Rift valley fever differential diagnosis

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [2]Associate Editor(s)-in-Chief: Aakash Hans, MD[3]

Overview

The majority of differential diagnoses for Rift valley fever arise from other diseases which are prevalent in travelers and present with fever. All these disease would share a similar history of recent travel to an endemic area, followed by development of fever and body aches. A few of these diseases are listed below.

Differential Diagnosis

• Malaria
  • The disease presents with fever like Rift valley fever, but the major difference is the pattern of fever in malaria. The fever recurs every 3-4 days in malaria while no such patterns are seen in RVF.
  • Malaria is common in African countries, so paying attention to the time and onset of fevers can be useful in distinguishing between the two diseases. The vast majority of cases of malaria occur in children under the age of 5 years.
• Typhoid fever
  • Typhoid usually has a pattern of step-ladder form of fever, meaning the temperature rises with each passing day.
  • The patient also complaints of bowel abnormalities along with fever. Individuals report either constipation or diarrhea along with fever.
  • A rash is seen on the chest, known as rose-spots in patients with Typhoid.
• Crimean-Congo hemorrhagic fever
  • It is a tick-borne viral disease of both wild animals and domestic animals, affecting humans.
  • The virus belongs to the Bunyaviridae family, which is commonly found in Africa.
  • Risk factors include handling body fluids of infected humans or animals.
• Ebola virus disease
  • It is caused by a virus belonging to the Filoviridae family.
  • It should be suspected in febrile indivisuals who have done the following within a time span 3 weeks before fever :
    • Traveled to an area of a country where the disease had recently occurred.
    • Have had contact with body fluids like blood and other secretions of animals or humans infected with the disease.
• Dengue
  • Patients with dengue also complain of fever but have greater joint pains than in Rift valley fever.
  • A characteristic feature of dengue fever is retro-orbital pain.
  • Dengue has a longer incubation period of 7 days, followed by a week of febrile phase, 1-2 days of the critical phase and 3-5 days of the recovery phase.
• Yellow fever
  • It is a rare disease caused by mosquitos found in South America and Africa.
  • There are vaccines for travelers traveling to these areas.
  • The disease is usually a self limiting febrile illness but may lead to cardiac, renal and hepatic complications.
• Lassa fever
  • The disease is usually seen in West Africa.
  • It is transmitted by rats and risk factors include handling food materials infected with rat feces or contact with infected humans.
  • The incubation period ranges from 2-21 days and most of the people do not report any symptoms.
  • Common symptoms are fever, throat pain, headache, swelling of the face, vomiting and diarrhea.
• Chikungunya
  • It is caused by the Aedes aegypti mosquito and is commonly seen in African and Asian countries.
  • The course of the disease is self limiting and involves fever, headaches and generalized body pain.
• Q fever
  • Q fever is caused by infection by a bacteria called Coxiella burnetii.
  • The bacteria is usually found in domestic animals such as sheep, goats, cats and ticks also.
  • Risk factors include drinking raw milk, breathing in contaminated dust or droplets.
  • Acute infection is characterised by fever, pneumonia and hepatitis. Chronic infections presents with cardiac, musculoskeletal or vascular symptoms.
• Zika virus
  • Patients exposed to the virus develop illness 3-12 days after being exposed.
  • Symptoms include headache,rash,fever and back pain.
  • Symptoms last for the next 4-7 days with most of patients having a full recovery.
• Marburg virus disease
  • Marburg virus is the pathogen responsible for the disease.
  • Infection in humans is caused due to exposure to mines and caves where Rousettus bats can be found.
  • Once the virus is transmitted from animals to humans, further spread is usually human-to-human and results from contact with bodyfluids.
  • Hypotension, metabolic disorders, immunosuppression and coagulopathy are the initial symptoms.

References

• https://www.who.int/en/news-room/fact-sheets/detail/rift-valley-fever
• https://www.cdc.gov/vhf/rvf/index.html