Viral haemorrhagic fevers


– Several diseases with different aetiologies and different modes of transmission are grouped under this term as they present with common clinical signs.
– Dengue haemorrhagic fever is a viral haemorrhagic fever that is described in a specific chapter (see Dengue).

Clinical features

– Common syndrome (CS):
• Fever higher than 38.5 °C;
• Haemorrhagic symptoms (purpura, epistaxis, haematemesis, melaena, etc.).

– The clinical signs are often nonspecific; the severity varies depending on the aetiology.


Reservoir/ Vector
Geographical distribution

Isolation
of patients

Clinical features

Estimated case
fatality rate

Ebola* Marburg

Bats (?)
Africa

Strict
isolation

CS + sudden onset general malaise, vomiting and diarrhoea

60-80%
Lassa*

Rodents
Central and West Africa

Strict
isolation

CS + facial oedema, purulent pharyngitis, proteinuria on reagent strip

10-25%


Junin and
Machupo*

Omsk

Crimean Congo*

FHSR
(hantavirus)*


Rodents
South America

Ticks
Europe, Asia

Livestock/Ticks
Africa, Asia

Rodents
Asia and Europe


Isolation

None

Strict
isolation

None

CS + vomiting, erythema of the face and, depending on the aetiology:

• periorbital oedema, cervical adenopathy, pharyngitis

• pharyngitis, reddened conjunctivae

• oedema of the soft palate, generalised petechial rash

• proteinuria on reagent strip


15-30%

2-5%

5-20%

< 1%

Kyasanur

Small mammals/Ticks
India

None CS + headache, muscle pain, prostration 2-10%
Rift Valley*

Livestock/Mosquitoes
Africa

Mosquito nets

Clinical signs:
• isolated fever
• SC (30-50%)
encephalitis
• retinitis and blindness



30-50%
Yellow fever*

Primates/Mosquitoes
Africa, South America

Mosquito nets CS + jaundice, proteinuria on reagent strip, oliguria, headache 10-30%

* Viral haemorrhagic fever with epidemic potential.

Laboratory

– A sample of whole blood must be send to a reference laboratory for serological diagnosis, with a clinical description of the patient. The sample may also be sent on filter paper. It is easier to transport, but the small volume of blood only allows a limited number of aetiologies to be tested.
– Protective clothing must be worn while taking or handling the sample (gown, gloves, glasses, mask, etc.).
– The sample must be sent in a triple packaging system for Category A infectious substances.

Management

Suspicion of haemorrhagic fever

(isolated case of fever with haemorrhagic symptoms in an endemic area)

– Isolation: isolation room (or if not available, use screens/partitions); restrict visitors (if a carer is strictly necessary, s/he must be protected with gown, gloves, mask).
– Standard precautions:
The majority of hospital-acquired infections have occurred due to a lack of respect for these precautions:
• Hand washing;
• Gloves for patient examination and when touching blood, body fluids, secretions, excretions, mucous membranes, non-intact skin;
• Gowns to protect skin and prevent soiling of clothing during consultations and activities that are likely to generate splashes or sprays of blood, body fluids, secretions, or excretions;
• Surgical mask and goggles, or face shield, to protect mucous membranes of the eyes, nose, and mouth during activities that may generate splashes of blood, body fluids, secretions, and excretions;
• Adequate procedures for the routine cleaning and disinfection of objects and surfaces;
• Rubber gloves to handle soiled laundry;
• Safe waste management;
• Safe injection practices.

Confirmed cases of Ebola, Marburg, Lassa, Crimean-Congo fevers or epidemics of unknown origin

– Strict isolation in a reserved area separate from other patient areas, with a defined circuit for entrance/exit and changing room at the entrance/exit; dedicated staff and equipment/supplies; use of disposable material if possible.
– Standard precautions (as above)
PLUS
– Droplet precautions AND contact precautions including personal protective equipment (PPE):
• two pairs of gloves,
• double gown or coverall suit,
• surgical cap or hood, mask, protective glasses,
• impermeable apron,
• rubber boots.
The PPE is to be worn systematically prior to entry into isolation area, regardless the tasks to be performed (care, cleaning, distribution of meals, etc.) and to be removed before leaving the isolation area.
– Disinfection of surfaces, objects, clothing and bedding with chlorine solution; safe handling and on site disposal of waste and excreta, etc.
– In the event of a death, do not wash the body. Prompt and safe burial of the dead as quickly as possible, using a body bag.

Confirmed cases of Yellow fever or Rift Valley fever

– Standard precautions.
– Patient under a mosquito net to prevent transmission.

For all patients: report to the Ministry of Health of the country.

Treatment

– Aetiological treatment: ribavirine for Lassa fever and Crimean-Congo fever.
– Symptomatic treatment:
• Fever: paracetamol (Chapter 1). Acetylsalicylic acid (aspirin) is contra-indicated.
• Pain: mild (paracetamol), moderate (tramadol), severe (sublingual morphine): see Pain, Chapter 1.
• Dehydration: oral rehydration salts and/or IV rehydration with Ringer lactate, see WHO protocol (Appendix 2).
• Seizures (Chapter 1).
• Vomiting: ondansetron PO
Children 6 months to < 2 years: 2 mg once daily
Children 2 to < 4 years: 2 mg 2 times daily
Children 4 to < 12 years: 4 mg 2 times daily
Children ≥ 12 years and adults: 4 to 8 mg 2 times daily
– For Ebola and Marburg haemorrhagic fevers: invasive procedures must be strictly limited. Health care staff is at risk of contamination when inserting and maintaining IV lines. An IV line must be well secured so that the patient, often confused, cannot pull it out.

Prevention

– Vaccination against yellow fever1 :
Children and adults: 0.5 ml single dose 
• Routine vaccination : children from 9 months of age, along with the measles vaccine.
• Mass vaccination campaign during an epidemic: children from 6 months and adults ; for pregnant women, only administer during an epidemic.
– Vaccination against Rift Valley fever: only during an epidemic.
– Vector control programmes for known vectors.
– Infection control measures are essential in all cases.



References

  1. Weekly epidemiological record-Relevé épidémiologique hebdomadaire 5 july 2013, 88th year / 5 juillet 2013, 88e année No. 27, 2013, 88, 269–284.
    https://www.who.int/wer/2013/wer8827.pdf?ua=1 [Accessed 10 december 2018]