Carriers of infection

Milk may be a carrier of diseases from animals or from other sources to humans. To avoid contamination before pasteurization, healthy animals should be separated from sick animals or those with infected udders. The animals should be clean, kept in clean housing with clean air, and handled by workers and equipment under strictly sanitary conditions. Post-pasteurization contamination can occur as a result of improper handling, due to exposure to contaminated air, improperly sanitized equipment, or an infected worker. 

Study has proved that these coliform bacteria indicate the presence of human or animal wastes in water. Coliform bacteria naturally exist in the intestines of humans and certain animals. Thus, the presence of these bacteria in water is accepted proof that the water has been contaminated by human or animal wastes. Although such water may contain no pathogens, an infected person, animal or a carrier of disease, could add pathogens at any moment Thus, immediate corrective action must be taken. The presence of coliform bacteria shows water is contaminated by human... 

Infektions-herd, m. focus of infection, -krank-heit, /. infectious disease, -quelle, /. source of iufection. -trkger, m. carrier of Jufeo-tion. 

HBV infection remains a major worldwide public health problem. The World Health Organization estimates that there are still 350 million chronic carriers of the vims, who are at risk of developing chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma. The success of IFN-a treatment - mainly performed as combined treatment with adenine-arabinoside - has been measured by the normalization of liver enzymes, loss of HBe antigen and of detectable viral DNA in the serum of patients. It has been estimated from several clinical trials that as many as 40% of treated HBV patients would respond to therapy with IFN-a or combined treatment with nucleoside analogues and IFN-a. 

Cysteine-cysteine chemokine receptor 5 (CCR5) A 32-bp deletion with a population frequency of about 0.1 in Caucasians results in truncated nonfunctional receptor. Carriers of this variant are partially protected from HIV infection, particularly the homozygous carriers. 

The first reports on this approach were published independently by three different groups using liposomes as carriers of antimonial drugs like meglumine antimoniate in experimental leishmaniasis infection (Alving et al., 1978 Black et al., 1977 New et al., 1978). 

A variety of other clinically important infections, such as brucellosis, listeriosis, salmonellosis, and various Mycobacterium infections, are of interest as these are often localized in organs rich in MPS cells. Liposome encapsulation has been demonstrated to improve therapeutic indices of several drugs in a number of infectious models. The natural avidity of macrophages for liposomes can also be exploited in the application of the vesicles as carriers of immunomodulators to activate these cells to an microbicidal, antiviral, or tumoricidal state. These studies were recently reviewed by Emmen and Storm (1987), Popescu et al. (1987), and Alving (1988). In addition to the treatment of "old" infectious diseases, the concept of MPS-directed drug delivery is of considerable interest for the therapy AIDS, possibly enabling control of human immunodeficiency virus replication in human macrophages. 

As carriers of antibiotic resistance (Chapter 3, Part 4) the emergence of antibiotic-resistant strains has had serious repercussions in the application of antibiotic therapy, and has seriously increased the danger of nosicomial infections. 

Answer . The frequency of sickle cell disease is elevated in many African populations because heterozygous carriers of the sickle cell mutation are resistant to malarial infection but do not develop sickle cell disease, which is autosomal recessive. Thus, there is a selective advantage for the mutation in heterozygous carriers, elevating its frequency in the population. 

We begin with the symptoms of sickle cell anemia. As the name implies, victims are frequently anemic that is, they have a content of hemoglobin in blood less than the normal range, the result of lysis of red blood cells, the carriers of hemoglobin (hemolytic anemia). In addition, disease victims are susceptible to chronic infections, may have enlarged spleens, and suffer intermittent bouts of pain, which can be severe, in the bones, joints, and periosteum. The disease can be debilitating. 

Neisseria meningitidis carriers Treatment of asymptomatic carriers of N. meningitidis to eliminate meningococci from the nasopharynx. Not indicated for treatment of meningococcal infection. 

Leukocyte Adhesion Deficiency Type 2. Patients with this condition have a defect in the transport or production of the carrier molecule for the carbohydrate L-fucose (guanosine disphosphate L-fucose). The lack of fucose affects the ability of neutrophils to interact with ligands on endothelial cells such as P-selectins and E-selectins (81). Patients are susceptible to recurrent infections similar to those afflicting patients with type 1 leukocyte adhesion deficiency, have periodontal problems, and, in addition, may exhibit growth retardation and neurologic defects. Treatment with oral fucose has been known to be effective in reducing the frequency of infections (80). 

Hepatitis A is common, particularly in areas of poor sanitation, and is transmitted by food or drink contaminated by a sulferer/carrier. Clinical symptoms include jaundice, and are usually mild. A full recovery is normally recorded. Hepatitis B is transmitted via infected blood. Symptoms of acute hepatitis B include fever, chill, weakness and jaundice. Most sufferers recover from such infection, although acute liver failure and death sometimes occur 5-10% of sufferers go on to develop chronic hepatitis B. Acute hepatitis C is usually mild and asymptomatic. However, up to 90% of infected persons go on to develop a chronic form of the condition. Hepatitis D is unusual in that it requires the presence of hepatitis B in order to replicate. It thus occurs in some persons concomitantly infected with hepatitis B virus. Its clinical symptoms are usually severe, and can occur in acute or chronic form. 

TMP-SMX is also used in the treatment of infection caused by ampicillin-resistant Shigella spp. and for antibiotic-resistant Salmonella spp.. The combination is also effective for covering the carrier state of Salmonella typhi, the agent of typhoid fever, and other Salmonella spp.. Successful treatment of traveler s diarrhea due to susceptible E. coli is another advantage of the use of this combination. The combination is not indicated in the therapy of enterohemorrhagic E. coli strains such as 0157 H7 because of the risk of developing hemolytic-uremic syndrome associated with the release of the cytotoxic enterotoxin by the drugs. 

Approximately 350 million people worldwide are chronic carriers of HBV, with the majority living in Asia and Africa. In the United States approximately one million people have chronic HBV infection. Although chronically infected, individuals may remain asymptomatic for long periods. Spontaneous loss of HBeAg occurs in 7% to 20% of patients each year, but spontaneous loss of HBsAg occurs in only 1% to 2% per year [14]. Health experts estimate that 2% of patients with chronic HBV infection develop cirrhosis each year, and that 15% to 25% of patients with chronic HBV infection will die prematurely from cirrhosis or hepatocellular carcinoma (HCC). 

Ciprofloxacin and levofloxacin are no longer recommended for the treatment of gonococcal infection in the USA as resistance is now common. However, both drugs are effective in treating chlamydial urethritis or cervicitis. Ciprofloxacin, levofloxacin, or moxifloxacin is occasionally used for treatment of tuberculosis and atypical mycobacterial infections. These agents may be suitable for eradication of meningococci from carriers or for prophylaxis of infection in neutropenic patients. 

Amebiasis is an infection of the large intestine produced by Entamoeba histolytica that causes symptoms that range from mild diarrhea to fulminant dysentery. Therapy includes treating the asymptomatic carrier of the cysts, as well as the acute amebic dysentery, and the amebic hepatitis and abscess in the symptomatic patient. 

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