarone (atovaquone-proguanil), Primaquine Phosphate, etc.

Treating Severe Malaria

Best done in a critical care unit (CCU), the typical steps in this kind of treatment include:

• Managing a very high fever
• Monitoring laboured breathing
• Managing low blood sugar and potassium

Typically, the quinine loading dose is administered to reduce the fever and slowly eliminate the parasite from the body. 

Treating Cerebral Malaria

Malaria with the worst neurological symptoms, including coma, is called cerebral malaria. Usually, clinicians and medical practitioners must determine the cause of the coma to determine the course of treatment. If this is unclear, the comatose condition may be attributed to other locally prevalent causes of encephalopathy. But if the case is registered in an area with a high malaria prevalence, the treatment for the same can be started immediately. The management of cerebral malaria follows a few standard steps :

1. Monitor the vitals of the patient every two hours.
2. Patients should not be left on a wet bed.
3. The patient should be aided with a sterile urethral catheter to help in urination.
4. A sterile nasogastric tube has to be inserted to aspirate the stomach.
5. If convulsions occur, an IV injection of benzodiazepine must be administered. 
6. A blood transfusion may be helpful in some cases. 

Prevention of Malaria

As with most other diseases, malaria is very much preventable. You can resort to easy and effective measures to prevent the contraction of the disease. A few simple ways to do this include:

• Cover your skin if you are in an area prone to malaria.
• Use a mosquito repellant or a mosquito net while sleeping (the Anopheles mosquito is most active between dusk and dawn).
• Use an apparel roll-on to repel mosquitoes.
• Don't let water accumulate in spaces like open drainage or sewage.
• Clear overgrowth from your neighbourhood. 
• If you belong to a place with little or no incidence of malaria, make sure to carry preventive medicine if you travel to a place with a high incidence. 
• You may also consult a doctor who can administer preventive malaria drugs before you travel to these places. 

Malaria is very much preventable and curable. Along with the proper treatment and timely diagnosis, a little public awareness can also go a long way in tackling this deadly parasite with appropriate treatment and timely diagnosis.