Several human diseases caused by protozoa are transmitted by a variety of arthropod vectors (Table). The vectors are not simply 'flying syringes', but represent a second host for the protozoan parasite.arasites which reside within the blood or internal organs of the host have logistical problems in terms of infecting a new host. In contrast to fecal-oral transmission, where infective stages are excreted into the environment, potential new hosts would not normally come into contact with the parasite.
If you have accumulated enough work credits (typically 40) the earliest you can collect Social Security retirement benefits is 62. At that age, your monthly payment would be about 75% of the amount you would receive by waiting to retire at SSA's full retirement age. Full retirement age:
When should you apply for Social Security? Retirement planning is complicated, beginning with the decision about when to begin taking your Social Security benefits. On one hand, if you need the money and donât expect to live into your 80s, it is tempting to take Social Security as early as possible â at age 62 â to benefit from the income stream. On the other hand, you can increase your monthly payment considerably by waiting until age 70.