Yellow fever:Signs, Symptoms, Causes, Prevention and Treatment

 










History of yellow fever 

Yellow fever disease is opined to have had it origin in Africa and was probably brought to the Americas on ships during the slave trade.
the first documented outbreak of yellow fever was in Yucatan peninsula during the 17th century. In the 18th century, an outbreak struck New England and several North American port cities. The city of Philadelphia is thought to have lost about one-tenth of its population during the 1793 yellow fever epidemic and the last major outbreak was recorded in 1905, in New Orleans.

The first recorded prove that yellow fever is transmitted by a mosquito was established by a Cuban physician, Dr. Carlos Finlay, in the late 19th century and this leads the the control of yellow fever. Max Theiler was the first to develop a vaccine against yellow fever in the 1930s. This success helped control and eliminate yellow fever from various countries in Africa and South America.

Epidemiology of yellow fever 

In the light of resent yellow fever outbreak in Angola, which has raise a global concern about yellow fever disease. Yellow fever is considered as one of the most dangerous infections diseases of public health importance. Here are few things you should know about yellow fever. 

Estimates made by World Health Organization gave account that yellow fever causes 200,000 illnesses in a year and estimates about 30,000 deaths every year in un-vaccinated populations and about 90% of infections cases occur in Africa.

Yellow fever an acute infections viral disease, is one of the potentially fatal illness common to man with fatality of about 20% and mortality of 3% in all cases.

Yellow fever is a viral hemorrhagic illness, of the laviviridae family, The virus is about 40 to 50 nm and is transmitted by female mosquito bites, Aedes aegypti found in the tropical and subtropical Africa and South America are the major transmitter of the disease. Yellow fever has an incubation period of three to six days, afterwards a toxic phase of the illness follows, where liver is damaged with the presence of jaundice a situation that gives the disease its name "yellow fever", and in more serious cases About 15% of patients enter this second phase of the disease a phase called the toxic relapsing fever phase that mostly result in vomiting blood (which gives the name of black vomit). This toxic phase is fatal in about 20% of cases, so the overall mortality rate of the disease of 3%.

Signs and symptoms 

Nausea

Pain

Muscle pain

Mild fever

Headache

Chills

Back pain

Loss of appetite

Abdominal pain

Vomiting

Appetite loss

Bleeding in eye noise and Gastrointestinal tract.

Diagnosis

Diagnosing yellow fever based on signs and symptoms can be difficult because early in its course, the infection can be easily confused with malaria, typhoid, dengue fever and other viral hemorrhagic fevers. Laboratory diagnosis of yellow fever is carried out by testing the serum to detect virus-specific IgM, neutralizing antibodies, MIA (microsphere-based immunoassay) and IgG ELISA, performed on blood sampled during acute illness. Tissues may be tested postmortem with transcription-polymerase chain (PCR ) reaction testing (which detects viral RNA), immunohistochemical stains, and viral culture.

Precautions to avoid yellow fever.

• Vaccinations.
• Avoid unprotected outdoor exposure in areas where mosquitos are rampant.
• Wear body covering cloths.
• Sleep under an insecticide treated mosquito net

Treatment of Yellow Fever

There is no established cure for yellow fever, an intensive care admission in the hospital may be necessary. Antibiotics and antiviral therapy has a desirable effect in the symptomatic treatment and other known established treatment. However pain reliever drugs with medications such as paracetamol should not be given because of its anticoagulant effect, which can be devastating in cases of internal bleeding that can occur with yellow fever.

Vaccination

Yellow fever vaccination is given because of two major reasons, to prevent international spread of yellow fever from inter-border movements and to prevent individuals from exposure. Yellow fever vaccine generally provides 10 years of immunity for anybody that takes the vaccine, afterwards a booster should be given in the setting of recurrent or ongoing exposure.

Individuals more than 9 months of age is recommended to have yellow fever vaccination, how ever anybody with previous exposure to yellow fever and got healed has developed a life long immunity to yellow fever.

Prevention is better than cure take a yellow fever vaccine today and prevent your self for the menace of the disease.