21. pox and herpes virus

MICROORGANISM

1. POX VIRUS RATHEESH R.L

2. THE MEDICALLY IMPORTANT SPECIES IS SMALL POX OR VARIOLLA MAJOR

3. MORPHOLOGY It is brick shaped Largest animal virus which is measuring 200-250 X 250-300 nm in size

4. PATHOGENESIS The virus transmitted by the respiratory route from the lesions in the respiratory tract of patients in early stage of the disease. Incubation period is about 12 days The virus entering through the respiratory system and accumulates in the lymph nodes and lead to primary viraemia .

5. Then the virus spreads through out the body and accumulates in the reticuloendothelial cells and further multiplication occurs leading to secondary viraemia . The symptoms are fever, malaise, rashus , vomiting and headache. The rashus will starts to appear on 3-5 days.

6. DIAGNOSIS Mainly demonstration of the virus methods is used. Specimen is collected from the pustules. Viruses can be demonstrated under an electron microscope CFT test, haemagglutination test and immunofluorescence test also used.

7. HERPES VIRUSES

8. Herpes viruses are double stranded DNA viruses about 100 nm in diameter which contains spherical capsules.

9. The medically important species are, Herpes simplex Varicella zoster Epstein- barr virus

10. HERPES SIMPLEX Man is the only natural host for herpes simplex virus. There are two types HSV-1 and HSV-2 HSV-1 is associated with occular and oral lesions and HSV 2 is associated with genital infections.

11. PATHOGENESIS HSV included in variety of clinical manifestations which include, Acute gingivostomatitis : it is a common manifestation of primary herpes infection. The features are ulceration in the mouth, tongue, gum and face. Neck glands will be enlarged with fever Other symptoms are sore throat and dysphagia.

12. Herpes labialis : it is otherwise known as cold sore. The most frequent site is at the vermilion border of lips but sores can occur elsewhere like cheek, chin, upper lip, nasal folds, inside nose etc. At first itching will occur then redness will develop and leads the production of papules.

13. Ocular herpes: it produce two types of symptoms Primary HSV keratitis: which is characterized by pain, photophobia and excessive lacrimation Recurrent HSV keratitis: it is a severe ophthalmic problem characterized by ulcers, conjunctivitis, iridocyclitis ( Iridocyclitis  is an inflammation of the iris and of the ciliary body), chorioretinitis and cataract.

14. Herpes genitalis : the lesionwill be produced in the genital area of the humans. The sites involved are prepuce (   foreskin in males and skin surrounding the clitoris in females), penis, scrotum, anus, vulva, vagina, vagina and cervix

15. Neonatal herpes: it is the infection that is very much danger to the premature infants. The symptoms start to appear after 10days of delivery characterized by poor feeding, weight loss, loose stool and respiratory distress. Spleenomegaly , jaundice and liver failure will develop in the latent stages.

16. herpes simplex meningitis : it is usually a mild form of meningitis. herpes simplex encephalitis : it is a severe disease of the brain. In the early stages the patient will be asymptomatic later symptoms will develop like seizures, visual defects, speech defects, behavioral changes and coma.

17. DIAGNOSIS 1. Smears are made from specimen collected from different sites of HSV infection and stained by toludine blue. Cowdry type A or Lipchutz intranuclear inclusion bodies may seen under the microscope. Cowdry  bodies are eosinophilic nuclear inclusions composed of nucleic acid and protein seen in cells infected with Herpes simplex virus Lipchutz intranuclear Inclusion bodies, sometimes called elementary bodies, are  nuclear  or cytoplasmic aggregates of stainable substances, usually proteins

18. 2. Virus can be isolated from infected material by inoculating in the chick embryo and can be isolate by mixing with rabbit kidney and human amnion tissue culture. 3. Serological tests are used like ELISA and RIA ( Radioimmunoassay  Test)

19. TREATMENT Antiviral therapy is prescribed, the main drug of choices are Acyclovir Valvaciclovir vidarabine

20. VARICELLA ZOSTER Varicella ( chicken pox) and herpes zoster (shingles) diseases are caused by a single virus, therefore it is named as Varicella zoster virus.

