What are the most common infection microorganism?

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Infectious diseases are disorders caused by organisms — such as bacteria, viruses, fungi or parasites. Many organisms live in and on our bodies. They're normally harmless or even helpful. But under certain conditions, some organisms may cause disease.

Some infectious diseases can be passed from person to person. Some are transmitted by insects or other animals. And you may get others by consuming contaminated food or water or being exposed to organisms in the environment.

Signs and symptoms vary depending on the organism causing the infection, but often include fever and fatigue. Mild infections may respond to rest and home remedies, while some life-threatening infections may need hospitalization.

Many infectious diseases, such as measles and chickenpox, can be prevented by vaccines. Frequent and thorough hand-washing also helps protect you from most infectious diseases.

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Symptoms

Each infectious disease has its own specific signs and symptoms. General signs and symptoms common to a number of infectious diseases include:

Fever
Diarrhea
Fatigue
Muscle aches
Coughing

When to see a doctor

Seek medical attention if you:

Have been bitten by an animal
Are having trouble breathing
Have been coughing for more than a week
Have severe headache with fever
Experience a rash or swelling
Have unexplained or prolonged fever
Have sudden vision problems

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Bacteria are living things that have only one cell. Under a microscope, they look like balls, rods, or spirals. They are so small that a line of 1,000 could fit across a pencil eraser. Most types of don't make you sick. Many types are helpful. Some of them help to digest food, destroy disease-causing cells, and give the body needed vitamins. Bacteria are also used in making healthy foods like yogurt and cheese.

But infectious bacteria can make you ill. They reproduce quickly in your body. Many give off chemicals called toxins, which can damage tissue and make you sick. Examples of bacteria that cause infections include Streptococcus, Staphylococcus, and E. coli.

Antibiotics are the usual treatment. When you take antibiotics, follow the directions carefully. Each time you take antibiotics, you increase the chances that bacteria in your body will learn to resist them causing antibiotic resistance. Later, you could get or spread an infection that those antibiotics cannot cure.

NIH: National Institute of Allergy and Infectious Diseases

Start Here

Germs: Learn How Germs Work and What You Can Do to Protect Yourself (Mayo Foundation for Medical Education and Research) Also in Spanish

Diagnosis and Tests

Acid-Fast Bacillus (AFB) Tests
(National Library of Medicine) Also in Spanish
Bacteria Culture Test
(National Library of Medicine) Also in Spanish
Gram Stain
(National Library of Medicine) Also in Spanish
Immunofixation (IFE) Blood Test
(National Library of Medicine) Also in Spanish
Immunoglobulins Blood Test
(National Library of Medicine) Also in Spanish
PCR Tests
(National Library of Medicine) Also in Spanish
Procalcitonin Test
(National Library of Medicine) Also in Spanish
Rapid Tests
(National Library of Medicine) Also in Spanish
Respiratory Pathogens Panel
(National Library of Medicine) Also in Spanish
Sputum Culture
(National Library of Medicine) Also in Spanish
White Blood Cell (WBC) in Stool
(National Library of Medicine) Also in Spanish

Prevention and Risk Factors

Germs and Hygiene: MedlinePlus Health Topic
(National Library of Medicine) Also in Spanish
Infection Control: MedlinePlus Health Topic
(National Library of Medicine) Also in Spanish

Treatments and Therapies

Antibiotics: MedlinePlus Health Topic
(National Library of Medicine) Also in Spanish

Antibiotic Resistance: MedlinePlus Health Topic
(National Library of Medicine) Also in Spanish
Bacterial vs. Viral Infections: How Do They Differ? (Mayo Foundation for Medical Education and Research) Also in Spanish
How Infections Spread (Centers for Disease Control and Prevention)
Probiotics: What You Need to Know
(National Center for Complementary and Integrative Health)
What Is Sepsis?
(National Institute of General Medical Sciences) Also in Spanish

Specifics

Anaerobic Infections (American Academy of Pediatrics) Also in Spanish
Brucellosis (Centers for Disease Control and Prevention)
Elizabethkingia (Centers for Disease Control and Prevention)
Glanders (Burkholderia Mallei) (Centers for Disease Control and Prevention)
Leptospirosis (Centers for Disease Control and Prevention)
Melioidosis (Centers for Disease Control and Prevention)
Necrotizing Fasciitis: All You Need to Know (Centers for Disease Control and Prevention) Also in Spanish
Necrotizing Skin Infections (Merck & Co., Inc.) Also in Spanish
Pseudomonas aeruginosa in Healthcare Settings (Centers for Disease Control and Prevention)
Q Fever (Centers for Disease Control and Prevention)
Shigellosis
(National Institute of Allergy and Infectious Diseases)
Trench Fever (VisualDX)
Vibrio parahaemolyticus (Centers for Disease Control and Prevention)
Vibrio Species Causing Vibriosis (Centers for Disease Control and Prevention) Also in Spanish
Yaws (World Health Organization) Also in Spanish

