Dear Editor,
The Government is now on a campaign of distributing filaricides described as Mass Drug Administration (MDA) by the World Health Organization. This is an attempt to eliminate filariasis by 2020. So far this aim is experiencing lots of challenges worldwide in endemic areas. Not sure there are lots of evidence supporting that but then again, we are talking about Guyana where “specialists” do not conform to international norms or medical evidence i.e. evidence- based medicine.
First let me explain filariasis. In Guyana we have drains which serves to drain the lands and roads whenever it rains. If those drains are blocked then the water accumulates creating a massive flood that Guyanese are all too aware of.
Our bodies have a similar system. These drainage systems are called lymphatic. If they become blocked then the water accumulates in that area. For example, if the lymphatic system in your leg is blocked then the leg swells due to an accumulation of water.
Filariasis is caused by a very small worm which is spread by the anopheles mosquitoes. If the mosquito bites an infected person, that mosquito can transfer the worms to someone else by simply biting that person and inoculating them with the worms. The worms then take up residence in the infected person’s lymphatic system. For example, if they block the lymphatic system of the leg then the leg swells resulting in what is colloquially known as “big foot” in Guyana. If someone is infected they can be treated with filaricides to kill the worms. That problem sorted.
What is happening in Guyana? Everyone is being given filaricides whether they are infected or not. As mentioned before this MDA lacks medical evidence despite it being championed by WHO. No trials have been done on its effectiveness in eradicating filariasis. We can look as tablets as a meal. If you eat stew fish today, tomorrow you still have to eat. It does not stay in the body forever. It is used and the waste excreted. Filaricides follow the same principle. Someone given the tablet today may be protected for that day or two before the tablet is broken down and excreted. What if a mosquito is to bite that person after the tablet is excreted. The fact is that they will get filariasis because the tablet is long gone out of their system. Common sense would dictate for this to be effective then all 800,000 population of Guyana have to get the filariasis tablet regime at the same time hence there may be a lag in potentially infected people. WHO argues that having the campaign over a six years period can address this. Fact is, this campaign has been going on worldwide since 2000 with not much success in eradicating filariasis globally. 2020 is less than two years away and I doubt whether this can or will ever be achieved since filariasis is a condition of third world countries that have struggling healthcare systems. I’m not sure who is responsible for implementing this programme but I’ll be grateful if they can provide the medical evidence underpinning this campaign. How successful has it been in other endemic countries in eliminating filariasis? The fact is all tablets do have side effects. The common filaricides used in these programmes are invermectin, diethylcarbamazine( DEC) and albendazole. DEC can affect the heart and kidneys among other side effects. It should not be used on heart patients. It should not be used by pregnant or breastfeeding women. Are we really checking for these problems before these medicines are administered? Invermectin and albendazole also have side effects for example the liver.
To me, it makes more sense trying to sort out the mosquito problems. Clear the clogged up drains. Clear the bushes which are like jungles in Georgetown and other areas. Not only at the time of Local Government Elections but all the time keep them cleared. Mosquitoes don’t vote. Educate people about having open waters in tanks. Spray the mosquitoes. I’m not very smart but that seems to be the logical thing to do. Not giving people tablets like Santa Claus distributing sweets when there is no evidence supporting it.
Finally, do not be confused between tablets and vaccines. Vaccines serve to build your immune system. Prepare your immune system for a specific infection. Say for example you have the measles vaccine, it will “teach” your immune system about the measles virus. So if the measles virus gets brave, ten years after you were given the vaccine, and decides to attack you, your body soldiers (immune system) is ready for it and will launch and all-out attack protecting you from the infection. This is not the same as the filaria tablets. They serve to kill the filaria worm. They do a great job but they only last a few days in your body.
Yours faithfully,
Dr. Mark Devonish MBBS MSc MRCP(UK) FRCP(Edin)
Consultant Acute Medicine
Nottingham University Hospital
UK
