CHICKEN POX

Chickenpox is a highly contagious disease caused by primary infection with varicella zoster virus (VZV). It usually starts with avesicular skin rash mainly on the body and head rather than on the limbs. Chickenpox is an airborne disease which spreads easily through coughing or sneezing by ill individuals or through direct contact with secretions from the rash. A person with chickenpox is infectious one to two days before the rash appears. They remain contagious until all lesions have crusted over (this takes approximately six days). Immunocompromised patients are contagious during the entire period as new lesions keep appearing. Crusted lesions are not contagiousThe early (prodromal) symptoms in adolescents and adults are nausea, loss of appetite, aching muscles, and headache. This is followed by the characteristic rash or oral sores, malaise, and a low-grade fever that signal the presence of the disease. Oral manifestations of the disease (enanthem) not uncommonly may precede the external rash (exanthem). In children the illness is not usually preceded by prodromal symptoms, and the first sign is the rash or the spots in the oral cavity. The rash begins as small red dots on the face, scalp, torso, upper arms and legs; progressing over 10–12 hours to small bumps, blisters and pustules; followed by umbilication and the formation of scabs. These symptoms of chickenpox appear 10 to 21 days after exposure to a contagious person. Adults may have a more widespread rash and longer fever, and they are more likely to experience complications, such as varicella pneumonia.

Exposure to VZV in a healthy child initiates the production of host immunoglobulin G (IgG), immunoglobulin M (IgM), and immunoglobulin A(IgA) antibodies; IgG antibodies persist for life and confer immunity. Cell-mediated immune responses are also important in limiting the scope and the duration of primary varicella infection. After primary infection, VZV is hypothesized to spread from mucosal and epidermallesions to local sensory nerves. VZV then remains latent in the dorsal ganglion cells of the sensory nerves. Reactivation of VZV results in the clinically distinct syndrome of herpes zoster (i.e., shingles), postherpetic neuralgia, and sometimes Ramsay Hunt syndrome type II. Varicella zoster can affect the arteries in the neck and head, producing stroke, either during childhood, or after a latency period of many years.

Treatment mainly consists of easing the symptoms as there is no actual cure of the condition. Some treatments are however available for relieving the symptoms while the immune system suppresses the virus in the body. As a protective measure, patients are usually required to stay at home while they are infectious to avoid spreading the disease to others. Also, sufferers are frequently asked to cut their nails short or to wear gloves to prevent scratching and to minimize the risk of secondary infections.

The condition resolves by itself within a couple of weeks but meanwhile patients must pay attention to their personal hygiene. The rash caused by varicella zoster virus may however last for up to one month, although the infectious stage does not take longer than a week or two.

Although there have been no formal clinical studies evaluating the effectiveness of topical application of calamine lotion, a topical barrier preparation containing zinc oxide and one of the most commonly used interventions, it has an excellent safety profile. It is important to maintain good hygiene and daily cleaning of skin with warm water to avoid secondary bacterial infection. Scratching may also increase the risk of secondary infection.

Acetaminophen (paracetamol) but not aspirin may be used to reduce fever. Aspirin use by someone with chickenpox may cause the serious, sometimes fatal disease of the liver and brain, Reye syndrome. People at risk of developing severe complications who have had significant exposure to the virus may be given intra-muscular varicella zoster immune globulin (VZIG), a preparation containing high titres of antibodies to varicella zoster virus, to ward off the disease.

Antiviral like acyclovir can be used. If oral acyclovir is started within 24 hours of rash onset it decreases symptoms by one day but has no effect on complication rates. Use of acyclovir therefore is not currently recommended for immunocompetent individuals (i.e., otherwise healthy persons without known immunodeficiency or on immunosuppressive medication). Children younger than 12 years old and older than one month are not meant to receive antiviral medication unless they are suffering from another medical condition which would put them at risk of developing complications. Infection in otherwise healthy adults tends to be more severe. Treatment with antiviral drugs (e.g. acyclovir or valacyclovir) is generally advised, as long as it is started within 24–48 hours from rash onset.Remedies to ease the symptoms of chickenpox in adults are basically the same as those used on children. Infection in adults is associated with greater morbidity and mortality due to pneumonia (either direct viral pneumonia or secondary bacterial pneumonia), hepatitis,and encephalitis. In particular, up to 10% of pregnant women with chickenpox develop pneumonia, the severity of which increases with onset later in gestation. Although the risk is higher with herpes zoster. Necrotizing fasciitis is also a rare complication( NF, commonly known as flesh-eating disease or flesh-eating bacteria syndrome, is a rare infection of the deeper layers of skin and subcutaneous tissues, easily spreading across the fascial plane within the subcutaneous tissue,as necrosis of the subcutaneous tissue and fascia with relative sparing of the underlying muscle) During pregnancy the dangers to the fetus associated with a primary VZV infection are greater in the first six months. In the third trimester, the mother is more likely to suffer from the adverse effects of the infection. For pregnant women, antibodies produced as a result of immunization or previous infection are transferred via the placenta to the fetus. Women who are immune to chickenpox cannot become infected and do not need to be concerned about it for themselves or their infant during pregnancy. Varicella infection in pregnant women could lead to viral transmission via the placenta and infection of the fetus. If infection occurs during the first 28 weeks of gestation, this can lead to fetal varicella syndrome (also known as congenital varicella syndrome). Effects on the fetus can range in severity from underdeveloped toes and fingers to severe anal and bladder malformation. Possible problems include:

