Infectious Diseases in Adults :- Infectious illnesses account for one-third of all fatalities in adults aged 65 and older. The usual warning signs and symptoms, such as fever and leukocytosis, are frequently missing in the elderly, making early detection more challenging. The only presenting issue in an older patient with an illness can be a change in mental status or a reduction in function. Pneumonia is estimated to be the cause of 90 percent of deaths in people 65 and older. The elderly are primarily affected by influenza-related mortality. The most frequent cause of bacteremia in older persons is urinary tract infections. Asymptomatic bacteriuria occurs frequently in the elderly; however, antibiotic therapy does not seem to be effective. 

The elderly are particularly affected by the recent surge of antibiotic-resistant bacteria as they are more likely to contract infections in hospitals and other institutional settings. It is difficult to treat colonization and active infection; careful commitment to hygiene precautions is required to stop the spread of resistant microorganisms. Despite improvements in antibiotic treatment, infectious illnesses continue to be a leading cause of death in older persons. Physicians face distinct challenges while treating infections in elderly persons due to the diagnostic and therapeutic complexities.

Fever in Adults 

Fever is a raised body temperature that occurs when the body’s thermostat—located in the brain’s hypothalamus—resets at a higher temperature, typically in response to an illness. Hyperthermia is the medical term for elevated body temperature that isn’t brought on by a reset of the thermostat. Several body parts allow for the measurement of body temperature. The most common sites are the rectum and the mouth. Other sites include the forehead, ear and ideally Armpit. A digital thermometer is typically used to measure temperature. 

Oral temperatures are considered elevated when

  • In the morning, they are greater than 99° F (37° C).
  • At any moment after the early morning, they are greater than 100.4° F (38° C).
  • They are higher than the known average daily temperature of an individual.

Causes of Fever in Adults 

Substances that cause fever are known as Pyrogens. Pyrogens can originate from both inside and outside the body. Examples of pyrogens created outside the body include microorganisms and the compounds they produce such as toxins. Pyrogens formed inside the body are usually produced by Macrophages and Monocytes. Fever may also result from inflammation, a reaction to an allergic reaction, a drug, Autoimmune disorders and undetected cancer, especially Lymphoma, Leukemia or kidney cancer. Fever is a symptom of many diseases. They can be generally divided into:

  • Infectious (most common)
  • Neoplastic (cancer)
  • Inflammatory

Most Common Causes 

Fever can be caused by almost all infectious diseases. However, the majority of infectious causes are:

  • Lower and upper respiratory tract infections
  • Urinary tract infections (UTIs)
  • Gastrointestinal infections
  • Skin infections

Risk factors

People who have certain conditions (risk factors) are more likely to get a fever. These elements consist of the following:

  • The person’s health status
  • Certain occupations
  • The person’s age
  • Use of certain drugs and medical procedures
  • exposure to diseases, such as those brought on by travel or by coming into contact with sick people, animals or insects.

Evaluation of Fever in Adults 

A doctor can identify an infection based on a patient’s medical history, physical examination and occasionally a few quick tests like a chest x-ray and urine tests. Dr Sheetu Singh initially evaluated people with an acute fever, they focused on two general issues:

  • Finding other symptoms such as cough or headache; The wide range of potential causes is reduced by these symptoms.
  • Determining whether the individual is chronically or seriously ill; many potential acute viral infections resolve on their own and are challenging for clinicians to specifically diagnose, that is identify the specific virus that is causing the infection. It can be less expensive, wasteful, and frequently useless to restrict testing to those who are gravely or chronically unwell. 

Warning signs 

Some symptoms and traits in patients with an acute fever are concerning. They include:

  • Stiff neck, headache or both
  • Low blood pressure 
  • A modification of mental state such as confusion
  • Petechiae, which are small, flat, purple-red spots on the skin that signify internal bleeding
  • Rapid breathing or rapid heart rate
  • Shortness of breath
  • a temperature that is greater than 104° F 40° C or less than  95° F 35° C
  • Recent travel to a region where an endemic (regular) infectious disease, like malaria, is present
  • Recent usage of immunosuppressants, medications that weaken the immune system 

Essentials for Older People: Fever 

Fever can be challenging in older people because the body may not respond the way it would in younger age. For instance, infection is less likely to result in fever in elderly, fragile individuals. Even when the temperature is raised due to an infection, it may be lower than the standard for a fever and the level of the fever may not be consistent with how serious the condition is. Similarly, other symptoms, such as pain may be less noticeable. A change in mental function or a decline in everyday functioning is frequently the only other early indicator of pneumonia or a urinary tract infection. 

However, older people with a fever are more likely to have a serious bacterial infection than younger adults with a fever. A respiratory or urinary tract infection is frequently the cause, much like in younger adults. Soft-tissue and skin infections are also common causes in older people. Serious respiratory viral infections such as influenza, COVID-19 and respiratory syncytial virus (RSV) are more common in older adults.


We examine the top 10 infectious diseases for 2023 in this post. Numerous various bacteria, ranging from a mild cold virus to pulmonary TB, can induce coughing and fever.

What is an infection?

An infection occurs when a microorganism- such as fungi, bacteria or virus enters a person’s body and causes harm. The immune system can frequently prevent these viruses from multiplying within the body. The microorganism relies on the host’s body to survive, procreate, and colonize. These infectious, quickly reproducing microscopic pathogens.

How can infections spread?

They can spread through a variety of channels, such as:-

  • Skin contact.
  • Transfer of body fluids
  • Contact with faces
  • Ingesting contaminated water or food
  • airborne particles or droplets being inhaled
  • Touching a surface that has been touched by a person who is infected with the disease.

