🚀 go-pugleaf

Kin Chong (khc12@cus.cam.ac.uk) wrote:
: I would like to find out more about drugs that can fight parasites.
: Being an engineer, i am illiterate on this subject. So please 
: bear with me. I am interested in a drug to counter river blindness,
: also known as onchocerciasis (or filariasis). It is a parasite
: that can lead to blindness and the disease is spread by blackflies 
: in africa. The drug to counter this is ivermectin, alternatively,
: also di-ethyl-carbamazine. Apparently, ivermectin is only manufactured in 
: France and in the US. 

: Could anyone please tell me the symptoms, the duration of treatment,
: and prevention? Is it a water-borne parasite that enters the body 
: by drinking the water? Or is it spread by blackflies? 

: Can anyone please tell me how i can get an equivalent 
: anti-parasitic drug in the UK, without prescription? I have checked
: with the local pharmacy, who tells me that there are no local 
: manufacturers. For all those wondering, my dad is going to Sierra Leone, 
: West Africa. Many thanks in advance for the help.

: Kin

The nematode Onchocerca volvulus causes river blindness. (aka
Onchocerciasis). Dermatitis is another significant sequella.
Blackflies of the Simulum species are the vector for humans. It
takes several months for the infective larvae to develop into
adults. The males and females then have a sort of orgy, with 2 or
3 females and 1 or 2 males winding themselves up into a little
ball. 7 to 34 months later, the gravid female releases
microfilarie which migrate out into the tissues of the host,
mainly into the dermis. Subsequent blackfly bites pick up the
larvae from an infected host and can then transfer them to
non-infected individuals. 
Blackflies oviposit into running water. The larvae hatch, travel
downstream, and attatch to sticks, vegetation, etc. In 2 days the
adult emerges. Blackflies tend to remain within a couple
kilometers of their larval hatching sites, but monsoon winds can
carry them many kilometers.

The pathogenesis of river fever is mostly unclear. Most of the
symptoms are attributed to hypersensitivty reactions in the host.
Diagnosis is based on obtaining larvae from a skin-punch biopsy.
Ivermectin is the drug of choice for treatment, and is available
from the Centers for Disease Control. Dosage is 150 ug/kg on an
empty stomach at least 2 hrs prior to the next meal. A single
dose is usually all that is needed. Pregnancy, CNS disorders,
breast feeding, meningitis, and age >5 are contraindications. 
DEC (Diethylcarbamazine citrate) is microfilaricidal. Side
effects are serious, and include pruritus, lymphadenopathy,
fever, headache,rash, n/v, vertigo, arthralgias and myalgias.
Cardiovascular collapse has also been described. Lower efficacy
and the severity of side effects make Ivermectin a preferred
treatment. (that is, Ivermectin has better efficacy and fewer
side effects :) ) 
Sumarin is a macrofilaricidal agent, but has major toxicities and
requires multiple IV doses. 

There is no drug that has been shown to prevent infection with O.
volvulus.

The above was liberally condensed from Harrison's. If you require
additional information let me know.


devin 

-- 
Devin Nickol
dnickol@netserv.unmc.edu
"Free your mind, and the rest will follow."