Parasitologists study parasites wherever they occur and whether they are viruses, bacteria, worms or insects. Parasites are organisms that use other species of plants and animals as hosts. The hosts provide the environment in which the parasite lives. In the history of life on earth, the parasitic lifestyle has been incredibly successful; in fact, the number of species of parasites exceeds the number of free-living species. It is no wonder that parasitology is a diverse field.
Parasitology is a dynamic field because the relationships between parasites and their hosts constantly are changing. Parasitism comprises an ecological relationship between two individuals of different species where the parasite’s environment is another living organism. Unlike the environment of free-living plants and animals, the environment of the parasite can fight back. Parasites and hosts are locked into a continuous struggle for survival, and understanding the mechanisms that each side in this battle use to gain advantage challenges parasitologists to understand biological phenomena at the cutting edge of a wide variety of scientific disciplines. As a result, parasitologists contribute significantly to our basic understanding of the way our biological world functions.
Many different career options exist within the field of parasitology because parasites affect the world in so many ways. Rewarding careers await parasitologists with interests in medicine and public health. Veterinary parasitologists play vital roles in controlling diseases of domestic animals. Agriculture and aquaculture are dependent upon parasitologists to assist in providing plant and animal food for an increasing human population. The following are several of the broad areas in which parasitologists work:
Perhaps the best-known aspect of the significance of parasites is the role they play in causing human disease. Insect parasites such as fleas and lice are, at best, annoyances to humans, and as vectors of diseases such as the bubonic plague and typhus they have been responsible for a great deal of human mortality. Mosquitoes not only transmit malaria but spread yellow fever, encephalitis and other viral diseases and also are responsible for introducing into humans several species of filarial worms that cause some of the most horrific diseases in medical literature. Emerging diseases such as Lyme disease, transmitted by ticks, increasingly are recognized as significant to human health.
Medical parasitologists use many approaches to combat parasites. Among the areas of research used are epidemiology (the scientific study of factors affecting the health and illness of individuals and populations), chemotherapy (the use of chemical substances to treat disease), immunology (a broad branch of biomedical science that covers the study of all aspects of the immune system in all organisms) and pathology (the study of the processes underlying disease and other forms of illness, harmful abnormality or dysfunction). Exciting advances that promise to reduce parasitic disease have come from parasitologists’ basic research in the fields of molecular and cellular biology, genetics and physiology. Promising breakthroughs in the development of vaccines against disease-causing parasites exist because of technological and conceptual advances in these fields as well as in allied disciplines such as immunology and biochemistry. The field of public health is allied closely with medical parasitology. Public health practitioners are employed by national, state and local governments and can work for international agencies such as the World Health Organization. Private industry, philanthropic and charitable organizations, military organizations and a variety of other institutions also employ the services of public health workers.
Agriculture, Aquaculture, and Veterinary Parasitology
Human health not only is affected directly by parasites that can infect humans but also is affected indirectly by parasites that cause diseases in plants and animals that are used as food for humans. The use of parasites as biological control agents against crop insects holds much promise for increasing agricultural production. Veterinary parasitologists care for domesticated animals used for food and work; they also care for companion animals. Veterinarians play an indirect role in human health when they control parasites in nonhuman animals that are transmissible to humans. Animals used by humans for sport and recreation also require the services of veterinary parasitologists. Pharmaceutical companies are important sources of employment for parasitologists. In this capacity, parasitologists might work on the development of chemotherapeutic drugs to eliminate animal parasites, which is of major economic significance. The discovery of these antiparasitic drugs for domesticated animals not only has benefited the agricultural industry but in some cases has aided humans when the same chemotherapeutic agents have been demonstrated to be effective in the treatment of disease-causing parasites.
Wildlife and Fisheries Parasitology
Career opportunities exist for parasitologists who can assist wildlife managers in developing programs designed to protect animals in their natural environment. Parasitologists working for government agencies, industry and universities survey wild animals for parasites and disease and develop strategies to reduce the negative impact of parasites on wildlife populations. Conservation biologists especially are interested in parasitic diseases of threatened and endangered species and use that information to formulate management plans for their protection. Monitoring parasites in wild animals that are capable of being transmitted to humans is another important function of parasitologists. Fisheries biologists need information on the role of parasites in causing fish disease and the fish parasites humans can acquire from eating fish. These scientists also might use parasite data to understand aspects of natural fish populations. Alterations of natural environments such as the damming of rivers, channelization of streams and cutting of timber can affect important game species by altering parasite abundance, and the advice of parasitologists often is sought before making such decisions.
