For people who live, work or travel extensively in the tropics
Especially those who have had Dengue and are worried about getting it again,
as subsequent infections can have a much more severe reaction
"...avoid getting bit by the dengue transmitting mosquito."
So what to do—short of never living in/ visiting/ working in any tropical place ever again?What if you do get bit again, despite precautions?
General info on Dengue
What are odds of getting and dying of hemorrhagic or shock dengue if you've had dengue and you get it again?
- DHF usually results from a second infection from a different serotype
- The theory is that antibodies that prevent reinfection by one serotype somehow help other serotype viruses do worse damage
- Most DHF cases are secondary infections. About 90 % of DHF patients have a previous history of dengue (secondary infections). But even if you have a second infection it does not mean that you will develop DHF. Usually 10- 12.5% of secondary infections develop DHF
- Your risk of dying from DHF with inadequate treatment is 10--15%
- Your risk of dying with adequate treatment is less than 1%, regardless of age group.
- In the majority of cases, the actual cause of death is dehydration from loss of plasma volume, not the hemorrhage itself.
Precautions for people who've already had dengue
- Avoid getting bit
- Research beforehand a physician, clinic, or hospital which you trust to give you adequate treatment should you develop DHF.
- If you are in endemic areas as part of a development program and you're far from major medical care (as we are), see if you can include part or all of the elements of a "dengue mini-clinic" in your program (see below) so you can monitor your own or other dengue cases locally.
Small dengue clinic list
- CBC Counter (for WBC, Hematocrit, and platelet count)
- Sphygmomanometer (for blood pressure monitor)
- Thermometers (for children, adults)
- IV fluids & setup: Normal saline solution
- Ring Lactate
Monitoring dengue patients for onset of DHF
- Hemorrhage, decrease in blood pressure, declining platelet count, or increasing hematocrit are all warning signs that DHF may be developing and you should head towards your medical backup/ hospital.
- If you're far from hospital, go early. Don’t wait.
- If you have any hemorrhage look for medical assistance. Hemorrhage by itself does not mean you will be hospitalized. Your physician needs to evaluate you.
- You can have dengue and mild hemorrhage without it being considered DHF.
- Typical hemorrhage is nosebleed, gum bleed, small red dots in skin (pitequeas), and vaginal bleeding. Less common is vomiting blood.
- Transition from dengue to DHF can happen pretty fast (hours, not days), so make sure to be prepared to respond in case of clinical deterioration.
- Attend to the patients overall state of well-being
- Check and close monitor blood pressure. If it is falling, then probably more fluid is needed possibly IV.
- Dehydration —Main characteristic of DHF is that people dehydrate faster, through capillary leakage. The fluid may collect in places other than the arteries and veins, such as lungs and abdomen.
- Get hematocrit, platelet count when symptoms/fever starts for baseline.
- Keep monitoring daily. If it goes up by 20% from what they had, this suggests dengue hemorrhagic fever, but don't want to wait this long.
- Do daily/ 2x daily hematocrits, if increasing could indicate leaking of the capillaries.
Criteria for hospitalization
- Increasing hematocrit
- Platelet count --less than 100,000mm3
- Any spontaneous bleeding
- Any warning sign for shock ( see shock related symptoms)
- If not adequately treated, dehydration is what kills people (shock from loss of fluid), not the hemorrhage.
- Give a lot of oral fluids and IV fluids without overload
- Can hydrate adequately just from drinking in most cases
Shock related symptoms
- Clinical deterioration
- Severe abdominal pain as dominant symptom (worse than headache, pain in bones)
- Change in mental status-does not respond, loses sense, can't wake up.
- Drastic change in temperature (cold, clammy or mottling skin)
- Severe vomiting
- Not passed urine in 4 – 6 hours
Infants exposed to antibodies via pregnancy or mothers milk
- An infant who has been exposed to antibodies through pregnancy or mothers milk and still has them will react exactly the same as somebody who had dengue before. Maternal antibodies usually last up to 6 months or more.
- You can do an IGG test for infant, to determine. If your baby has antibodies or not.
- If a baby tests positive for IGM, they had their own direct infection.
- Not all babies get IGG from breast milk.
- If they test negative for IGG, they will respond to a subsequent dengue infection as an initial infection, not as a more dangerous second infection.
- Retest the baby six months after breastfeeding stops to see If he has own immunity, usually mom's antibodies only last 3-6 months.
- Classic dengue is generally milder in young people. But the risk of DHF increases in infants (less than 1 year) due to the presence of maternal antibodies. Risk of fatality from DHF with adequate treatment is similar across different age groups.
- More children contract dengue, because they have not been exposed to the virus previously and are susceptible.
At the hospital
- Frequent (daily or twice daily) platelet count, hematocrit, blood pressure.
- Adequate but not excessive hydration, IV If necessary.
- Monitoring of patient well-being
- Platelet count
- Must have stable or increasing platelet count higher than 50,000
- (below 50,000 risk of spontaneous bleeding is higher)
- Blood pressure
- Stable blood pressure (shows good hydration)
- Stable or falling (indicative of no or improvement in capillary leakage)
- Pass 48 hours without fever
- No vomiting
- Doesn't have respiratory distress
- From fluid in lungs.
- Improved general constitution