Facts about Crimean-Congo hemorrhagic fever and the role of intensive care in treatment and outcome.

Sir,

Crimean-Congo hemorrhagic fever (CCHF) is an acute, viral, zoonotic disease with hemorrhagic manifestations and considerable mortality in humans. The virus is widely distributed around the world and reports of outbreaks have recently increased.[12]

CCHF is caused by an RNA virus as a Nairovirus genus from Bunyaviridae family. Predominant host of CCHF virus are wild and domestic mammals and birds. Sheep, goats and cattle develop high titres of virus in blood, but tend not to fall ill. Human are usually infected with CCHF virus through a tick bite or close contact with viral-contaminated tissues or blood of the domestic animals. Blood and secretion of the infected patients could distribute the infection so medical laboratory staffs and health-care workers included in high-risk groups.[13]

The incubation period of CCHF depends on the method of transmission. It can extend to 7 days following a tick bite or up to 14 days after blood transfusion. The onset of the illness is sudden, with fever, muscular pains, headache, vomiting and abdominal pain. A hemorrhagic state develops from the 3rd to 5th day and manifests with petechiae, purpura, epistaxis, hemoptysis, hematemesis, melena and hematuria. Mortality rate is about 15-30% and it can develop up to 50%. Usually, death occurs from massive hemorrhage and cardiac arrest, from the 7th to 9th days after onset of the illness. In patients who recover, body temperature decreases within the 10th and 20th days and bleeding stops; however, convalescence can last up to 4 weeks or longer.[145]

Studies about pathogenesis of CCHF reveal endothelial damage resulting from either direct infection of the cells and indirect effect of viral and host factors. Thrombocytopenia and leukopenia are two common finding in the laboratory tests. CCHF is an acute infection without any long-term sequelae or disability, the only relevant outcome is survival. Delay in diagnosis, decreases the efficacy of treatment and aggravates the outcome of the disease so; early diagnosis is essential in CCHF cases and it is currently possible by clinical presentations in endemic region plus detection of viral RNA by reverse transcriptase-polymerase chain reaction (RT-PCR). Serological methods such as ELISA and immune-fluorescent assays may also provide a sensitive and specific diagnosis approximately 7 days following disease onset.[135]

Ribavirin (a synthetic purine nucleoside analogue) has been shown to inhibit viral replication of the CCHF virus in vitro. It has been used in the treatment of CCHF, but its efficacy is controversial.[1] The World Health Organization (WHO) currently recommends Ribavirin as a potential therapeutic drug for CCHF; although, some studies had showed that oral Ribavirin treatment in CCHF patients did not affect on viral load or disease progression.[2]

The nature of viral disease like CCHF is nonstop, progressive and/or self-limited; so intensive care and patient physiology play an important role in outcome of the patient. CCHF treatment is based on supportive and conservative therapy plus Ribavirin and dependent on stage of clinical presentation, steroid administration because the pharmaceutical options for CCHF are limited.[234]

Base on our observations, we believe a real uncertainty exists over the benefit of Ribavirin in the treatment of CCHF. Corticosteroid prescription is dependent on patient's clinical stage. We prescribe steroid in hemorrhagic period before disseminated intravascular coagulopathy (DIC) development [Figure 1].

Figure 1

Clinical stage in CCHF presentation (Ergonul O. Crimean-Congo haemorrhagic fever. Lancet Infect Dis 2006;6:203-14)

Criteria for clinical suspicious to CCHF

Patient admission in isolated intensive care unit (ICU) and careful attention to the fluid and electrolyte balance, ventilation support for appropriate tissue oxygenation, mild sedation, hemodynamic support, and appropriate blood product transfusion have a significant effect on patient's outcome.[3]

According to clinical response that was seen in most of our admitted patients who were treated in intensive care unit by an evidence-based treatment strategy; we propound our strategy entitled Remedial Treatment Protocol (RTP) in CCHF [Table 1].

Table 1

Remedial treatment protocol in CCHF patients (RTP in CCHF)