[Pedia 3b] Reviewer Virology (Banez) - Nikka Faj PDF

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PEDIA 3B FINALS REVIEWER – VIRAL INFECTIONS (Bañez) Medicine2017 77 Must knows and FAQs I. HERPES SIMPLEX VIRUS Serotypes HSV 1 HSV 2 Mouth and skin above the waist Genital organs EPIDEMIOLOGY  Majority of women with HSV infection are asymptomatic  3 Distinct Times of Acquisition:  Congenital – i...

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PEDIA 3B FINALS REVIEWER – VIRAL INFECTIONS (Bañez)

Medicine2017

Must knows and FAQs

I. HERPES SIMPLEX VIRUS Serotypes HSV 1 HSV 2

Mouth and skin above the waist Genital organs

EPIDEMIOLOGY  Majority of women with HSV infection are asymptomatic  3 Distinct Times of Acquisition:  Congenital – in utero  Perinatal – during delivery  Postnatal

DIAGNOSIS 1. Viral DNA by PCR of CSF  test of choice in HSV encephalitis  Sensitivity: 75% neonatal CNS Infection 95% beyond neonatal period 2. Type-specific antibodies  for adults/adolescents  not useful in neonatal HSV infections  HSV-2 type specific antibody tests useful for genital infections  IgM tests are unreliable TREATMENT

CLINICAL MANIFESTATIONS 1. Perinatal Infection  acquired from primary or recurrent HSV infected cervico-vaginal secretions  Presents as either:  Disseminated disease: Skin lesions (75%)  Encephalitis  Skin, Eye, Mouth lesions 2. Primary Herpetic Gingivostomatitis  Most common primary infection in CHILDHOOD  Enanthem: painful vesicles on lip, gums, buccal mucosa, anterior tongue & hard palate vesicles rapidly become shallow tan-yellow ulcers with erythematous halo  Gingivitis  Often presents with fever 3. Herpes Labialis  Most common form of REACTIVATION  usually found in the vermilion border 4. Genital Herpes  Most common manifestation of primary infection in ADOLESCENTS/ADULTS  MOT: Genital-genital (HSV2) or oral-genital (HSV1)  Vesicular or ulcerative lesions on genital organs with  Severe PAIN (vs primary syphilis:painless discharge)  Itching, dysuria, vaginal/urethral discharge  Tener inguinal lymphadenopathy 5. Meningoencephalitis  Most common cause of fatal FOCAL encephalitis  predilection for frontal/parietal lobes  unusual cause of aseptic meningitis  caused by HSV 1: 75% mortality  If untreated → acute, fulminant course →coma and death

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 Drug of choice: ACYCLOVIR  Has poor bioavailability so it is given IV when the infection is severe Neonatal Infections Acyclovir (Irrespective of 15-20 mg/kg/dose q 8 Presentation) hours x 14-21 days IV Herpes Encephalitis 21 days for herpes encephalitis

II. EBSTEIN BARR VIRUS  causes >95% of infectious mononucleosis Age Group Presentation Infants  asymptomatic or mild/inapparent Young Children  indistinguishable from other childhood infections Adolescents  50% of cases → TRIAD Adults 1. Fatigue 2. Pharyngitis 3. Generalized Lymphadenopathy CLINICAL MANIFESTATIONS TRIAD   

Fever Exudative Pharyngitis Generalized Lymphadenopathy

Signs and Symptoms 1. Fever – up to 39˚C x 1-2 weeks up to 5 weeks 2. Adenopathy  90%, non-tender, bilateral, usually in the anterior, posterior cervical & submandibular nodes  if epitrochlear suggestive of infectious mononucleosis 3. Pharyngitis  mod to severe with marked tonsillar enlargement

PEDIA 3B FINALS REVIEWER - VIRAL INFECTIONS

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4. Palatal Petechiae  maybe mistaken as strep throat but not responsive to penicillin 5. Organomegaly a. Splenomegaly – 50% b. Hepatomegaly – 10%

TREATMENT  Bed rest  No contact sports/activities that can cause rupture of spleen until it is not palpable  Steroids: rarely needed

Other Distinct Disorders associated with EBV

III. CYTOMEGALOVIRUS

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 1 virus associated with malignancy  MALIGNANT PROLIFERATIONS  Nasopharyngeal carcinoma  Burkitt’s lymphoma  Hodgkin disease  X-linked lymphoproliferative syndrome (Duncan syndrome)

