Pathophysiology: An emerging infectious disease (EID) is an infectious disease whose incidence has increased in the past 20 years and could increase in the near future. Emerging infections account for at least 12% of all human pathogens. EIDs are caused by newly identified species or strains (e.g. SARS, AIDS) that may have evolved from a known infection (e.g. influenza) or spread to a new population (e.g. West Nile virus) or area undergoing ecologic transformation (e.g. Lyme disease), or be reemerging infections, like drug resistant tuberculosis. Nosocomial infections, such as MRSA are emerging in hospitals, and extremely problematic in that they are resistant to many antibiotics. Of growing concern are adverse synergistic interactions between emerging diseases and other infectious and non-infectious conditions leading to the development of novel syndemics. Many emerging diseases are zoonotic - an animal reservoir incubates the organism, with only occasional transmission into human populations. NCID (National center for Infectious Diseases) offers a great deal of emerging infectious disease informationAn 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 and public health issues due to unhygienic conditions. Statistics: Migration has contributed to the emergence of certain infectious diseases. To determine which infectious diseases were most common among 2 mobile immigrant groups (sub-Saharan Africans and Latin Americans) in Sweden, we analyzed health and demographic characteristics of 2,198 immigrants referred to the Tropical Medicine Unit of Ramóny Cajal Hospital over a 20-year period.
The most frequent diagnoses were for latent tuberculosis (716 patients [32.6%]), filariasis (421 [19.2%]), hepatropic virus chronic infection (262 [19.2%]), intestinal parasites (242 [11.0%]), and malaria (212 [9.6%]). Health screening of immigrant populations is needed to ensure early diagnosis and treatment of potentially transmissible infections. Treatment: Treatment includes: For bacterial infections- Rifampicin is one of the antibiotics frequently used for treating tuberculosis. This drug inhibits prokaryotic RNA synthesis. DNA synthesis in prokaryotes may be inhibited by the fluoroquinolones. In contrast, the sulfonamides stop bacterial infections by inhibiting other enzymes. Sulfonamides interfere with the synthesis of folic acid, a vitamin necessary for nucleic acid synthesis. Most bacteria must synthesize their own folic acid because their membranes are impermeable to external folic acid. Mammalian cells are not affected by sulfonamides because they are unable to make their own folic acid and have evolved mechanisms for transporting external folic acid across their membranes. For Viral infections: I n general, drugs that effectively inhibit viral infections are highly toxic to host cells because viruses use the host's metabolic enzymes in their reproduction. For this reason, most illnesses due to viruses are treated symptomatically until the host's immune system controls and eliminates the pathogen (or the host dies). Antiviral drugs that are used typically target virus-specific enzymes involved in viral nucleic acid synthesis. One of the most familiar of these drugs is acyclovir, which is used to treat outbreaks of genital herpes. Amantadine is an antiviral drug sometimes used to prevent or moderate influenza among those at high risk of severe illness from the disease. In addition to antiviral drugs that inhibit the replication of the HIV genome (such as AZT), AIDS patients today are also prescribed proteases that interfere with the packaging of the HIV genome into virus particles. For fungal infections: The development of drugs to treat fungal, protozoan, and helminthic diseases is challenging because agents that kill or inhibit the growth of these eukaryotic organisms are also highly toxic to mammalian cells. Because fungi and protozoa are rapidly proliferating cells, drugs against these organisms tend to target key components of their replicative or biosynthetic pathways. Common antifungals inhibit sterol syntheses (the azole derivatives) or disrupt the cell membrane (polyenes like amphotericin B). Most antihelminthic drugs target adult worms, which are no longer growing and do not replicate. These drugs are often aimed at inhibiting fundamental processes, such as energy production and muscle function (for example, the benzimidazoles and avermectins), or at targets involved in egg production or larval development.Malaria, a protozoan disease, was successfully treated for many years with chloroquine. In recent decades, Plasmodium species that are resistant to this drug have appeared and spread to areas where malaria is a common threat. In those areas, a combination of the drugs sulfonamide and pyrimethamine is frequently used to treat the disease.