A bacterial infection is a quick growth of a harmful strain of bacteria on or inside the body. Harmful bacteria can cause a few illnesses like pneumonia, , food poisoning and meningitis. Bacterial infections are one of the primary causes of foodborne illness. Common symptoms include nausea, diarrhea, fever, abdominal pain, chills, vomiting's and fatigue. Maximum sexually transmitted diseases (STDs) are caused by harmful bacteria. Mostly they might not be related to any symptoms of the disease but still can cause significant damage to the reproductive system. Bacterial skin infections are generally caused by gram-positive strains of bacteria such as Staphylococcus and Streptococcus. Few of the bacterial infections include folliculitis, impetigo and boils. Viruses are like hijackers. This can damage, slaughter, or change the cells and make sick. Different viruses attack certain cells in the body such as the blood, liver or respiratory system.

Infectious diseases have constituted a huge threat to human lives since the beginning of the human existence. Numerous infectious diseases have defeated through the discovery of antibiotics and antiviral agents. In modern times, natural products or herbal medicine have been playing a wide role in treating several clinical diseases. Most chemical drugs that are extensively used today have been isolated from the natural products, and thus these natural products will continue to be major raw materials for the production and development of new drugs. Currently, various scientific experiments are being conducted in order to fill this gap by evaluating the efficacy of natural product which may include infection by multidrug-resistant bacteria, infectious septic shock, coccidiosis, leishmaniasis, viral influenza and biofilm formation.

Molecular Pathology is a relatively recent authority that has achieved remarkable progress over the past decade. It emphasizes the study and recognition of disease through the examination of molecules within organs, tissues or bodily fluids.  Many diseases like cancer are caused by mutations or alterations in the genetic code of a person, and recognition of specific hallmark mutations allows clinicians to analyze a disease and choose the appropriate treatment.  As a result, molecular analysis is leading the way towards personalized medicine by accepting us to forecast a patient’s response to certain anti-cancer therapy based on their own genetic make-up. Molecular Pathology includes the development of molecular and genetic approaches to the diagnosis and allocation of human tumors. 

Gastrointestinal infections are often encountered infections in primary care caused by virus, bacteria and parasites. The gastrointestinal infections involve gastroenteritis or the inflammation of the gastrointestinal tract including both the stomach and the small intestine. Gastrointestinal infections are caused by a large number of microorganisms like Campylobacter, Adenovirus, Clostridium difficile, Rotavirus, Escherichia coli, Salmonella etc. All age groups are affected by the gastrointestinal infections. The management of gastrointestinal infection is done by antiemetic medications, rehydration, antibiotics, other anti-motility agents etc. Born out of expanding awareness on the subspecialty gastrointestinal pathology services, rising and evolving marketing efforts by the gastrointestinal pathology related companies.

The pathogenesis of infectious diseases throwback the relationship among the human host, the infectious agent, and the external environment. The diseases which are caused by germs or microorganisms and that may infect any part of the body are known as Infectious Diseases. They are caused by pathogenic microorganisms like fungi, bacteria and virus. Germs can spread either through direct or indirect contact. The infectious agent can be either endogenous or exogenous. Vaccination, preservation of proper hygiene and medicines that helps in the preventing and controlling of infections. Infectious diseases have a range of causes, and they can be found all over the globe. These diseases are examined contagious or communicable, meaning that they can be passed from person to person.

The Novel Coronavirus disease is an infectious disease which is caused by a newly discovered coronavirus (COVID-19). In humans, coronaviruses cause respiratory tract infections which can range from mild (common cold) to lethal (SARS, MERS, and COVID-19) and it recovers without requiring any special treatment. This specific infectious disease can even found in birds and mammals. People with medical problems like chronic respiratory diseases, diabetes, cancer and cardiovascular diseases, and other chronic diseases and also in elder people are more likely to develop serious illness which can cause to death. At present, no specific treatment is there for this disease caused by a novel coronavirus.