 Most common opportunistic infection in HIV/AIDS  Most common cause of congenital infection  Usually asymptomatic ; infection remains for LIFE SOURCE: Saliva Breast milk

DIAGNOSIS 1. CBC  Atypical Lymphocytosis– highest degree in EBV 2. Serologic Tests a. Heterophil Antibody Test (Monospot Test)  IgM antibodies in sheep/horse cell agglutination  Positive in: a. 50% : children 90% of cases)  Abrupt fever (38.5-40C)lasts 4-7 days (mean 3 days), malaise, irritability, lethargy, anorexia, diarrhea, N/V, abdominal discomfort, sore throat, respi symptoms, meningitis DISTINCT CLINICAL MANIFESTATIONS/CLINICAL SYNDROME 1. Herpangina  COX A  Vesicles and ulcers on ANTERIOR PILLARS (most common site), soft palate, uvula, tonsils, pharyngeal wall, posterior buccal surface Gingivostomatitis Vesicles found anteriorly (lips, gums, vermilion border)

Herpangina Vesicles found posteriorly (palate, uvula tonsils)

2. Hand, Foot, and Mouth Disease  Coxsackie A16 – most common  Enterovirus 71 – most severe with neurologic and cardiopulmonary involvement  Highly contagious; starts as Herpangina-like (vesicles on the mouth, associated with drooling, dysphagia)

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eventually the vesicles seen on hands and feet 

Some may be seen on the buttocks (mistaken as varicella/chicken pox)

3. Pleurodynia or Bornholm’s Disease  Coxsackie B and Echovirus 4. Respiratory Manifestations (URTI)  Sorethroat  Coryza  Tonsilitis  Wheezing  Exacerbations of asthma  Pneumonia  Parotitis 5. Myocarditis and Pericarditis  usually Coxsackie B viruses  mild to severe 6. Neurologic Manifestations MANIFESTATIONS CHARACTERISTICS Viral Meningitis Most common cause (>90%) in mumps immunized population; infants < 3 months old Encephalitis 10-20% of proven encephalitis 7. GUT Manifestations nd  Orchitis – 2 only to mumps as causes  Nephritis  IgA Nephropathy DIAGNOSIS 1. VIRAL ISOLATION  Specimen: Stool, throat, CSF, Blood, Biopsy  Coxsackie A viruses unable to grow in culture → hard to isolate  Less specific in stool alone since viral shedding x 6-12 weeks in asymptomatic patients  When suspecting Viral Meningitis: use CSF specimen 2. Direct Testing for nucleic acid  RT-PCR for Enterovirus RNA in CSF  requested in viral meningitis  overcomes imperfect sensitivity and delayed results of culture TREATMENT  No specific therapy  Supportive therapy only

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V. POLIO VIRUS

Antigenic DRIFT Antigenic SHIFT

EPIDEMIOLOGY  Mode of Transmission: FECAL to ORAL  Incubation Period  3 – 6 days: Abortive Poliomyeltis  7 – 21 days: Paralysis in Paralytic Poliomyeltis CLINICAL FORMS 1. Non – paralytic poliomyelitis (aseptic meningitis) -1%  (+)Nuchal spinal signs  Abnormal superficial & Deep reflexes 2. Paralytic poliomyelitis – 0.1% a. Spinal Paralytic Poliomyelitis  Asymmetric flaccid paralysis or paresis  Usually one of the leg followed by one arm  Absent DTR (Deep tendon reflexes)  No Sensory loss b. Bulbar Poliomyelitis – may occur without apparent spinal cord involvement c. Polio encephalitis (rare) DIAGNOSIS VIRAL ISOLATION  2 stool specimens  Taken 24-48 hours apart  Within 14 days of onset of paralysis

• MINOR variations of Influenza B or A • Seasonal EPIDEMIC • MAJOR variations in HA or NA (Only with Influenza A) • Pandemics

CLINICAL MANIFESTATIONS 

Abrupt onset, with a predominance of systemic symptoms including high fever, myalgias, chills, headache, malaise, and anorexia (more than any other respiratory viruses)  Febrile (2 – 4 days), cough may persist longer  Indistinguishable from RSV, PARAINFLUENZA, & ADENOVIRUS COMPLICATIONS 1. Acute Otitis Media (25% of cases) 2. Pneumonia – primary viral or secondary bacterial infection (S. aureus) 3. Unusual Clinical Manifestations:  Acute Myositis (Influenza type B)  Toxic shock syndrome  Myocarditis  Encephalitis, myelitis, Guillian-Barre syndrome  Reye syndrome (use of salicylates during influenza type B infection)

