Lower respiratory infections

In the health  the lower respiratory tract is normally sterile owing to a highly efficient defence system and lower respiratory tract is frequently compromised by smoking

LOWER RESPIRATORY TRACT INFECTIONS 

Lower respiratory infections cause disease in the air sacs and the infection that results is called pneumonia. This part of the paper will address the various types of pneumonia (eg, generally, chronic interstitial pneumonia and fungal) and agents that cause them.

Acute respiratory infections are a public health problem of constant and widespread. Cause a greater burden of disease in the world that infection with human immunodeficiency virus, malaria, cancer or heart attacks.In  United States, causing more diseases and deaths than any other disease, and there was little change in mortality from respiratory tract infection for more than five decades.1 2 the results of an acute lower respiratory tract depends on the virulence of the organism and response of inflammation in the lung.

Changes in the characteristics of the aging population and the swelling numbers of immunocompromised patients with conditions increased the number of people in danger. A wide selection of new pathogens also provides challenges for the microbiology laboratory. Overtreatment of uncomplicated acute bronchitis, which is largely due to viruses, has led to unprecedented levels of multidrug resistance among invasive pathogens such as Streptococcous pneumoniae. Guidelines for a rational approach to evaluation and treatment of patients with acute bronchitis have been published recently in an attempt to reduce misuse of antibiotics and an attempt to prevent further increases in resistance rates. The role of the laboratory are very limited.

PNEUMONIA 

Pneumonia. It comes in a variety of situations and treatment should vary depending on the situation. It is classified as community or hospital acquired, depending on where the patient contracted the infection. Sometimes it is fatal in older people or those who are immunocompromised. The most common treatment is antibiotics and vary in their side effects and effectiveness. Pneumonia is the leading cause of death among children under five years. The most common cause of pneumonia is a bacterial pneumonia, Streptococcus pneumoniae accounts for two thirds of bacteremic pneumonia.

A dangerous type of lung infection with a mortality of about 25%. For optimal management of a pneumonia patient, the following assessment - pneumonia severity (including whether to treat as home, hospital or intensive care), identification of the bacteria, the analgesia for chest pain, need for supplemental oxygen, physical therapy, hydration, bronchodilators and possible complications of emphysema or lung abscess.

Community respiratory infections appropriate use of fluoroquinolones is a therapeutic option. These have been shown to be targeted in vitro and typical and atypical pathogens of interest. newer fluoroquinolones (eg moxifloxacin or gatifloxacin) have extended the activities Gram + ve, and once a day and, consequently, the potential first-line treatment of lower respiratory tract infections. However, clinical response is the best indicator of effectiveness of moxifloxacin or gatifloxacin, and have proved effective against community-acquired respiratory tract infections clinically.

Skin and soft tissue infection

 

SKIN AND SOFT TISSUE INFECTION .

 

Skin infections are common and can be caused by a wide range of organisms, including bacteria, fungi, viruses, protozoa, bacteria, mycoplasma and rickettsia. They range from acute to chronic and mild to life threatening. Because the skin has a limited repertoire of responding to insults, clinical manifestations of a skin infection similar to those caused by other substances or mechanisms, for example, allergic reactions such as toxic epidermal necrolysis toxic epidermal , or autoimmune skin diseases such as pemphigus.

 

Skin infections can cause superficial skin structures (for example hair follicles), the external intruder (eg, bites or chips) or hematogenously (foe example , an infection spread by gonococci). Therefore, the approach to identify a specific cause of skin infection mandates attention to detail, and the history, physical examination, laboratory tests and other diagnostic methods. The good news is that you can see signs of infection and also visually assess response to treatment. Thus, if empirical therapy fails, a more powerful diagnostic approach can arise.

Normal skin is heavily colonized by bacterial flora. The most common are the different pathogenic Gram-positive bacteria such as Staphylococcus epidermidis (coagulase negative). Skin infections and soft tissue are usually caused by Staphylococcus aureus (S. aureus) and Streptococcus pyogenes. This article discusses the common and some not so common bacterial skin infections, including the impetigo, folliculitis, furncles and jewelry, cellulitis and erysipelas, gangrenous cellulitis, staphylococcal skin syndrome and burned scarlet. Impetigo and ecthyma are bacterial infections of the skin often caused by S. aureus and / or a group of Streptococcus.

 

Mild impetigo topical antibiotics and local, while widespread or severe one and in ecthyma systemic antibiotics like, cloxacillin, erythromycin, cephalexin, or azithromycin should be used. Folliculitis, furunculosis and anthrax infections by S. folliculocentric aureus varies with the depth and extent of ovarian follicles (t) and the surrounding tissue. These conditions can be treated by local or systemic antibiotics like cloxacillin, cephalexin, erythromycin, amoxicillin / clavulanic acid or vancomycin. Staphylococcal scalded skin syndrome is a toxin mediated exfoliative skin disease caused by S. Phase II aureus group. Intravenous antibiotics such as penicillinase-resistant anti-staphylococcal methicillin, cloxacillin, cephalosporins or erythromycin are necessary.

 

Erysipelas and cellulitis are acute infections of the skin and subcutaneous tissue caused most frequently group beta-hemolytic streptococci (erysipelas) or S. aureus requiring systemic antibiotics like oral or intravenous penicillin, erythromycin, cephalexin, cloxacillin, vacomycin, minocycline, or ciprofloxacin, depending on the severity of the case suspect organism and culture / sensitivity results. Cellulite is characterized by necrosis, gangrene, infection of the skin and underlying subcutaneous tissue due to various pathogens occur in a different position. Ampicillin, gentamicin, and either metronidazole or clindamycin intravenously with standard doses recommended for treatment.