Pediatric infectious diseases, also known as childhood infectious diseases are the infectious diseases that mainly are caused in children of different age groups. Pediatric infectious diseases specialist deals with the infections occurring in children and the treatment method fluctuates from children to adults. Common pediatric infections include Pneumonia- diagnosed in nearly 2% of infants < 1 year and in 4% of children aged 1 to 5 years. It is estimated that 90% of pediatric pneumonia are caused by viral agents. Other infections include Otitis Media which is caused in children who live with the adults who smoke.

Rare diseases are caused by precipitating agents rather than genetic or some environmental factors. Generally a very tiny percentage of the population are affected by some rare disease. In some parts of the globe, an orphan disease called a rare disease in which rarity means there is lack of a market large enough to gain a support and resources to locate treatments for it that are anticipated by the government granting economically advantageous conditions to create and sell such treatments. Globally, nearly one-third of the population deaths are owed to these infections. In addition, the non-infectious causes of death are frequently having a mysterious infectious etiology.  

Infections which are caused by germs or other microorganisms that may infect any part of the body are known as infectious diseases. Infectious diseases prevention and control is more helpful to prevent and control the transmission of infections. Aseptic technique is usually applied for preventing the infections caused by various means or germs. Sterilization is also another process or technique of killing microorganisms by the application of heat. Disinfection is another process of killing harmful microorganisms. Various infectious diseases can be prevented by avoiding direct contact with the contagious person. Many harmful infections can also be controlled and avert by creating public awareness on different infectious diseases and their outbreaks.

A vaccine can gives energetic immunity against particular harmful diseases by stimulating the immune system to attack the agent. After energizing by a vaccine, the antibody-producing cells, which are ready to respond to the agent ought it ever gain entry to the body. A vaccine also converse passive immunity by providing antibodies or lymphocytes already made by an animal or human donor. Vaccines are usually conducted by injection, but some are given orally or even nasally. Vaccines applied to mucosal surfaces, seem to energize a greater antibody response and may be the most effective route of managing. In addition to the development of memory B cells, vaccination is also advantageous at the population level. When an enough number of individuals in a population are immune to a disease, as would occur if a large proportion of a population were vaccinated, herd immunity is attained.

The most frequent causes of food, air, and water-borne illnesses are viruses, bacteria and parasites. The airborne disease can propagate when a contagious person coughs, sneezes, or talks, spewing nasal and throat secretions into the air. When you inhale airborne pathogenic organisms, they take up accommodation inside you. You can also pick up microbes when you touch an infected surface, and then touch your own nose, eyes, or mouth. Because these illnesses travel in the air, and they’re dense to control. Food- or water-borne diseases are not conveyed from casual contact with another person. A person can come into exposure with food- or water-borne bacteria by eating or drinking something which has bacteria in it. Countless diseases are spread through the air are:

Fungal infections are produced by Fungi which are present everywhere on earth. Fungal infections take place when the fungus grabs the particular area of the body and is difficult to handle for our immune system. Fungal infection in skin looks like a rash. Ringworm is a skin infection which is produced by fungus. Fungal meningitis is less common but can be life-threatening. Fungal infections in the lungs are a serious kind of infection. The symptoms are similar to other illnesses, such as the flu or tuberculosis.  Fungal nail infections may happen to people of any age but it is more common in older people. The symptoms are thickening, distorted shape. Some other fungal infections are:

Pulmonary pathology involves a large spectrum of both neoplastic and non-neoplastic diseases which affect the lungs. Countless diseases are the result of the unusual relationship of the lung with the outside world. Every breath which human takes brings the world into the body of infectious agents, organic and inorganic particles, and noxious agents of all types. Pulmonary pathology is reported in relation with primary biliary cirrhosis which involves lymphocytic bronchitis and bronchiolitis, OP, and chronic interstitial pneumonia, including LIP. Rare reports also emerged which describes pulmonary hemorrhage and glomerulonephritis, or microscopic polyangiitis, in individuals with primary biliary cirrhosis.

