Prepared by : Assoc. Prof Dr Zarina Dato’ Abdul Latiff,
Novel H1N1 is a new influenza virus which was first detected in humans, in the United States in April 2009. With the rapid spread of confirmed cases globally, WHO signaled a pandemic of H1N1 flu on June 11 2009. Spread of novel H1N1 virus is thought to occur in the same way that seasonal flu spreads. Flu viruses are spread mainly from person to person through coughing or sneezing by people with influenza. Sometimes people may become infected by touching something – such as a surface or object – with flu viruses on it and then touching their mouth or nose. The symptoms of novel H1N1 flu virus in people include fever, cough, sore throat, runny or stuffy nose, body aches, headache, chills and fatigue. A significant number of people who have been infected with this virus also have reported diarrhoea and vomiting. Illness with the new H1N1 virus has ranged from mild to severe. While most people who have been sick have recovered without needing medical treatment, hospitalizations and deaths from infection with this virus have occurred.
Based on local reports, certain individuals are at “high risk” of serious complications. This includes people 65 years and older, children younger than five years old, pregnant women, and people of any age with certain chronic medical conditions. About 70 percent of people who have been hospitalized with this novel H1N1 virus have had one or more medical conditions previously recognized as placing people at “high risk” of serious seasonal flu-related complications. This includes pregnancy, diabetes, heart disease, asthma and kidney disease.
With the rapid increase in the number of confirmed H1N1 cases within Malaysia, medical practitioners are now challenged with an overwhelming number of patients, with influenza-like illness, who have sought medical attention for a probable diagnosis of H1N1 flu. The following is a summary of the management guidelines for Influenza A-H1N1 for paediatric patients based on the Malaysian Ministry of Health.
A confirmed case of novel influenza A(H1N1) in children is defined as a child (< 12 years old) who has influenza-like illness (fever ≥ 38 °C with cough and/or sore throat) and confirmed positive laboratory tests either by real-time PCR or viral culture.
Signs and Symptoms
Most influenza A(H1N1) infection in children are mild and self-limiting. The common symptoms on presentation are fever ≥ 38 0C (100%) and cough (100%), sore-throat (66%), myalgia (44%), vomiting and diarrhea ( 25%). Other uncommon presentations are altered conscious level (10%) or hypotension or sepsis-like picture. (Mexico and U.S case series)
Only 10% of influenza A(H1N1) infection require admission. The two most common reasons for admission are pneumonia and dehydration. Mild cases of Influenza-like illness do not need admission and no investigations are needed. For children nursed at home, they will need to be monitored daily by parents or guardian for appearance of new symptoms or worsening of symptoms that suggest complications.
Criteria for admission
Children with influenza-like illness (fever ≥ 38 °C with cough and/or sore throat) with moderate to severe disease as listed as below:
- Severe respiratory distress
- Increased respiratory rate.
- Oxygen saturation ≤92% on pulse oximetry, breathing air or on oxygen.
- Respiratory exhaustion or apnoeic episode
- Evidence of severe clinical dehydration or clinical shock
- Altered conscious level
- Other clinical concerns e.g. a rapidly progressive or an unusually prolonged fever or persistent diarrhea or vomiting
Once admitted, all hospitalized patients (those with moderate to severe disease) with confirmed or suspected novel influenza A H1N1 should be started on antiviral treatment. The antiviral treatment maybe stopped if the RT-PCR results are negative.
Patients admitted with moderate to severe disease with co-morbid factors (Table 1) should be observed more closely as they may have more severe and rapid progression of disease.
|Table 1 : List of co-morbid factors
Respiratory specimens that are taken to diagnose InfluenzaA-H1N1 infections are nasopharyngeal aspirate or nasal / throat swab. These specimens are taken under full PPE.
Care-givers who look after their children should be given a 3-ply surgical mask. Visitors should be limited to caregiver only.
Post exposure chemoprophylaxis in children
Chemoprophylaxis is indicated for close contact who fulfill the following criteria:
- Children < 2 years old with co-morbidity (Refer Table 1). AND
- Within 48 hours of close contact with a confirmed index patient.
Close contact are defined as those living in the same house / premise (household contacts) and those who have sustained close contact (< 3feet) for at least 4 hours.
Recommendation for Home Assessment for Pediatric patients
For children nursed at home, child need to be monitored daily by parents or guardian for appearance of new symptoms or worsening of symptoms that suggest complications.
Drugs used in treatment and prophylaxis for children
Most commonly used anti-viral for influenza is oseltamivir. Duration of chemoprophylaxis is for 10 days (daily dose) and for treatment 10 days (BD dose)
The reported side effects are gastrointestinal i.e. nausea, vomiting and abdominal pain. These side effects may be mitigated by administration with food. There are limited data on the use of oseltamivir in children less than 12 months of age, studies in older children had shown oseltamivir to be effective in treatment of seasonal flu by reducing duration of symptoms. Use of oseltamivir was also associated with a reduction in the incidence of antibiotic use and lower respiratory tract infections.
Postpartum women who are not ill with influenza should be encouraged to initiate breastfeeding early and feed frequently. Women with influenza-like illness are recommended to use facemasks when providing infant care and feedings. Hand hygiene and cough etiquette (cover nose and mouth during coughing/sneezing) must be practiced at all times.
Babies born to infected H1N1 mother can be discharged home if they are asymptomatic and clinically well. However , in this situation mother will have to be advised regarding the home assessment tool.
Infection control guidelines
Standard infection control principles and droplet precautions must be practiced by all health care staff dealing with patients who have or are suspected of having influenza.
- Health care workers and visitors must perform hand hygiene regularly, including when removing gloves.
- Patients with Influenza like illness (ILI) should be encouraged to perform hand hygiene frequently.
Personal protective equipment
Personal Protective Equipment (PPE) – Advice for use during Procedures (including Collection of Swabs for Influenza Diagnosis)
- Health care workers should routinely wear a surgical mask, protective eyewear and disposable gloves if they are undertaking an examination of an individual with ILI that may lead to coughing (e.g. collecting nose and/or throat swabs).
- All health care workers in the same room when aerosol-generating procedures are undertaken on ILI patients should use N95 respirators, protective eyewear, a disposable gown and disposable gloves. Aerosol-generating procedures include endotracheal intubation, nebulized medication administration, airway suctioning, bronchoscopy, diagnostic sputum induction, positive pressure ventilation via face mask, and high frequency oscillatory ventilation. These procedures should only be performed in a single room with the door closed.
- Administration of medication via nebulisers is not recommended. Use spacers where possible.
|Table 2. Use of Personal Protective Equipment (PPEs)|
|Entry to cohorted area but no contact with patients||Close Contact with patient (within 3 feet)||Aerosol generating procedures ° (see Reference 1 below)|
|Plastic Apron||No °°||Yes||Yes|
|Eye Protection||No||Risk Assessment@||Yes|
Home Assessment Tool for Parents and Caregivers
For children nursed at home, they need to be monitored daily by parents or guardian for appearance of new symptoms or worsening of symptoms that suggest complications.
Children should be brought to the nearest hospital for further assessment if they developed the following symptoms and signs:
- Lethargy or poor oral intake
- Change in mental status or behavior eg. drowsiness , irritability
- Signs of dehydration: sunken eyes, dry tongue, absence of tears during crying or poor urine output.
- Increasing respiratory rate: fast breathing, noisy breathing, presence of chest recession (chest in-drawing)
- Persistent fever > 3 days.