Yellow fever has an incubation period of five to six days. In the initial phase that lasts for three to four days, there is mild fever with rigors and chills and yellowing of the skin. The yellowing occurs as the disease affects liver causing hepatitis [7].

The patient also complains of headache, joint and muscle pain, loss of appetite, abdominal pain, back pain, nausea and vomiting, fatigue, weakness and dehydration. The next phase is remission, which lasts for 48 hours. Most patients recover after this phase.

If not treated completely, the disease becomes worse and the sufferers enter a more toxic, third phase of infection. It can lead to a condition called viral hemorrhagic fever with shock, jaundice and abdominal pain [8] [9].

In the toxic phase, there can be bleeding in the mouth, the eyes and the gastrointestinal tract. This will cause vomiting containing blood. It results in damage to the liver, kidneys, and the circulatory system. The World Health Organization estimates that about 50% of people worldwide who reach this severe phase of infection die, while half recover.

• Fever

  Yellow Fever Vaccine Centers [web.archive.org]

  […] against yellow fever. [who.int]

  For residents of West Tennessee, and particularly Memphis, yellow fever posed the greatest threat. The disease caused fevers, chills, hemorrhaging, severe pains, and sometimes a jaundicing of the skin, which gave yellow fever its name. [tennesseeencyclopedia.net]

• Chills

  The patient suffered from fever, chills, sweating, headaches, backaches, myalgia, epigastric pains, nausea, vomiting, diarrhea and prostration. He was unvaccinated and had been working in areas where cases of jungle yellow fever had been confirmed. [ncbi.nlm.nih.gov]

  The initial symptoms include sudden onset of fever, chills, severe headache, back pain, general body aches, nausea, and vomiting, fatigue, and weakness. Most persons improve after the initial presentation. [web.archive.org]

  In the initial phase that lasts for three to four days, there is mild fever with rigors and chills and yellowing of the skin. The yellowing occurs as the disease affects liver causing hepatitis. [symptoma.com]

  Yellow fever appears with a sudden onset of fever, chills, headache, backache, nausea, and vomiting. The skin and eyes may appear yellow—a condition known as jaundice and a sign that gives rise to the disease’s popular name. [britannica.com]

  Some people will develop yellow fever illness with initial symptoms including: Sudden onset of fever Chills Severe headache Back pain General body aches Nausea Vomiting Fatigue (feeling tired) Weakness Most people with the initial symptoms improve within [cdc.gov]

• High Fever

  Yellow fever has an incubation period of 3 to 6 days and sudden onset of symptoms with high fever, myalgia, headache, nausea/vomiting and increased transaminases. The disease ranges from asymptomatic to severe forms. [ncbi.nlm.nih.gov]

  […] sometimes followed by more serious symptoms (such as jaundice, high fever, and hemorrhage), and is caused by a flavivirus (species Yellow fever virus of the genus Flavivirus ) transmitted especially by the yellow-fever mosquito Examples of yellow fever [merriam-webster.com]

  The severe form is characterized by high fever, jaundice, bleeding, and eventually shock and failure of multiple organs. Top of Page Treatment No specific treatments have been found to benefit patients with yellow fever. [web.archive.org]

  Severe symptoms include: High fever Yellow skin (jaundice) Bleeding Shock Organ failure Severe yellow fever disease can be deadly. If you develop any of these symptoms, see a healthcare provider immediately. [cdc.gov]

• Fatigue

  The initial symptoms include sudden onset of fever, chills, severe headache, back pain, general body aches, nausea, and vomiting, fatigue, and weakness. Most persons improve after the initial presentation. [web.archive.org]

  For some people who recover, weakness and fatigue (feeling tired) might last several months. A few people will develop a more severe form of the disease. [cdc.gov]

  Symptoms of yellow fever include sudden fever, severe headache, nausea, vomiting and fatigue, according to the Center for Disease Control and Prevention. Reporting by Herculano Coroado; Writing by Mfuneko Toyana [reuters.com]

