The main means of prevention is through the promotion of safe handling, cooking and consumption of food. This includes washing raw vegetables and cooking raw food thoroughly, as well as reheating leftover or ready-to-eat foods like hot dogs until steaming hot.

Another aspect of prevention is advising high-risk groups such as pregnant women and immunocompromised patients to avoid unpasteurized pâtés and foods such as soft cheeses like feta, Brie, Camembert cheese, and bleu. Cream cheeses, yogurt, and cottage cheese are considered safe. In the United Kingdom, advice along these lines from the Chief Medical Officer posted in maternity clinics led to a sharp decline in cases of listeriosis in pregnancy in the late 1980s.

Bacteremia should be treated for 2 weeks, meningitis for 3 weeks, and brain abscess for at least 6 weeks. Ampicillin generally is considered antibiotic of choice; gentamicin is added frequently for its synergistic effects. Overall mortality rate is 20–30%; of all pregnancy-related cases, 22% resulted in fetal loss or neonatal death, but mothers usually survive.

Yersiniosis is usually self-limiting and does not require treatment. For severe infections (sepsis, focal infection) especially if associated with immunosuppression, the recommended regimen includes doxycycline in combination with an aminoglycoside. Other antibiotics active against "Y. enterocolitica" include trimethoprim-sulfamethoxasole, fluoroquinolones, ceftriaxone, and chloramphenicol. "Y. enterocolitica" is usually resistant to penicillin G, ampicillin, and cephalotin due to beta-lactamase production.

Throughout history treatment relied primarily on β-lactam antibiotics. In the 1960s nearly all strains of "S. pneumoniae" were susceptible to penicillin, but more recently there has been an increasing prevalence of penicillin resistance especially in areas of high antibiotic use. A varying proportion of strains may also be resistant to cephalosporins, macrolides (such as erythromycin), tetracycline, clindamycin and the quinolones. Penicillin-resistant strains are more likely to be resistant to other antibiotics. Most isolates remain susceptible to vancomycin, though its use in a β-lactam-susceptible isolate is less desirable because of tissue distribution of the drug and concerns of development of vancomycin resistance. More advanced beta-lactam antibiotics (cephalosporins) are commonly used in combination with other drugs to treat meningitis and community-acquired pneumonia. In adults recently developed fluoroquinolones such as levofloxacin and moxifloxacin are often used to provide empiric coverage for patients with pneumonia, but in parts of the world where these drugs are used to treat tuberculosis resistance has been described.

Susceptibility testing should be routine with empiric antibiotic treatment guided by resistance patterns in the community in which the organism was acquired. There is currently debate as to how relevant the results of susceptibility testing are to clinical outcome. There is slight clinical evidence that penicillins may act synergistically with macrolides to improve outcomes.

When infection attacks the body, "anti-infective" drugs can suppress the infection. Several broad types of anti-infective drugs exist, depending on the type of organism targeted; they include antibacterial (antibiotic; including antitubercular), antiviral, antifungal and antiparasitic (including antiprotozoal and antihelminthic) agents. Depending on the severity and the type of infection, the antibiotic may be given by mouth or by injection, or may be applied topically. Severe infections of the brain are usually treated with intravenous antibiotics. Sometimes, multiple antibiotics are used in case there is resistance to one antibiotic. Antibiotics only work for bacteria and do not affect viruses. Antibiotics work by slowing down the multiplication of bacteria or killing the bacteria. The most common classes of antibiotics used in medicine include penicillin, cephalosporins, aminoglycosides, macrolides, quinolones and tetracyclines.

Not all infections require treatment, and for many self-limiting infections the treatment may cause more side-effects than benefits. Antimicrobial stewardship is the concept that healthcare providers should treat an infection with an antimicrobial that specifically works well for the target pathogen for the shortest amount of time and to only treat when there is a known or highly suspected pathogen that will respond to the medication.

Ribavirin is one medication which has shown good potential for the treatment of HPIV-3 given recent in-vitro tests (in-vivo tests show mixed results). Ribavirin is a broadscale anti-viral and is currently being administered to those who are severely immuno-compromised, despite the lack of conclusive evidence for its use. Protein inhibitors and novel forms of medication have also been proposed to relieve the symptoms of infection.

Furthermore, antibiotics may be used if a secondary bacterial infection develops. Corticosteroid treatment and nebulizers are also a first line choice against croup if breathing difficulties ensue.

