WEEK 1: EMERGING VIRAL DISEASES Flashcards

Question

Influenza When did it emerge? DNA or RNA? Source? Current status? Expected long term outcome?

Answer 1

Notable pandemics include the 1918 Spanish flu, the 1957 Asian flu, the 1968 Hong Kong flu, and others. Influenza viruses have been circulating and evolving for a long time, leading to various strains. Genetic Material: Influenza viruses have a segmented negative-sense RNA genome. They do not have DNA as their genetic material. The RNA segments encode the virus's proteins. Source: Influenza viruses primarily infect birds and, to a lesser extent, pigs. They can jump from animals to humans, leading to human influenza outbreaks. Waterfowl, especially wild ducks, are natural reservoirs for many influenza A viruses. Current Status: Influenza is a seasonal respiratory illness, and different strains of the virus continue to circulate in humans and animals. The global status of influenza varies from year to year. Annual vaccination campaigns target the predominant strains of the virus to reduce its impact. Influenza is a significant public health concern, but its status and prevalence fluctuate depending on the specific strains in circulation. Expected Long-term Outcome: Influenza is expected to remain a recurring respiratory infection in the long term. Vaccination and antiviral drugs are key tools for controlling and mitigating the impact of seasonal influenza. Researchers continually monitor and adapt the composition of flu vaccines to match the strains expected to circulate in a given flu season. In the long term, research and surveillance efforts will continue to improve our ability to respond to influenza outbreaks and to develop new strategies for prevention and treatment. Public health measures, such as hygiene and social distancing, will also play a role in controlling the spread of the virus. It's important to note that the specific strains of influenza in circulation and their impact can vary from year to year.

Answer 2

Polio has likely been in existence for thousands of years, but the recognition and documentation of the disease date back to ancient civilizations. The modern understanding of polio and its causative agents, the polioviruses, developed in the late 19th and early 20th centuries. Major outbreaks occurred in the 20th century, leading to intensified efforts to develop vaccines. The inactivated polio vaccine (IPV) was introduced in the 1950s, and the oral polio vaccine (OPV) in the 1960s, leading to a significant reduction in cases. Genetic Material: Polioviruses are single-stranded RNA viruses. They do not have DNA as their genetic material. Source: Polioviruses are transmitted through the fecal-oral route, primarily via contaminated water and food. The virus primarily infects the human gastrointestinal tract and can enter the central nervous system, leading to paralysis. Current Status: Great progress has been made in the global eradication of polio. As of my last knowledge update in September 2021, cases of wild poliovirus were at historic lows, and the disease was endemic in only a few countries. This achievement was the result of extensive vaccination campaigns and public health efforts. However, there were still challenges in reaching all children with vaccines, and vaccine-derived poliovirus outbreaks were a concern. The situation with polio may have evolved since then, and it's important to refer to organizations like the World Health Organization (WHO) for the latest information. Expected Long-term Outcome: The long-term goal for polio is its global eradication. Efforts are focused on eliminating all remaining cases of wild poliovirus and stopping the circulation of vaccine-derived polioviruses. Once eradication is achieved, vaccination can be discontinued. However, challenges include vaccine access, vaccine hesitancy, and surveillance to detect and respond to cases. In the long term, polio eradication would be a major public health achievement, similar to the eradication of smallpox. Continual monitoring and vaccination for a period even after eradication will be required to prevent any resurgence of the disease.

Answer 3

Emergence: Monkeypox was first identified in 1970 when outbreaks occurred in remote villages in Central Africa, including the Democratic Republic of Congo (DRC). The disease was named due to its similarity to smallpox and its initial transmission from animals to humans. The emergence of monkeypox was relatively recent in the medical literature. Genetic Material: The monkeypox virus has a double-stranded DNA genome. This distinguishes it from some other viruses like Ebola and Zika, which have RNA genomes. Source: The natural reservoir hosts of the monkeypox virus are believed to be various types of rodents. Transmission to humans typically occurs through close contact with these animals, their bodily fluids, or through consumption of undercooked meat. Human-to-human transmission is also possible, but it is less efficient than with diseases like smallpox. Current Status: Monkeypox is a rare disease, and outbreaks have occurred sporadically in Central and West Africa. The virus is not typically endemic in the United States or many other parts of the world. Cases of monkeypox outside of Africa are infrequent and often associated with travel to or from affected regions. The situation with monkeypox can vary, and local public health agencies and the World Health Organization (WHO) monitor outbreaks. Expected Long-term Outcome: The long-term outcome of monkeypox depends on continued surveillance, public health measures, and research. In the long term, efforts will continue to focus on prevention, early detection, and control of outbreaks. There is no specific antiviral treatment for monkeypox, so vaccination and containment measures are crucial. The virus will likely continue to circulate in wildlife populations in endemic regions, and sporadic outbreaks may occur. Public health measures and surveillance are essential for minimizing the impact of the disease in affected regions and for preventing its spread to other parts of the world.