Hemorrhagic fever

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Classification according to ICD-10
A94 Arthropod-borne viral disease, unspecified
A96.- Hemorrhagic fever caused by arenaviruses
A98.- Other viral hemorrhagic diseases, not elsewhere classified
A99 Unspecified viral hemorrhagic disease
ICD-10 online (WHO version 2019)

Hemorrhagic fevers (from ancient Greek αἷμα haima , German 'blood' and ancient Greek ῥήγνυμι rhēgnymi , German 'tear, break' ; old German term blood-breaking fever ) are severe, infectious fever diseases that are accompanied by bleeding . They are caused by viral infections , which is why it is also called viral hemorrhagic fever (AF) .

The causative agents of hemorrhagic fever are native to all continents except Antarctica , but mostly occur in Africa , South America or Southeast Asia . Fatal AF are extremely rare in Central Europe and North America . They are occasionally introduced by travelers who have become infected abroad. Special isolation wards for highly infectious patients are kept at several hospitals in Germany .

species

Hemorrhagic fevers (as a name introduced in 1962 by the virologist Daniel Carleton Gajdusek ) are caused by viruses that are partly related to one another (see also virus taxonomy ). These are:

Pathogen from the family Arenaviridae (arenaviruses, transmission through contact with rodents)

Pathogens from the Bunyaviridae family (bunyaviruses)

Pathogen from the Filoviridae family (transmitted through contact with infected monkeys and humans)

The Cuevavirus has so far only been detected in bats, but there is a risk of the host switch to humans in Europe.

Pathogen from the family Flaviviridae (Flaviviruses)

Pathogen from the Togaviridae family (Togaviruses with the genus Alphavirus )

The detection of these diseases based on the symptoms alone is not clearly possible. For this, a precise virological diagnosis must be carried out. Only a few laboratories are able to do this, as all viruses that are characterized by high transferability and high virulence are assigned to the highest security level L4 and the samples must be processed in high-security laboratories .

In Germany , if hemorrhagic fever is suspected, the relevant examinations are carried out by the Robert Koch Institute in Berlin, the Institute for Virology in Marburg or the Bernhard Nocht Institute for Tropical Medicine in Hamburg.

transmission

The pathogens originate primarily from rodents and primates , so are zoonoses and are z. B. by mosquitoes ("mosquitoes") and ticks or through the preparation and consumption of infected animals to humans. Lassa fever is mainly transmitted through contact with infected animal feces or urine. On average, about a week passes between infection and the outbreak of the disease, but the incubation period can be between 2 and 21 days, as with Ebola . Some haemorrhagic fevers can be transmitted from person to person ( droplet infection , blood contact or body excretions such as stool , urine , vomit, sweat, etc.). The infectivity increases with the viral load that develops a patient. The infectivity is highest in clinically difficult cases in which the characteristic bleeding symptoms also occur.

Nosocomial infections, i.e. infections that are acquired in the hospital and spread according to hygienic standards, are feared . Disease caused by other pathogens, which can also include fever and bleeding, are far more common in areas where hemorrhagic fever is endemic . For this reason, viral hemorrhagic fevers were often only recognized when there were subsequent infections or the more common causes could be ruled out.

Symptoms and Treatment

In addition to a high fever (> 38.5 ° C), symptoms include liver and kidney dysfunction with edema . Caused by so-called capillary leakage , both internal bleeding and bleeding into the tissue ( bruises ) can occur. In many cases, stool and urine are also bloody. It can often lead to shock and circulatory collapse as well as cramps and symptoms of paralysis . The occurrence of cerebral symptoms and a particularly strong tendency to bleed worsens the prognosis, and permanent neurological damage such as B. Hearing loss can be expected.

So far, there have hardly been any successful drug treatments for most hemorrhagic fevers. The antiviral drug ribavirin turned out to be the most promising treatment option . There is a vaccination against yellow fever . A vaccine against the Junin virus (Argentine hemorrhagic fever) is currently only approved in Argentina. Other vaccines are currently being developed and some have already been successfully tested in animal experiments. The most helpful, however, is prevention through insect repellants and compliance with basic hygienic rules.

Reporting requirement

Most hemorrhagic fevers are dangerous to life-threatening. Since they are also infectious and there is a risk of contagion, they must be reported under the laws of various countries.

In Germany, the Infection Protection Act (IfSG) prescribes in Section 6 IfSG a general obligation to report by name in the event of suspected diseases or deaths from viral hemorrhagic fevers . In addition, according to this law, direct or indirect evidence of other pathogens haemorrhagic fever must be reported by name in accordance with Section 7 IfSG, provided the evidence indicates an acute infection. In contrast to almost all other infections, immediate isolation is mandatory in the case of hemorrhagic fevers that can be transmitted from person to person ( Section 30 (1) sentence 1 IfSG [quarantine], together with pulmonary plague).

In Austria, virus-related hemorrhagic fever is notifiable in the event of suspicion, illness or death in accordance with Section 1 Paragraph 1 Number 1 of the 1950 Epidemic Act . Doctors and laboratories, among others, are obliged to report this ( Section 3 Epidemics Act).

literature

Web links

Individual evidence

  1. ↑ Alphabetical directory for the ICD-10-WHO version 2019, volume 3. German Institute for Medical Documentation and Information (DIMDI), Cologne, 2019, p. 275
  2. ↑ Werner Köhler: Fever, hemorrhagic. 2005, p. 396.