Does the mosquito have more of a role in certain cancers than is currently appreciated? - The mosquito cocktail hypothesis

The International Agency for Research on Cancer recognises five viruses, one bacterium and three parasites as having a causal relationship to cancer, and one virus, HIV, that by suppressing the immune system assists in the development of cancer. In addition numerous researchers have claimed links between cancer and other viruses and bacteria, many of which have been isolated from tumours. Excluding the non-causal HIV, 33 infectious agents linked with cancer have been identified in the literature, 27 of which have one thing in common: they are all present in mosquitoes. There are over 3000 species of mosquito and very few have been fully analysed, so the six remaining infectious agents may be present in some unexamined species. This hypothesis proposes that more cancers than are presently appreciated may arise from the long-term outcome of a mosquito bite, which by releasing a complex cocktail of up to 60 infectious agents directly into the blood stream, often results in contemporaneous immuno-suppression and a multiplicity of co-infections. These co-infections may act synergistically in whole, or in part, and in complex ways. Whether and if so which type of cancer ensues will depend on the constituent ingredients in the cocktail, determined by multiple factors such as the mosquito's drinking and feeding patterns, number of previous blood-meals and the variety of intermediate hosts from which these meals are taken. Only a few mosquito species carry malaria, dengue fever, chikungunya and the other recognised serious human ailments. This hypothesis suggests that the number of species carrying the cancer cocktail will be few in number but collectively have a worldwide presence.