TREATMENT  

No specific treatment Supportive treatment

CONTROL MEASURES OPV • Local Health Center • Primary series – 3 doses (Philippines) • Private Practice • 3 doses (Primary) + 2 Boosters (Philippines)

IPV • areas not at risk to wild type, immunodeficient patients • 3 doses (Primary) + 2 Boosters

VI. INFLUENZA  Types A, B, and C  Epidemic Disease: Type A and B  Influenza A sub classified by 2 surface antigens:  Hemaggutinin (HA) & Neuraminidase (NA)

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TREATMENT/MANAGEMENT • ANTI- VIRAL TREATMENT IS RECOMMENDED FOR:  High risk children with confirmed or suspected influenza  Children who are hospitalized  Children who have severe or progressive disease DOC: Oseltamivir (5 – 7 days) • Increase fluid intake • Control of fever with Paracetamol or Ibuprofen (NOT ASPIRIN)

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• Antibiotics – for bacterial super-infection ONLY  Suspected if with recrudescence of fever, prolonged fever, clinical deterioration (if uncomplicated, child should be well after 48-72 hours) PREVENTION • INFLUENZA VACCINE Recommended in:  Children 6 months – 18 years old  High risk children: chronic heart/lung/metabolic diseases, renal & hemoglobinopathies  Children on long term aspirin treatment

VII. PARAINFLUENZA 

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Primarily UPPER RESPIRATORY TRACT as low grade fever, rhinorrhea, cough, Pharyngitis x 1-3 days → hoarseness, barking cough, inspiratory stridor Articularly associated wth CROUP (laryngotracheitis/laryngotraheobronchitis) accounting for >50% of hospitalizations, 15% of bronchiolitis and pneumonia

DIAGNOSIS  

Based only on clinical and epidemiologic criteria CXR: “Steeple sign” or progressive narrowing of subglottic region

MANAGEMENT  

NO specific antiviral drug Preferred Management: Single dose of Oral Dexamethasone (0.6 mg/kg)

VIII. RESPIRATORY SYNCYTIAL VIRUS (RSV)   

Most common cause of Bronchiolitis & Pneumonia in 95% will present with signs and symptoms within 6 months  virus remains at the site of the bite (not yet at the nerve)  ONLY TIME WHEN VACCINATION IS EFFECTIVE 2. Prodome (2 -10 days) – virus reaches spinal cord 3. Acute neurologic phase (2 – 7 days) a. Encephalitic or furious rabies (80%)  Hyperactive episodes (combative, bizarre behaviour, apprehensive)  Hydrophobia (agitation, cringing due to painful contractions of laryngeal muscles upon drinking; eventually becomes psychologic; becomes agitated at site of water  Aerophobia (pathological aversion or sensitivity to air/movement of air) b. Paralytic or dumb rabies (20%)  Paralysis of bitten area → respiratory paralysis  Often missed; (-) hydrophobia & aerophobia  Recent or past encounter of animal  Rabies suspected if with paralysis/encephalitis 4. Coma (4 -10 days)  Complications: Myocarditis, DI, SIADH  Outcome: death due to respiratory paralysis

XII. HUMAN PAPILLOMA VIRUS  Majority ASYMPTOMATIC PREVENTION  Vaccine efficacy is OPTIMAL if administered before onset of sexual activity  Antibody response highest at age 9 – 15 years old  For Females 10 – 18 years old  Recommended schedule:  Bivalent (HPV 16 18) – 0, 1 and 6 months  Quadrivalent (HPV 6 11 16 18) - 0, 2 and 6 mos  Use of QUADRIVALENT HPV in males 10 -18 years of age for prevention of anogenital warts is optional

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DIAGNOSIS  usually made clinically  Pathognomonic: HYDROPHOBIA & AEROPHOBIA in a patient with history of exposure enough to make a diagnosis TREATMENT  No Specific Treatment  Rabies is better prevented than treated  Almost 100% mortality rate

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PREVENTION

4. ANTI – TETANUS PROPHYLAXIS

1. POST EXPOSURE PROPHYLAXIS (PEP)

5. PRE EXPOSURE PROPHYLAXIS (PrEP)  Benefits:  Need for RIG is eliminated even CAT III exposure  PEP vaccine is reduced from 5 to 2 doses  Day 0, 7, 28  IM or ID  0.5 ml PVRV or 1.0 ml PCECV (IM)  0.1 mo PVRV, PCECV (ID)

