What are Neglected Tropical Diseases and How to Detect Them?
What is malaria?
Malaria is a serious mosquito-borne disease caused by a parasite called Plasmodium which spreads to humans through the bite of an infected Anopheles mosquito. It is quite common in tropical regions including several areas in Africa, Southern Asia, Central and South America, along with some Pacific islands and areas of Middle East.
What are the signs and symptoms of malaria?
Initial symptoms of malaria may resemble those of flu or several other bacterial, viral, and parasitic infections. Symptoms of malaria include fever, shaking chills, sweats, fatigue, headache, muscle pains, nausea, sore throat, difficulty breathing and yellow skin or whites of the eyes. The incubation period for malaria is typically 7 to 30 days. However, infections caused by some types of malaria parasites may not show symptoms for several months after exposure, and people who get infected several times may not develop any symptoms. Your symptoms can come and go in circles, and the severity of the symptoms may vary according to your age, health status, and the type of malaria parasite that you have been infected with malaria may also cause more serious problems in young children, pregnant women, immunocompromised people, and those aged over 65. In severe cases, malaria can damage many organs including the lungs, heart, kidneys, brain, or cause seizures, which can be fatal if left untreated.
Which options are available for testing, vaccination, and treatment against malaria?
A blood smear test can both help detect a malaria infection and determine the type and quantity of malaria parasite you have in your blood. There are also rapid tests available for the detection of malaria, which are usually followed with a confirmatory blood smear.
Anti-malaria medicines are commonly used to prevent and treat malaria. Depending on your condition, health status, symptoms, and the type of malaria parasite you have been infected with. In severe cases, exchange blood transfusions may also be applied.
What is typhoid fever?
Typhoid fever is a serious bacterial infection caused by the bacterium Salmonella Typhi, which typically transmits through contaminated food or water. The bacteria can transmit through the excrement or urine of an infected person. Hence, typhoid fever is common in regions with poor sanitation and lack of access to sanitary water.
What are the signs and symptoms of typhoid fever?
Common symptoms of typhoid fever include prolonged fever that can be as high as 40°C, fatigue, headache, nausea, stomach pain, cough, and diarrhea or constipation. Some patients may also develop a rash. Communities without access to proper sanitation, clean water, and access to healthcare are at highest risk. Moreover, children are thought to be among the more vulnerable groups against typhoid fever. In severe cases, a typhoid infection may cause serious complications such as internal bleeding and might cause death.
Which options are available for testing, vaccination, and treatment against typhoid fever?
Typhoid fever can easily be detected by a blood test. As for prevention, two vaccines have been available for several years against typhoid fever. The injectable vaccine utilizing purified antigen can be applied to people over 2 years old, and the live attenuated vaccine in capsule form can be applied to people over 5 years old. However, these vaccines do not offer long-lasting protection. In December 2017, WHO prequalified a new conjugate vaccine for typhoid, which offers longer lasting immunity to be used in children older than 6 months.
What is dengue fever?
Dengue is a viral infection which spreads to humans through the bite of mosquitoes infected with dengue virus (DENV). The virus is transmitted by female mosquitoes of the species Aedes aegypti and the species Ae. albopictus, both of which also spread chikungunya, yellow fever and Zika viruses. Dengue is common throughout tropical and sub-tropical regions; however, dengue outbreaks emerge in several countries around the world including the Americas, Africa, the Middle East, Southeast Asia, Australia, and the Pacific Islands. In fact, according to data by Centers for Disease Control and Prevention (CDC), almost half of the world population lives in regions at risk of dengue.
What are the signs and symptoms of dengue fever?
Only about 25% of the infected people develop symptoms, which typically include fever but may also include nausea, headache, rash, and aching of the bones, muscles, joints, and eyes. These symptoms usually fade after 2 to 7 days.
However, around 5% of the infected people develop severe dengue, which may cause life-threatening complications such as internal bleeding. Severe dengue is a medical emergency, its early signs develop typically 24–48 hours after your fever has faded away. Hence, please make sure to check your symptoms, and immediately get medical care if you experience symptoms such as abdominal pain or tenderness, fatigue, restlessness persistent vomiting, blood in vomit or stool, bleeding nose or gums, or rapid breathing.
Which options are available for testing, vaccination, and treatment against dengue fever?
There are various reverse transcriptase–polymerase chain reaction (RT–PCR) tests and rapid diagnostic tests available for the detection of active infections with the dengue virus. Moreover, serological tests, which assess levels of IgG and IgM antibodies, can be used to detect recent and past infections.
There is no specific treatment for dengue fever. People with mild symptoms can usually recover at home with the help of certain fever reducers and pain killers to control their symptoms. For more severe cases, patients may require medical care in hospitals or emergency treatments.
Licensed in 2015, Dengvaxia® (CYD-TDV) developed by Sanofi Pasteur became the first, and currently only, dengue vaccine available. The vaccine is targeted for those living in endemic areas, between 9-45 years of age, who have had at least 1 episode of prior dengue infection. It has been approved for use in around 20 countries worldwide.
What is chikungunya?
Chikungunya is a viral infection spread to humans through the bite of Aedes mosquitoes infected by the chikungunya virus (CHIKV). So far it has been identified in more than 60 countries worldwide, but is endemic in Africa, Southeast Asia, Pacific Region, and the tropical/subtropical regions of the Americas.
What are the signs and symptoms of chikungunya?
Symptoms of chikungunya include sudden onset of fever, debilitating joint pain, muscle pain, rash, nausea, joint swelling, and headache. Chikungunya is considered as a non-fatal disease, and people are likely to be immune against future infections after recovery. Most people recover fully shortly, however, in some cases the joint pain may last as long as months or even years.
Which options are available for testing, vaccination, and treatment against chikungunya?
Blood tests are widely used in the detection of chikungunya. While there is currently no vaccine or medicine against chikungunya, it is possible to recover at home with the help of certain pain and fever reducers.
What is zika virus disease?
Zika virus disease is a viral infection which is primarily transmitted through the bite of infected Aedes mosquitoes. Still, the zika virus can also transmit from an infected mother to her fetus during pregnancy or spread through sexual intercourse.
What are the signs and symptoms of zika virus disease?
Most people infected with the zika virus either develop mild symptoms or no symptoms at all. Common symptoms of zika virus disease include fever, headache, joint pain, muscle pain, conjunctivitis, and rash, which typically last a few days to a week. However, zika virus disease may cause congenital abnormalities such as microcephaly and complications such as preterm birth, fetal loss, and still birth during pregnancy. In are cases, it can also cause Guillain-Barré syndrome (GBS).
Which options are available for testing, vaccination, and treatment against zika virus disease?
Diagnosis of a the zika infection require laboratory testing of blood, urine, vaginal fluids, or semen. There are currently no specific treatments or approved vaccines against ZIKV infection. Most people can recover at home and take common medicines to reduce pain and fever. However, as zika infection during pregnancy is associated with congenital malformations and other complications, pregnant women experiencing signs and symptoms of a zika infection should seek medical attention.