  Symptoms of yellow fever include sudden fever, severe headache, nausea, vomiting and fatigue. Without early treatment, nearly 50% of people suffering from an advanced stage of Yellow fever do not survive. [africanews.com]

• Burkina Faso

  Africa The Americas (*click here for 2018 updated Brazil map) Countries in Africa with Risk of Yellow fever Transmission Angola Equatorial Guinea Mauritania Benin Ethiopia Niger Burkina Faso Gabon Nigeria Burundi Gambia, the Senegal Cameroon Ghana Sierra [fitfortravel.nhs.uk]

  Africa Angola Guinea Benin Guinea-Bissau Burkina Faso Kenya Burundi Liberia Cameroon Mali Central African Republic Mauritania Chad Niger Congo Nigeria Cote d'Ivoire Senegal Democratic Republic of the Congo Sierra Leone Equatorial Guinea Southern Sudan [southafrica-newyork.net]

  The Yellow Fever Virus (YFV) occurs in the following countries: Africa Americas Angola, Benin, Burkina Faso, Burundi, Cameroon, Central African Republic, Chad, Congo, DRC, Ethiopia, Gabon, Gambia, Ghana, Guinea, Guinea Bissau, Equatorial Guinea, Ivory [victoriafalls-guide.net]

  Burkina Faso over 9 mo. Burundi over 9 mo. Cameroon over 9 mo. Cape Verde over 9 mo. Central African Republic over 9 mo. Chad over 9 mo. Congo: Democratic Republic of the Congo over 9 mo. Congo: Republic of the Congo over 9 mo. [wikitravel.org]

• Easy Bruising

  The principal symptoms of dengue fever are high fever, severe headache, severe pain behind the eyes, joint pain, muscle and bone pain, rash and mild bleeding (e.g., nose or gums bleed, easy bruising). [pe.com]

  bruising, unusual bleeding; little or no urination; or vomiting, loss of appetite, jaundice (yellowing of the skin or eyes). [rxlist.com]

  bruising, unusual bleeding ; little or no urination; or vomiting, loss of appetite, jaundice (yellowing of the skin or eyes). [emedicinehealth.com]

  In addition to the above symptoms, the following symptoms and signs may also develop: Abdominal pain Prevention Bleeding from the gums, nose, eyes, and/or stomach Blood in the stool and blood in the vomit Easy bruising of the skin Kidney failure Confusion [medicinenet.com]

• Vomiting

  Symptoms may include: Fever, headache, muscle aches Nausea and vomiting, possibly vomiting blood Red eyes, face, tongue Yellow skin and eyes (jaundice) Decreased urination Delirium Irregular heartbeats (arrhythmias) Bleeding (may progress to hemorrhage [nlm.nih.gov]

  The second patient-a 22-year-old black woman-developed a sore throat and fever accompanied by headache, myalgia, nausea, and vomiting 4 days after yellow fever vaccination. [ncbi.nlm.nih.gov]

  Famous early American Cotton Mather described it as “turning yellow then vomiting and bleeding every way.” Internal bleeding in the digestive tract causes bloody vomit. Many victims become delirious before dying. [history.com]

• Nausea

  Our patient presented with a clinical syndrome of fever, headache, nausea, and vomiting, which quickly progressed to multiorgan failure and ultimately death on hospital day 4. [ncbi.nlm.nih.gov]

  Yellow fever is spread through infected mosquitoes and has a wide array of symptoms from nausea and vomiting to kidney failure, jaundice and bleeding. [news.bbc.co.uk]

• Loss of Appetite

  The patient also complains of headache, joint and muscle pain, loss of appetite, abdominal pain, back pain, nausea and vomiting, fatigue, weakness and dehydration. The next phase is remission, which lasts for 48 hours. [symptoma.com]

  Yellow fever has 3 stages: Stage 1 (infection): Headache, muscle and joint aches, fever, flushing, loss of appetite, vomiting, and jaundice are common. Symptoms often go away briefly after about 3 to 4 days. [nlm.nih.gov]

