So far, the only diseases completely eradicated by humankind are smallpox, declared eradicated in 1980, and rinderpest, declared eradicated in 2011. In April 2012, the World Health Assembly declared that the failure to completely eradicate polio would be a programmatic emergency for global public health, and that it "must not happen. "These efforts have hugely reduced the number of cases; from an estimated 350,000 cases in 1988 to a low of 483 cases in 2001, after which it remained at a level of about 1,000–2000 cases per year for a number of years.By 2015, polio was believed to remain naturally spreading in only two countries, Pakistan and Afghanistan, although it continued to cause outbreaks in other nearby countries due to hidden or reestablished transmission. Between 2016 and 2020 worldwide cases of wild polio (mostly in these countries) remained below 200 per year, with only 6 confirmed cases in 2021. Circulating vaccine-derived polioviruses
The oral polio vaccine, while highly effective, has the disadvantage that it comprises a live virus which has been attenuated so that it cannot cause severe illness. The vaccine virus is excreted in the stool, and in under-immunized communities it can spread from person to person. This is known as circulating vaccine-derived poliovirus (cVDPV). With prolonged transmission of this kind  the weakened virus can mutate and revert to a form that causes illness and paralysis.
Decreased respiratory effort: Central nervous system impairment leads to decreased respiratory effort. The respiratory center of the brain is located in the pons and medulla and is primarily driven by elevated carbon dioxide levels in the blood (hypercapnia) with decreased oxygen levels (hypoxemia) serving as a less potent stimulus. Central nervous system disorders, such as stroke and tumors, may cause hypoventilation. Drugs may decrease respiratory effort as well, such as opioids, sedative-hypnotics, and alcohol. These lower respiratory drive by blunting the response of the respiratory center of the brain to hypercapnia. Metabolic disorders could also decrease respiratory effort. Hypoglycemia and hypotension depress the central nervous system and compromise the respiratory system. Respiratory muscle weakness: Neuromuscular disorders may lead to respiratory muscle weakness, such as spinal cord injury, neuromuscular diseases, and neuromuscular blocking drugs. Respiratory muscle fatigue can also lead to respiratory muscle weakness if patients breathe over 70% of their maximum voluntary ventilation. Breathing over an extended period of time near maximum capacity can cause metabolic acidosis or hypoxemia, ultimately leading to respiratory muscle weakness. Diagnosis
Diagnosis requires clinical evaluation, as detailed below. Initial assessment
After determining the scene is safe, approach the patient and attempt to converse with him or her. If the patient responds verbally, you have established that there is at least a partially patent airway and that the patient is breathing (therefore not currently in respiratory arrest). If the patient is unresponsive, look for chest rise, which is an indicator of active breathing. A sternal rub is sometimes used to further assess for responsiveness.