The primary method for controlling the incidence of gaffkaemia is improved hygiene. Other measures include limiting damage to the exoskeleton (preventing the bacterium's entry), reducing the water temperature, and reducing the stocking density. Antibiotics may be effective against the bacterium, but only tetracycline is currently approved by the U.S Food and Drug Administration for use in American lobsters.

"S. pneumonia" can be treated with a combination of penicillin and ampicillin.

For suspected Gram-negative enteric(including "E. coli") meningitis a combination of cefotaxime and aminoglycoside, usually gentamicin, is recommended. This treatment should last for 14 days after sterilization and then only cefotaxime for another 7 days creating a minimum of 21 days of therapy post-sterilization.

Ticks should be removed promptly and carefully with tweezers and by applying gentle, steady traction. The tick's body should not be crushed when it is removed and the tweezers should be placed as close to the skin as possible to avoid leaving tick mouthparts in the skin; mouthparts left in the skin can allow secondary infections. Ticks should not be removed with bare hands. Hands should be protected by gloves and/or tissues and thoroughly washed with soap and water after the removal process.

A match or flame should not be used to remove a tick. This method, once thought safe, can cause the tick to regurgitate, expelling any disease it may be carrying into the bite wound.

No specific treatment for CTF is yet available. The first action is make sure the tick is fully removed from the skin, then acetaminophen and analgesics can be used to help relieve the fever and pain. Aspirin is not recommended for children, as it has been linked to Reye’s syndrome in some viral illnesses. Salicylates should not be used because of thrombocytopenia, and the rare occurrence of bleeding disorders. People who suspect they have been bitten by a tick or are starting to show signs of CTF should contact their physicians immediately.

Although frequently employed to treat patients experiencing the cytokine storm associated with ARDS, corticosteroids and NSAIDs have been evaluated in clinical trials and have shown no effect on lung mechanics, gas exchange, or beneficial outcome in early established ARDS.

Some types of arthritis medications are designed to reduce inflammation by inhibiting the tumor necrosis factor-alpha pathway to immune cell activation; these drugs are known as TNF-alpha blockers. One study found that three different TNF-alpha blockers afforded a slight reduction in antibody presentation after vaccination against influenza in a group of immunocompromised patients, however it did not significantly affect patients' protective factor gained from inoculation. More research is necessary before any conclusions may be made regarding the efficacy of TNF-alpha blockers at reducing the effects of a cytokine storm in hospitalized flu patients.

CAP is treated with an antibiotic that kills the offending microorganism and by managing complications. If the causative microorganism is unidentified (often the case), the laboratory identifies the most-effective antibiotic; this may take several days.

Health professionals consider a person's risk factors for various organisms when choosing an initial antibiotic. Additional consideration is given to the treatment setting; most patients are cured by oral medication, while others must be hospitalized for intravenous therapy or intensive care.

Therapy for older children and adults generally includes treatment for atypical bacteria: typically a macrolide antibiotic (such as azithromycin or clarithromycin) or a quinolone, such as levofloxacin. Doxycycline is the antibiotic of choice in the UK for atypical bacteria, due to increased clostridium difficile colitis in hospital patients linked to the increased use of clarithromycin.

Most newborn infants with CAP are hospitalized, receiving IV ampicillin and gentamicin for at least ten days to treat the common causative agents "streptococcus agalactiae", "listeria monocytogenes" and "escherichia coli". To treat the herpes simplex virus, IV acyclovir is administered for 21 days.

There is no cure for polioencephalitis so prevention is essential. Many people that become infected will not develop symptoms and their prognosis is excellent. However, the prognosis is dependent on the amount of cellular damage done by the virus and the area of the brain affected. Many people that develop more severe symptoms can have lifelong disabilities or it can lead to death. Supportive treatments include bed rest, pain relievers, and a nutritious diet. Many drugs have been used to treat psychiatric symptoms such as Clonazepam for insomnia and Desvenlafaxine or Citalopram for depressed mood.

Host tropism is the infection specificity of certain pathogens to particular hosts and host tissues. This type of tropism explains why most pathogens are only capable of infecting a limited range of host organisms.

Researchers can classify pathogenic organisms by the range of species and cell types that they exhibit host tropism for. For instance, pathogens that are able to infect a wide range of hosts and tissues are said to be amphotropic. Ecotropic pathogens, on the other hand, are only capable of infecting a narrow range of hosts and host tissue. Knowledge of a pathogen's host specificity allows professionals in the research and medical industries to model pathogenesis and develop vaccines, medication, and preventative measures to fight against infection. Methods such as cell engineering, direct engineering and assisted evolution of host-adapted pathogens, and genome-wide genetic screens are currently being used by researchers to better understand the host range of a variety of different pathogenic organisms.