Ecological and Systematic Parasitology
These exciting areas of parasitology are rooted in the study parasite evolution and their interactions with the environment through their hosts. These basic areas of inquiry often lead to breakthroughs in applied areas of parasitology with direct or indirect benefits to humans. The field of parasite taxonomy (the science of classifying living things) and systematics (the study of the diversity of organism characteristics) currently are experiencing a resurgence of activity because of new methods that recently have been incorporated into the discipline. Techniques developed by molecular biologists have been applied to questions regarding relationships among taxonomic groups of parasites and are providing powerful new insights. The study of ecological aspects of host-parasite relationships has benefited greatly from the use of computer technology, vastly increasing the ability of parasitologists to quantify and analyze the dynamics of parasite populations. The tools of molecular biology also are being assimilated into the field of ecological parasitology, and the promise of new discoveries regarding parasite life cycles, detection and identification of parasites, patterns of parasite transmission and colonization are extremely exciting.
Applications of basic research in parasite systematics are likely to be forthcoming and will provide career opportunities for parasitologists. Ecological parasitologists can assist medical parasitologists in assessing the potential role of global warming on public health by evaluating changes in patterns of parasite distribution and colonization.
Biochemistry and Molecular Biology of Parasites
Powerful technological advances have revolutionized the study of biology at the subcellular level. The promise of advances in parasitology from the application of these tools is great and will lead to many new career opportunities. The genetics of parasites can be explained at levels never before possible using techniques such as polymerase chain reaction (a molecular biology technique for enzymatically replicating DNA without using a living organism such as E. coli or yeast). Many applications could come from enhanced knowledge of parasite genetics, including the development of diagnostic tools for the detection and specific diagnosis of parasites.
Job opportunities for immunologists who desire to work with parasites are likely to increase because of new technical developments in the field and because of new practical applications of that technology. One important thrust in parasite research today is the development of vaccines against parasites of human and domestic animals. The benefits of lifelong immunity among individuals and the goal of imparting complete protection to entire populations is an important driving force in the effort to discover vaccines against parasites. In recent years, the development of specific diagnostic tests for parasites has been one of the major successful applications derived from basic research in immunoparasitology. Clearly, further advances in basic research are on the horizon and application of this new knowledge will benefit both medical and veterinary parasitology.
Academic careers are intellectually rewarding, and parasitologists have played an important role in the education of university students. One reason for the success of parasitologists in the academic community is the fact that parasitologists are among the most broadly trained of all biologists. Because examples of parasites can be found throughout the plant and animal kingdom, most parasitologists have a good working knowledge of biological diversity. A university position offers individuals a challenging and rewarding career that combines both teaching and research. Research opportunities allow faculty to ask creative questions and design studies to answer these questions. Teaching has many rewards, including the satisfaction of seeing young people exposed to new knowledge and watching students apply that knowledge to their own scientific curiosity.
Parasitology is a broad and diverse field with many career options. Most parasitologists are attracted to the field because of their scientific curiosity. Parasitology represents a great career for intelligent young people with inquisitive minds. Research opportunities are virtually unlimited. The variety of basic and applied research in fields from the molecular to the global level are unsurpassed in other fields of biology.
A parasitologist’s university education should sharpen the scientific curiosity and knowledge base begun in high school. Emphasis should be placed on attainment of a broad-based education in biology and chemistry. Overspecialization in one narrow field of the biological sciences will not lead to the range of knowledge required by most successful parasitologists. A good background in mathematics, computer science and statistics will provide the computational skills that are required in virtually all areas of parasitology. The development of good writing and speaking skills is fundamental because all scientists must be able to communicate their ideas and results to others. Job opportunities in parasitology exist for people who attain a B.S. degree; possible positions include jobs in the food, agriculture and pharmaceutical industries. Positions in clinical laboratories, environmental firms or universities might involve work with parasites.
Individuals working on master’s degree in biology will have the opportunity for research with a parasitologist as a research advisor. Thesis research might involve laboratory or field study of parasites. Master’s students should work toward conducting a research project that can be published in a scientific journal. Although most parasitologists attaining an M.S. degree continue towards a doctoral degree, job opportunities that use the parasitology education and skills attained at the master’s level are available. Examples of jobs include the fields of wildlife management, fisheries biology, aquaculture, animal husbandry and human health care.
Most parasitology researchers hold either a Ph.D. or an M.D. Advantages of attaining a doctoral degree are numerous. Most tenure-track university faculty positions require a Ph.D., which greatly enhances opportunities to conduct research and to gain funding to support research activities.
The salary range for parasitologists is highly dependent on experience and the specific area of focus. In general, the entry-level salary is about $31,250, the average salary is $51,020 and the maximum salary is about $87,060.