Zika, sex and pesticides

Sunday, February 21 2016
Newsday – newsday.co.tt

Aedes Aegypti mosquitoReporter JANELLE DE SOUZA reviews the debate over the rise of the Zika virus in the Caribbean, as Trinidad and Tobago joins the list of countries reporting cases of the mosquito-borne illness.

Could the use of a popular pesticide to control the mosquito population be responsible for the most feared outturn of Zika, head and brain deformity in babies born to mothers who were afflicted by the virus? Can the Zika virus be transmitted through sexual intercourse? These were among the most pressing fears as another of those big diseases with the small names manifested its entry into Trinidad and Tobago last week. Zika’s arrival plus the global debate over its spread and consequences deepened national concern and stimulated emergency measures that were laid down by the Health Ministry several weeks ago as the relatively new virus preoccupied countries far and near, with health emergencies and intense action to contain it.

In all the debate about what spreads Zika, there is one confirmed way: bites from the Aedes Aegypti mosquito, an insect that lives en masse among us in Trinidad and Tobago even outside health emergencies, and is responsible for our annual cycle of dengue and its debilitating consequences.

But while the Aedes Aegypti is the identified culprit, researchers continue to posit that the virus could also be transmitted through sex and certain insecticides.

They maintain their emphasis that the virus is relatively new among Caribbean, Central and South American populations, and accordingly were not clear how this stranger pest would behave.

With that in mind, none of them have been able to proffer any specific treatment, vaccine or preventive drug for Zika. Any treatment would merely be to minimise symptoms.

So that, as of January 25, there were Zika cases in 22 countries and jurisdictions in the Americas, several countries in Central America, as well as Guyana, Barbados, Haiti, Suriname, Brazil, French Guiana, Venezuela, Colombia, Martinique and Puerto Rico, and as of February 17, Trinidad and Tobago. But the background to Zika point to a disease that was discovered some seven decades ago in 1947, by scientists conducting research in the Zika Forest near Lake Victoria in Uganda.

They were said to have isolated a novel virus in a sick rhesus monkey. They were able to extract and examine the virus, which they named after its original founding location.

Speaking at a media conference on Zika last month at the Caribbean Public Health Agency (CARPHA) headquarters in Federation Park, Port-of-Spain, Dr Karen Polson-Edwards, Senior Technical Officer, Vector-borne Diseases and Neglected Tropical Diseases at the agency pointed to the similarity between Zika symptoms and those of dengue and chikungunya. Lasting from two to seven days, conditions include fever, skin rashes, conjunctivitis, headache, muscle and joint pain, and a general feeling of being unwell.

She noted, however, that serious complications can sometimes occur in persons who are infected.

Polson-Edwards explained that in 2013, during large outbreaks of Zika in French Polynesia and Brazil, health authorities reported a potential link between the virus and microcephaly (babies born with small heads) in pregnant mothers who contracted Zika, especially during the first three months.

“As at January 17, 2016, more than 3,500 cases of microcephaly and 46 related deaths have been reported in areas where the Zika is circulating,” the CARPHA expert said. “We still do not understand the relationship between Zika Virus and microcephaly in babies but the possibility that there is a link gives reason for public health concern.” There was also a significant increase of patients with Guillain– Barré syndrome (GBS) — a rare nerve disorder that causes muscle weakness and even limb paralysis — and meningitis, in areas in which Zika is prevalent. GBS can lead to severe infections, blood clots, and autonomic neuropathy which is basically damage to the nerves that help your organs — heart, lungs, liver, kidney, stomach, etc — to function While Zika itself is not terminal, there have been Zika-related deaths. Reports indicate there were two such deaths during the first week of February, and one in November last, in Colombia.

The three patients, who were confirmed Zika cases, died as a result of GBS.

Transmission In a new twist to the unfurling Zika Virus story, some Brazilian and Argentine doctors and researchers have published separate reports stating that a pesticide used to reduce the spread of mosquitoes could be the cause of microcephaly in new born babies, rather than the virus itself.

According to a recent article on the Ecologist website, Latin American doctors are proposing that Pyriproxyfen, a pesticide introduced to drinking water tanks in Brazil since 2014, could be to blame.

The website explained that Pyriproxyfen was a growth inhibitor of mosquito larvae, which alters the development process from larva to pupa to adult, thereby killing or disabling developing mosquitoes.

A report published by the Argentine doctors’ organisation, Physicians in the Crop-Sprayed Towns (PCST), stated that most of the persons infected with Zika in Brazil were from areas where the insecticide was used.

“Malformations detected in thousands of children from pregnant women living in areas where the Brazilian state added Pyriproxyfen to drinking water are not a coincidence, even though the Ministry of Health places a direct blame on the Zika virus for this damage,” the report stated.

Source: www.newsday.co.tt/news/0,224315.html

1 Responses to “Zika, sex and pesticides”


  • Never been a fan of spraying. This of course is nothing new since I was a child ministry of health sent a team to visit our home. They spray around the barrels, place granules in our barrels, told us to keep the area clean.

    In India they found that the easiest way to control the spread of mosquito larvae was to release thousands of sardines in stagnated water and ponds. The sardines feasted on the mosquito larvae.

    There are simple contraptions that everyone can make, take a 2 liter soft drink bottle, cut the top off just at the point where it gets larger, invert it and use some dark electrical tape to cover it, then put some water and yeast in it. Every two weeks change it. The mosquito is attracted to the yeast, they get in and can’t get out. It will take 5 minutes to do this and it is very effective. More importantly it is better than spraying.

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