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Common Viral infections in Africa: Surveillance for HAI Resp infections
4th Nov 2014, 5th ICAN/ICAZ conference
Division of Global Disease Detection and Emergency Response
Center for Global Health
Dr. Linus Ndegwa, MPHE, HCS,SHEA AmbInfection Control, Manager
Global Disease Detection-GDD
Centers for Disease Control and Prevention-Kenya
Influenza
Influenza: serious respiratory illness, can be debilitating and cause complications leading to hospitalization and death
Most affected: very young, persons with underlying medical conditions and elderly
2
Global impact of influenza
Globally, seasonal influenza causes 3-5 million cases of severe illness and 300,000-500,000 deaths
Past pandemic influenza associated with millions of deaths
1918: “Spanish Flu” 1957: “Asian Flu” 1968: “Hong Kong Flu”
20-40 million deaths 1-4 million deaths 1-4 million deaths 3
Influenza virus
Influenza A and B viruses are of epidemiological interest in humans
Types B and C limited to humans
Type A viruses are more virulent and affect many species
Antigenic determinants of influenza A and B are: Haemagglutinin (HA) and Neuraminidase (NA) glycoproteins
4
Influenza Virus
Hemagglutinin It is a glycoprotein Receptor that binds host cells
inducing penetration of the virus
Antigenic sites at the outer surface
Antibodies to HA are protective
5
Influenza Virus
Neuraminidase (NA): 9 known
Helps release virions from cells
Antibody to NA can help modify disease severity
6
Influenza Virus
Antigenic drift and shift:
arises from mutations in the antigenic sites reducing biding of neutralizing antibodies
7
Influenza Virus
Antigenic shift (genome re-assortment)
arises when the HA is exchanged in a virus e.g. H1 replaced by H5
8
Influenza virus
Influenza A viruses subtypes:
– 16 HA (H1-H17)
– 9 NA (N1-N9) subtypes
9
Epidemiology of Influenza
Virological Pattern: Northern Hemisphere
10
Epidemiology of Influenza
Virological Pattern: Southern Hemisphere
11
Epidemiology of InfluenzaVirological Pattern: Kenya
12
Burden of seasonal influenza in Kenya
Influenza circulates at least 11 months per year Influenza detected in : 10-12% of respiratory hospitalizations annually, >30% during periods of peak circulation 8.7% of rHAI in 30months surveillance
Highest rates in children < 6 months Influenza-associated hospitalizations in children
<5 years are 3-7 times higher than in the United States, despite less care-seeking
persons with HIV more likely to spread influenza in their homes
Current Epidemic and Pandemic Threats!
Pathogen Date of first report
Laboratory-confirmedcases
Deaths Case Fatality Proportion
Date of last reportedcase
A(H5N1) January, 2004 668 393 58.8% Sep, 2014
A(H7N9) February, 2013
453 175 38.6% Aug, 2014
Middle East Respiratory SyndromeCoronavirus
June, 2012 885 319 36% Oct, 2014
Transmission
Influenza viruses transmitted via air droplets Close contact (up to 3-6 feet) is required for transmission Transmission may also occur through:
– direct skin-to-skin contact – indirect contact with respiratory secretions – Touching contaminated surfaces then touching the eyes,
nose or mouth)
15
Transmission
Incubation period 1-2 days
Individuals may spread influenza virus from up to 2 days before to 5 days after onset of symptoms
Children can spread the virus for 10 days or longer
Immunocompromized persons also tend to shed the virus longer
16
Clinical Presentation
17
Complications of Human Influenza
Pneumonia– primary influenza pneumonia the most severe– secondary bacterial pneumonia being the most common – mixed viral and bacterial pneumonia frequently occurs
Secondary bacterial pneumonia is most commonly caused by :– Streptococcus pneumoniae, – Staphylococcus aureus– Haemophilus influenzae
Chronic cardiac and pulmonary disease predispose Reye’s syndrome in children with Flu B
18
Influenza Prevention and Control
Non pharmacologic– Surveillance – Isolation and quarantine– Social distancing– Respiratory protection– Cough and sneeze etiquette– Hand washing
Pharmacologic– Vaccination– Antiviral drugs
19
Historically no routine
surveillance for HAIs
Kenyan hospitals:
– Patient overcrowding
– Inadequate hand hygiene
We set up surveillance
for respiratory HAI started
Infection Control and Prevention in Kenya
Objectives
To document respiratory HAIs occurring on selected wards in 3 Kenyan hospitals
To identify the viruses causing respiratory HAIs
Surveillance sites Prospective surveillance
Site: 3 selected hospitals
– Kenyatta National hospital: 1800 beds
– Mbagathi District hospital: 200 beds
Apr 1, 2010
Wards
– Medical
– Pediatric
– The ICU
Surveillance Sites
Hospitals
Case Definition: Respiratory HAIs
Inclusion Criteria:
– Patients admitted >3 calendar days• Admit date: Day 1
– New onset fever/hypothermia
• (≥38°C or <35°C)
• No fever/hypothermia in past 3 days
– New onset of cough or sore throat
Written consent
Laboratory tests
Nasopharyngeal/oropharyngeal swabs collected
Samples tested by real time RT-PCR
Samples collected and tested for:
– Influenza A & B
– Adenovirus
– Respiratory syncytial virus (RSV)
– Human metapneumovirus (HMPV)
– Parainfluenza virus 1, 2 and 3. (PIV 1,2,3)
Laboratory tests
Specimens positive for influenza A were subtyped
– Seasonal H1N1
– Pandemic H1N1
– H5N1
– H3N2
Surveilance
Surveillance officers at each site
Review of in-patients records for new onset of signs and symptoms
Approved by:
– Kenya Medical Research institute ERC
– CDC- Atlanta IRB
Results
Sampling for Respiratory HAI
18545 cases of fever or hypothermia
documented
1255 occurred >3days after admission
with no fever in past 3days
379 with respiratory symptoms
concurrent with fever/hypothermia
In 17 instances, patient
refused swabbing or no
consent obtained112 Swabbed
Respiratory HAIs : Demographics
Conclusion
Surveillance showed that rHAI occurred consistently during the 30 months period
Rates are similar to those in other developing nations
Most cases were positive for at least 1 viral pathogen
Infection control should be strengthened
Continued HAI surveillance critical to monitor the burden of HAIs and impact of control measures
Acknowledgements
ICAN president: Prof. Shaheen
ICAN president: prof Val
Founder and president OASIS: Prof SolomKin
Kenyatta National Hospital
Mbagathi District Referral Hospital
New Nyanza Provincial Hospital
Ministry of Health – Kenya
CDC – Kenya
Div. Healthcare Quality Promotion
CDC – Atlanta
The findings and conclusions in this presentation/report are those of the
author and do not necessarily represent the views of the Centers for
Disease Control and Prevention
Are there any questions?
Protect your patients. Protect yourself. Protect your family.
Asante Sana (Thank you)