  […] of appetite, and nausea or vomiting About 15% of people face a second, more serious phase involving high fever, jaundice, bleeding and deteriorating kidney function Half of those who enter the "toxic" phase usually die within 10 to 14 days Source: WHO [bbc.com]

  Initial symptoms usually include sudden onset of fever, chills, headache, joint and muscle pain, loss of appetite, abdominal pain, back pain, nausea and vomiting, fatigue, weakness and dehydration. Most patients recover after this stage. [travel.gc.ca]

• Black Vomit

  At one time it was called “Black Vomit” because of the characteristic black putrid vomit it produces. There are approximately 200,000 cases of yellow fever, resulting in 30,000 deaths, each year in tropical endemic areas of Africa and the Americas. [infoplease.com]

  The trademark of the disease, however, was the victim’s black vomit, composed of blood and stomach acids. Although its cause was unknown until 1900, yellow fever was transmitted from person to person by the female Aedes aegypti mosquito. [tennesseeencyclopedia.net]

  The trademark of the disease, however, was the victim's black vomit, composed of blood and stomach acids. Although its cause was unknown until 1900, yellow fever was transmitted from person to person by the female Aedes aegypti mosquito. [web.archive.org]

  Bleeding in the mouth, the eyes and in the gastrointestinal tract can cause vomits containing blood (giving the name black vomit). Approximately 20% of cases entering the toxic phase end in fatality. [tripadvisor.com]

• Hematemesis

  Jaundice, extreme albuminuria, and epigastric tenderness with hematemesis often occur together after 5 days of illness. There may be oliguria, petechiae, mucosal hemorrhages, confusion, and apathy. [msdmanuals.com]

  Hemorrhage and erosion of the gastric mucosa lead to hematemesis, popularly known as black vomit. Fatty infiltration of the myocardium, including the conduction system, can lead to myocarditis and arrhythmias. [emedicine.com]

• Jaundice

  Yellow fever has 3 stages: Stage 1 (infection): Headache, muscle and joint aches, fever, flushing, loss of appetite, vomiting, and jaundice are common. Symptoms often go away briefly after about 3 to 4 days. [nlm.nih.gov]

  Abstract For more than 95% of acute febrile jaundice cases identified through surveillance for yellow fever, a reemerging arthropod-borne viral disease, no etiological exploration is ever done. [ncbi.nlm.nih.gov]

  Symptoms may include sudden onset of fever, relative bradycardia, headache, and, if severe, jaundice, hemorrhage, and multiple organ failure. [msdmanuals.com]

• Scleral Icterus

  icterus Jaundice Epigastric tenderness Hepatomegaly The following will also often be apparent: Petechiae Purpura Mucosal bleeding Gastrointestinal bleeding (gross or occult) Organ ischemia, which primarily affects the kidneys and central nervous system [emedicine.com]

• Hypotension

  In the late stages of yellow fever, patients present with the following: Tachycardia Hypothermia or hyperthermia Hypotension Individuals who are severely hypoperfused appear mottled and cyanotic; they are also often obtunded. [emedicine.com]

• Tachycardia

  Shock, tachycardia, bleeding, oliguria, proteinuria and azotemia confer a poor prognosis. Although convalescence may be prolonged, survivors usually have no lasting sequelae. [orpha.net]

  On general physical examination, the findings include tachycardia, yellowness of eyes and skin, coated tongue, state of dehydration and dark colored urine. The laboratory testing helps to confirm the diagnosis. [symptoma.com]

  In the late stages of yellow fever, patients present with the following: Tachycardia Hypothermia or hyperthermia Hypotension Individuals who are severely hypoperfused appear mottled and cyanotic; they are also often obtunded. [emedicine.com]

• Slow Pulse

  Often, the high fever is paradoxically accompanied by a slow pulse. After four days, most patients improve and their symptoms disappear. [dermnetnz.org]

