This document discusses the syndromic approach to diagnosing viral infections. It defines a syndrome as a set of signs and symptoms that are correlated. There is no single test to diagnose viral diseases, so syndromic testing looks at patterns of symptoms. Major clinical syndromes presented include fever, influenza-like illness, respiratory illness, rash, and others. For each syndrome, typical viral causes are outlined. The syndromic approach guides diagnosis of viral diseases based on presenting symptoms.

1. Syndromic approach in
Diagnostic virology
Present by
Faris K-2013 MSc MLT Microbiology
Moderator
Mr. T. Gopakumar, Asst. Professor
Dept of MLT, GMCT

2. 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.

3. What we discus here?
 Different types of syndromes
 Syndrome related viral infection

4. 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)

5. 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

6. Syndromes
 Congenital viral infections

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

8. 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

9. 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

10. INFLUENZA LIKE ILLNESS
Case Definition: Sudden onset of fever>100 0F
 Cough and or/sore throat AND
 An absence of other diagnosis

11. 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

12. Causes of ILI & SARI

13. 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

14. Differential diagnosis-Denguefever

15. 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

16. 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

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

19. Measles rash-early

20. Measles -late rash

21. RUBELLA RASH

22. ENTEROVIRUS RASH

23. Hand foot mouth disease

24. Hand foot mouth disease

25. Hand foot mouth disease

26. Exanthem subitum (Roseola infantum)
•
Human Herpes Virus
HHV-6/HHV-7

27. Chicken pox rash

28. Erythema infectiosum(ParvovirusB19)

29. Dengue rashes

30. Dengue rashes
 •
 •
 fev Dengue
Hemorrhagic
Fever(DHF)

31. Rickettsial infection

32. Rickettsial infection-eschar

33. Fever with parotitis (mumps like infection)

34. 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)

35. Acute encephalitis syndrome causing agents

36. AES in immunocompromised

37. 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.

38. ARDS causing agents

39. Acute Jaundice syndrome
• Definition :acute onset of jaundice and severe illness
AND
• Absence of known predisposing factors

40. Causes acute Jaundice syndrome

41. 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

42. Causes of watery diarrhoea

43. 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

51. Viral conjunctivitis

52. 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

53. Acute hemorrhagic conjunctivitis
 Enterovirus
 Diffuse patchy conjunctival
haemorrhage
 Hemorrhagic patches
diffusely distribute in the
bulbar conjunctiva -3 days
after onset

54. Complication of AHC
 Moderate epithelial
keratitis and conj.
hyperemia
 0.3-3% in AHC

55. 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

56. Molluscum contagiosum

57. Congenital infections
 Rubella
 CMV
 Herpes
 Varicella
 Parvovirus B19 infection

66. Non immune hydrops

67. 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.