Archive for the ‘Anti-Infectives’ Category

posted by admin on Jun 28

EpidemiologyImpetigo is a common superficial skin infection that is usually caused by S. aureus, but it can also be caused by group A beta-hemolytic streptococci or a combination of the two. Bullous impetigo is usually caused by a toxigenic staphylococcus strain that causes epidermal cleavage. Impetigo is more commonly seen in children, especially those between 2 and 5 years of age. The rash usually occurs on intact skin, but streptococci require traumatized skin to cause infection. Two to 5% of impetigo cases are complicated by post-streptococcal glomerulonephritis, but clusters with rates as high as 15% have been reported.
Signs and SymptomsImpetigo typically occurs around the nose and mouth or on the limbs. It begins as a vesicle (<5 mm) or cloudy pustule that spontaneously ruptures to expose a well-demarcated, red, weeping, shallow erosion. In bullous impetigo, vesicles progress to form bullae (>5 mm) before eroding. A characteristic honey-colored crust accumulates on the lesions. The infections spread both radially and by autoinoculation to form satellite lesions. Lesions are typically asymptomatic, but some patients may report mild pruritis. Regional adenopathy is common, but systemic symptoms are unusual. Without treatment, lesions can persist for months.
DiagnosisThe diagnosis is based on clinical assessment. In recurrent or resistant cases, Gram stain and culture of the lesions should be performed. The differential diagnosis of impetigo includes varicella (chickenpox), herpes simplex virus, candidiasis, atopic or contact dermatitis, scabies, and guttate psoriasis. Impetigo can also arise secondarily from these lesions.
TreatmentTreatment should provide coverage for both S. aureus and streptococci. Topical treatment with mupirocin 2% ointment/cream (Bactroban) works well for isolated lesions. It should be applied three times daily for 7 to 14 days or until the infection is clear. Oral antibiotics are favored by many experts, especially when impetigo is extensive. Options for systemic treatment include cloxacillin, dicloxacillin, clindamycin, amoxicillin-clavulonate, azithromycin, clarithromycin, first- and second-generation cephalosporins, and second-generation fluoroquinolones. Patients should be warned to use contact precautions until lesions begin to heal.
Recurrent ImpetigoRecurrent impetigo has been linked to carriage of S. aureus, especially in the nares. Mupirocin ointment applied to the nares twice daily for 5 days can reduce nasal carriage and infection. The 5-day treatment can be repeated monthly in difficult cases.
Ecthyma (Ulcerative Impetigo)Ecthyma can be considered an ulcerative variation of impetigo. It is caused by streptococci and begins as vesicles or bullae, typically on the legs. These lesions progress to a deeper erosion and have a thick crust that is sometimes gray. Ecthyma arises in minor wounds that are neglected. It should be treated with systemic antibiotics to minimize scarring.*110/348/5*