  The main symptoms of yellow fever are a high temperature, a slow pulse, albuminuria, jaundice, congestion of the face, and hemorrhage, or bleeding. [medicalnewstoday.com]

  Often, the high fever is paradoxically associated with a slow pulse. After three to four days most patients improve and their symptoms disappear. However, 15% enter a "toxic phase" within 24 hours. [web.archive.org]

  Often, the high fever is paradoxically associated with a slow pulse. After three to four days most patients improve and their symptoms disappear. However, 15% enter a “toxic phase” within 24 hours. [tmb.ie]

• Fever with Relative Bradycardia

  Symptoms may include sudden onset of fever, relative bradycardia, headache, and, if severe, jaundice, hemorrhage, and multiple organ failure. [msdmanuals.com]

• Myalgia

  The illness was characterized by fever, headache, myalgia, gastrointestinal symptoms, hepatic and renal dysfunction, and (in the fatal case), shock and coagulopathy, compatible with YEL-AVD. [ncbi.nlm.nih.gov]

• Purpura

  […] of fever (Faget sign) Conjunctival injection Skin flushing As the disease progresses, additional physical findings include the following: Scleral icterus Jaundice Epigastric tenderness Hepatomegaly The following will also often be apparent: Petechiae Purpura [emedicine.com]

• Yellow Discoloration of the Skin

  In severe cases, a person may develop high fever, jaundice (a condition that involves yellow discoloration of the skin and the whites of the eyes), bleeding (especially from the gastrointestinal tract), and eventually shock and failure of many organs. [cdc.gov]

  If you have signs or symptoms of hepatitis (inflammation of the liver) caused by a virus, or unexplained jaundice (yellow discoloration of the skin), you are not eligible to donate blood. [redcrossblood.org]

• Erythema

  He presented to us with an unusual painful erythema Th7-9 triggered by touch in the respective skin area due to a cervical spinal cord lesion affecting the dorsolateral parts of C6/7. [ncbi.nlm.nih.gov]

  […] autre maladie virale; maladie virale non classée ailleurs maladie virale autre ou nca adenovirus; Coxsackie diseases; dengue fever; Ross River fever adénovirus; maladie à coxsackie; dengue; fièvre de la Ross River infections other viral exanthem A76; erythema [hetop.eu]

• Conjunctival Injection

  A physical exam may reveal the Faget sign or pulse fever dissociation, facial flushing, and conjunctival injection. During the most toxic phase, patients develop jaundice, dark urine, and vomiting. [ncbi.nlm.nih.gov]

  injection Skin flushing As the disease progresses, additional physical findings include the following: Scleral icterus Jaundice Epigastric tenderness Hepatomegaly The following will also often be apparent: Petechiae Purpura Mucosal bleeding Gastrointestinal [emedicine.com]

• Photophobia

  Yellow fever has an abrupt onset after an incubation period of 3--6 days, and usually includes fever, prostration, headache, photophobia, lumbosacral pain, extremity pain (including the knee joints), epigastric pain, anorexia, and vomiting. [cdc.gov]

• Epistaxis

  The initial onset is abrupt with fever, myalgia, headache, vomiting, and minor gingival hemorrhage or epistaxis lasting for about 3 days. [ncbi.nlm.nih.gov]

• Dark Urine

  In this phase people are likely to develop jaundice (yellowing of the skin and eyes, hence the name ‘yellow fever’), dark urine and abdominal pain with vomiting. Bleeding can occur from the mouth, nose, eyes or stomach. [web.archive.org]

  Call your doctor right away if you have signs of liver problems like dark urine, not hungry, stomach pain, light-colored stools, or yellow skin or eyes. [drugs.com]

• Oliguria

  The patient presented with hemorrhagic fever, jaundice and oliguria at day 3 after onset, which rapidly progressed to multisystem organ failure with extremely elevated liver, pancreatic and myocardial enzymes. [ncbi.nlm.nih.gov]

