Hepatitis B is the most dengerous viral hepatitis caused by the hepatitis B virus.This is the only hepanda virus causing infection in humans. And humans are the only basis of infection as yet known.The incubation period is about 4-20 weeks.
Hepatitis B also identified as 'serum hepatitis' or 'long incubation hepatitis. The infective B virus, known as version or dale particle (42 nm) comprises an inner core or nucleocapsid (27 nm) surrounded by an outer  envelope or capsule of surface protein (HBsAG).The core or nucleocapsid is formed of core protein (HBsAG) containing incompletely double-stranded circular DNA and a DNA polymerase.

HBeAG is a protein formed via definite self cleavage of the core gene product, which is secreted individually by the cell.
The virus &the capsular material (HBsAG) circulate in the blood, and individual incubating or suffering from acute hepatities ,is highly infectious as long as the blood. Generally HBsAG appears in the blood in the late phase of the incubation period & before th prodromal phase of infection. In acute hepatitis B, appearance of HBsAG is the first and specific evidence of HB virus infection ,HBsAG may be present in the blood only for a few days, but generally persists for 3-4 weeks or throughout the clinical illness or can persist for up to 5 months. Antibody to HBsAG (anti-HBs) usually appears after 3-6 months that is after clearance of HBsAG &persists for many years to life-long. The persistence of HBsAG after the acute illness indicates chronic hepatities (or carrier state).disappearance of HBsAG and presence of anti-HBs indicates recovery from recurrent infection. Chronic hepatities infection is marked by the presence of HBsAG & anti-HBc in the blood.In this situation patient may be asymptomac, but is highly infectious when markers of continuing viral replication, such HBeAG,HBe is present. In the blood, presence of anti-HBs indicates either a before infection, in which case anti-HBc is usually also present, or previous vaccination if anti-HBc is no present. In the blood HBcAG does not appears, but anti-body to this core antigen(anti-HBc) appears at the earlier stage of the disease and quickly reaches a high tire, which then steadily reduces and persists to a lower level. On the other hand HBeAG appears in the blood only transiently at the outset of the disease and there is also invention of antibody (anti-HBe) indicates active replication of the virus in the liver.    .    

source of hepatitis B

As humans are the major source of hepatitis B infection, so its extend generally occurs through human blood or blood products & use of infected injection materials. Besides the viruses also occur in the human semen, saliva & vaginal secretion, so infection may also spread through close personal contact, such as sexual intercourse (mostly in male homosexuals).  Vertical or direct transmission from mother to child during and after birth is also an important way of hepatitis B virus. 

Investigetion

1. Serum bilirubin is variably reasonably or markedly elevated.
2. Serum AST (SGOT)&ALT (SGPT) are elevated (20-400 U/L),(normal 35 U/L)
3. The prothrombin time is enlarged in severe cases.
4. Serum HBsAG & HBcAG test may be positive (in hepatitis B)
5. Ultrasonogram of hepatobiliary system.
6. Liver biopsy (if needed) is confirmatory-usually not necessary
7. Blood count -lymphocytes         
8. Serological test may be useful

Treatment of Hepatities B

. complete bed rest till serum bilirubin comes down to common level and jaundice subsides.

.2.In case of hepatitis B, the patient should be isolated.
3. Patient with serious illness should be hospitalized.
4.abundance of water and glucose by mouth ,if  the patient vomits, glucose may be given by i. v route,5% dextrose in aqua 500ml & 25% glucose 200-300ml daily.
5. Diet, all diet but excess amount of fatty diet and alcohol. Total calorie intake should be maintained within 2000-3000kcal
6. Bowel should be clear by using laxative, such as milk of magnesia (MGSO4) or lactulose 3-6 tsf daily in the morning in blank stomach.
7. Vitamin supplement e.g. vitamin B complex may be given commonly.
8. Antibiotic-if the patient has got fever or any characteristic of secondary infection, a course of suitable antibiotic (amoxicillin or cephalosporin etc) should be advised.
9. Alcohol should be controlled for 1 year or life-long (for non-habitual)
10. Drugs which are metabolized in the liver should  be restricted such as-
a. Sedatives
b.Antiemetics
c. Analgesic as paracetamol
d.Cotrimoxazole & other sulphonamides
e.Hepatotoxic anti T-B drugs  .

HIV INFECTION & AIDS

                                                        Hiv infection spread
firstly, some cases of severe opportunistic infections e.g. pneumocystis carina pneumonia and abnormal neoplasm, such as Kaposi’s sarcoma, which can only be seen in severely immunocompromised patients i.e. indefective cell mediated immunity-were found in some previously healthy homosexual individuals in the lack of any known cause of underlying immune defects (such as iatrogenic immunosupression e.g. chemotherapy patients, or malignant neoplasm, or severe malnutrition), this situation was then eventually renowned as the acquired immunodeficiency syndrome or AIDS. After finding of HIV virus as the cause of AIDS dissimilar stages of the disease have been described later on, such as a healthy person with seropositive HIV virus at one end of the disease spectrum &severe opportunistic infection or unusual neoplasm like Kaposi’s sarcoma at the other end. In 1987, a meaning of AIDS was described, which included 23 opportunistic infections (such as pneumocystis pneumonia) and unusual neoplasm (like Kaposi’s sarcoma)with loss if weight, diarrhea, dementia and a positive HIV infection, In 1993 CDC (center for disease control and prevention )extended the AIDS definition, and added that, a person with a positive HIV serology and who have ever had a CD4 lymphocyte percentage below 14% is to be considered as a patient of AIDS. 
      




































 

Source of AIDS

AIDS is caused by infection with humane retroviruses recognized as 'human immunodeficiency virus. in addition classic AIDS virus, a group of related viruses designated as HIV - found in some west African patients having same genetic organization as HIV-1,but considerably different glycoprotein contents, manifested AIDS-like illnesses in some patients, but most cases found asymptomatic.