21. PATHOGENESIS The virus is entering to the body through the respiratory system and accumulates in the lymphatic system of the humans. The incubation period is 10-21 days and finally reaches to the targetted organ which is the skin. It produces two types of disease like varicella/ chicken pox and herpes zoster/ shingles disease.

22. varicella/ chicken pox The disease usually affects the children. Incubation period is 7-23 days It is characterized by the formation of vesicular rashus mostly over the trunk. When the vesicular rashus are breaking down it leads to the formation of crust.

23. COMPLICATIONS OF CHICKEN POX Secondary bacterial infection: it is the most common complication of varicella. Hemorrhagic chicken pox: hemorrhagic symptoms will occur after 2-3 days after the onset of rashus . In this stage hemorrhage in the skin, epistaxis, maleena and hematuria will occur.

24. Viral pneumonia: it is mainly occurs because of the immuno -compromise state. Encephalitis: it is also occurs because of the immuno -compromise state.

25. HERPES ZOSTER/SHINGLES It may occur at any age but it is usually a disease of old age affecting to people with age more than 50 years. The features are The first symptoms of shingles are usually pain and burning. The pain is usually on one side of the body and occurs in small patches. A red rash typically follows.

26. Rash characteristics include: red patches fluid-filled blisters that break easily a rash that wraps around from the spine to the torso a rash on the face and ears itching

27. Other symptoms are fever chills a headache fatigue muscle weakness

28. complications Secondary bacterial infection: As in the case of chicken pox , mild secondary infection is common. Neuralgia: post herpetic neuralgia is common Encephalitis it is a very rare complication

29. Dessiminated herpes zoster it occurs in immunocompromised patients Ocular zoster infections in the eyes are common after the infection.

30. DIAGNOSIS Three methods are used Direct method Virus isolation method Serological tests.

31. Direct method Smears of scrapings of the base of the lesions will show the presence of multinucleate giant cells, also known as tzanck cells. Electron microscopy: fluid taken the vesicles and observed under the microscope will show the presence of virus. Immuno-fluresence method

32. Virus isolation method Vesicle fluid and scrapings from the base of fresh lesions are the most suitable specimens for the isolation of virus by mixing with the human serum.

33. Serological tests It includes CFT test Neutralization test Immuno fluorescence test RIA test ELISA

34. TREATMENT Vaccines are available Passive immunization: zoster immune globulin active immunization: live attenuated varicella vaccine.

35. EPSTEIN-BARR VIRUS  A virus in the herpes family that is best known as the cause of  infectious mononucleosis . EBV infection is characterized by  fatigue  and general malaise. Infection with EBV is common and is normally temporary and minor. 

36. PATHOGENESIS It produces three types of diseases Infectious mononucleosis/ glandular fever Burkitt’s lymphoma Nasopharyngeal carcinoma

37. Infectious mononucleosis/ glandular fever It is an acute self limiting lympho proliferative disease of young adults and rarely in children resulting from the infection with EBV. EBV is transmitted via intimate contact with body secretions, primarily oropharyngeal secretions . The disease is probably transmitted by kissing, hence it is known as kissing disease.

38. The symptoms may include: fever sore throat swollen lymph glands in the neck and armpits headache fatigue muscle weakness swollen tonsils night sweats

39. Burkitt’s lymphoma cancer of the lymphatic system, caused by the Epstein–Barr virus, chiefly affecting children

40. Nasopharyngeal carcinoma Nasopharyngeal cancer  is a rare type of head and neck  cancer . It starts in the upper part of your throat, behind the nose . The symptoms are A lump in your neck caused by a swollen lymph node. Blood in your saliva. Bloody discharge from your nose. Nasal congestion. Hearing loss. Frequent ear infections. Headaches.

41. DIAGNOSIS Hematological investigations: Shows decreased leukocytes count Abnormal lymphocyte count The virus can be observed under electron microscope Serological studies include CFT test, GEL diffusion test, immunoflurescence study.

42. TREATMENT Get adequate of rest. Drink a lot of water and other liquids to stay hydrated. gargle with warm salt water, to make your  sore throat  feel better. Take painkillers like  acetaminophen  or  ibuprofen