dengue

HOW TO DIAGNOSE DENGUE : 

HOW TO DIAGNOSE DENGUE DR . Nadeem-Ur-Rasool Department Of Pediatrics Lahore General Hospital , Lahore

Dengue Transmission Cycle : 

Dengue Transmission Cycle

Bleeding from where? : 

Bleeding from where? Bleeding into skin From Gums From Nose Into our food passages Blood in urine

Child with Dengue : 

Child with Dengue

Bleeding into Skin : 

Bleeding into Skin

Bleeding from Mouth : 

Bleeding from Mouth

Bleeding Per Rectum : 

Bleeding Per Rectum

Slide 8: 

Máculo-Pápular Rash JMCC

Slide 9: 

JMCC Rash

Bleeding spots in skin : 

Bleeding spots in skin Dengue Normal

Skin bleeds : 

Skin bleeds

Bleeding into the eye : 

Bleeding into the eye

What do we experience ? : 

What do we experience ? 2–7 days after the mosquito had its dinner on us we may develop Sudden onset of fever, chills, headache Back pain with severe muscle and joint pains Pain behind the eyes and on moving the eyes Nick name - Break bone fever- pains so severe Red patches or spots on the skin Mild nose bleeds This is the ordinary classical Non dangerous form!

What is the end result? : 

What is the end result? Complete recovery is the rule Severe weakness many persist for many days after the fever leaves us

Dengue – The bleeding form : 

Dengue – The bleeding form Blood vessels are affected There is severe oozing into tissues Bleeding into all possible parts of body Blood clotting mechanism is disrupted Blood pressure falls and many end in collapse and death In the best centers 5% of this type of Dengue will reach their forefathers

Rare types of Dengue : 

Rare types of Dengue Brain fever Liver damage Heart damage Severe bleeding into stomach

Pathophysiology : 

Pathophysiology Transmitted by the bite of Aedes mosquito (Aedes aegypti) Incubation 3-14 days Acute illness and viremia 3-7 days Recovery or progression to leakage phase

Pathophysiology : 

Pathophysiology Dengue virus enters and replicates within monocytes, mast cells, fibroblasts Innate and adaptive immune response Cytokine release: TNF-a, IL-2, IL-6, IL-8 Compliment activation Antibody dependent enhancement (ADE) thought to contribute to severe infections T-cell activation: CD4 and CD8 cells cytokine production

Pathophysiology : 

Pathophysiology Capillary Leak Syndrome: Transient increased capillary permeability due to endothelial cell dysfunction Widening of tight junctions Cytokine release and complement activation Leukopenia, Thrombocytopenia and Hemorrhagic diathesis: Direct viral bone marrow suppression Platelet destruction in DHF ?Molecular mimicry between viral protein and coagulation factors

Slide 20: 

Exams and Investigations

Physical Examination may reveal the following: : 

Physical Examination may reveal the following: Low BP A weak, rapid pulse Rash Red eyes Red throat Swollen glands Enlarged liver (hepatomegaly)

Laboratory Tests in Dengue Fever : 

Laboratory Tests in Dengue Fever Clinical laboratory tests tests CBC—WBC, platelets, hematocrit Albumin Liver function tests Urine—check for microscopic hematuria RFT’s Dengue-specific tests Virus isolation Serology PCR ECG Abdominal & Chest U/S BT , CT ,PT , APTT Serum Electrolytes ABG’s FDP

Test may iclude the following: : 

Test may iclude the following: Hematocrit Platelet count Electrolytes Coagulation studies Liver enzymes Blood gases Torniquet test (causes petechiae below the torniquet) X-ray of the chest (may demonstrate pleural effusion) Serologic studies (demonstrate antibodies to Dengue viruses) Serum studies from samples taken during acute illness and convalescence (High in titer to Dengue antigen)

Laboratory Findings : 

Laboratory Findings Leukopenia Thrombocytopenia (<100,000) Modest liver enzyme elevation (2-5x nml) Serology: Acute phase serum IgM (+6-90 days) ELISA Acute and convalescent IgG (99% sens, 96% spec) Hemagglutination inhibition assay (HI) is gold standard. Paired acute and convalescent HI assay, positive if >4 fold titer rise

Slide 25: 

Outbreak Investigations Surveillance Vaccine Trials Viral Isolation Nucleic Acid Detection RT-PCR Real time RT-PCR Isithermal Amplification Methods Detection Of Antigens Serology

