Arthralgia and polyarthritis - usually in young women with involvement of small joints of hands or feet, at times larger joints. Arthritis may be acco

Complications - are caused directly by the virus. No secondary bacterial infection. 1. Arthralgia and polyarthritis - usually in young women with involvement of small joints of hands or feet, at times larger joints. Arthritis may be accompanied by tenosynovitis and peripheral neuritis. 2. Encephalitis - Rare, affects adults more frequently and develops usually within a day or two of the appearance of rash. 3. Guillain-Barre syndrome. 4. Thrombocytopenic purpura - appears after about a week and may occasionally persist for several months. 5. Hepatitis. Diagnosis - 1. Virus isolation - Virus may be recovered from nasopharynx, blood, urine and stools. Inoculated into tissue cultures. 2. Serological tests - (a) Haemagglutination-inhtibition test - HAI antibody level rises within 24-18 hours, reaches a peak in 6-12 days and persists for a long time. (b) Complement fixation test -Determination of rubella-specific IgM or IgA antibody if there is delay in obtaining blood sample. Treatment - Bed rest and analgesics suffice for the uncomplicated attack. Rubella proven by antibody estimation in first 4 months of pregnancy is a strong indication for termination. PREVENTION - Rubella immunization: (a) Combined measles, mumps and rubella (MMR) vaccine is given routinely to all children in second year of life. (b) All female adults are screened when they reach child-bearing age and are immunized if non-immune with monovalent rubella vaccine. (c) Routine screening and immunization in immediate postnatal period. Immunized mothers excrete the vaccine virus in breast milk, but this is not a contraindication to vaccination or breast-feeding. Congenital rubella syndrome Pathogenesis - The foetus is infected during maternal viremia and the virus gains access to foetal tissues, causing a cytopathic effect or merely promoting an immune response. Defects - The consequences of rubella in pregnancy are varied and unpredictable, ranging from foetal death to birth of an infected but otherwise normal child. 1. TEMPORARY DEFECT - if cytopathic damage to non-organ tissue: (a) Thrombocytopenic purpura. - at birth or shortly after. (b) Hepatosplenomegaly. (c) Hepatitis. (d) Low birth weight. 2. PERMANENT DAMAGE - (Triad of Gregg) if cytopathic effect early in organogenesis: (a) Cataracts and retinopathy. (b) Microcephaly. (c) Congenital heart defects (PDA with or without PS most common) LATE CONGENITAL RUBELLA In some infants, particularly those infected after the first trimester, there is no obvious congenital defect, but the infant sheds the virus. In this group, late congenital rubella features include: 1. Growth retardation. 2: Behaviour disorders. 3. Psychiatric manifestations. 4. High-tone deafness. 5. Insulin-dependent diabetes mellitus PROCEDURES TO BE ADOPTED IN A PREGNANT WOMAN - (a) Suspicion of having rubella-Accurate diagnosis should be established by serological tests. If HAI antibody is present, explain the degree of risk to the patient and decide about termination of pregnancy. (b) Suspicion of having been in contact with rubella - (i) If possible, confirm the diagnosis by serological studies on the original case. (ii) If contact is close and the pregnant woman has decided to continue with pregnancy give 1500 mg. of immunoglobulin IM as soon as primary sample of serum is obtained. If there is no detectable antibody, give further 1500 mg. immunoglobulin within 3-4 days (iii) If she does not want to continue with pregnancy, or if the contact is not close, do not give immunoglobulin. (iv) In either case, take a second sample of blood after 3-4 weeks to see if there has been sera-conversion. The risk to the foetus when the mother has a subclinical attack is not known with certainty but appears to be slight. Should the mother develop an illness with serological evidence of rubella, the risks should be explained and decision taken about termination of pregnancy. 7. CHICKEN POX Epidemiology- Age - Primarily children, uncommon in adults in whom the disease tends to be more severe. Causative agent - Virus is identical to virus of herpes zoster and hence designated varicella zoster virus (V-Z virus). Transmission - Droplet discharges from air passages. May be direct skin contact or by recently contaminated utensils. Incubation period - 14 to 15 days. Period of infectivity - From 7 days before onset of rash until 6 days after development of last vesicle. Clinical features - Stage of invasion or pradramata - not constant. Headache, sore throat and fever for 24 hours. Prodromal rashes - Erythmatous, scahatiniform, morbilliform or urticarial. Rarely hemorrhagic. Stage of eruption -1 ENANTHEM - Earliest lesions on buccal and pharyngeal mucosa 2. EXANTHEM - (a) Evolution - in crops; at first back, then chest, abdomen, face, and lastly limbs. (b) Character - At first macule, in few hours dark pink papule which soon turns into vesicle - (i) superficial i e 'on' rather than 'In' the skin (glass pox), (ii) elliptical or oval ("tear drop" vesicles) with axis parallel to ribs, (iii) unilocular, hence collapse if pierced with needle. Vesicles turn into pustules in 24 hours. Scabs in 2 to 5 days. (c) Distribution-centripetal, i.e. more on upper arms and thighs and upper part of face, and in concavities and flexures. Less commonly lesions on genital mucous membranes, conjunctivae and cornea. (d) Crapping - Rash matures very quickly and most spots dry up within 48 hours of