UPDATE ON

LASSA FEVERby

Dr Ahoma Mbanuzuru (21/01/2016) Nnewi

Introduction:“A situation where the ‘healer’

succumbs to the disease he is supposed to heal, calls for an urgent need to improve our disease surveillance. .”

Since 1969 !!!Doctors, Nurses, and other healthcare workers have not exempted

from LF.

1989 – some HCW died of Lassa epidemic in Ekpoma, Enugu, Aba & Ezinihite Aboh-Mbaise, Imo State

1993 – Doctors and nurses died in Lafia

2008 – Three Nurses, one of them pregnant, and a doctor died in Abakiliki.

2012 – Two doctors and 4 Nurses were among those that died, including a ‘Corper’. Anambra State were among the affected 12 States.

Lack of attention to good medical practice and emergency preparedness contributes to LF outbreaks killing HCWs in Nigeria .

Current LF OutbreakStarted since November 2015 from Bauchi State. It has been reported in over 200 people with over

43 deaths including a medical doctor from Rivers State.

Unconfirmed reports claim different number of deaths and cases(Prof Sabitu Kabiru).

Affected states include Bauchi, Nasarawa, Niger, Taraba, Kano, Rivers, Plateau, Gombe, Edo, Oyo, Lagos,FCT, Ekiti and Delta.

No reported case in Anambra State as of today.Emmergency Health Council meeting held on

Tuesday (19th January 2016), Agenda: Lassa fever outbreak.

Questions for Consideration:

1) How many of our Healthcare workers (Doctors, Nurses, Lab Scientists, Pharmacists, etc) are adequately trained to handle or recognize Lassa fever case.

2) If by chance, we have a case of Lassa Fever in our hospital today, how prepared are we?

3) How readily available are the personal protective equipments (PPEs)?

4) Is Ribavirin available in our Pharmacy?

5) How ready are our isolation wards, if any?

6) How do we collect the sample and send to Irrua for diagnosis? Logistics 

An acute viral illness that occurs mainly in West Africa, often associated with persistent high fever.

Discovered in 1969 when 2 missionary nurses died in Nigeria (Lassa, Borno State).

Caused by Lassa virus. Incubation Period: 6-21 days.

WHAT IS LASSA FEVER?

Lassa VirusFamily of

Arenaviridae, a single-stranded RNA virus.

Inactivated by:Heating to 560CpH <5.5 or > 8.5UV/gamma irradiationdetergents

EPIDEMIOLOGYEndemic in most West African countries:

Nigeria, Guinea, Liberia, Sierra Leone, Ghana, Senegal, Gambia, Mali, Upper Volta, Central Africa.

About 80% of cases are mild or with no observable symptoms. Remaining 20% have severe multisystem disease.

In overall, only 1% of infection with Lassa virus result in death.

Epidemiology contd.During epidemics, case-fatality rate can reach

50%.

Estimated 100,000-300,000 cases with approx 5000 deaths annually.

Approx 15-20% of patients hospitalised for LF die from the illness within 7-10 days.

Death rates are particularly high for women in 3rd Trimester of pregnancy, and for fetuses, about 95% of which die in utero of infected mothers.

Pathogenesis Endothelial cell damage/capillary leak

Platelet dysfunction

Suppressed cardiac function

Cytokines and other soluble mediators of shock and inflammation

• Reservoir/Host: Rodent, “multimammate rat” Mastomys natalensis. Also known as hairless tailed rat.

• Transmission is by exposure to the excreta of infected Mastomys (urine and faeces), viz:

1. Direct contact with these materials, or eating food contaminated with these materials or through cuts or sores.

2. Bush rat prepared as food.3. Aerosol or air-borne transmission by

inhaling tiny particles in the air contaminated with rodent excretions

MODE OF TRANSMISSION

MODE OF TRANSMISSION contd.4. Human to human contact –

through blood, tissues, secretions, or excretions of individual infected with LF.

5. Nosocomial transmission (in Healthcare setting, via medical equipments, or person to person).

• Signs and symptoms of LF occur 1-3 weeks(5-21 days) after px come in contact with the virus.

• Clinically, LF is difficult to distinguish from malaria, typhoid fever, yellow fever and other haemorrhagic fevers.

• Symptoms include: fever (>38 C), facial swelling, muscle fatigue, red eye (conjunctivitis), mucosal bleeding, abortion,orchitis,etc

• GIT – Nausea, vomiting(bloody), diarrhoea(bloody),stomach ache, constipation, dysphagia(difficulty in swallowing),hepatitis.

CLINICAL FEATURES

• CVS – Pericarditis, hypertension, hypotension, tachycardia(abnormal high heart rate).

• Resp System – Cough, chest pain, dyspnoea, pharyngitis, pleuritis.

