Neuro infectious diseases are the infectious diseases which are observed in the nervous system. Viral and immune mediated disorders of the nervous system are among the most challenging neurological disorders. The most common neuro immune disorder is multiple sclerosis and hiv is the most common viral infection of the nervous system.

Pediatric infectious diseases/ childhood infectious diseases are the infectious diseases which are caused in children of different age groups. Pediatric infectious diseases specialist’s takes care of the infections occurring in children and the treatment methods vary for children from adults.

Sexually transmitted diseases/ sexually transmitted infections are the infectious diseases which are transmitted through sexual contact with an infected individual and also transmitted during vaginal or other types of sexual intercourse including oral and anal sex.

Infectious diseases vaccines are the vaccines which prevent the infectious diseases and infectious diseases like diphtheria, haemophilus influenzae serotype b infection, hepatitis b, measles, meningitis, mumps, pertussis, poliomyelitis, rubella, tetanus, tuberculosis and yellow fever are preventable through vaccines.

Vaccines are the products that are able to produce immunity from a disease and can be administered through needle injections, by mouth and by aerosol. Vaccination is the injection of a killed or weakened organism that produces immunity in the body against that organism.

Antimicrobials/ antibiotics/ antibacterials are the drugs used in the treatment and prevention of bacterial infections. They may either kill or inhibit the growth of bacteria. Few antibiotics possess antiprotozoal activity. Antibiotics are not effective against viruses such as the common cold or influenza and their inappropriate use allows the emergence of resistant organisms.

Infectious diseases prevention and control is helpful to prevent the transmission of infectious diseases. Aseptic technique is normally applied to prevent the infections caused by different means. Sterilization is another process of killing microorganisms by the application of heat. Disinfection is the process of killing harmful microorganisms. Some infectious diseases can be prevented by avoiding direct contact with the contagious person. Infections can also be controlled and prevented by creating public awareness on various infectious diseases and their outbreaks. Infections can be cured by various antimicrobials.

Treatment of viral infections such as HIV involves patient care and moral support including antiretroviral therapy. Bacterial infections can be treated by administering antibiotics to the patients. Yeast infections can be primarily treated by sterilisation methods. Parasitic infections can be treated by antiparasitic drugs. Diseases such as cancer can be treated by chemotherapy. Recent techniques have proved that there is no disease that cannot be treated.

Medical diagnosis is the process of determining which disease or condition explains a person's symptoms and signs. Laboratory tests may identify organisms directly (e.g., visually, using a microscope growing the organism in culture) or indirectly (e.g., identifying antibodies to the organism). General types of tests include microscopy, culture and immunologic tests (agglutination tests such as latex agglutination, enzyme immunoassays, western blot, precipitation tests and complement fixation tests) and nucleic acid/ non nucleic acid based identification methods. Sub types of diagnoses include clinical, laboratory, radiology, principal and admitting diagnosis. Advanced methods have been implemented to diagnose the infection in any part of the body. Examples include biomarkers/ elisa test/ chest x ray/ skin biopsy/ tympanometry and tympanocentesis.

Epidemiology studies the patterns, causes and effects of health and disease conditions. It is the cornerstone of public health and informs policy decisions and evidence based practice by identifying risk factors for disease and targets for preventive healthcare. Epidemiologists help with study design, data collection, statistical analysis of data, interpretation and dissemination. Epidemiology helped to develop methodology used in clinical research, public health studies and to a lesser extent basic research in the biological sciences.

Antimicrobial/ antibiotic/ antibacterial stewardship promotes the appropriate use of antimicrobials which improves patient outcomes reduces microbial resistance and decreases the spread of infections caused by multidrug resistant organisms.

Mechanism of resistance towards antimicrobials by microorganisms includes the following mechanisms of enzymatic destruction, enzymatic modification, altered target and decreased uptake. Mechanism of resistance is due to the inactivation or modification of antibiotics, an alteration in the target site of the antibiotic that reduces its binding capacity, the modification of metabolic pathways to circumvent the antibiotic effect and the reduced intracellular antibiotic accumulation by decreasing permeability and/ or increasing active efflux of the antibiotic.

Immunology of infections means the battle between pathogens and the host immune defences. Immunology is the branch of science concerned with the various aspects related to immune system, innate and acquired immunity. Immunology also deals with laboratory techniques involving the interaction of antigens with specific antibodies.

An Infectious disease whose occurrence has increased in the past years or threatens to increase is termed as emerging. These diseases include new infections, previously unrecognized infections and old infections reappearing due to antimicrobial resistance, public health issues and unhygienic conditions.