  Shock, tachycardia, bleeding, oliguria, proteinuria and azotemia confer a poor prognosis. Although convalescence may be prolonged, survivors usually have no lasting sequelae. [orpha.net]

  There may be oliguria, petechiae, mucosal hemorrhages, confusion, and apathy. Disease may last > 1 week with rapid recovery and no sequelae. [msdmanuals.com]

• Headache

  Yellow fever has 3 stages: Stage 1 (infection): Headache, muscle and joint aches, fever, flushing, loss of appetite, vomiting, and jaundice are common. Symptoms often go away briefly after about 3 to 4 days. [nlm.nih.gov]

  The second patient-a 22-year-old black woman-developed a sore throat and fever accompanied by headache, myalgia, nausea, and vomiting 4 days after yellow fever vaccination. [ncbi.nlm.nih.gov]

  The patients usually present with fever, headache, yellowing of the skin and internal bleeding. Yellow fever can be prevented by a vaccine. [symptoma.com]

• Nystagmus

  […] encephalitis due to SLE, JE, or Murray Valley encephalitis (MVE) virus begin as fever, headache, and stiff neck, and progress to an altered level of consciousness and focal neurologic deficits (e.g., tremors, pathologic reflexes, cranial nerve palsies, nystagmus [ncbi.nlm.nih.gov]

A diagnosis of yellow fever is established on the basis of complete medical history including history of travel and vaccination status.

On general physical examination, the findings include tachycardia, yellowness of eyes and skin, coated tongue, state of dehydration and dark colored urine.

The laboratory testing helps to confirm the diagnosis. These include:

• Complete blood count: The findings in a complete blood count for patients with yellow fever include leukopenia, thrombocytopenia, increased hemoglobin and hematocrit levels and initial hemoconcentration.
• Coagulation studies: These studies reveal reduced fibrinogen and clotting factors II, VI, VII, VIII, XI, and X. It also indicates prolonged clotting time.
• Urinalysis: It indicates elevated urinary proteins and urobilinogen levels.
• Liver function tests: These tests reveal elevated serum AST levels, direct bilirubin levels and hypoalbuminemia.
• Polymerase chain reaction (PCR) assay: It helps in the detection of viral genome in tissue or in blood.
• Enzyme-linked immunosorbent assay (ELISA): This serologic test aids in making the correct diagnosis. A rise in yellow fever-specific antibody titer confirms a diagnosis.

There is no specific treatment for yellow fever. Treatment is supportive and effective treatment involves complete bed rest under mosquito nets.

Antipyretics and analgesics are helpful to control fever and pain respectively. Drugs like antacids and histamine blockers are used to control gastric bleeding. Blood transfusions can be given for severe bleeding.

Oral or intravenous intake of fluids help to maintain dehydration, blood volume, increase blood pressure and correct hypoglycemia. Dialysis may be needed if kidney failure develops.

Mortality due to yellow fever varies according to the severity of the disease. It varies from 50% without medical treatment to about 5% with complete medical care.

Mortality rate is higher with life-threatening hemorrhagic fever, jaundice, liver and kidney failure. Death usually occurs within 7 to 10 days of the toxic phase of yellow fever. Those who recover have life-long immunity. So overall, the prognosis is good if diagnosed and treated properly.

Yellow fever is caused by an enveloped RNA virus called yellow fever virus [3]. The individuals who are more at risk of developing yellow fever include travelers to certain parts of South America and Africa. The risk of the disease can increase with various factors like travel to endemic areas, visiting rural areas or participating in outdoor activities such as camping, cycling, hiking or fieldwork.

Yellow fever is endemic in tropical areas of South America and Africa [4]. About 15% of the cases who develop yellow fever can have serious complications. The World Health Organization estimates that there are 200,000 cases of yellow fever worldwide each year, resulting in 30,000 deaths.

Due to decreased immunity to infection, deforestation, climate changes and increased urbanization, yellow fever appears to be on the rise internationally. Yellow fever transmission with a high risk have been identified in 45 countries, many of them with tropical climates.