Images

Hot Tub Rash (Pseudomonas Folliculitis) (VisualDX)

Statistics and Research

Bleach vs. Bacteria
(National Institute of General Medical Sciences)
Fighting Bacteria with Viruses
(National Institutes of Health) Also in Spanish
Oh What a Tangled Biofilm Web Bacteria Weave
(National Institute of General Medical Sciences)

Clinical Trials

ClinicalTrials.gov: Bacterial Infections
(National Institutes of Health)
ClinicalTrials.gov: Fasciitis, Necrotizing
(National Institutes of Health)

Journal Articles References and abstracts from MEDLINE/PubMed (National Library of Medicine)

Article: Neutrophil CD64 index as a superior indicator for diagnosing, monitoring bacterial...
Article: Characterization of a Glycolipid Synthase Producing α-Galactosylceramide in Bacteroides fragilis.
Article: Functional Characterization of Largemouth Bass (Micropterus salmoides) Soluble FcγR Homolog in...
Bacterial Infections -- see more articles

Find an Expert

Centers for Disease Control and Prevention Also in Spanish
National Foundation for Infectious Diseases
National Institute of Allergy and Infectious Diseases

Children

Blood Culture (For Parents) (Nemours Foundation)
Moraxella Catarrhalis: A Common Cause of Childhood Illnesses (American Academy of Pediatrics)
Shigella Infections (Shigellosis) (For Parents) (Nemours Foundation) Also in Spanish
What Are Germs? (Nemours Foundation) Also in Spanish

Teenagers

Arcanobacterium Haemolyticum Infections (American Academy of Pediatrics) Also in Spanish
Why Should I Care about Germs? (Nemours Foundation) Also in Spanish

Women

Vibrio and Pregnancy (Organization of Teratology Information Specialists) Also in Spanish

Patient Handouts

Actinomycosis (Medical Encyclopedia) Also in Spanish
Bacterial vaginosis -- aftercare (Medical Encyclopedia) Also in Spanish
Blood culture (Medical Encyclopedia) Also in Spanish
Gram stain (Medical Encyclopedia) Also in Spanish
Gram stain of skin lesion (Medical Encyclopedia) Also in Spanish
Necrotizing soft tissue infection (Medical Encyclopedia) Also in Spanish

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MEDICAL ENCYCLOPEDIA

Actinomycosis
Arterial stick
Bacterial vaginosis -- aftercare
Blood culture
Brucellosis
Complement fixation test to C. burnetii
Culture - duodenal tissue
Erysipeloid
Gram stain
Gram stain of skin lesion

Gram stain of tissue biopsy
Hot tub folliculitis
Lepromin skin test
Leptospirosis
Lymph node culture
Lymphangitis
Necrotizing soft tissue infection
Nocardia infection
Noma
Pleural fluid gram stain
Psittacosis
Pulmonary actinomycosis
Pulmonary nocardiosis
Q fever - early
Rat-bite fever
Rickettsial pox
Serology for brucellosis
Serology for tularemia
Shigellosis
Stool Gram stain
Swimming pool granuloma
Tularemia
Typhus
Yaws

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Antibiotics
Botulism
C. diff Infections
Campylobacter Infections
Cellulitis
Chlamydia Infections
E. Coli Infections
Haemophilus Infections
Infection Control
Lyme Disease
Meningococcal Infections
Mycobacterial Infections
Pneumococcal Infections
Salmonella Infections
Staphylococcal Infections
Streptococcal Infections
Tetanus
Tick Bites
Traveler's Health
Tuberculosis
Vaccines
Whooping Cough

National Institutes of Health

The primary NIH organization for research on Bacterial Infections is the National Institute of Allergy and Infectious Diseases

Other Languages

Find health information in languages other than English on Bacterial Infections

Disclaimers

MedlinePlus links to health information from the National Institutes of Health and other federal government agencies. MedlinePlus also links to health information from non-government Web sites. See our disclaimer about external links and our quality guidelines.

What are the most common infection causing microorganism?

Viral infections.

the common cold, which mainly occurs due to rhinovirus, coronavirus, and adenovirus..

encephalitis and meningitis, resulting from enteroviruses and the herpes simplex virus (HSV), as well as West Nile Virus..

warts and skin infections, for which HPV and HSV are responsible..

What type of infections are the most common?

What are common infectious diseases?.

Common cold..

The flu (influenza)..

COVID-19..

Stomach flu (gastroenteritis)..

Hepatitis..

Respiratory syncytial virus (RSV)..

What are 4 common bacterial infections?

Many are mild; some are severe. Examples of bacterial infections include whooping cough, strep throat, ear infection and urinary tract infection (UTI).