DIAGNOSIS AND MANAGEMENT OF SWINE FLU

A MOHAMED KASIM

TOPICS TO BE DISCUSSED:

• DIAGNOSTIC TESTS FOR SWINE FLU.

• INDICATIONS FOR TREATMENT.

• PRIMARY AND ALTERNATIVE REGIMENS .

• ANTI-VIRAL PROPHYLAXIS AND VACCINATION.

DIAGNOSTIC TESTS FOR SWINE FLU:• NON SPECIFIC FINDINGS:1- COMPLETE HEMOGRAM: Leucopenia, thrombocytopenia and anemia.

2- LIVER FUNCTION TEST:- Raised liver enzymes and elevated bilirubin.

3- OTHERS: Increased CPK and LDH.

4- X-RAY: Bilateral infiltrates(lower lobe predominance).

5- CT CHEST: Patchy consolidation or ground glass opacities.

SPECIFIC FINDINGS:

1- RT-PCR: Highly sensitive and very high specific. Usually recommended for clinical diagnosis faster turnaround time.Specimens usually taken from nasopharyngeal swab or throat swab, sometimes tracheal aspirates in intubated patients.

2- VIRAL CULTURE: Moderately sensitive and has highest specificity, usually recommended for public health surveillance and not useful in clinical situations due to long turnaround time.

3- RAPID ANTIGEN TEST: Not recommended nowadays.

INDICATIONS FOR TREATMENT:1- ILLNESS REQUIRING HOSPITALISATION.

2- PROGRESSIVE, SEVERE OR COMPLICATED ILLNESS, REGARDLESS OF PREVIOUS HEALTH STATUS.

3- EXTREMES OF AGE.

4- PREGNANT WOMEN AND WOMEN UPTO TWO WEEKS OF POSTPARTUM.

5- INDIVIDUALS WITH HIGH RISK MEDICAL CONDITIONS AND THOSE WHO ARE OBESE

ANTIVIRALS USED IN SWINE FLU:Common anti-viral agents used to treat are neuraminidase inhibitors and M-protein inhibitors.

1- Oseltamavir and Zanamavir – Neuraminidase inhibitors.

2- Amantadine and Rimantadine- M-protein inhibitors.

PRIMARY REGIMENS FOR ADULTS:

1- Oseltamavir 75mg BD for 5days.2- Zanamavir 2 inhalations of 5mg each for 5days.

ALTERNATIVE AND NEWER REGIMENS:

1-Peramavir 600mg IV single dose – longer duration, may be considered for severe disease.

2- Zanamavir 600mg IV BD for 5days in patient not tolerating oral oseltamavir or suspected/confirmed cases of oseltamavir resistance.

SUPPORTIVE CARE:1- IV fluids.

2- Anti-pyretics.

3- Oxygen support for hypoxic patients.

4- Low tidal volume ventilation for mechanically ventilated patients.

5- Patients with Pandemic H1N1 can develop pneumonia and should be treated for Community acquired pneumonia.

6- Adjunctive approaches have been evaluated including ECMO, NAC and glucocorticoids.

PREVENTION OF SWINE FLU:• 1- Face masks- N-95 or triple layered surgical mask.

• 2- Frequent hand wash.

• 3- Adherence to cough etiquettes by the patient.

• 4- Contact surfaces should be disinfected with sodium hypochlorite or household bleach (5%).

• 5- Adult patients should be isolated until their symptoms subside.

• 6- In children the isolation period is little longer due to prolonged excretion of viruses.

ANTI-VIRAL PROPHYLAXIS Prophylaxis should be considered for adults and children who had close contact with a confirmed or suspected cases.1- Adults who are at high risk for complications of influenza.

2- Pregnant women and women who are up to two weeks post-partum.

3- Children who are less than 5yrs of age or who are at high risk for complication for influenza.

4- Healthcare workers and emergency medical personnel.

DOSE REGIMENS FOR PROPHYLAXIS:

1- Oseltamavir 75mg once daily for 10 days.

2- Zanamavir inhaled powder – 10mg once daily for 10days.

VACCINATION• 1- H1N1 vaccine should be given to all patients from six month of age or older.

• 2- Priority should be health-care personnel.

• 3- Available Vaccines are IIV, LAIV, RIV. The most common used is the IIV.

• 4- The selection of vaccine subunits is based on the strain prevalence in the previous year. Efficacy is 70-80%.

• 5- It takes 2 to 3 weeks for the immunity to develop.

• 6- Risks of GBS, narcolepsy, transverse myelitis have been reported

THANK YOU.