· Damage to brain: encephalitis, microcephaly, hydrocephaly, aplasia of brain

· Damage to the eye: optic stalk, optic cup, andlens vesicles, microphthalmia, cataracts, chorioretinitis, optic atrophy

· Other neurological disorder: damage to cervical and lumbosacral spinal cord, motor/sensory deficits, absent deep tendon reflexes, anisocoria/Horner's syndrome

·Damage to body: hypoplasia of upper/lower extremities, anal and bladder sphincter dysfunction

·Skin disorders: (cicatricial) skin lesions, hypopigmentation

Infection late in gestation or immediately following birth is referred to as "neonatal varicella". Maternal infection is associated with premature delivery. The risk of the baby developing the disease is greatest following exposure to infection in the period 7 days prior to delivery and up to 7 days following the birth. The baby may also be exposed to the virus via infectious siblings or other contacts, but this is of less concern if the mother is immune. Newborns who develop symptoms are at a high risk of pneumonia and other serious complications of the disease.

Shingles(Herpes zoster)-After a chickenpox infection, the virus remains dormant in the body's nerve tissues. The immune system keeps the virus at bay, but later in life, usually as an adult, it can be reactivated and cause a different form of the viral infection called shingles (scientifically known as herpes zoster). Many adults who have had chickenpox as children are susceptible to shingles as adults, often with the accompanying condition postherpetic neuralgia, a painful condition that makes it difficult to sleep. Even after the shingles rash has gone away, there can be night pain in the area affected by the rash.Shingles affects one in five adults infected with chickenpox as children, especially those who are immune suppressed, particularly from cancer, HIV, or other conditions. However, stress can bring on shingles as well, although scientists are still researching the connection. Shingles are most commonly found in adults over the age of 60 who were diagnosed with chickenpox when they were under the age of 1. .

 

 The chickenpox vaccine is not part of the routine childhood vaccination schedule in the India,the vaccine is currently advisable only to people who are particularly vulnerable to chickenpox. A vaccinated person is likely to have a milder case of chickenpox if infected.

Monday, April 7

                                               World Health Day 201

 Malaria: The disease is caused by the protozoan parasite Plasmodium.The most common species of Plasmodium responsible for most malaria cases are Plasmodmflaciparum and Plasmodium vivax. The parasite is transmitted to humans via the vector female Anopheles mosquito. The mosquito bearing the protozoa transmits the disease to humans by biting at night. The parasite then attacks the red blood cells and reaches the liver causing symptoms like fever, chills and anemia.

   Kala Azar: Leishmaniasis or Kala Azar:  It is caused by protozoan parasite of the genus Leishmania. In India, Leishmania donovani is the only parasite causing the disease. The parasite is transmitted to humans by female sand flies. Upon entry, the parasite attacks the immune system and causes ulcers or sores at the site of entry.

   Dengue: is caused by a virus that is transmitted to humans by the vector Aedes Aegypti mosquito.

  Plague:  It is a deadly disease caused by the bacteria Yersina pestis. It is primarily transmitted by rodents. But it is also spread through insects that acquire the infection from rats harboring the bacteria. Common insect that acquires the bacteria from rodents is flea. The bacteria enter the blood stream after a flea bite and attack the cells of the immune system. They secrete toxins which causes clots and tissue death.

  Filariasis: Lymphatic filariasis is commonly caused by thread like filarial worms or nematodes. Wuchereria bancrofti is the most common filarial worm, causing the disease in 90 percent of the cases. The worm is carried by and transmitted to humans by mosquitoes –mainly Culex mosquito. The worm invades the lymphatic system causing profuse selling mainly in the legs.

  Chickungunya:  caused by a virus classified under the family Togaviridae, genus Alphavirus. It is transmitted to humans by Aedes mosquito (mainly Aedes aegypti) in the daytime. Common symptoms of the disease are similar to dengue.

  Lyme disease: Lyme disease is caused by the spirochete bacterium Borrelia burgdorferi. It is transmitted to humans by black-legged ticks that are infected with the bacteria. Upon entry, the bacterium attacks the central nervous system and causes neurological problems.

  Yellow fever: caused by the yellow fever virus and spread by female mosquito of Aedes aegypti species. The virus affects the cells of the immune system and causes symptoms like fever, chills, nausea and muscle pain.