Yellow fever virus is transmitted to humans through the bite of an infected mosquito, Aedes aegypti. Some other mosquitoes such as Tiger mosquito can also serve as a vector for this virus. Yellow fever virus is taken up by a female mosquito by feeding on infected humans. The mosquito can then transmit the virus to other humans. Yellow fever virus can also be transmitted by mosquitoes from monkeys to humans by a sylvatic cycle [5]. It mostly occurs in travelers while visiting or working in jungle border areas.

Mosquitoes that spread viruses usually bite during the day time, particularly around sunrise and sunset. Viruses reach the stomach of the infected mosquitoes and then reach the salivary glands via blood stream. When the infected mosquito bites a person, the virus is transmitted to blood system of the person through mosquito’s saliva.

After transmission of the virus from a mosquito to human, the virus replicates in the lymph nodes, particularly the dendritic cells. From there, the viruses reach the hepatocytes in liver. This results in eosinophilic degradation and release of cytokines [6]. If left untreated, it can lead to complications such as cytokine storm, shock, and multiple organ failure, causing fatality.

Wikipedia: Yellow Fever Encyclopedia article on this viral disease, its transmission, diagnosis, prevention, treatment and history. [curlie.org]

Rapid vaccination of populations vulnerable to epidemic-prone vaccine-preventable diseases is a major component of emergency response. [ncbi.nlm.nih.gov]

Prevention - Prevention Symptoms - Symptoms Treatment - Treatment Yellow fever virus is found in tropical and subtropical areas in South America and Africa. The virus is transmitted to humans by the bite of an infected mosquito. [web.archive.org]

Yellow fever is a viral infection caused by flavivirus that is transmitted by the bite of an infected mosquito. The virus is found in tropical and subtropical areas in South America and Africa [1][2].

In most of the cases, symptoms take 3 to 6 days to develop and include fever, chills, jaundice, loss of appetite, nausea, headache, backache, and muscular aches.

Vaccination may be effective against yellow fever. Untreated cases can lead to severe complications like bleeding, shock, organ failure, and sometimes death.

Yellow fever is a viral disease which is transmitted by the bite of an infected mosquito. The virus is more common in subtropical areas.

The patients usually present with fever, headache, yellowing of the skin and internal bleeding. Yellow fever can be prevented by a vaccine.

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2. Barnett ED, Wilder-Smith A, Wilson ME. Yellow fever vaccines and international travelers. Expert review of vaccines. Jul 2008;7(5):579-587.
3. Liceaga E. [The etiology of yellow fever, 1898]. Salud publica de Mexico. Sep-Oct 1989;31(5):708-719.
4. Barnett ED. Yellow fever: epidemiology and prevention. Clinical infectious diseases : an official publication of the Infectious Diseases Society of America. Mar 15 2007;44(6):850-856.
5. Barrett A, Higgs, S. Yellow fever: A disease that has yet to be conquered. Annu Rev Entomol. 2007;52.
6. Monath TP, Barrett AD. Pathogenesis and pathophysiology of yellow fever. Advances in virus research. 2003;60:343-395.
7. Monath TP. Treatment of yellow fever. Antiviral research. Apr 2008;78(1):116-124.
8. Cleri DJ, Ricketti AJ, Porwancher RB, Ramos-Bonner LS, Vernaleo JR. Viral hemorrhagic fevers: current status of endemic disease and strategies for control. Infectious disease clinics of North America. Jun 2006;20(2):359-393, x.
9. Quaresma JA, Pagliari C, Medeiros DB, Duarte MI, Vasconcelos PF. Immunity and immune response, pathology and pathologic changes: progress and challenges in the immunopathology of yellow fever. Reviews in medical virology. Sep 2013;23(5):305-318.
10. Roukens AH, Visser LG. Yellow fever vaccine: past, present and future. Expert opinion on biological therapy. Nov 2008;8(11):1787-1795.