Epidemic Hemorrhagic Fevers: Clinical Manifestations, Medical Groups And Treatment
Crimean Congo Hemorrhagic Fever
Epidemic Hemorrhagic Fevers
Since 1930, several viruses other than yellow fever virus are known to produce hemorrhagic manifestations. The hemorrhagic fevers can be grouped under three headings.
- Mosquito-borne hemorrhagic fevers, eg, Denque types 1,2,3 and 4, Chikun-gunya, yellow fever virus.
- Zoonotic viruses which may be transmitted to man, eg, Korean hemorrhagic fever, Argentinian hemorrhagic fevers, Junin, Machupo or Bolivian hemorrhagic fever and Lassa fever.
- Tick-borne hemorrhagic fevers, eg, Kyasanur forest disease, Omsk hemorrhagic fever and Crimean Congo hemorrhagic fever group. The vectors in some hemorrhagic fevers have not been identified yet.
Hemorrhagic fevers of South Asia: Viral hemorrhagic fevers occurring in Philippines, Malaysia, Vietnam and eastern parts of India are collectively referred to as “hemorrhagic fevers of south east Asia”. These are all transmitted by Aedes aegypti mosquitoes. All types of dengue viruses (especially type 2) and chikungunya virus are responsible for most of the cases.
Pathologically, the lesions consist of capillary dilatation and increased permeability and congestion of the blood vessels. Hemorrhage is seen in several organs including the lungs, kidneys, brain, myocardium and liver. Hypovolemic shock and renal failure may develop because of blood loss and the renal lesions. Lungs show edema. Liver may show extensive damage resulting in gross disturbances of hepatic function. Skin may show purpura and ecchymosis caused by mild trauma. Some cases show splenomegaly. Fibrinogen levels in the plasma are reduced and fibrin degradation products are increased, thereby suggesting the development of disseminated intravascular coagulation. Leucocytosis may occur in a few. There is no consistent pattern of platelet levels, though thrombocytopenia may develop in some cases.
Viral Hemorrhagic Fever in Hoima district
Children suffer more than adults. There is abrupt onset of fever, upper respiratory catarrh, cough, headache, nausea, vomiting and abdominal pain. Unlike classical dengue, myalgia and arthralgia are absent.
Petechial and maculopapular rashes occur over the forehead, forearms and legs. Cyanosis may develop due to pulmonary involvement. Convulsions and respiratory failure portend a fatal outcome. Death usually occurs around the fourth or fifth day due to extensive gastro-intestinal hemnorrhage with hematemesis and melena and circulatory failure. Renal failure is uncommon in the mosquito-born variety, though it is common in Korean hemorrhagic fever. The non-fatal cases recover rapidly.
Treatment: No specific treatment is available and therefore the management is supportive. Loss of blood and shock have to be corrected by blood replacement. Organ failure is managed on appropriate lines. Administration of blood components to rectify the hemorrhagic diathesis is useful. Corticosteroids have been tried, but there is no proof of consistent benefit.
Clinical Features Of Chikungunya
Chikungunya virus which belongs to group A arboviruses produced a dengue-like illness. Epidemics have been reported from south and east Africa and southern and eastern parts of India. The disease derives its name from the sudden onset of severe joint pain which cripples the victim. In India, Aedes aegypti is the mosquito vector.
The incubation period is about 9 days. The onset, if sudden with abrupt fever, headache and body pains. Large joints like knees, ankles, shoulders and wrists show acute inflammation. Fever and joint pains persist for up to six days after which they subside. Hemorrhagic manifestations occur occasionally. These are associated with a bad prognosis. Treatment consists of symptomatic measures and drugs like aspirin, indomethacin or other anti-inflammatory agents.
© 2014 Funom Theophilus Makama