Dengue

[Dedworth]

Had dinner with some friends on Sunday - Mei Ling is a midwife from Malaysia earlier they'd been and visited one of her nurse pals who is now a patient in the hospital works at with Dengue Fever.

Not the sort of thing you want to bring back from holiday

Has any forum member ever had it ?

[grahamw48]

When I was living in Bicol province I became ill and had to be taken to the local hospital to be put on a drip after a few days high fever. The doctor there said it (my temp') was 41.5C and I was lucky not to have dropped dead, but the actual cause of the fever was never identified. I lost probably a couple of stone in around 10 days, and was very weak for at least 3 weeks afterwards.

[Slip]

Bloke I work with got it in Thailand about 8 years ago. Went for a month but was to ill to travel back and was off for three months.

[Doc Alan]

Thankfully I haven’t had dengue, so maybe don’t qualify for posting on this thread !


It’s not surprising some members have had dengue, and many of us probably know people who have suffered this increasingly common viral infection. Of course there’s a separate thread on this and the other main mosquito-borne infection, malaria.



Half the world’s population is now thought to be at risk of contracting dengue. Still there is no vaccine, although several are being tested and might be available in the next year or two. The difficulty is that the vaccine needs to work against all four dengue virus types. If you’re infected by one type, there is no lasting immunity to the others.


At least of all the estimated 50 million infections each year, only about 20,000 deaths occur, sadly often in children. Up to 1 in 10 sufferers develop the more severe dengue haemorrhagic fever or dengue shock syndrome.


There were fears of a dengue outbreak - among many other health concerns – following Typhoon Haiyan / Yolanda, but the disease does not appear to have reached epidemic levels.


During the 19th century, dengue did not cause frequent epidemics. This reflected slow pace of transport and limited travel at that time. In the past 50 years, it seems to have increased in frequency ( or at least diagnosis ) 30-fold. Other factors include population growth ; migration to cities ; inadequate urban infrastructure like water supplies, and waste disposal.


Dengue may not be acquired ( yet ) in the UK, but travellers from endemic areas ( mainly south and south-east Asia, South and Central America, Africa and the Caribbean ) are being diagnosed after returning – between 200 – 500 a year.


The well known precautions to avoid mosquito bites listed in separate threads need to continue even when a vaccine becomes available. Apart from malaria, there are other diseases spread by mosquitoes ( Yellow Fever, vaccine not needed for Philippines but recommended for visiting Brazil’s World Cup ; chikungunya , no vaccine, but natural immunity after infection ; filariasis ; and a rare type of encephalitis/ brain inflammation ).


I count myself lucky not to have had many of the illnesses which I’ve diagnosed in others .

[Dedworth]

Thanks for your usual comprehensive write up Doc - are antimalarial tablets useful for preventing dengue or is it another virus that happens to be spread by mosquitos

[Doc Alan]

Antimalarial tablets are not recommended for preventing ( or treating ) dengue, or any of the other mosquito-borne infections. They're caused by different viruses ( and a parasitic worm for filariasis ).


It’s true to say at present there is no vaccine or specific medicine to treat dengue. “ Supportive “ treatment – as in the other thread – rest, fluids, and paracetamol – is sufficient for most cases.


Of course new drugs ( and diagnostic blood tests ) are needed to help make dengue treatable. Two antimalarials ( a quinoline derivative and doxocycline ) have been found recently to have anti-dengue virus action, but more work is needed.



In malaria-endemic countries, fever ( present in all cases of malaria at the start ) is often presumed by health workers to be due to malaria. Treatment is given without confirmation by blood testing using microscopy to look for parasites. The alternative, “ RDT “ ( rapid diagnostic test ) gives a result in 15 minutes with a finger-prick of blood. They may not be trained in use of tests ; don’t trust “ negative “ results ; have little confidence or resources to treat other causes of fever ; and patients themselves demand antimalarials ! This is a waste of drugs, leads to drug-resistance, and won’t treat other causes.


Dengue is one of these causes. Fever is a very common sign that on its own is little help in making a diagnosis. Most are due to self-limiting viral infections. The type of fever, severity, and pattern may all help in reaching the right diagnosis.



Dengue would be high on the list of causes for fever in the Philippines – and for a traveller recently returned from there to UK. Obviously it helps to give a complete medical history to the health worker.