Buscar este blog

jueves, 2 de mayo de 2013

ABCD of Dengue. 2011 ENGLISH VERSION. C. Cases and Clinic

This is the third post in a 4 part series, about Dengue, which originally appeared at blogtorchey.blogspot.com in Spanish on June 2011.

We have already seen how the Aedes reproduces and transports the dengue virus. In this installment we focus on its effects on us. I will start by differentiating the two general variants of the disease: the classic dengue and the hemorrhagic dengue. Even though considered two different entities, they clinically show a linear evolution: we all start with the symptoms of the classic dengue and, in some cases evolving to hemorrhagic dengue. I will not go into deep medical details, but it is important to mention that the presence of the virus in the blood produces an initial inflammatory response which produces in the body symptoms of classic dengue. In light of certain factors, the body may trigger a second inflammatory response by producing an accelerated use of platelets and dehydration which typify the symptoms of a hemorrhagic dengue.

The classic dengue has a variety of symptoms, hence often mistaken. An important example came about in 2009 with the presence of influenza, when a patient’s symptoms could be considered suspect of dengue and flue, assuming an important epidemiological challenge. At present dengue’s cardinal symptoms, those that determine a suspicious case are fever, headache, myalgia and arthralgia (bone and muscle pain); there is practically no case where these symptoms are not presents. Sometimes an allergic rash is present and may be preceded by a manifestation similar to a cold or simply sore throat and cough. With lower frequency we will find diarrhea, nausea or abdominal pain. Classic dengue symptoms last 3 to 4 days and, though we will not talk therapeutics in detail, the most important part of the treatment focuses on being well hydrated (4 to 5 liters of water or saline solution every day) and controlling the fever; use of antibiotics is usually a preventive measure (viruses are not attacked with antibiotics) and there are no antiviral medications or other drugs at present that may revert or reduce the duration of the symptoms.

Hemorrhagic dengue often manifests on the fourth or fifth day after the fever began. It’s a paradoxical and critical period as it comes about at the right moment the patient starts to feel better and the fever drops (which cause the symptoms to be underestimated). The essential symptoms are those that, after the classic dengue manifestation, they present abnormal bleeding: bleeding of the gums, nose bleeding, extended menstrual period, faces with blood or too dark. As well, presence of red punctiform spots on the skin usually on shins and forearms is a bottom-line manifestation of hemorrhagic dengue. At this point medical and lab evaluation are of utmost importance, as most cases require intravenous hydration, supervision of platelet levels, supervision and control of hemorrhages; very few are those cases that can be treated as out-patients (outside the hospital.)

Finally, I want to address some questions on the matter. First: this is a serious disease and has a large complication potential. I find that many patients feel that “nothing is being done” to them while at the hospital and want to be discharged. The reality is that although they do not require expensive or specialized medication, the sole administration of intravenous saline solution prevents many complications and, in case of hemorrhage, it can be controlled and patient’s complications be avoided. The second one is recovery. When patients are released, they want to return to their regular daily routines; it must be understood that hemorrhagic dengue (even the classic one) is a disease which, like pneumonias or kidney infections, significantly deplete the body reserves. Third and last, it is important to always seek medical advice when the main symptoms are present, in addition to the evaluation and proper treatment, the respective authorities must be notified of the case.

I hope this information is helpful. Wait for the next installment: D. Diagnosis and Epidemiology. Cheers.

ABCD DENGUE. 2011 ENGLISH VERSION. B: garBage, trash and water containers

This is the second post in a 4 part series, about Dengue, which originally appeared at blogtorchey.blogspot.com on Spanish on June 2011, by that time, little was known about Dengue and misleading information was a current language on the streets. In an effort to avoid our past experiences, the post hasn’t been edited. Whenever necessary or possible, 2013 remarks and comments will be properly pointed out.

B – Garbage, trash and water containers

First I wish to clarify about a question from the previous publication. An infected person has millions of viral particles in through its bloodstream (viraemia); when a mosquito bites and infected person and absorbs its blood, within the blood DV viral particles are included; thus, when a virus-free Aedes female (reminding you that from this species, only the female bites), she becomes the carrier and a virus transmission vector.

Now, addressing section B, we come into one of the definite issues in this disease’s prevention: water containers. As mentioned before, the virus needs the mosquito in order to spread and, in turn, the mosquito needs the water in order to reproduce. There is an anecdote presented in a course of Dengue where I participated. It explains the importance of this occurrence. In the '50s there was no dengue in the country or in a large portion of Central America. It is said that a cargo ship arriving from Brazilian coasts (where dengue did exist), carried a shipment of used tires and on route called ports in Central America; I don’t know if it ever called Mexico.
It turned out that the tires had wastewater containing mosquito eggs and larvae carrying DV which, when reaching port, infected Central America inhabitants and from there extending to the north, arriving to Mexico, thus reintroducing dengue.

So close is the relationship between the water and mosquito’s life cycle (and hence dengue) that dengue season begins with the rainy season. Why talk of trash and garbage? The mosquito does not need a large water stagnation to lay eggs, just a small accumulation in a bucket, a can turned upside down or any waste product able to collect water. It is here, in this close relationship where we must begin prevention: without water containers, dengue can be prevented.

The Ministry of Health’s campaign "Patio limpio" (clean patio) promotes the removal of cans, buckets, junk and any garbage container to prevent the potential of stagnant water. For this individual work, we only need to go outside, walk around checking and identifying where water accumulates on the house roof. We must get rid of waste, protect or keep buckets and canisters turned over; cisterns, water tanks or other fastened deposits should be covered and/or sealed. In waterloggings, ponds and other deposits which given their nature cannot be covered, temephos or abate (a substance that breaks the surface tension of water and prevents mosquitoes from standing on the surface to deposit its egg) must be used.

No matter how much we try to eradicate potential mosquito "nests" with the abovementioned measures, mosquitoes always appear. I do not have the official figures, but consider the 10 kms (6.2 miles) the mosquito may travel; and probably a few more depending on the wind speed. Hence, if there are no mosquitoes or dengue around us, the source could be a colony or a distant bog. In that case we must take precautions against the mosquito. Some of these measures are spraying (fumigation) our homes and surroundings (further below we will discuss spraying as a health campaign), use repellents even more at dawn and dusk (females’ feeding hours), place window screens and bed or hammock (pavilions) nets.
That's it for the B; wait for the next installment of C: Cases and dengue clinic.