• Nervous System – Hearing deficit, meningitis, encephalitis, seizures

CLINICAL FEATURES contd

COMPLICATIONS OF LASSA FEVER

1. Increased risk of death especially pregnant women in their 3rd trimester

2. Miscarriage is common in pregnant women who became infected with LF(spontaneous abortion)

3. Hearing loss (different degrees of deafness)

WHO ARE AT RISK?1. Individuals who live or visit areas with a

high population of Mastomys rodents, infected with Lassa virus (rural areas).

2. Exposure to individuals infected with Lassa virus (rural and urban)

3. Healthcare workers viz doctors, nurses, pharmacists, ward attendants, lab scientists, etc

CLINICAL CASE DEFINITIONUnexplained fever ≥38 c for ≥ 1weekOne of the following:

-No response to standard Rx for most likely cause of fever (malaria, typhoid fever).

-Re-admitted within 3 weeks of in-patient care for an illness with fever. plus... pharyngitis, conjunctivitis, bleeding/ edema, increased AST/ or proteinuria

Confirmed case:Suspected case with lab confirmation (positive IgM

or viral isolation) or epidemiological link to confirmed cases or outbreaks.

DIAGNOSIS:Ensure patient fits into the case definition of LF.Lab: 1. FBC: Lymphopenia and/ or

Thrombocytopenia 2. LFT: elevated aspartate aminotransferase(AST) in the blood

3. Urinalysis: ProteinuriaLF is most often diagnosed by using enzyme-linked

immunosorbent serologic assays (ELISA), which detects IgM and IgG antibodies as well as Lassa antigen.

Reverse transcriptase PCR assay.Immunohistochemistry performed on tissue specimen,

can be used (post-mortem).

TREATMENT OF LASSA FEVERRibavirin (IV)especially in early course of the

illness( within first 6 days).It is given for 10 days.Loading dose: 33mg per kg body weight, then

16mg/kg body weight every 6 hours for 4 days,Then 8mg/kg body weight every 8 hours for

remaining 6 days.

Supportive care (appropriate fluid & electrolyte balance, oxygenation, and blood pressure, pcm, vit K, antibiotics, possible transfusion, etc.)

Treatment contd.For Prophylaxis:Tablets: Adults 500mg every 6 hours for 5 daysChildren (>5years) 500mg every 12 hours for 5 days.

Major toxicity: reversible mild hemolysis, and suppression of erythropoesis.

contra-indicated in pregnancy (but may be given if mothers life is at risk).

Does not appear to reduce the incidence or severity of deafness.

Poor Prognostic FactorsHigh viraemiaSerum AST level >150 IU/LBleedingEncephalitisEdema3rd trimester of pregnancy

Primary , Secondary and TertiaryCommunity/Village based programme for

rodent control and avoidanceHospital training programmes to avoid

nosocomial spread: High index of suspicion, barrier nursing, UNIVERSAL PRECAUTION

Diagnostic procedureChemotherapy (ribavirin)

PREVENTION and CONTROL

1. Avoid contact with Mastomys rodents, esp in the geographic regions where outbreaks occur.

2. Put food away in rodent-proof container. Discard food eaten by rats.

3. As few staff as possible should attend to patients with LF, and these staff should wear protective clothing including masks, gloves, gowns &goggles.

4. When there is contact with the secretions, excretions, blood, tissues, or other body fluids of a person suffering LF, individuals should be screened.

5. Use plastic bed cover to avoid contamination of mattress. Decontaminate instruments like Sphyg, Steth, thermometer, etc after each use.

6. Report any suspicion without delay to appropriate authorities.

Isolation Wards:

Some Important Notes:FGN has set up Rapid Response Committee on LF

– Drugs, Personal protective equipments for HCW, as well as increased Health Education are in place.

Only 2 Labs in the country so far have the capacity to screen blood for LF viz: Irrua Specialist Hospital, Edo State and Central Medical Lab, LUTH, Lagos.

Blood samples are being sent by courier.Once a patient fits into the case definition, with the

lab results, BLOOD sample must be collected for confirmation, before commencement of treatment with Ribavirin.

Some Impt Notes contd:Treatment with Ribavirin must commence

immediately after collecting blood sample according to the treatment regimen, once a case is suspected.

Once suspected case is confirmed, ALL identified contacts of the case must submit themselves for screening.

Never transfer patient to isolation unit without fulfilling above conditions.

On no account must a patient be abandoned because such person is suspected or confirmed to have LF.

All cases that fit into the clinical case definition must be reported immediately to appropriate authorities.

Lassa Fever Survey Form QMD3-1 must be completed on each blood sample collected from suspected cases.

CONCLUSION:One confirmed case of LF is treated as epidemic.

After 47 years, since 1st cases of LF were diagnosed, Nigerians including health workers are still been killed in outbreaks.

We can only attribute this weak health system in general, and lack of attention to good medical practice in particular.

Adequate surveillance will help in tackling LF.

Thank You