So, here are 10 significant prevalent infections in 2023.

1- Bronchitis: An inflamed bronchi is known as bronchitis. This produces sputum and a cough. They are typically brought on by a virus and will heal on their own. It is an upper respiratory tract infection (URTI) that is most frequently seen. When treating bronchitis, Dr. Sheetu Singh takes a thorough, patient-centered approach. She emphasizes on giving each bronchitis patient individualized care using her broad medical knowledge and sympathetic personality. Your immune system creates swelling and mucus buildup in your airways when they are stimulated.

2- Common colds and influenza: Colds and influenza (flu) are both contagious respiratory infections, although they are brought on by various viruses. Different viruses, such as rhinoviruses, parainfluenza, and seasonal coronaviruses, can cause the common cold, however, only influenza viruses can cause the flu. Colds are usually milder than flu. Compared to those who have the flu, cold sufferers are more likely to have a runny or congested nose. In most cases, significant health issues like bacterial infections, pneumonia, or hospitalization are not brought on by colds. Flu can have serious associated complications.

3- Conjunctivitis: Conjunctivitis, also referred to as “pink (or red) eye,” is an inflammation of the eye and eyelid lining. The eye whites seem pink and could be discharged with something sticky. There are three main kinds of causes for conjunctivitis:-

  • Infective conjunctivitis- infection caused by a virus or bacteria. This illness may spread quickly. 
  • Allergic conjunctivitis: An allergic response to something such as pollen or dust mites.
  • Irritant conjunctivitis- Objects that can irritate the conjunctiva come into touch with the eye, such as stray eyelashes or chlorinated water, or shampoo.

4- COVID-19: The SARS-cov-2 virus is the infectious agent that causes coronavirus illness. Most virus-infected people will develop a mild to severe respiratory illness, but they will recover without the need for special treatment. Serious illness is more likely to affect the elderly and those with underlying medical illnesses including cancer, diabetes, cardiovascular disease, or persistent respiratory issues. Early symptoms of COVID-19 may include a loss of smell or taste. Other symptoms may include:-

  • Muscle aches
  • Shortness of breath or difficulty breathing
  • Sore  throat
  • Runny nose
  • Headache
  • Rash
  • Chest pain

5- Gastroenteritis: Gastroenteritis is a very common condition that causes vomiting and diarrhea. It is usually caused by a viral tummy bug or bacteria that can be related to food. It affects people of all ages but is simply common in young children. A virus known as rotavirus is responsible for the majority of illnesses in children. An intestinal infection known as viral gastroenteritis has symptoms such as watery diarrhea, stomach cramps, nausea, and occasionally fever. 

6- HIV/AIDS: The immune system of the body is attacked by the human immunodeficiency virus. Acquired immunodeficiency syndrome may result from untreated HIV. There is currently no effective treatment available. When someone contracts HIV, they are permanently infected and can be controlled with proper medical care. HIV is caused by a virus. It may also spread from mother to child during pregnancy, childbirth, and breastfeeding. It can also spread through sexual contact, drug use or sharing of needles during illicit injections and contact with infected blood.

7- Malaria: Malaria is caused by plasmodium parasites. Humans are the only significant repository for four Plasmodium species—Plasmodium falciparum, Plasmodium vivax, Plasmodium Ovale, and Plasmodium Malariae—all of which cause disease in people. It can manifest in a variety of forms, from a minor chronic sickness to an acute illness that poses a serious threat to life. The majority of malaria deaths are caused by one or more major complications like breathing problems, cerebral malaria, anemia, organ failure or low blood sugar.

8- Pneumonia: Pneumonia is an infection of one or both of the lungs caused by viruses, bacteria or fungi. It is a dangerous infection when bacteria and other liquids fill the air sacs. It can be identified if there are typical symptoms linked with new chest X-ray shadowing. Signs and symptoms of pneumonia may include cough, fatigue, fever, sweating, nausea, vomiting chest pain or shortness of breath. There are two main types:-

  1. One or more lung chambers can become infected with lobar pneumonia.
  2. One or more lung chambers can become infected with lobar pneumonia.

9- Sore throat: Sore throat is usually caused by viruses like flu, cold or COVID-19. They may occasionally be brought on by bacteria. Most people recover without any kind of treatment. A sore throat can also be caused by:-

  • Pharyngitis
  • Laryngitis
  • Tonsillitis
  • Glandular fever

10- Tuberculosis (TB): Tuberculosis is a highly infectious bacterial disease that mostly affects the lungs. It can affect any part of the body including the nervous system, glands and bones. TB can spread when a person with sneezes, illness coughs or sings. This may release microscopic droplets containing the germs into the atmosphere. There are numerous symptoms associated with active TB, the majority of which are respiratory. Dr. Virendra Singh treats tuberculosis with a combination of expertise, compassion and innovation. Dr. Virendra Singh represents excellence in tuberculosis treatment via his commitment to improving tuberculosis care and his sympathetic approach. The symptoms include:

  1. Cough
  2. Fever
  3. Unexplained fatigue
  4. Blood in sputum
  5. Night sweats
  6. Chest pain
  7. Appetite loss
  8. Weight loss

Dr. Sheetu Singh, a nationally renowned pulmonologist, Director ILD & Pulmonary Rehab Clinic, is an expert in chest-related conditions. She got her training from SMS Medical College, Jaipur followed by a visit to Cleveland Clinic, USA.

Contact Info

Address: Mahavir Jaipuriya Rajasthan Hospital Milap Nagar, JLN Marg, Jaipur

Mobile: (+91)-8696666380


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