The diseases caused by germs and which may infect any part of the body are called infectious diseases. They can be spread by any means where there is a germ. They are caused by pathogenic microorganisms such as bacteria, virus, parasites and fungi. Germs can be spread by direct or indirect contact. Vaccination, maintenance of proper hygiene and medicines help in the prevention of infection.

Animal infectious diseases/ zoonosis are important threat to human health since the emergence of human diseases is dominated by zoonotic pathogens. Infectious diseases affect livestock and also wild animals focusing on characterizing the conditions for the pathogen spread and maintenance in the host population.

Microbial forensics and molecular basis of bacteria is defined as a scientific discipline which is used to analyse microorganism/ toxin release.

Malaria is a mosquito borne infectious disease affecting humans and other animals caused by parasitic protozoans (a group of single celled microorganisms) belonging to the plasmodium type. Malaria symptoms typically include fever, fatigue, vomiting and headaches which can be observed in 10-15 after being bitten by mosquito. In severe cases it can cause yellow skin, seizures, comaor and even death.

Hepatitis is caused by the inflammation of the liver and characterized by the presence of inflammatory cells in the tissue of the organ. Hepatitis may occur with limited or no symptoms but often leads to jaundice, poor appetite and malaise. Hepatitis is acute when it lasts less than six months and chronic when it persists longer.

Tuberculosis is a bacterial infection caused by a bacterium called mycobacterium tuberculosis which spread through the lymph nodes and blood stream to any organ in your body. It is most commonly found in the lungs which attack the lungs and it can also attack any part of the body such as the kidney, spine and brain.

Sepsis/ septicaemia is a life threatening condition that arises when the body's response to infection injures its own tissues and organs and the signs and symptoms of sepsis include fever, increased heart rate, increased breathing rate, confusion, cough with pneumonia and painful urination with a kidney infection. Severe sepsis causes poor organ function or insufficient blood flow. Insufficient blood flow may be evident by low blood pressure, high blood lactate and low urine output. Septic shock means the low blood pressure which occurs due to sepsis that does not improve even after injecting reasonable amounts of intravenous fluids.

Surgical site infections are the infections which may occur within 30 days after the operation and are observed in the parts of skin and subcutaneous tissue of the incision.

Urinary tract infections are the infections which are observed in any part of the urinary system (kidneys, ureters, bladder and urethra). Mostly infections are observed in the lower urinary tract (bladder and urethra). Women are at greater risk than men.

Ebola viral infection is caused by virus transmitted through body fluids and through air. It occurs rarely but it is very deadly which results in death and outbreak. Ebola virus disease symptoms are very severe which appears in 2-3 days. Ebola primary symptoms include fever, sore throat, muscular pain and headaches then followed by vomiting, diarrhea, rash, decreased function of the liver and kidneys then loss of blood internally and externally finally leading to low blood pressure and fluid loss resulting in death.  Zika virus disease is caused by a virus transmitted primarily by aedes mosquitoes. People with zika virus disease can have symptoms including mild fever, skin rash, conjunctivitis, muscle and joint pain and malaise or headache.

Blood stream infections/ bacteraemia/ septicaemia/ blood poisoning occurs when a bacterial infection elsewhere in the body such as in the lungs or skin which enters the blood stream. This is dangerous because the bacteria and their toxins can be carried through the blood stream to the entire body.

Nosocomial infections/ hospital acquired infections/ health care associated infections are the infections that are contracted from the environment or staff of a healthcare facility and they spread in the hospital environment, nursing home environment, rehabilitation facility and clinic or other clinical settings.

Antimicrobial/ antibiotic/ antibacterial resistance is the ability of microorganisms to resist the effects of drugs that means diseases causing germs do not get killed and their growth is not stopped.  Antibiotic resistant infections are of greater risk which cannot be avoided completely. Infections with resistant organisms are difficult to treat requiring costly and sometimes toxic alternatives.

Microbial pathogenesis is the study of the molecular mechanisms used by microorganisms to cause disease in humans and animals. By understanding how pathogens cause disease helps in the development of new therapeutic approaches. Virulence is the measure of the pathogenicity of an organism. The degree of virulence is related directly to the ability of the organism to cause infection despite host resistance mechanisms, it is affected by numerous variables such as the number of infecting bacteria, route of entry into the body, specific and nonspecific host defence mechanisms and virulence factors of the bacterium.

Infectious diseases can be caused by bacteria, virus, fungi and parasites through direct contact, indirect contact, insect bites and food contamination. Each infectious disease has its own specific signs and symptoms. General signs and symptoms common to a number of infectious diseases include fever, diarrhoea, fatigue and muscle aches.