syndromic approach in diagnostic virology

Syndromic approach in

Diagnostic virology

Present by

Faris K-2013 MSc MLT Microbiology

Moderator

Mr. T. Gopakumar, Asst. Professor

Dept of MLT, GMCT

Syndrome

A syndrome is a set of medical signs and symptoms that are correlated with each other and, often, with a specific disease.

There is no single step diagnostic procedure in viral disease – we rule out a viral disease in syndrome based testing.

What we discus here?

Different types of syndromes Syndrome related viral infection

Major Clinical Syndromes

1.Fever

2. Influenza like illness(ILI)

3. Severe acute respiratory illness (SARI)

4. Dengue like illness DLI(fever + myalgia)

5. Fever + Arthralgia

6. Fever + rash(measles like)

7. Fever + parotitis(mumps like)

Syndromes

8. Acute encephalitis syndrome(AES)

9. Acute Respiratory Distress Syndrome(ARDS)

10. Acute jaundice syndrome

11. Acute diarrhea syndrome

12. Acute hemorrhagic fever syndrome

13. Syndromes involving conjunctivitis

Syndromes

Congenital viral infections

1.Fever

Elevation of body temperature that exceeds the normal daily variation. Shift from normothermic to febrile levels

Normal body temperature

Normal body temp. in healthy humans(18-40yrs) mean oral temp=36.8◦ C (98.2◦F+/_0 .7◦F) Normal daily temp.variation-0.5-0.9◦C Rectal temp.-0.4◦C or 0.7◦F higher than oral readings

Fever without a focus Diagnostic challenge Fever may be due to many reason • Bacteremia/Sepsis • Secondary to a focal infection • Any non specific presentation of a disease • Parasitic, Fungal infection • Viral (acute onset) hyper/hypothermia tachypnea/tachycardia Shock

INFLUENZA LIKE ILLNESS

Case Definition: Sudden onset of fever>100 0F

Cough and or/ sore throat AND An absence of other diagnosis

Severe Acute Respiratory Illness (SARI)

Case definition for persons> 5years - Sudden onset of fever, and Cough or sore throat, AND Shortness of breath/difficulty in breathing

OR Any child <5yrs old clinically suspected of having pneumonia or severe /very severe pneumonia

Causes of ILI & SARI

DLI(fever+myalgia)

Definition:

• A diagnosis of DLI is established on the basis of clinical features and supporting non serologic laboratory investigations •With negative /incomplete serologic testing can be included

Differential diagnosis-Denguefever

Conditions that mimic febrile phase of dengue viral infection

FLU LIKE SYNDROMES

FEVER WITH DIARRHEA RASH

Iillnesses with Neurological manifestations

Others

INFLUENZA CHIKUNGUNYA

HIV (seroconversion state)

Rubella Measles Chikungunya Drug reactions

Meningococca l infection

Rota virus other enteric infections

Other causes of meningoencephalitis

Febrile seizures

Leptospirosis Rickettsial infection Enteric fever Malaria Viral hepatitis Brucellosis

Conditions that mimic critical phase

Bacterial Viral Parasitic

Leptospirosis Rickettsial infections

Acute gastero enteritis

Typhoid Bacterial sepsis

Septic shock

Viral hepatitis Other causes of Viral hemorrhagic fevers like Kayasanur forest disease ,Crimean congo hemorrhagic fever

Malaria

Others- acute leukemia

-other malignancies -other causes of acute

abdomen -platelet disorders

Fever with rash (measles like illness) rash is an area of skin that has become redden/swollen/irritated

Measles rash-early

Measles -late rash

RUBELLA RASH

ENTEROVIRUS RASH

Hand foot mouth disease

Hand foot mouth disease

Hand foot mouth disease

Exanthem subitum (Roseola infantum)

• Human Herpes Virus HHV-6/HHV-7

Chicken pox rash

Erythema infectiosum(ParvovirusB19)

Dengue rashes

Dengue rashes

• • fev Dengue

HemorrhagicFever(DHF)

Rickettsial infection

Rickettsial infection-eschar

Fever with parotitis (mumps like infection)

Acute encephalitis syndrome(AES)

Definition • A person of any age, at any time of the year with acute onset of fever, a change in mental status (confusion, disorientation, coma, inability to talk) AND/OR New onset seizures(excluding simple febrile seizure)

Acute encephalitis syndrome causing agents

AES in immunocompromised

Fever with ARDS

Acute respiratory distress syndrome (ARDS) occurs when fluid builds up in the air sacs (alveoli) lungs. less oxygen can reach bloodstream.

Acute onset PaO2 /FiO2 (fraction of inspired oxygen) <200mmHg. X-ray bilateral infiltrates. Pulmonary arterial occlusion.

ARDS causing agents

Acute Jaundice syndrome

• Definition :acute onset of jaundice and severe illness AND

• Absence of known predisposing factors

Causes acute Jaundice syndrome

Acute Diarrhea Syndrome

• Definition :Acute diarrhea and severe illness AND absence of known predisposing factors •Diarrhea :Increased frequency of defecation or recent change in consistency and character of stools •If lasts more than 3 weeks it is known as chronic diarrhea . Viral infections cause watery diarrhea

Causes of watery diarrhoea

Acute hemorrhagic fever syndrome

DEFINITION: Acute onset of fever of less than 3 weeks duration And any two of the following. Hemorrahagic or purpuric rash Epistaxis (bleeding from nose) Hemoptysis (coughing up of blood)

Blood in stool Other hemorrhagic symptoms AND absence of known predisposing factors

Viral conjunctivitis

Acute hemorrhagic conjunctivitis

Signs are similar in EV70,CoxsackieA24,A24v Oedematous swelling of lids in 72-100% cases

(swelling subsides in 3-4 days) Pre-auricular lymph node enlargement - majority

are tender Upper conjunctiva becomes inflamed with

injection, infiltration, and follicle formation. Follicular conjunctival response

Acute hemorrhagic conjunctivitis

Enterovirus Diffuse patchy conjunctival

haemorrhage Hemorrhagic patches

diffusely distribute in the bulbar conjunctiva -3 days after onset

Complication of AHC

Moderate epithelial keratitis and conj. hyperemia

0.3-3% in AHC

Molluscum contagiosum

Produced by Pox virus Transmission-direct contact in children Sexual activity in adults Round, whitish-pink, nodules (2-3mm) with

umblicated centre Frequent in eye lid margin Unilateral lesions Multiple in immunocompromised

Molluscum contagiosum

Congenital infections

Rubella CMV Herpes Varicella Parvovirus B19 infection

Non immune hydrops

Conclusion

Syndromic approach in diagnosis means choosing a diagnosis process based on clinical presentations, sign and symptoms.

Syndromic approach is necessary for the diagnosis of viral infections.