Because "B. suis" is facultative and intracellular, and is able to adapt to environmental conditions in the macrophage, treatment failure and relapse rates are high. The only effective way to control and eradicate zoonosis is by vaccination of all susceptible hosts and elmination of infected animals. The "Brucella abortus" (rough LPS "Brucella") vaccine, developed for bovine brucellosis and licensed by the USDA Animal Plant Health Inspection Service, has shown protection for some swine and is also effective against "B. suis" infection, but currently no approved vaccine for swine brucellosis is available.

Shade, insect repellent-impregnated ear tags, and lower stocking rates may help prevent IBK. Early identification of the disease also helps prevent spread throughout the herd. Treatment is with early systemic use of a long-acting antibiotic such as tetracycline or florfenicol. Subconjunctival injections with procaine penicillin or other antibiotics are also effective, providing a "bubble" of antibiotic which releases into the eye slowly over several days.

Anti-inflammatory therapy can help shorten recovery times, but topical corticosteroids should be used with care if corneal ulcers are present.

"M. bovis" uses several different serotyped fimbriae as virulence factors, consequently pharmaceutical companies have exploited this to create vaccines. However, currently available vaccines are not reliable.

Subcutaneous cysts may be surgically opened to remove less mature bots. If more matured, cysts may be opened and "cuterebra" may be removed using mosquito forceps. Covering the pore in petroleum jelly may aide in removal. If larvae are discovered within body tissues, rather than subcutaneously, surgical removal is the only means of treatment. Ivermectin may be administered with corticosteroids to halt larval migration in cats presenting with respiratory cuterebriasis, but this is not approved for use in cats. There is not yet a known cure for cerebrospinal cuterebriasis.

Methicillin-resistant Staphylococcus aureus (MRSA) evolved from Methicillin-susceptible Staphylococcus aureus (MSSA) otherwise known as common "S. aureus". Many people are natural carriers of "S. aureus", without being affected in any way. MSSA was treatable with the antibiotic methicillin until it acquired the gene for antibiotic resistance. Though genetic mapping of various strains of MRSA, scientists have found that MSSA acquired the mecA gene in the 1960s, which accounts for its pathogenicity, before this it had a predominantly commensal relationship with humans. It is theorized that when this "S. aureus" strain that had acquired the mecA gene was introduced into hospitals, it came into contact with other hospital bacteria that had already been exposed to high levels of antibiotics. When exposed to such high levels of antibiotics, the hospital bacteria suddenly found themselves in an environment that had a high level of selection for antibiotic resistance, and thus resistance to multiple antibiotics formed within these hospital populations. When "S. aureus" came into contact with these populations, the multiple genes that code for antibiotic resistance to different drugs were then acquired by MRSA, making it nearly impossible to control. It is thought that MSSA acquired the resistance gene through the horizontal gene transfer, a method in which genetic information can be passed within a generation, and spread rapidly through its own population as was illustrated in multiple studies. Horizontal gene transfer speeds the process of genetic transfer since there is no need to wait an entire generation time for gene to be passed on. Since most antibiotics do not work on MRSA, physicians have to turn to alternative methods based in Darwinian medicine. However prevention is the most preferred method of avoiding antibiotic resistance. By reducing unnecessary antibiotic use in human and animal populations, antibiotics resistance can be slowed.

There is usually an indication for a specific identification of an infectious agent only when such identification can aid in the treatment or prevention of the disease, or to advance knowledge of the course of an illness prior to the development of effective therapeutic or preventative measures. For example, in the early 1980s, prior to the appearance of AZT for the treatment of AIDS, the course of the disease was closely followed by monitoring the composition of patient blood samples, even though the outcome would not offer the patient any further treatment options. In part, these studies on the appearance of HIV in specific communities permitted the advancement of hypotheses as to the route of transmission of the virus. By understanding how the disease was transmitted, resources could be targeted to the communities at greatest risk in campaigns aimed at reducing the number of new infections. The specific serological diagnostic identification, and later genotypic or molecular identification, of HIV also enabled the development of hypotheses as to the temporal and geographical origins of the virus, as well as a myriad of other hypothesis. The development of molecular diagnostic tools have enabled physicians and researchers to monitor the efficacy of treatment with anti-retroviral drugs. Molecular diagnostics are now commonly used to identify HIV in healthy people long before the onset of illness and have been used to demonstrate the existence of people who are genetically resistant to HIV infection. Thus, while there still is no cure for AIDS, there is great therapeutic and predictive benefit to identifying the virus and monitoring the virus levels within the blood of infected individuals, both for the patient and for the community at large.

