After infection, trypanosomes multiply in the blood and lymph (first-stage, haemolymphatic) and, following a variable incubation period (from days to months), unspecific symptoms and signs such as headache, fever, weakness, joint pain, and lymphadenopathy appear.

Salmonella Typhi lives only in humans. In persons with typhoid fever the bacteria initially enter through the intestinal tract and eventually invade the  bloodstream. The resulting illness is often non-specific and clinically non-distinguishable from other febrile illnesses. Symptoms include:

prolonged high fever
fatigue
headache
nausea
abdominal pain
constipation or diarrhoea
rash, in some cases.
Severe cases may lead to serious complications or even death.

The rise in the number of cases of skin cancer over the past decades is strongly related to increased exposure to the sun during outdoor activities and to artificial sources of UV radiation such as sunlamps and tanning beds. Overexposure is also the underlying cause of harmful effects on the eyes and immune system.

Adopting a few simple precautions can greatly reduce the risk of these health conditions:

WHO works with Member States and partners to increase public understanding of the effects of overexposure to ultraviolet radiation.

Universal health coverage means that all people have access to the health services they need, when and where they need them, without financial hardship. It includes the full range of essential health services, from health promotion to prevention, treatment, rehabilitation, and palliative care.

Currently, at least half of the people in the world do not receive the health services they need. About 100 million people are pushed into extreme poverty each year because of out-of-pocket spending on health. This must change.

WHO identifies achieving universal coverage as a strategic priority, with the goal of 1 billion more people benefitting from universal health coverage by 2023.

In countries with fragile health systems, we focus on technical assistance to build national institutions and service delivery to fill critical gaps in emergencies. In more robust health system settings, we drive public health impact towards health coverage for all through policy dialogue for the systems of the future and strategic support to improve performance.

Urbanization is one of the leading global trends of the 21st century that has a significant impact on health. Over 55% of the world’s population live in urban areas, a proportion that is expected to increase to 68% by 2050. As most future urban growth will take place in developing cities, the world today has a unique opportunity to guide urbanization and other major urban development trends in a way that protects and promotes health. 

Vaccines train your immune system to create antibodies, just as it does when it’s exposed to a disease. However, because vaccines contain only killed or weakened forms of germs like viruses or bacteria, they do not cause the disease or put you at risk of its complications.

Vaccines protect against many different diseases, including:

WHO is working with countries and partners to improve global vaccination coverage, through the “Global Vaccine Action Plan 2011-2020”. Through the plan, WHO:

Violence against children includes all forms of violence against people under 18 years old. For infants and younger children, violence mainly involves child maltreatment (i.e. physical, sexual and emotional abuse and neglect) at the hands of parents and other authority figures. Boys and girls are at equal risk of physical and emotional abuse and neglect, and girls are at greater risk of sexual abuse. As children reach adolescence, peer violence and intimate partner violence, in addition to child maltreatment, become highly prevalent.

Youth violence is a global public health problem. It includes a range of acts from bullying and physical fighting, to more severe sexual and physical assault to homicide. 

WHO works with Member States to build resilient and proactive health systems that can anticipate the needs and challenges during emergencies so that they are more likely to reduce risks and respond effectively when needed.

The magnitude of the physical and human costs from volcanoes can be reduced if adequate emergency prevention, preparedness, response and recovery measures are implemented in a sustainable and timely manner. This includes, ensuring early warning systems are in place, evaluating the population, and raises awareness about the risks of volcanic activities.

Wildfires or forest fires can have significant impact on mortality and morbidity depending on the size, speed and proximity to the fire, and whether the population has advanced warning to evacuate.

Wildfire smoke is a mixture of air pollutants of which particulate matter is the principal public health threat.

The magnitude of the physical and human costs from wildfires can be reduced if adequate emergency prevention, preparedness, response and recovery measures are implemented in a sustainable and timely manner. 

WHO works with Member States to build resilient and proactive health systems that can anticipate the needs and challenges during emergencies so that they are more likely to reduce risks and respond effectively when needed. 

Yellow fever infections can cause serious illness and can be fatal in severe cases. Early supportive treatment in hospitals improves survival rates. There is currently no specific anti-viral drug for yellow fever but specific care to treat dehydration, fever, and liver and kidney failure improves outcomes. Associated bacterial infections can be treated with antibiotics. Patients need to stay under mosquito nets during the day to limit the risk of spread to others through bites of mosquitoes.