Necrotizing soft tissue infections infection is a rare but very serious bacterial infection that can destroy the muscles, skin and underlying tissues. Necrotizing refers to something that causes tissue death. Many types of bacteria can cause this type of infection. A severe form and often fatal necrotizing infections of soft tissues caused by Streptococcus pyogenes, which is sometimes called "flesh-eating bacteria." Necrotizing soft tissue infections infection develops when bacteria enter the body, usually through small cut or scratch. Bacteria begins to grow and release harmful substances (toxins) which kills bacteria, interfering with blood flow to the tissues, breaking material in tissues, which rapidly spread the bacteria, leading to widespread effects, such as shocks .

 

The first sign of infection may be a small red, painful spot or bump on the skin. This quickly turned into a bronze medal, very painful or purple patch that grows rapidly. The centre may become black and die. The skin can break open and oozing fluid. The wound may quickly grow in less than an hour. Symptoms may include malaise, fever, sweats, chills, nausea, dizziness, profound weakness, and, finally, shock. Without treatment, death comes quickly.

 

 

 

Diseases spread - Diseases control - Prevention of infectious disease

INFECTION ,INFECTIOUS DISEASES SPREAD ,  PREVENTION AND CONTROL 

ROUTES OF TRANSMISSION 


Infectious or contagious diseases are all caused by some infectious agents - such as bacteria, viruses, fungi or parasites. Some infectious diseases can be transmitted from  one person to next. Some is transmitted by the bites of insects and animals. Others are acquired from eating contaminated food or water or other environmental exposures.

A contagious  (infectious ) disease can be transmitted from one source. Definition of transmission plays an important role in understanding the biology of an infectious agent, and in the fight against the disease it causes. Transmission can be through several mechanisms. Respiratory diseases and meningitis are often acquired through contact with aerosol droplets spread by sneezing, coughing, talking, kissing or even sing. Gastrointestinal diseases are often acquired through contaminated food and water. Sexually transmitted diseases are acquired through contact with bodily fluids, generally as a result of sexual activity. Some contaminants can be spread through contact with an infected person, inanimate object (known as a vector liabilities) as a coin passed from one person to another, while others penetrate the skin diseases directly. 

Transmission of infectious or contagious   diseases may also include a vector. Vectors may be mechanical or biological. A mechanical vector contains an infectious agent outside the body and sends it passively. There is an example of mechanical vector is a fly that landed on the cow manure, pollution of the annexes for the bacteria in the stool, and then landed in the food before consumption. The pathogen  never enters the body of the flies.

In contrast, biological vectors of pathogens in their body and deliver pathogens actively in new hosts , usually a bite. Biological vectors are often responsible for serious blood diseases such as malaria, viral encephalitis, Chagas disease, Lyme disease and African sleeping sickness. Biological vectors are usually but not exclusively, arthropods such as mosquitoes, ticks, fleas and lice. Vectors are often necessary in the life cycle of a pathogen. A common strategy to fight against the infectious disease vectors is to interrupt the life cycle of a pathogen by killing the vector.

The relationship between virulence and transmission is complex and has important implications for long-term evolution of a pathogen. Since it takes several generations for a microbe and a host of new species co-evolution, an emerging pathogen may hit its first victims particularly difficult. It usually occurs in the first wave of a new disease mortality rates are higher. If a disease is rapidly fatal, the host may die before the microbe can be that way to another host. However, this cost could be overwhelmed by short-term benefit of higher infectiousness if transmission is linked to virulence, as in the case of cholera (the explosive diarrhea helps bacteria to find new hosts) or many infections respiratory (sneezing and coughing for creating infectious aerosols).

PREVENTION AND CONTROL 

Methods of prevention of infection depends on the source and route of transmission. 

• Eradication of reservoir : There is no provision in the tank to an unusual disease to humans are the only natural reservoir of infection, it may be possible to eliminate the disease through intensive screening, treatment and vaccination. What has been done in cases of smallpox there. If an animal or a complete eradication of the reservoir environment is unlikely, but local control methods can reduce the risk of human infection (eg kill rodents to control fever, leptospirosis and other diseases) .
• For arthropode - vector - borne infections :  Destroys the carrier (which can be quite certain cases). Act to avoid biting (eg, insect repellent spray, mosquito nets).
• For food borne infection : Improve food handling and preparation is less contamination during processing, transportation or preparation. naturally present in foods can kill the body preparation and cooking. Improve supervision and regulation of food and better health education for the public need.
• For faeco-oral infections :  Improvement in  water supply  and sanitation. About 30%  ( thirty percent ) of the world's  population  have  no access to adequate safe drinking water ,and over half  have no adequate sanitation.
• For blood borne infections : Prevention of blood transfusion and handling of contaminated medical equipment which is use during transfusion .And routine testing of donated blood for infectious disease or infection even in most developed countries.
• For infections spread by airborne and direct contact:  In some respiratory infections which is caused by some air-borne infectious agents or microorganisms and some infections which is spread by direct contact ,we can control it by isolating the patients. Isolation is so useful but it is impractical in patients .In  severe immunodeficient patients ,it could be useful to protect them from infectious agents which is responsible for infection.