2. RABIES VACCINE  Given at:  Adults – deltoid area  Infants – anterolateral aspect of the thigh  Never administer at gluteal area  Day 0 is the day of the bite and followed by day 3, 7, 14, 28, 30  COMPLETE VACCINATION REGIMEN until DAY 28/30 if biting animal:  Lab proven to have rabies OR  Have signs and symptoms or rabies OR  Killed/died without lab testing OR  Cannot be observed for 14 days  MAY OMIT DAY 28/30 if biting animal:  Is alive AND remains healthy >14 days observation  Is killed or died within 14 days oberservation but FAT (-) AND confirmed without signs and symptoms of rabies 3. RABIES IMMUNOGLOBULIN  Infiltration of all CATEGORY III w/ RIG is MANDATORY

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XIV. HIV  Mother to Infant Transmission (Vertical)  Primary route of transmission  60 – 70 %( Intrapartum)  30 – 40 % (Before Delivery)  Risk of Transmission  In chronically infected women (9 – 16%)  In women with HIV postnatally • most commonly thru breastfeeding • substitute milk formula to breast milk CLINICAL MANIFESTATIONS • Symptoms more common in children than adults 1. Recurrent bacterial infections 2. Chronic parotid swelling 3. Lymphoproliferative Interstitial Pneumonitis 4. Early onset of progressive neurologic disorder 1. Infections  Recurrent bacterial infections caused by encapsulated organisms (pneumococcus, salmonella)

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 PCP Pneumonia  Most common OPPORTUNISTIC infection in children  Higher prevalence TB/HV co –infection in developing countries  Oral Candidiasis  Most common FUNGAL infection in HIV patients  Viral infections with Herpes viruses pose a significant problem; RSV and Adenovirus may present with prolonged symptoms and persistent viral shedding 2. Respiratory Tract  Recurrent otitis media and sinusitis are common  Initially, URTIs are common  Lymphoproliferative Interstitial Pneumonitis (LIP)  Most common Chronic LRT abnormality 3. Hematologic  Malignant diseases infrequent in children  Common reported neoplasms:  Non-Hodgkins’s Lymphoma  Primary CNS lymphoma  Leiomyosarcoma

DIAGNOSIS • 3 C’s  Confidential  Counselling  Consent 1. Serologic Test  Maternal antibodies may persist until 18 months of age, so antibody tests are not reliable for diagnosis in children less than 18 months of age  Detects IgG  ELISA (Screening Test)  WESTERN BLOT Assay (Confirmatory Test) 2. Definitive Virologic Diagnosis  HIV DNA PCR (preferred test)  Performed at 6 weeks old  A (+) virologic test should be confirmed by a repeat test 3. Laboratory Diagnosis of HIV among Children  More than 18 months  Antibody Testing → ELISA, Western Blot  Less than 18 months  Virologic testing HIV DNA PCR

4. SIGNS THAT MAY INDICATE POSSIBLE HIV INFECTION WHO PEDIATRIC CLINICAL ST AGING Clinical Staging I II III IV

HIV-associated Clinical Disease Classification Asymptomatic Mild Moderate/Advanced Severe

Category

A B B

• Clinical Staging 1: ASYMPTOMATIC • Persistent generalized Lymphadenopathy • Clinical Staging 2: MILD (mostly skin manifestations) • Unexplained persistent hepatosplenomegaly • Papular pruritic eruptions • Extensive molluscum contagiosum • Fungal nail infections • Recurrent oral ulcerations • Unexplained persistent parotid enlargement • Linear gingival erythema • Herpes zoster • Recurrent or chronic upper respiratory tract infection (otitis media/sinusitis) • Clinical Staging 3: ADVANCED  Unexplained moderate malnutrition not adequately responding to standard treatment  Unexplained persistent diarrhea (>14days)  Unexplained persistent fever (37.5 for > 1 month)

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PEDIA 3B FINALS REVIEWER - VIRAL INFECTIONS

Medicine2017

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Persistent oral Candidiasis Oral hairy leukoplakia Acute necrotizing ulcerative gingivitis or periodontitis Pulmonary tuberculosis Severe recurrent bacterial pneumonia Symptomatic lymphoid interstitial Pneumonitis Chronic HIV associated disease including bronchiectasis  Unexplained anemia (...