posted by admin on May 28

Hepatitis С virus is transmitted primarily through large or repeated percutaneous exposures to blood. During a medical evaluation, it is important to obtain a history of high-risk practices associated with transmission of the virus. Risk factors for HCV infection include the following:Injection and other illegal drug use – Currently, most new HCV infections are associated with injection drug use. Approximately 50% to 60% of these individuals are infected within 3 months of initiation of injection behavior. Even individuals who infrequently used injection drugs in the remote past may be at risk for infection with HCV. Intranasal cocaine use has also been associated with the acquisition of HCV.Transfusion and organ transplantation – Improved screening of blood and organ donors has made transmission of HCV by transfusion or transplantation rare. The introduction of HCV antibody detection testing in 1992 significantly reduced the risk of disease by these routes. With the implementation of this testing in blood banks, the risk for HCV infection from blood transfusion is now less than 1 in 103,000 transfused units. The residual risk results from blood donations that occur in the period between infection and the development of detectable antibodies.Hemodialysis -The prevalence of HCV antibody among hemodialysis patients is approximately 10%, and the infection is presumed to have been transmitted by inadequate infection control practices.Health care workers – The prevalence of HCV infection among health care workers is similar to that in the general population (approximately 2%). Needle-stick injury is the primary risk factor for HCV transmission, and the incidence of seroconversion after such an injury is 3% to 4%. Transmission of HCV from blood splash to the conjunctiva has also been reported.Sexual activity – Transmission of HCV does occur through sexual activity, but at low frequency. The estimated seroprevalence of HCV is 2% to 3% among partners of HCV-infected individuals who are in long-term monogamous relationships. Thus, monogamous couples do not need to use barrier protection but should be advised that condoms may reduce the risk of HCV transmission. HCV-infected individuals who have multiple sexual partners or who are in short-term relationships should be advised to use condoms to prevent the transmission of HCV (as well as other sexually transmitted disease).Household contact – HCV transmission by normal household contact is extremely uncommon. There is no evidence that casual contact, such as kissing, hugging, or sharing eating utensils, is associated with HCV transmission. However, sharing household items that may be contaminated with blood, such as razors, toothbrushes, or nail care tools, should be avoided.Tattooing/body piercing – These activities have been associated with HCV transmission, and contaminated equipment or supplies have been implicated.Vertical transmission – Among infants born to HCV-positive, human immunodeficiency virus (HIV)-negative women, the incidence of HCV infection is 5% to 6%, but the incidence is higher among children born to HCV and HIV co-infected mothers (14-20%). Infants born to HCV-positive women should have their blood tested for either HCV RNA at approximately 6 months of age or HCV antibody at 15 months of age (after maternal antibodies have waned). Breastfeeding does not appear to transmit HCV. Current therapeutic modalities for HCV are contraindicated during pregnancy, and no studies have evaluated the use of elective cesarean section for the prevention of mother-to-infant HCV infection.*78/348/5*

posted by admin on Dec 26

This affliction of college-age students is often jokingly referred to as the “kissing disease.” The symptoms of mononucleosis, or “mono,” include sore throat, fever, headache, nausea, chills, and a pervasive weakness or tiredness in the initial stages. As the disease progresses, lymph nodes may become increasingly enlarged, and jaundice, spleen enlargement, aching joints, and body rashes may occur.
Theories on the transmission and treatment of mononucleosis are highly controversial. Caused by the Epstein-Barr virus, mononucleosis is readily detected through a monospot test, a blood test that measures the percentage of specific forms of white blood cells. Because many viruses are caused by transmission of body fluids, many people once believed that young people passed the disease on by kissing. Although this is still considered a possible cause, mononucleosis is not believed to be highly contagious. It does not appear to be easily contracted through normal, everyday personal contact. Multiple cases among family members are rare, as are cases between intimate partners.
Treatment of mononucleosis is often a lengthy process that involves bed rest, balanced nutrition, and medications to control the symptoms of the disease. Gradually, the body develops a form of immunity to the disease and the person returns to normal activity.

posted by admin on Dec 20

Measles have been one of the most frequent of the childhood diseases. The condition is quite infectious, and is accompanied usually by a rash, with fever, cough, and inflamed eyes. Measles are caused by a specific virus which spreads easily from one person to another.
From ten to fourteen days after a child has been in contact with another who has had measles, symptoms like those of a severe cold develop. The child becomes drowsy and irritable. The eyes water and look red and the child avoids light. The appetite is poor. By the end of the third or fourth day the rash appears with individual spots that are at first pinhead size and pale red but then enlarge, become elevated and a darker red. The eruption is seen first usually on the face, scalp, and behind the ears, but then gradually covers the whole body. The fever increases as the rash breaks out. After the second or third day the rash begins to fade, the temperature falls and after seven days, usually, the patient is on the way to complete recovery.
During the first few months of life the child often has immunity from measles by antibodies derived from its mother. As the immunity wears off the child becomes susceptible, and most cases occur in children three or four years old. The child may be injected with globulin which provides immunity against measles. In 1962 a vaccine useful to prevent measles was developed by Dr. John Enders based on isolation of the measles virus.
Since the development of antibiotic drugs secondary complications of measles are more easily controlled. During the acute illness the child is kept at rest, given plenty of fluids, such as citrus drinks, a soft diet and good nursing. For itching of the skin a calamine lotion is used. The eyes are protected against irritation. For more severe cases convalescent serum or gamma globulin may be used. Measles are not a serious disease except for very small babies. Prevention and control of pneumonia at the earliest sign is most important.