1. A N A D A P T A T I O N F R O M C D C P R E S E N T A T I O N , W H O
F A C T S H E E T S A N D N E M A E P I D E M I C S U P D A T E .
A N U G O M A . E M E K A
Lassa Fever Presentation.

2. Welcome & Introductions
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 Logistics
 Emergency exits
 Restrooms

3. Agenda
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 Lassa fever Disease
 Importance of Topic.
 Clinical Signs and Symptoms.
 Diagnosis and Treatment
 Preventing Lassa fever

4. What is Lassa Fever?
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 A viral haemorrhagic fever caused by
the Arenavirus Lassa. A single
stranded RNA virus that is animal-
borne. This was discovered following
the death of two Nurses in Nigeria in
1969 and named after the town in
Borno state, Nigeria, where it was
first discovered.
 Transmitted from rodents to humans.
The species of rats transmitting this
disease is prevalent in West Africa.
(‘The multimammate rat’, mastomys
species-complex), and is spread via
their urine and droppings.

5. What is Lassa Fever?
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 There is secondary human to human
transmission, via body fluids exchange or
in hospitals, via reused needles or
contaminated medical equipment
 The virus can be transmitted through
direct contact with these materials or via
cuts and sores or via poorly stored food
(as Mastomys rodents are home
scavengers)
 It can also be airborne via inhalation of
tiny particles in air contaminated with
rodents excreta.
 Also since mastomys are consumed as
food source, it may also occur via direct
contact when they’re caught and
prepared for food.

6. What is Lassa Fever?
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 It’s seasonal, with clusters in late
rainy and early dry season,
affecting all age groups and both
sexes.
 Its is endemic in areas of West
Africa including Nigeria, Liberia,
Sierra Leone and Guinea.
 Annual incidence of 100,000 to
300,000 with approximately
5,000 deaths in West Africa.
 Incubation period is 5-21 days

7. Importance of Topic.
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 There is a recent outbreak in
Nigeria over the past 7weeks,
which has claimed 40 lives, with
Edo state accounting for 22 of
this.
 11 of the 36 states in Nigeria
have been affected by this and a
total of 397 cases have been
reported, out of which 87 have
been confirmed.
397 cases
40 deaths
12 States

8. Map of States With Lassa fever Cases in Nigeria
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9. Graphical Display of Prevalence in Nigeria
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1
15
326
1
1
5
6
5
4
29
4
Prevalence of lassa Fever in
Nigeria as at 12th Feb 2012
Anambra
Ebonyi
Edo
Gombe
Lagos
Nasarawa
Ondo
Plateau
Rivers
Taraba
Yobe
Anambra 1
Ebonyi 15
Edo 326
Gombe 1
Lagos 1
Nasarawa 5
Ondo 6
Plateau 5
Rivers 4
Taraba 29
Yobe 4

10. Clinical Signs and Symptoms
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 Gradual fever onset
 Headache
 Malaise
 Other Non-specific symptoms
 Pharyngitis
 Myalgia, retro-sternal pain
 Cough
 Gastrointestinal symptoms
 Few have the Classic symptoms of :
- Bleeding
- Neck/facial swelling
- Shock

11. Clinical Signs and Symptoms
0 10 20 30 40 50 60 70 80 90 100
Swollen Neck or Face
Bleeding
Deafness
Conjunctivitis/Subconjunctival
Hemorrhage
Abdominal Pain/Tenderness
Cough
Dizziness
Retro-sternal Pain
Headache
Fever
Arthralgias/Myalgias
Sore throat/Pharyngitis
Weakness
Vomiting
Diarrhea
Chills
Lymphadenopgathy
Confusion
Percent

12. Clinical Signs and Symptoms
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 Case fatality of Hospitalized cases:15-
20%
 Its severe in pregnant women and their
offspring.
-Increase 3rd Trimester mortality (>30%)
-Increased fetal/neonatal mortality (>85%)
 Deafness is a common sequela, not
related to severity of acute illness, maybe
bilateral/unilateral and may persist for
life in one-third of those affected.

13. Diagnosis and Treatment
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 Clinical diagnosis is often difficult
 ELISA (Enzyme-linked immunosorbent
assays) for antigen, IgM, and IgG
 Postmortem tissue
Immunohistochemistry
 Reverse trancription-PCR for reasearch.
 Supportive Measures
 Drug of Choice is: Ribavirin
-Most effective when started within first
6days of illness.
-It is presently contraindicated in
pregnancy but maybe warranted if
mother is at risk)
-Doesn’t reduce incidence of severity of
deafness.
-Side effects are: reversible mild hemolysis
and suppression of erythropioesis

14. Preventing Lassa Fever
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 Avoid contact with Mastomy rodents
and bush burning
 Store food properly in rodent-proof
containers
 Keep homes clean and discourage
rodent entry.
 Using rodent as food source is
discouraged.
 Clean traps and dispose carcass neatly.
 Prevent person-person transmission
via use of PPEs (Masks,Gloves,Gowns
and Goggles) especially for health
workers
 Sterilize equipment after use
 Isolate infected patients from contacts.

15. Questions
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