For this year's circulating influenza strains, the vaccine is not fully protective against one of the strains of influenza covered by the vaccine and we are seeing more cases despite vaccination. This is not uncommon specifically for the influenza vaccine that is developed for each annual season with some uncertainty about the major strains of influenza that will circulate in the future.
Histoplasma spores when inhaled can cause a pneumonia called histoplasmosis with the fungus growing in the lung and may invade into other parts of the body. Larger inner city areas are typically attracting larger pigeon populations and hence with increased risk for the transmission of histoplasma from pigeons droppings to people.
In most cases, the malaria parasite has to first pass from a human host into a mosquito as the mosquito takes a blood meal, and then from the mosquito into another human via the mosquito’s saliva. This severely limits the amount of person-to-person transmission that exists. In fact, the only mechanisms for direct transmission between humans are when malaria parasites are passed between a mother and her unborn child via the placenta (congenital transmission) and through unscreened blood transfusions.
With your preference mentioned - you cannot protect yourself completely even when following all precautions. Get tested regularly. Consider also that you should not want to spread STDs to others.
The virus(es) who cause the disease are not transmitted by animals. Need good hand hygiene, washing with soap and water and handling diapers with disposable gloves in children who have the disease.
Diseases which are transmitted by mosquitos such as malaria, or ticks, such as Africa tick bite fever,.. and a few more such as hemorrhagic fever and West Nile and Yellow fever
Diseases that are food and water-borne: Hepatitis A, typhoid, paratyphoid, amebiasis, cholera, dysenteria.
Airborne diseases -such as Tuberculosis- particularly in certain areas of South Africa
Sexually-transmitted disease such as HIV-AIDS
Diseases transmitted from animals such as rabies, plague (Anthrax)
Soil- and -water associated such as schistosomiasis, leptospirosis
The risk depends on where you go, what you do and how long you stay in a particular area
Other consideration: allergic reactions to previous flu shot (this is not common).