Bacterial infection

Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at January 7, 2016
StartDiseasesBacterial infection

Bacteria are one of the most abundant organisms on the planet, and they exist on nearly every surface in almost every condition imaginable, from the depths of the ocean to the glaciers of the arctic. Though many bacteria are beneficial and live with humans daily, when bacteria get into a place where they shouldn't be, like a cut, it can lead to bacterial infection. As the bacteria divide and reproduce, they create toxins that have a host of effects that are detrimental to human life.


Definition & Facts

Bacterial infection is caused when bacteria get into the body, often through contaminated food or water, or through a cut. There they rapidly reproduce, causing various problems ranging from inflammation and pain, to stomach ailments and gastrointestinal ailments.

In some cases, rampant bacterial infection can lead to incredibly devastating consequences, including coma, paralysis, and death. Examples of significantly dangerous bacteria are E. Coli, Yersinia Pestis (bubonic plague), and the various Staph bacteria.

Many common ailments, such as sinus infections or pneumonia, have either a viral or bacterial cause, and the symptoms vary as well. Bacterial versions of common respiratory ailments for instance often include significantly elevated fever, sudden onset of symptoms, and might not clear up completely without antibiotics.

Symptoms & Complaints

The true hallmark of a bacterial infection over a viral infection is that the symptoms will most often be more severe, come on faster, and take longer to resolve, if they do at all without antibiotics.

High fever is a common, almost universal hallmark of any bacterial infection. Low blood pressure, loss of appetite, diarrhea, vomiting, headache, sore throat, sneezing, sinus congestion and more are all symptoms. For significant infections, fatigue and muscle weakness will also be present, as the body rallies to fight the infection.

Depending on the location of the infection, the type of bacteria, and overall health of the afflicted individual, complaints and symptoms may vary widely. An infected cut may appear red, swollen, and it will likely throb with pain. Bacterial infections in cuts or other abrasions will often leak pus as well, a byproduct of the body fighting off the disease.

Bacterial infections in the chest or sinuses will also often be accompanied by dark green mucous, caused by white blood cells fighting the infection. Though this also happens with viral infections, again the duration will be longer and the congestion will generally be worse with bacteria. Strep throat is an example of both of these attributes, as the pain is significantly worse than a simple sore throat and it nearly always needs to be treated with antibiotics.

Larger, systemic infections like blood poisoning will cause organ damage, respiratory failure, and can lead to death.


Bacteria are an incredibly diverse organism, and there are many all over the human body and within it that do everything from helping absorb vitamins, to helping fight off other invading infectious agents, as well as helping process and eliminate waste. With all the beneficial bacteria around, there's possibly even more infectious ones that when introduced to the body, especially for a patient with a weak immune system, can cause tremendous harm.

Harmful bacteria like E. Coli or Staph will get into a place that they are capable of inhabiting, and multiply over and over. This releases toxins that damage the surrounding tissue, causing cell death and disruption, and creating inflammation that is even more harmful for the body. Immune cells respond by attacking the infection, but the toxins released often have a negative effect on white blood cells, further hampering the body's efforts to remove the invader.

The combination of inflammatory immune response - which includes fever - with the cellular destruction caused by the toxins released by the bacteria, is what causes the various reactions that are associated with the different bacterial infections. In the digestive tract, the buildup of toxins causes diarrhea as the body attempts to flush out the bacteria and the poison they're releasing. In the sinuses, the increased production of mucous is to move the bacteria out after trapping it, while also fighting it from within.

Diagnosis & Tests

Antibiotics only work on bacteria, so diagnosing and identifying whether it's bacteria at all, and then what type, is key to addressing the sickness. Based on the description of symptoms by the patient, the doctor will proceed on the best way to identify the underlying infectious agent, and if they presume it to be a bacteria, further steps to test blood, saliva, or the infected site itself will be taken.

Blood tests can be done to check for different strains of bacteria, and the results are often quick. Common bacterial infections like strep throat involve saliva testing, using swabs that can be returned within hours and tell if there is an infection present, which informs physicians on the course of treatment.

Treatment & Therapy

Treating bacterial infections is usually a simple administering of antibiotics, which help the body fight the infection and clear it up quickly. Bacterial infections respond rapidly to treatment, clearing up the majority of symptoms like fever within 24 to 48 hours. For major systemic infections, stabilization in a hospital is often required concurrent to administration of antibiotics. There are multiple different kinds of antibiotics, and most common infections clear up with a simple 5 day dosage of a popularly prescribed medicine. Some bacteria are resistant and require different types of antibiotics, or multiple courses of treatment, before they clear up completely.

Prevention & Prophylaxis

Prevention of bacterial infection rests largely on proper hygiene practices. Routinely washing hands with soap and for at least 20 seconds, can drastically reduce the rate of infection among the general public.

Beyond that, a healthy diet, exercise, and plenty of rest help bolster the immune system and prevent bacteria from taking root to begin with. A healthy lifestyle also increases the body's ability to fight infection and allow it to recover more quickly. Exercise, eating [[healthy diet|nutritious food\\, and maintaining good hygiene habits will go a long way towards enabling an infection-free life.