ICD-11 code : 1D61.2;
Preferred Label : Lassa fever;
ICD-11 definition : A disease endemic in some areas of sub-Saharan Western Africa caused by infection
with Lassa virus. Infection is mild or asymptomatic in most cases but can cause severe
illness or death. When it is symptomatic, the onset of the disease is usually gradual,
starting with fever, general weakness headache and malaise. After a few days, sore
throat, muscle pain, chest pain, nausea, vomiting, diarrhoea, cough and abdominal
pain may follow. As the disease progresses, in severe cases facial swelling, fluid
in the lung cavity, bleeding from the mouth, nose, vagina or gastrointestinal tract
and low blood pressure may develop. Shock, seizures, tremor, disorientation, and coma
may be seen in the later stages. Among hospitalized patients, approximately 15% die
of Lassa fever disease. In fatal cases, death usually occurs within 14 days of symptom
onset. During pregnancy, Lassa fever can cause high maternal and foetal mortality,
especially late in pregnancy. In the third trimester, fetal death and maternal death
rates can exceed 80% and 30% respectively. Prolonged convalescence in some patients
has been documented leading sometimes to sequelae. Sudden hearing loss has been reported
with varying incidence and up to 25% of recovered patients, both during acute disease
and after recovery. In most circumstances hearing loss is reported to be permanent.
Other sequelae including neurological signs, visual impairment, joint pain, transient
hair loss and psychological disorders have been reported to a lesser extent. The incubation
period of Lassa fever ranges from 2–21 days. Transmission occurs either through exposure
to food or household items that are contaminated with urine or faeces of infected
Mastomys rat, or directly via contact with infected rats. Although to a much less
extent, Lassa virus may also spread between humans through direct contact with blood,
urine, faeces or other bodily secretions of a person infected with Lassa fever. Person-to-person
transmission may occur primarily in health-care settings, where the virus may also
be spread by contaminated medical equipment, such as re-used needles. Diagnosis occurs
by identification of Lassa virus in blood samples by molecular or serologic methods.;
ICD-11 synonym : LF - [Lassa fever];
ICD-11 acronym : LF;
Origin ID : 515020316;
UMLS CUI : C0023092;
Automatic exact mappings (from CISMeF team)
Currated CISMeF NLP mapping
ICD-10 Mapping
Semantic type(s)
UMLS correspondences (same concept)
A disease endemic in some areas of sub-Saharan Western Africa caused by infection
with Lassa virus. Infection is mild or asymptomatic in most cases but can cause severe
illness or death. When it is symptomatic, the onset of the disease is usually gradual,
starting with fever, general weakness headache and malaise. After a few days, sore
throat, muscle pain, chest pain, nausea, vomiting, diarrhoea, cough and abdominal
pain may follow. As the disease progresses, in severe cases facial swelling, fluid
in the lung cavity, bleeding from the mouth, nose, vagina or gastrointestinal tract
and low blood pressure may develop. Shock, seizures, tremor, disorientation, and coma
may be seen in the later stages. Among hospitalized patients, approximately 15% die
of Lassa fever disease. In fatal cases, death usually occurs within 14 days of symptom
onset. During pregnancy, Lassa fever can cause high maternal and foetal mortality,
especially late in pregnancy. In the third trimester, fetal death and maternal death
rates can exceed 80% and 30% respectively. Prolonged convalescence in some patients
has been documented leading sometimes to sequelae. Sudden hearing loss has been reported
with varying incidence and up to 25% of recovered patients, both during acute disease
and after recovery. In most circumstances hearing loss is reported to be permanent.
Other sequelae including neurological signs, visual impairment, joint pain, transient
hair loss and psychological disorders have been reported to a lesser extent. The incubation
period of Lassa fever ranges from 2–21 days. Transmission occurs either through exposure
to food or household items that are contaminated with urine or faeces of infected
Mastomys rat, or directly via contact with infected rats. Although to a much less
extent, Lassa virus may also spread between humans through direct contact with blood,
urine, faeces or other bodily secretions of a person infected with Lassa fever. Person-to-person
transmission may occur primarily in health-care settings, where the virus may also
be spread by contaminated medical equipment, such as re-used needles. Diagnosis occurs
by identification of Lassa virus in blood samples by molecular or serologic methods.