Acute Febrile Illness (AFI), which goes by other medical terminologies including Acute Undifferentiated Fever (AUF), Acute Fever (AF) or Short Febrile Illness (SFI) is generally defined as a fever that subsides by itself in three weeks, or in some instances, lasts for a maximum period of a fortnight i.e. two weeks. Because the exact underlying causes of acute febrile illness are yet to be identified, doctors from the medical community worldwide have yet to reach a common consensus on the exact definition of acute febrile illness.

Nevertheless, certain factors can be stated as triggering a rise in body temperature above the normal levels, which is 98.6 Fahrenheit or 37 Celcius, and ultimately resulting in acute febrile illness.

These include an epidemic of certain infectious diseases due to geographical regions or seasonal changes in a particular country or city. The harmful microbes instigating AFI comprise viruses, bacteria, protozoa, and rickettsia that cause malaria, scrub typhus, rickettsial fevers, dengue, leptospirosis, and influenza. Furthermore, in a minority of cases, signs of AFI are detected in the patient, but the exact causative aspect cannot be diagnosed.

Also Read: Influenza Virus: Debunking Common Myths About The Contagious Disease

Hence, acute febrile illness is broadly categorized into three sub-types, based on the signs and severity of the illness, which are:

Diagnosed Acute Febrile Illness (Diagnosed AFI)

Non-Malarial Acute Febrile Illness (Non-Malarial AFI)

Undiagnosed Acute Febrile Illness (Undiagnosed AFI)

Due to the wide prevalence of AFI, particularly in tropical nations including India, in the monsoons as well as phases between seasonal changes, it is important to understand how AFI presents in people and ensure immediate medical care is given, so as to ensure a speedy recovery.

Symptoms Of Acute Febrile Illness

The overlapping feature of AFI with other vector-borne illnesses does pose a challenge for physicians to distinguish the symptoms from that of a common cold, viral fever, or malarial infection. Specific traits that doctors associate with acute febrile illnesses comprise the following:

A high fever that lasts for more than 4 days and does not subside with the usual dose of antibiotics or antivirals, with body temperatures constantly being above normal
Rashes on skin
Hemorrhages
Jaundice
Myalgia
Arthralgia
Typhoid

Diagnosis Of Acute Febrile Illness

The wide array of indicators that fall under the umbrella of acute febrile illness invariably results in medical practitioners having to conduct various analyses to certainly conclude an instance of AFI. Besides scrutinizing the external symptoms and medical history of the affected individual, the primary diagnostic tests consist of:

Peripheral Smear Examination

In this test, the medical expert takes a sample of blood from the patient and examines it under the microscope, to look for any anomalies in the structure, number, and size of red blood cells, white blood cells, and platelets.

Rapid Diagnostic Test (RDT)

A sterilized needle is used to prick the patient and merely a drop of blood is drawn onto an antigen plate. The antigen on the plate is a protein specific to any one of the infectious diseases – malaria, dengue, jaundice, typhoid, or other regional diseases. The blood sample is then promptly analyzed under a lens, to spot if it binds to the antigen on the plate. Post this analysis, a quick laboratory diagnosis confirming if the viral or bacterial strain causing malaria, dengue, jaundice or typhoid is present in the system of the patient, so as to enable initiating treatment procedures instantly. Also Read: Learn About Prevention Of Malaria In Mosquito Season

ELISA (Enzyme-Linked Immunosorbent Assay)

This biochemical assay utilises an antibody as a ligand (binding agent), to discern if the specific protein called an antigen, which is found on the cell membranes of infectious germs, is present in the blood sample of the patient. The ELISA test is usually used to figure out an instance of rickettsial infections or leptospirosis.

PCR (Polymerase Chain Reaction)

This is a detailed evaluation of the DNA samples in the blood of the patient, wherein they are amplified and the signal is compared to a standard DNA from a healthy individual and the DNA from the causative microbial agent. In case the DNA signal from the patient’s blood sample correlates with that of the infectious microorganism, then the diagnosis of the specific case of AFI can be confirmed.

Treatment Options For Acute Febrile Illness:

Depending on the characteristic features and severity of fevers in the individual afflicted with AFI, the healthcare provider begins the appropriate course of treatment, to guarantee the complete elimination of fever symptoms within two to three weeks.

Essentially, antimalarial drugs, antibiotics or antivirals are prescribed, to be taken in a strict course following meals. In addition, multivitamin supplements are also strongly advised to be taken, to avoid serious instances of lethargy, dizziness, nausea, vomiting, and headaches.

Frequently Asked Questions

What Is Another Name For A Febrile Condition?

A febrile condition is often referred to as a fever or febrile state.

What Are The Classifications Of Febrile Conditions?

Based on duration and underlying causes, febrile conditions and illness can be classified as acute, chronic, or recurrent

Is Malaria A Febrile Disease?

Yes, malaria is classified as a febrile disease, commonly causing high fever and chills.

What Is Short-Term Febrile Illness?

Short-term febrile illness refers to a fever lasting less than a week, often due to infections.

How Do You Treat Febrile Fits?

Febrile fits are treated by cooling the child and using antipyretics. Also, a medical evaluation is recommended.

What Age A Febrile Fit Can Occur?

Febrile fits typically occur in children aged 6 months to 5 years during fevers.

What Is Febrile Status?

Febrile status refers to a prolonged febrile state, often with persistent high fever and potential complications.

Is Febrile Illness Serious?

Febrile illness can range from mild to serious, depending on the underlying cause and duration.

How Long Is Acute Febrile Illness?

Acute febrile illness usually lasts from a few days to two weeks, depending on the cause.

What Is The Blood Test For Acute Febrile Illness?

Blood tests for acute febrile illness may include a complete blood count (CBC) and specific tests for infections.

What Is The Difference Between Acute Febrile Illness And A Fever?

Acute febrile illness is a broader term indicating fever associated with symptoms, while a fever is simply an elevated body temperature.

What Are The Complications Of Acute Febrile Illness?

Complications can include dehydration, febrile seizures, or exacerbation of underlying conditions, depending on the cause.

What Is Acute Febrile Illness In India?

In India, acute febrile illness often refers to infections like dengue, malaria, and typhoid, prevalent in the region.

Conclusion

More in-depth research is required to significantly prevent AFI, and to lower the number of cases of acute febrile illness, especially in tropical countries. Apart from this, investigative studies that clearly outline the causes, symptoms, diagnostic measures and treatment methodologies to efficiently tackle AFI would help doctors treat these ailments successfully and at a quicker pace. This would prevent transmission of AFI amongst a huge, dense population, where infectious germs thrive, as is common in tropical countries and naturally enhance the overall quality of health.

(This article is reviewed by M Sowmya Binu Health And Nutrition Expert

Author Profile, Kalyani Krishna:

With a dual Bachelor's degree in Commerce and Law, coupled with over 15 years of extensive experience in mainstream media, Kalyani Krishna is a seasoned professional adept in writing, editing, and content strategy. Passionate about the health sector, she specializes in crafting meticulously researched articles that are both factual and grammatically flawless and deliver accurate and valuable insights to the audience.

References:

Acute Undifferentiated Febrile Illness in Patients Presenting to a Tertiary Care Hospital in South India: Clinical Spectrum and Outcome

Department of General Medicine, Christian Medical College, Vellore, Tamil Nadu, India

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5126753/

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9436081/

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