  Chagas’ disease: Chagas’ Disease is widely found in communities of Latin America. It is caused by the protozoan parasite Trypanosoma cruzi and transmitted by a large insect called ‘kissing bug’ (Reduviidae Tratominae). The parasite damage several organs and mainly affects heart function.

  Japanese encephalitis: It is a viral disease that is spread through infected Culex mosquito. The virus mainly affects the central nervous system and causes headache, fever, meningitis, coma, tremors, paralysis and loss of coordination. Several cases of the disease have been found in India. The most affected states include Tamil Nadu, Karnataka and Kerala.

  Scrub typhus:Scrub typhus is a mite-borne infectious disease caused by Orientia tsutsugamushi (previously called Rickettsia tsutsugamushi).Scrub typhus is transmitted by some species of trombiculid mites ("chiggers")which are found in areas of heavy scrub vegetation. The name of the diseases derives from the type of vegetation (ie, terrain between woods and clearings) that harbors the vector.No vaccine is available.

BLOCK LEVEL FUNCTION CONDUCTED AT MANGANAM,VIJAYAPURAM ON 7/4/2014

1.                 DENGUE FEVER

Dengue is transmitted by the bite of a mosquito infected with one of the four dengue virus serotypes. It is a febrile illness that affects infants, young children and adults with symptoms appearing 3-14 days after the infective bite.

Dengue is not transmitted directly from person-to-person and symptoms range from mild fever, to incapacitating high fever, with severe headache, pain behind the eyes, muscle and joint pain, and rash. There is no vaccine or any specific medicine to treat dengue. People who have dengue fever should rest, drink plenty of fluids and reduce the fever using paracetamol or see a doctor.

Severe dengue (also known as dengue hemorrhagic fever) is characterized by fever, abdominal pain, persistent vomiting, bleeding and breathing difficulty and is a potentially lethal complication, affecting mainly children. Early clinical diagnosis and careful clinical management by trained physicians and nurses increase survival of patients.

April 7 is World Health Day. The theme this year is ‘Vector-borne diseases – small bite, big threat’ and one of the most common vector-borne diseases is dengue fever. 

The incidence of dengue has risen significantly in the past few decades. According to the World Health Organisation (WHO), more than 2.5 billion people in the world are now at risk of suffering from dengue.

Dengue is a mosquito borne viral infection. In simple words, dengue is caused by dengue virus that gains entry into the human body via mosquito bites. Because dengue is a viral disease, there is no definitive drug that can treat it. But the complications of dengue can be prevented well with accurate diagnosis and early detection.

Here’s what our experts Dr Pradip Shah, consultant physician, and Dr Bela Sharma, senior consultant, internal medicine, FMRI, had to say about factors involved in diagnosis of dengue, and some commonly used diagnostics tests.

Factors involved in diagnosis of dengue:

Warning signs, duration of the symptoms and appropriate physical examination are main factors involved in dengue diagnosis. ‘Diagnosis of dengue is usually done based on patient’s symptoms and physical examination, especially in endemic areas. A probable diagnosis is made on the findings of fever with the following symptoms: nausea and vomiting, rash and generalized pain. Warning signs typically occur before the onset of severe dengue. Diagnosis should be considered in anyone who develops a fever within two weeks of being in the tropics or subtropical region,’ explains Dr Bela.

Common tests used in dengue diagnosis:

1.  Complete Blood Count:  Both the experts highlighted low platelet count as an important factor in dengue diagnosis. ‘A complete blood count (CBC) is of significant importance for clinical diagnosis of dengue. If a patient has high fever and is found to have a low platelet count, dengue is suspected’, says Dr Pradip. Normal platelet count in a healthy individual is about 2.5 lakh cells/cubic mm.

2. ELISA test for dengue NS1 Ag: Viruses have the tendency to attack platelets and destroy them, thereby lowering the platelet count. ‘But, a low platelet count does not always mean that you are suffering from dengue. Your platelet count can be lowered in any kind of viral infection. That the reason why we need more specific tests to confirm dengue. ELISA NS1 Antigen test is a specific test for detecting dengue virus antigen. But this test may show negative results in the early stages of the disease. So the test needs to be repeated on the 2nd ,3rd or 4th day for confirmatory results,’ explains Dr Pradip.

3. PCR for detecting viral DNA: ‘Detection of NS1 during the early phase of a primary infection may be greater than 90% but for subsequent infections it is only 60–80%. So, PCR and viral detection test is considered. This test is more reliable in the first 7 days of infection, when NS1 Ag test may be negative despite infection,’ says Dr Bela.

4. Serum IgG and IgM test: ‘Serum antibody tests are useful for confirming a diagnosis in the later stages of the infection,’ mentions Dr Bela. Once the virus gains entry into the body, the immune cells begin to produce antibodies IgG and IgM against the virus. The level of these antibodies increases gradually and remains high for a really long time. So it is also a useful indicator of a previous infection.