Mode of transmission:

1.Sexual contact is the main mode of transmission of HIV. About 60%are homosexual or bisexual.
2. Intravenous route-about 20%of patients is heterosexual men and women intravenous drug users, and is related to the sharing of needles. About 7% are homosexual or bisexual men, who are also using intravenous drugs.
transfusion of contaminated of blood &blood products, if not screened or treated, may be a significant way of AIDS transmission
3.Infected mothers are efficiently (30-40%)transmit the virus to their infants perinatally during the first and second trimester. Virus can also be transmitted from mother to infant via breast feeding

Snake bite

Clinical feature:Pain at the site of the bite,nausea,vomiting,profuse sweating, thirst and collapse. There may be local redness Swelling  and extravasations of blood.
Treatment:
A. General measures:
1. Immobilise the patient and apply tourniquet proximal to the site of bite and suck out venom (after incision if needed) instantly.
2.The site of the bite should be cleaned and then left strictly alone; otherwise the danger of infection is increased. If skin necrosis occurs, sloughs should be excised (with skin grafts applied as suitable if possible)
 3. Hospitalization (specially in young children) whenever possible.
4. Maintain B.P by I.V fluid &blood transfusion if needed.
5. Sedatives are needed if the patient is apprehensive.
6. Appropriate antitetanus prophylaxis should be given taking account of the patient’s immune state
Specific management:
1. If there is a clear proof of systemic poisoning, antivenom should be given in advance stage. several local affects particularly necrosis may be avoided or minimized if antivenom can be given within 4 hours of bite.
Depending on the severity of poising,20-100ml antivenom is diluted in 2-3 volumes of isotonic  saline. This is then given by slow intravenous infusion (15 drops per minut)
2. Adrenaline (1:1000 solution) must be instantly available. If a reaction occurs the drip is stopped temporarily and 0.5 ml adrenaline is given at the first sign of anaphylaxis, it is speedily effective and the drip can be restarted with care. Several injections of adrenaline may specify.
3. Antihistaminic drug may be given i.v previous to the antivenom injection is started.
4. For children over 10 years and adults with no symptoms 2 hours after the bite-rest and antihistaminic drug is advisable  

Diarrhea

the meaning of the term 'diarrhea' is different to different people commonly, the term in used to mean 'enlarged stool frequency and loose watery stools’. But rationally diarrhea is defined as the passage of stool more than three times a day' or’ when the stool is fluid or semisolid, passage of stool irrespective of frequency is defined as diarrhea’ passage of frequent but formed stool is not usually considered as diarrhea. Urgency of defecation and faucal incontinence is a common feature of any variety of diarrheas.
Prevention of diarrhea:
Diarrhea diseases are related with overloading and unsanitary situation with poor personal hygiene. Infection results from ingestion of food or water contaminated Diarrhea is a very general problem and usually used terminology among our people. In spite of that with infected human faces. Infection is extending by direct contamination of food or drink through unwashed hands soiled with faces and also by house files. So all sorts of possibility causing diarrhea should be cut off initially  to prevent the final breakout.
 

Dengue Fever

Dengue is a viral febrile disease of humans, caused by a flavivirus. The main carrier of this viruses is a mosquito, known as Aedes aegypti,and is the summer season. After infection, humans are usually infective in the first three days of the illness-that is the viraemice stage of the disease. The healthy Aedes mosquitos become infective about two weeks after feeding on an infected individual and persist as carrier for the rest part of their lives.There are four antigenic serotypes (den-1,Den-2,Den-3& Den-4)of dengue virus, but all are producing a similar clinical syndrome. After infection of an individual, the immunity develops which is life-long for the same serotype of the virus infected & only a few months for the other serotypes. The usual incubation period is 7-10 days, but it can be as short as 2 days and as long as 15 days. This occurs endemically in the tropical &sub-tropical countries specially in the South-east Asia & epidemically in the other zones of the world.

Types of dengue fever

Clinically two types of dengue fever are recognized
1Classic dengue fever:
a. .There may be a prodromal phase of malaise & headache for two days
B.Fever-acute & sudden onset of high fevr with chills;fever is usually continuous or saddleback pattern and biphasic,initial phase lasts for 3-7 days,then after a remission period of few hours to 2 days, second phase of fever appears & lasts fo 1-2 days.
c.Rash-appears in about 80% of patients.Initially,transient macular rashes appear in the first 1-2 days,then followed by maculopapular, morbilliform or scarlatiniform,or petecheal rashes from 3-5th day.It usually appears first on the dorsum of the hands and feet and then spread to the arms,legs,trunk, and even to the neck but rarely to the face, & lasts for 2 hours to a few days,followed by desquamation.
d.During remision or convalescent period,severe fatigue & a feeling of unwell with depression are common for several weeks
2.Haemorrhagic fever:
a.It generally occurs in children but may also occur in adults
b.There may be a mild start with symptoms like upper respiratory tract infection,which is then followed by an abrupt onset of haemorrhage into the skin,ear,nose and gums, & haematemesis and melaena.

prevention of dengue fever

1.Isolaion of the patient & treatment under a mosquito net
2. Control of aedes mosquito by

a. Abolishing the breeding places by a              

3. Isolation n integrated
b.Destroying adult mosquitos by spraying insecticides.
c.Avoiding aedes mosquito’s bites at day time approach of environmental sanitation and biological control. specially in the peak feeding period i.e. in the morning for several hours, by using mosquito net or by using repellents containing deet (less then 30%) on the exposed skin or by using mosquito coil,
d.Dengue vaccine a live attenuated tetravalent dengue vaccine is at an advanced stage of development, but yet not available for clinical use.