Slide 26: 

NS1 detection Virus isolation RNA detection IgM Secondary IgM Primary Viraemia IgG Secondary IgG Primary Infection ≥25 60 80 0 -2 -1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16-20 21-40 41-60 61-80 90 >90 Days O.D O.D Onset of symptoms (days) Approximate time-line of primary and secondary dengue virus infections and the diagnostic methods that can be used to detect infection

Comparison of diagnostic tests according to their accessibility and confidence : 

Comparison of diagnostic tests according to their accessibility and confidence ACCESSIBILITY Direct Method INdirect Method Virus isolation Genome detection NS1 detection Serology IgM Serology IgG CONFIDENCE

Summary of operating characteristics and comparative costs of dengue diagnostic methods : 

Summary of operating characteristics and comparative costs of dengue diagnostic methods

Interpretation of dengue diagnostic tests : 

Interpretation of dengue diagnostic tests

Advantages and limitations of dengue diagnostic methods : 

Advantages and limitations of dengue diagnostic methods

Proposed model for organization of laboratory services : 

Proposed model for organization of laboratory services Functions

Dengue laboratory diagnosis: examples of good and bad practice : 

Dengue laboratory diagnosis: examples of good and bad practice

POSITIVE TORNIQUET TEST : 

POSITIVE TORNIQUET TEST

Slide 34: 

Virus Isolation: Cell Culture

Special Test (ELISA) : 

Special Test (ELISA) ELISA Plate IgM-capture ELISA

Dengue rapid test device : 

Dengue rapid test device

DHF is characterized by; : 

DHF is characterized by; Raised haematocrit (PCV) due to plasma leakage Redused platelet count Hepatomegaly Haemorrhagic symptoms with bleeding into the skin

Differential Diagnosis : 

Differential Diagnosis Viral: Influenza, HIV, Hepatitis A, Yellow Fever, Hantavirus, Measles, Rubella, Coxsackie and other enteroviruses, parvovirus B19, Chikungunya virus, EBV Bacterial: Typhoid, Scarlet fever, Meningococcemia Parasitic: Malaria, Leptospirosis, Rickettsial disease, Leishmaniasis, Chagas disease Fungal: Cryptococcus, Blastomycosis, Histoplasmosis Non-Infectious: Malignancy, rheumatic, vasculitis, drug fever, other miscellaneous

Differential Diagnosis : 

Differential Diagnosis Mosquito Borne Illnesses Protozoa: Malaria Roundworm: Filariasis, dirofilariasis Alphaviruses: Chikungunya fever, Mayaro fever, Ross River fever, Eastern, Western, and Venezuelan equine encephalitis Flaviviruses: West Nile fever, Zika fever, St. Louis encephalitis, Japanese encephalitis, Yellow Fever Bunyaviruses: LaCrosse encephalitis, Oropouche virus, Bwamba fever, California encephalitis

Differential Diagnosis of Dengue : 

Differential Diagnosis of Dengue Influenza Measles Rubella Malaria Typhoid fever Leptospirosis Meningococcemia Rickettsial infections Bacterial sepsis Other viral hemorrhagic fevers

VIRAL HEMORRHAGIC FEVERS : 

VIRAL HEMORRHAGIC FEVERS *Patients may be contagious;nosocomial infections are common. † Chikungunya virus is associated reported in some cases.

Patient Follow-Up : 

Patient Follow-Up Patients being treated at home should be instructed regarding; The appearance of danger signs and told to return should any occur. Repeat clinical evaluation should be considered, with timing based on the physician's judgment, remembering that DSS most commonly occurs at 3-6 days after symptom onset. Patients with bleeding manifestations should have serial hematocrit and platelet levels checked at least daily until their temperature is normal for 1-2 days. If the blood sample was taken the first five days after the onset of symptoms, a convalescent-phase sample to measure IgM antibody is needed between 6-30 days after the onset of symptoms. A blood sample should be taken from all hospitalized patients at the time of discharge or death

Indications for Hospital Discharge : 

Indications for Hospital Discharge Absence of fever for 24 hours (without anti-fever therapy) and return of appetite Visible improvement in clinical picture Stable heamatocrit 3 days after recovery from shock Platelets >50,000/mm³ No respiratory distress from pleural effusions/ ascites