Oral and Maxillofacial Pathology involves investigating the oral growths, injuries in the mouth and to identify the sicknesses of the mouth, jaws and related structures like salivary organ, temporomandibular joints, facial muscles and perioral skin (the skin around the mouth). Dental X-rays gives some non-invasive and painless methods for identifying cavities in teeth. The world dental market is to cross US $60 Billion by the year 2024. The specialists focus on surveying the disease that affects the oral cavity and surrounding.

Microbiology is the study of microorganisms, these being unicellular (single cell), multicellular (cell colony), or acellular (lacking cells). Microbiology enclose numerous sub-disciplines including protistology, virology, immunology, bacteriology, mycology and parasitology. Eukaryotic microorganisms possess membrane-bound organelles and include fungi and protists, whereas prokaryotic organisms—all of which are microorganisms—are conventionally classified as lacking membrane-bound organelles and involve Bacteria and Archaea. Microbiologists traditionally depend on culture, staining, and microscopy. However, less than 1% of the microorganisms present in common environments can be cultured in isolation using current.

Surgical Pathology is the most compelling and time consuming branch of pathology with a primary focus on examining tissues with the naked eye or under a microscope for definitive diagnosis of disease. Surgically removed specimens are received from sources like core biopsies, small biopsies of skin, for the diagnosis of cancer, and the operating room where tumors are extracted. Surgical pathology includes macroscopic (gross) and microscopic (histologic) tissue analysis where the molecular properties of tissue samples are assessed by immunohistochemistry or other laboratory tests. Histological sections of tissue are prepared for microscopic viewing using either chemical fixation or frozen section.

Lower respiratory tract infections vary from upper respiratory tract infections by the area of the respiratory tract they affect. While lower respiratory tract infections include the airways below the larynx, upper respiratory tract infections occur in the structures in the larynx or above. People who have lower respiratory tract infections will circumstance coughing as the primary symptom. People with upper respiratory tract infections will feel these type of symptoms mainly above the neck, such as sneezing, headaches, and sore throats. They may also experience body aches, especially if they have a fever.

Cytopathology is a branch of pathology which studies and diagnoses diseases on the cellular level. It is regularly used to aid in the diagnosis of cancer, but also helps in the diagnosis of certain infectious diseases and other inflammatory conditions. Cytopathology is mainly used on samples of free cells or tissue fragments that spontaneously exfoliate or are removed from tissues by abrasion or fine needle aspiration, in contrast to histopathology, which studies whole tissues. Cytopathology is often, less precisely, called "cytology", which means "the study of cells". Cytopathology is commonly used to explore diseases including a wide range of body sites, frequently to aid in the diagnosis of cancer but also in the diagnosis of some infectious diseases and other inflammatory conditions. Cytopathologic tests are sometimes called smear tests because the samples may be smeared across a glass microscope slide for subsequent staining and microscopic examination.

The facet of epidemiology concerned with recognizing health-related causes and effects. Analytical epidemiology aims to research and study risk and protector factors of diseases and recognize factors in a diseased population that varies from a non-diseased population. Where descriptive epidemiology helps to report because of disease within a population and it helps to understand the occurrence of disease. The normal way to gain this knowledge is by group comparisons. Such comparison starts from one or more hypotheses about how the determinant may influence occurrence of disease. Analytical epidemiology controls the cause of an outbreak. Using the case control method, the epidemiologist can look on the major factors which may cause the disease.

Histopathology is the study of morbid tissue, like breast lumps or specimens of the gut which is suspected of cancer, as well as examination underneath the magnifier. Histopathologists scrutinize the tissues which have been taken from patients inside the clinic or through an operation. They use scientific ways to induce if any disease is present and what treatments should be done. The tissue is first scrutinized with the attention to look for any visible abnormalities and to select out things to appear at in further detail. Immunopathology is a branch of medicine which deals with the immune responses associated with illness. It involves study of pathology of an organism, organ system, or disease with a connectedness to the immune system, immunity, and immune responses.