Story of SCIENTIFIC RESEARCH
At a snakehead pond in Mekong Delta of Vietnam….
People recognized that feed intake of pond was reduced in some near days. Some of fishes have been died.
The farmer thought about a bad feed. Did It cause this situation ???
Biocom people didn’t think so. They have gone for a research….
10 of 12 fishes presented with an anormal abdomen. They are bigger than others.
Body weight among them is very different from others.
4 of 12 fishes presented with small red spots into their skin, called petechiae, at pectoral fins and pelvis fin.
........Go ahead to macro-lesions
10 of 12 fishes were shown with from much to very much of transudate in their abdomen
In some fishes, transudate was transformed into gel forms.
All of 12 fishes have the empty stomaches and oesophaguses and there are no ulcers nor bleeding on their surfaces. They are almost normal.
11 of them have the good and transparent peritoneals. Not any anormal.
All of 12 fishes presented the hypertrophic livers and some necrosis areas with pale color and diffused on them.
Be suspected that:
** These are not an acute disease. It developed and processed in a long time.
** Bacterial infection shown is not primary nor main cause of the death.
** There is no any relationship between death and feed.
==> Something else caused the lesions in the liver ? by a local blockage of liver circulatory system.
......... Going further with microscopic lesions
Under x400 microscope, all of 12 spreads of gills liquid presented embryonated and unembryonated eggs with high density.
Also, 2 of 12 spreads of abdominal liquids have been found 2 larvaes among much of embryonated eggs. These 2 larvaes are suspected to belong the Gnathostoma spp.
Dozens of spreads have been done continuously and ....
finally, an adult, alive, be moving Gnathostoma was appeared under x400 microscope field.
A scientific investigation closed after 7 hours of continuous work.
1/ All of 12 surveyed fishes have been affected with Gnathostoma spp. The scientific name is GNATHOSTOMIASIS. Vietnamese name is BỆNH GIUN ĐẦU GAI. This is the main reason why fish eats less or not to eat, grows slowly and they are not in uniform weight, big belly and die.
2/ The level of affection is assessed as serious. The duration of affection is estimated to be at least 2-3 weeks before the investigation. Microbial infections are not important until the time of surveying.
3/ This disease (Gnathostomiasis) can spread to humans by swallowing larvae L1 or L2. The disease causes serious consequences in humans, especially when larvae migrates into the nervous system. Some authors call this disease "emerging disease". The farmers and the technicians should not survey themselves when there is not suitable protective equipments.
For a detail knowledge on this disease in humans please refer to the website of the Institute of Malariology Parasitology and Entomology of Quy Nhon at http://www.impe-qn.org.vn/impe-qn/vn/portal/InfoDetail.jsp?area=58&cat=1068&ID=2035
There is an important distinction between transudates and exudates.
* Transudates are caused by disturbances of hydrostatic or colloid osmotic pressure, not by inflammation. They have a low protein content in comparison to exudates and thus appear clearer.
* Exudate: extravascular fluid due to vessel alteration during inflammation (increased permeability, vascular constriction then dilation). This results in an extracellular fluid of high protein content, with cell debris present and high specific gravity (>1.020).