Rift valley fever

What it is

From: Orphanet

Rift Valley fever (RVF), caused by the Rift Valley fever virus (RVFV), is an arbovirus characterized by a usually self-limiting febrile illness but that in some cases can also manifest with thrombosis, vision loss, hemorrhages and/or neurological symptoms.

Reported clinical features and what the terms mean

The following findings are associated with this condition in Orphanet. They are not a checklist for diagnosing yourself, and they do not all occur in every affected person. Some are examination, imaging or laboratory findings that cannot be recognised at home.

The frequency labels describe how often a finding was reported among people with the condition in the source. They do not give the chance that a person with that symptom has the condition. Definitions below reproduce HPO terminology; they explain the term, not the likely severity in an individual.

Fever · Very frequent (99-80%)

Body temperature elevated above the normal range.

Increased circulating IgG level · Very frequent (99-80%)

An abnormally increased level of immunoglobulin G in blood.

Viremia · Very frequent (99-80%)

The presence of virus in the blood.

Anorexia · Frequent (79-30%)

Lack of desire to eat (loss of appetite).

Abnormality of the eye · Occasional (29-5%)

Any abnormality of the eye, including location, spacing, and intraocular abnormalities.

Increased circulating IgM level · Occasional (29-5%)

An abnormally increased level of immunoglobulin M in blood.

Muscle weakness · Occasional (29-5%)

Reduced strength of muscles.

Ocular pain · Occasional (29-5%)

An unpleasant sensation characterized by physical discomfort (such as pricking, throbbing, or aching) localized to the eye.

Periodic fever · Occasional (29-5%)

Episodic fever that recurs at regular intervals.

Photophobia · Occasional (29-5%)

Excessive sensitivity to light with the sensation of discomfort or pain in the eyes due to exposure to bright light.

Retinal hemorrhage · Occasional (29-5%)

Bleeding located within the retina. Retinal hemorrhages range from the smallest dot and blot hemorrhage to massive sub-hyaloid hemorrhage.

Retinal vasculitis · Occasional (29-5%)

Inflammation of retinal blood vessels as manifested by perivascular sheathing or cuffing, vascular leakage and/or occlusion. It can affect veins, arteries or both.

Retinitis · Occasional (29-5%)

Inflammation of the retina of the eye.

Scotoma · Occasional (29-5%)

A regional and pathological increase of the light detection threshold in any region of the visual field surrounded by a field of normal or relatively well-preserved vision.

Other findings in the same source

From: Orphanet

Additional reported features include Reduced visual acuity (Occasional (29-5%)); Abnormal bleeding (Very rare (<4-1%)); Abnormal thrombosis (Very rare (<4-1%)); Anemia (Very rare (<4-1%)); Back pain (Very rare (<4-1%)); CSF pleocytosis (Very rare (<4-1%)); Decerebrate rigidity (Very rare (<4-1%)); Elevated circulating hepatic transaminase concentration (Very rare (<4-1%)); Excessive salivation (Very rare (<4-1%)); Gingival bleeding (Very rare (<4-1%)). This is a selected summary, not a complete description of the condition.

When it may begin

From: Orphanet

All ages

Frequency and the population described

From: Orphanet

Annual incidence: <1 / 1 000 000; Europe; Class only.

Which doctor should you see?

The suggested department for discussing Rift valley fever is Infectious Diseases, with a general physician / infectious disease specialist as the relevant type of clinician. General physician / Family Medicine; paediatrician for children. Referral depends on symptoms.

This is an editorial referral starting point. The appropriate clinic depends on the person’s age, symptoms, previous diagnosis and local services. The first clinician can decide whether another specialty or a team is needed; a department label does not confirm the diagnosis.

How to prepare for an assessment

Bring a short timeline of the main symptoms: when they first appeared, whether they are constant or episodic, what seems to change them, and how they affect daily activities. Include previous reports, discharge summaries, current medicines and supplements, allergies, and any relevant family history. A dated record is more useful than trying to match every feature in an online article.

Ask the clinician what is already established and what remains uncertain. If a test is suggested, ask what question it answers, what its limitations are and how the result would change the next step. The information here is not an instruction to arrange every possible test. In children, bring growth, developmental and school information if it is relevant to the concern.

• Which exposure or organism is suspected, and what evidence would confirm it?
• Are precautions, vaccination or advice for close contacts relevant to this infection?
• What should happen if symptoms worsen or do not improve as expected?

Treatment discussions and follow-up

The material gathered for this draft does not provide a complete condition-specific treatment pathway for Rift valley fever. That gap does not mean that treatment is unavailable. A clinician needs to establish the diagnosis and review current guidance before recommending medicines, procedures, rehabilitation or other support.

Before leaving the appointment, clarify the next review date, who will communicate results, and whom to contact if the situation changes. Discuss difficulties with sleep, work, school, mobility, eating or emotional wellbeing when these are relevant. Practical support may require coordination between the treating clinician and other services.

The collected references do not establish a complete prevention or long-term outlook section for this entry. Missing information should not be interpreted as proof that prevention is impossible or that a particular outcome is inevitable. Ask what is known for the exact subtype, stage and personal circumstances, and which uncertainties remain.

When to seek emergency help

Severe breathing difficulty, collapse, new stroke-like symptoms, a seizure that is prolonged or repeated without recovery, uncontrolled major bleeding, or an immediate risk of self-harm require emergency help. In India, call 112 or reach the nearest emergency department. This is a general, non-exhaustive warning list; it is not a condition-specific triage tool.