Dengue and Chikungunya
Dengue
Overview
Dengue (DENG-gey) fever is a
mosquito-borne disease that occurs in tropical and subtropical areas of the
world. Mild dengue fever causes a high fever, rash, and muscle and joint pain.
A severe form of dengue fever, also called dengue hemorrhagic fever, can cause
severe bleeding, a sudden drop in blood pressure (shock) and death.
Millions of cases of dengue
infection occur worldwide each year. Dengue fever is most common in Southeast
Asia and the western Pacific islands, but the disease has been increasing rapidly
in Latin America and the Caribbean.
Researchers are working on dengue
fever vaccines. For now the best prevention is to reduce mosquito habitat in
areas where dengue fever is common.
Symptoms
Many people, especially children and
teens, may experience no signs or symptoms during a mild case of dengue fever.
When symptoms do occur, they usually begin four to seven days after you are
bitten by an infected mosquito.
Dengue
fever causes a high fever — 104 F degrees — and at least two of the following
symptoms:
·
Headache
·
Muscle, bone and joint pain
·
Nausea
·
Vomiting
·
Pain behind the eyes
·
Swollen glands
·
Rash
Most people recover within a week or
so. In some cases, symptoms worsen and can become life-threatening. Blood
vessels often become damaged and leaky. And the number of clot-forming cells
(platelets) in your bloodstream drops. This can cause a severe form of dengue
fever, called dengue hemorrhagic fever, severe dengue or dengue shock syndrome.
Signs
and symptoms of dengue hemorrhagic fever or severe dengue — a life-threatening
emergency — include:
·
Severe abdominal pain
·
Persistent vomiting
·
Bleeding from your gums or nose
·
Blood in your urine, stools or vomit
·
Bleeding under the skin, which might
look like bruising
·
Difficult or rapid breathing
·
Cold or clammy skin (shock)
·
Fatigue
·
Irritability or restlessness
When to see a doctor
Call or go to the nearest
emergency room if you've recently visited a region in which dengue fever is
known to occur and you develop emergency symptoms, such as severe abdominal
pain, vomiting, difficulty breathing, or blood in your nose, gums, vomit or
stools.
If you develop a fever and milder
symptoms common to dengue fever, call your doctor.
Causes
Dengue fever is caused by any one of
four types of dengue viruses spread by mosquitoes that thrive in and near human
lodgings. When a mosquito bites a person infected with a dengue virus, the
virus enters the mosquito. When the infected mosquito then bites another
person, the virus enters that person's bloodstream.
After you've recovered from dengue
fever, you have immunity to the type of virus that infected you — but not to
the other three dengue fever virus types. The risk of developing severe dengue
fever, also known as dengue hemorrhagic fever, actually increases if you're
infected a second, third or fourth time.
Risk factors
Factors that put you at greater risk
of developing dengue fever or a more severe form of the disease include:
·
Living or
traveling in tropical areas. Being
in tropical and subtropical areas increases your risk of exposure to the virus
that causes dengue fever. Especially high-risk areas are Southeast Asia, the
western Pacific islands, Latin America and the Caribbean.
·
Prior
infection with a dengue fever virus. Previous
infection with a dengue fever virus increases your risk of having severe
symptoms if you're infected again.
Complications
If severe, dengue fever can damage
the lungs, liver or heart. Blood pressure can drop to dangerous levels, causing
shock and, in some cases, death.
Prevention
One dengue fever vaccine, Dengvaxia,
is currently approved for use in those ages 9 to 45 who live in areas with a
high incidence of dengue fever. The vaccine is given in three doses over the
course of 12 months. Dengvaxia prevents dengue infections slightly more than
half the time.
The vaccine is approved only for
older children because younger vaccinated children appear to be at increased
risk of severe dengue fever and hospitalization two years after receiving the
vaccine.
The World Health Organization
stresses that the vaccine is not an effective tool, on its own, to reduce
dengue fever in areas where the illness is common. Controlling the mosquito
population and human exposure is still the most critical part of prevention
efforts.
So for now, if you're living or
traveling in an area where dengue fever is known to be, the best way to avoid
dengue fever is to avoid being bitten by mosquitoes that carry the disease.
If you are living or traveling in
tropical areas where dengue fever is common, these tips may help reduce your
risk of mosquito bites:
·
Stay in
air-conditioned or well-screened housing. The
mosquitoes that carry the dengue viruses are most active from dawn to dusk, but
they can also bite at night.
