Why mosquitoes cannot transmit HIV – By Chioma Obinna

Information is power, and if you are not informed, you are deformed. I find this piece very informative, interesting and knowledgeable.

Today, available statistics have shown that estimated 1.6 million people die of HIV&AIDS annually. In Nigeria alone, government reports claim that over 300,000 Nigerians die yearly of complications arising from AIDS.

If these estimated numbers die of HIV/AIDS, have you ever imagined what the situation will be like? Thank God, HIV doesn’t have that ability. If mosquitoes spread HIV the way they spread malaria, millions of people will definitely lose their lives on daily basis, particularly in developing countries like Nigeria where mosquitoes are endemic.

Before now, there have been reports about concern of the possibility of mosquitoes transmitting AIDS (Acquired Immune Deficiency Syndrome) when the disease was first recognized and many people still feel that mosquitoes may be responsible for transmission of this infection from one individual to another.

However, Entomologists say that although mosquitoes function the same way as hypodermic needles – they can both inject chemicals and extract blood but cannot transmit HIV.

According to a former Navy Entomologist and Current Technical Advisor for the American Mosquito Control Association, Joe Conlon explains; “If mosquitoes carry West Nile Virus and other blood-borne diseases, shouldn’t they logically be able to transmit HIV, too? It is definitely not a stupid question, but that is not the case. Mosquitoes can not transmit HIV.

Conlon reassured that first of all, when a mosquito bites you, it draws your blood into its gut. Acids there kill the HIV virus.

“Even if the mosquito’s stomach acids did not render the virus harmless, it would not be able to get back out of the insect.

That is because mosquitoes use two different tubes to suck up blood and to inject you with saliva that stops your blood from clotting up while it’s drinking. Even if a mosquito had virus-containing blood from another human inside it, the blood would never exit the bug through its salivary glands and into your blood stream.

“For a mosquito to transmit a disease, it must pick up the virus. The virus has to survive in the gut and then get outside the gut into the body cavity and then eventually into the salivary glands to be injected into something else. It is a very complicated process, and with HIV, it just doesn’t happen,” he explained.

Malaria parasites, on the other hand, are able to grow in the mosquito gut, then, migrate specifically to the salivary glands to continue their lifecycle in another human.

Reasons

Mosquitoes’ mouth parts do not operate like a hypodermic needle. The tube which injects the host with saliva is separate from the canal which the mosquito uses to suck blood from the same host. Therefore blood only flows into the mosquito and only saliva is injected; blood is not flushed out of the same canal.

Insect-borne diseases like Encephalitis and malaria are spread because they multiply within the mosquito, these diseases then move into the insect’s salivary glands and are injected into the host with the saliva. If a mosquito feeds on an HIV-positive person the virus cannot survive and replicate within the mosquito’s gut as HIV requires specialist cells found only in humans in order to multiply.

HIV circulates in the blood at lower levels than malaria and other inset-borne diseases. The mosquito does not take enough units of HIV from the infected person to initiate infection.

Even if it was possible for the mosquito to inject HIV into an uninfected person, the person would have to be bitten by 10 million mosquitoes who had previously been feeding on an HIV positive host in order to receive one unit of HIV.