Malaria: Still a Killer Disease
Malaria is a chronic parasitic infection spread by the female anopheles mosquitoes. The disease can be deadly if left untreated. From a global point of view, malaria constitutes a serious health problem, with an estimate of 200 million new cases every year.
Who is at risk?
WHO recorded that in 2015; approximately 3.2 billion people were at risk of malaria. Malaria cases and deaths are common in tropical and sub-Saharan African countries. However, Asia, Latin America, and, to a lesser extent, the Middle East, are also at risk. In 2015, 95 countries and territories had ongoing malaria transmission.
Infants, children under 5 years, pregnant women and patients with HIV/AIDS, as well as non-immune migrants, mobile populations and travelers are at considerably high risk of contracting malaria.
National malaria control programmes need to take special measures to protect these population groups from malaria infection, taking into consideration their specific circumstances.
The symptoms of malaria begin 10 to 4 weeks after infection, although a person may feel ill as early as 7 days later. Symptoms include, fever, headaches, vomiting, chills and flu. These symptoms may be mild and difficult to recognize as malaria. If not treated within 24 hours, P. falciparum malaria can progress to severe illness, often leading to death.
Children with severe malaria frequently develop one or more of the following symptoms: severe anaemia, respiratory distress in relation to metabolic acidosis, or cerebral malaria. In adults, multi-organ involvement is also frequent. In malaria endemic areas, people may develop partial immunity, allowing asymptomatic infections to occur.
According to WHO report released in December, there were 214 million cases of malaria in 2015 and 438 000 deaths.
Between 2000 and 2015, malaria incidence among infants, children and pregnant women fell by 37% globally and during the same period, malaria mortality rates among populations at risk decreased by 60%. An estimated 6.2 million malaria deaths have been averted globally since 2001 and more than two thirds (70%) of all malaria deaths occur in this age group. Between 2000 and 2015, the under-5 malaria death rate fell by 65% globally, translating into an estimated 5.9 million child lives saved between 2001 and 2015.
Sub-Saharan Africa continues to carry a disproportionately high share of the global malaria burden. In 2015, the region was home to 88% of malaria cases and 90% of malaria deaths.
Some 15 countries – mainly in sub-Saharan Africa – account for 80% of malaria cases and 78% deaths globally. Since 2000, the decline in malaria incidence in these 15 countries (32%) has lagged behind that of other countries globally (53%).
Mode of Transmission
In most cases, malaria is transmitted through the bites of female Anopheles mosquitoes. There are more than 400 different species of Anopheles mosquito; around 30 are malaria vectors of major importance. All of the important vector species bite between dusk and dawn. The intensity of transmission depends on factors related to the parasite, the vector, the human host, and the environment.
Anopheles mosquitoes lay their eggs in water, which hatch into larvae, eventually emerging as adult mosquitoes. The female mosquitoes seek a blood meal to nurture their eggs. Each species of Anopheles mosquito has its own preferred aquatic habitat; for example, some prefer small, shallow collections of fresh water, such as puddles and hoof prints, which are abundant during the rainy season in tropical countries.
Transmission is more intense in places where the mosquito lifespan is longer and where it prefers to bite humans rather than other animals.
Transmission also depends on climatic conditions that may affect the number and survival of mosquitoes, such as rainfall patterns, temperature and humidity. In many places, transmission is seasonal, with the peak during and just after the rainy season. Malaria epidemics can occur when climate and other conditions suddenly favour transmission in areas where people have little or no immunity to malaria. They can also occur when people with low immunity move into areas with intense malaria transmission, for instance to find work, or as refugees.
1. In 2015, 95 countries and territories had ongoing malaria transmission
2. About 3.2 billion people – almost half of the world’s population – are at risk of malaria.
3. Between 2000 and 2015, malaria incidence among populations at risk fell by 37% globally. In that same period, malaria death rates among populations at risk fell by 60% globally among all age groups and by 65% among children under 5.
4. Sub-Saharan Africa carries a disproportionately high share of the global malaria burden. In 2015, the region was home to 88% of malaria cases and 90% of malaria deaths.
It is imperative that you take precautionary measures to avoid your risk of infection. Here are ways to prevent malaria:
- Stay in well- screened areas at night
- Always use mosquito nets (treated if possible)
- Use mosquito repellent
- Go for long sleeves
- Take preventive medicines
- Stay inside between dusk and dawn if possible
- Determine your level of risk
Make sure you have information about your surroundings or the area you intend to travel to and the risks of contracting malaria in such areas. Successful malaria prophylaxis depends on your knowledge.