·
Wear
protective clothing. When you go into
mosquito-infested areas, wear a long-sleeved shirt, long pants, socks and
shoes.
·
Use
mosquito repellent. Permethrin can be applied to
your clothing, shoes, camping gear and bed netting. You can also buy clothing
made with permethrin already in it. For your skin, use a repellent containing
at least a 10 percent concentration of DEET.
·
Reduce
mosquito habitat. The mosquitoes that carry the
dengue virus typically live in and around houses, breeding in standing water
that can collect in such things as used automobile tires. You can help lower
mosquito populations by eliminating habitats where they lay their eggs. At
least once a week, empty and clean containers that hold standing water, such as
planting containers, animal dishes and flower vases. Keep standing water
containers covered between cleanings.
Chikungunya
What
is Chikungunya?
Chikungunya is a mosquito-borne viral disease, very
similar to dengue. The mosquitoes which spread it are Aedes aegypti and Aedes
albopictus. These mosquitoes acquire the virus when they feed on an infected
person. The virus spreads in the system of the mosquito and reaches its
salivary glands. Soon after, when the mosquito feeds on a person, it infects
him.
The infection lasts for 2 to 12 days.
If you notice any of the following symptoms, you
need to consult your family physician or a general physician immediately:
- ·
Continuous high fever (above 38.5 degree
Celsius)
- ·
Debilitating joint pain and redness or
soreness in the joint areas
- ·
Rashes on the skin
- ·
Nausea
- ·
Vomiting
- ·
Sensitivity to light
- ·
Headache
How
does Chikungunya occur?
Once the Aedes mosquito bites a person suffering
from Chikungunya, the Chikungunya virus enters the mosquito’s system. After
getting infected when the mosquito feeds on another person, the virus gets
transmitted to the person.
The virus travels through his body and spreads to
various glands in the body. It enters the bloodstream and causes inflammation
of the blood vessels, causing them to swell and leak.The Chikungunya virus
usually targets joints, muscles, skin, and less frequently, the liver, kidneys,
eyes and the central nervous system.The Chikungunya virus mainly infects the
muscle cells of the body. Once it infects a muscle cell, it keeps reproducing
till the cell dies and then the viruses move onto a new cell.If you contract
this disease you may experience severe muscle pains, joint pains, fever and
rash.
What
are the symptoms of Chikungunya? How is Chikungunya diagnosed?
The
symptoms of Chikungunya include:
- ·
High fever
- ·
Severe muscle and joint pain
- ·
Severe headache
- ·
Nausea
- ·
Vomiting
- ·
Rash on the skin due to damaged blood
vessels
- ·
Enlarged painful lymph node in the neck
- ·
Sore throat
- ·
Painful abdominal cramps
- ·
Cold fingers and toes
- ·
Dizziness
- ·
Constipation
Chikungunya symptoms can often be confused with the
symptoms of dengue. However, certain symptoms such as debilitating joint pains
are unique only to Chikungunya. In fact, it is said dengue plus arthritis is
equal to Chikungunya.
In dengue, the muscle pain is very noticeable.
Diagnosis
A special blood test known as ELISA blood test
(enzyme-linked immunosorbent assay) is done to confirm the presence of Chikungunya
virus in a patient. During the test, if IgM antibodies are found (which can
last up to one year in the blood) it confirms the presence of Chikungunya virus
in the body.
These antibodies reveal the presence of the Chikungunya
virus.
What
are the complications of Chikungunya?
Some
complications of Chikungunya include:
- ·
Neurological imbalances
- ·
Seizures
- ·
Myocarditis or inflammation of the heart
muscle
- ·
Ocular disease or eye disease (uveitis,
retinitis)
- ·
Jaundice caused by liver damage
- ·
Acute renal disease when kidneys get
affected
- ·
Severe bullous lesions
- ·
Neurological diseases, such as
meningoencephalitis, Guillain-Barré syndrome, myelitis, or cranial nerve
palsies
What
is the treatment for Chikungunya?
Chikungunya is a self-remitting illness. There is no
particular medication or treatment available for chikungunya.
The doctor may advise you to take plenty of rest,
fluids, and provide you painkillers. Even while prescribing pain-killers,
paracetamol is recommended for treating the pain and fever. Nonsteroidal
anti-inflammatory drugs are never prescribed.
The usual treatment for the severe form of Chikungunya
consists of:
·
Providing Intravenous (IV) fluid and
electrolyte replacement
·
Monitoring blood pressure
·
Blood transfusion to replace blood loss,
if any