Treatments used to combat autoimmune diseases and conditions caused by eosinophils include:

- corticosteroids – promote apoptosis. Numbers of eosinophils in blood are rapidly reduced

- monoclonal antibody therapy – e.g., mepolizumab or reslizumab against IL-5, prevents eosinophilopoiesis

- antagonists of leukotriene synthesis or receptors

- imatinib (STI571) – inhibits PDGF-BB in hypereosinophilic leukemia

Monoclonal antibodies such as dupilumab and lebrikizumab target IL-13 and its receptor, which reduces eosinophilic inflammation in pateints with asthma due to lowering the number of adhesion molecules present for eosinophils to bind to, thereby decreasing inflammation. Mepolizumab and benralizumab are other treatment options that target the alpha subunit of the IL-5 receptor, thereby inhibiting its function and reducing the number of developing eosinophils as well as the number of eosinophils leading to inflammation through antibody-dependent cell-mediated cytotoxicity and eosinophilic apoptosis.

General biocides such as copper, Junction, or ZeroTol offer a potential solution to bacterial wilt of turf grass, however such chemical control ages must be applied after every mowing which may be economically impractical and ultimately phytotoxic. If bacterial wilt is present of the golf course, the best option may be to designate a mower for use on infected greens only in order to prevent the spread of the pathogen to other greens. Other viable methods include simply limiting the number of wounds the plant incurs, thereby limiting entry sites for the pathogen. A simple example would be less frequent mowing. It has also been proven that the disease is most devastating in grass cut to a length of between 1/8 and 3/16 of an inch, but less so in grass over 1/4 of an inch in length or longer, which presents an additional argument for limiting mowing. Another example is limiting sand topdressing as this is also a very abrasive technique which can create small wounds which allow entry of bacteria into the plant.

A major factor complicating the control of Xanthomonas campestris pv. graminis is weather. While it is not possible to control the weather per se, a study found great decreases in pathogen efficacy at temperatures below 20 °C, suggesting that cooling measures may be effective in combating this pathogen.

Ideally, resistant strains of the host plant should be used to control such a plant pathogen, however no resistant cultivars of turf grass have been identified to date. While no completely resistant cultivars exist, golf course owners can find solace in the fact that certain cultivars such as Penncross and Penneagle are more resistant to bacterial wilt and may thus reduce the need for frequent chemical applications and other cultural controls. Researchers are making gains towards the identification of resistant cultivars as evidenced by the finding that variation in genetic linkage groups 1, 4, and 6 accounted for over 43% of resistance among Italian rye grass.

A 1987 study found evidence of a possible biocontrol strategy for bacterial wilt of turf grass. The researchers found that antiserum to Pseudomonas fluorescens or Erwinia herbicola from hosts which have survived infections by the corresponding pathogens is capable of reducing wilt symptoms in turf grass caused by Xanthomonas campestris pv. graminis. The researchers did note, however, that while it is important to ensure the presence of a higher number of competing bacterial cells in order to reduce symptoms, one should take care to avoid over-infecting the host with a new bacterial pathogen.

Further gains towards host resistance were made in 2001 when researchers found that inoculation of meadow fescue during breeding with a single aggressive strain of the bacterial wilt pathogen greatly increased resistance in offspring, thereby demonstrating the potential of selective breeding to reduce bacterial wilt pathogenesis on turf and rye grasses.

Treatment of acute rotavirus infection is nonspecific and involves management of symptoms and, most importantly, management of dehydration. If untreated, children can die from the resulting severe dehydration. Depending on the severity of diarrhoea, treatment consists of oral rehydration therapy, during which the child is given extra water to drink that contains specific amounts of salt and sugar. In 2004, the World Health Organisation (WHO) and UNICEF recommended the use of low-osmolarity oral rehydration solution and zinc supplementation as a two-pronged treatment of acute diarrhoea. Some infections are serious enough to warrant hospitalisation where fluids are given by intravenous therapy or nasogastric intubation, and the child's electrolytes and blood sugar are monitored. Probiotics have been shown to reduce the duration of rotavirus diarrhoea, and according to the European Society for Pediatric Gastroenterology "effective interventions include administration of specific probiotics such as "Lactobacillus rhamnosus" or "Saccharomyces boulardii", diosmectite or racecadotril." Rotavirus infections rarely cause other complications and for a well managed child the prognosis is excellent.