Chagas Disease Treatment , Prevention ( Kissing Syndrome )
SUMMARY
Kissing offers many health benefits, but may also transmit a small number of disease-causing agents such as bacteria and viruses. Colds, glandular fever (kissing disease), herpes infection, warts, hepatitis B and meningococcal disease may all be transmitted by kissing. However, the risk of disease from kissing is small and kissing can be good for physical and mental health.
How disease is spread-( Transmission )
In Chagas-endemic areas, the main mode of transmission is through an insect vector called a triatominebug. A triatomine becomes infected with T. cruzi by feeding on the blood of an infected person or animal. During the day, triatomines hide in crevices in the walls and roofs. The bugs emerge at night, when the inhabitants are sleeping. Because they tend to feed on people's faces, triatomine bugs are also known as "kissing bugs". After they bite and ingest blood, they defecate on the person. Triatomines pass T. cruziparasites (called trypomastigotes) in feces left near the site of the bite wound.
Scratching the site of the bite causes the trypomastigotes to enter the host through the wound, or through intact mucous membranes, such as the conjunctiva. Once inside the host, the trypomastigotes invade cells, where they differentiate into intracellular amastigotes. The amastigotes multiply by binary fission and differentiate into trypomastigotes, which are then released into the bloodstream. This cycle is repeated in each newly infected cell. Replication resumes only when the parasites enter another cell or are ingested by another vector.
Rhodnius prolixus
Rhodnius prolixus is the second most important triatomine vector of the Chagas parasite due to both its sylvatic and domestic populations in northern South America as well as to its exclusively domestic populations in Central America. It has a wide range of ecotopes, mainly savanna and foothills with an altitude of between 500 meters to 1,500 meters (0.31 miles to 0.93 miles) above sea level and temperatures of between 16°C to 28°C (61°F to 82°F). Sylvatic R. prolixus, as virtually all Rhodnius spp., is primarily associated with palm tree habitats and has a wide range of hosts including birds, rodents, marsupials, sloths, and reptiles.
Rhodnius prolixus is also known as the kissing bug because it feeds on people's faces.
Diseases can be spread from person to person in a number of ways:
- Contact spread – some diseases are spread directly from person to person, for example during kissing, or indirectly when you touch a contaminated surface or object.
- Droplet spread – infected droplets from the nose and throat can usually travel around one metre before they drop onto a surface. Sometimes infected droplets can also linger in the air. Infection occurs when the infected droplet is inhaled or someone comes into contact with a contaminated surface or object.
- Airborne spread – some infected particles from the nose and throat can remain in the air for a long time because of their tiny size. They are called droplet nuclei and can be inhaled directly into the lungs.
Signs and symptoms
The acute phase lasts for the first few weeks or months of infection. It usually occurs unnoticed because it is symptom-free or exhibits only mild symptoms that are not unique to Chagas disease. These can include fever, fatigue, body aches, headache, rash, loss of appetite, diarrhea, and vomiting. The signs on physical examination can include mild enlargement of the liver or spleen, swollen glands, and local swelling (a chagoma) where the parasite entered the body.
The most recognized marker of acute Chagas disease is called Romaña's sign, which includes swelling of the eyelids on the side of the face near the bite wound or where the bug feces were deposited or accidentally rubbed into the eye. Rarely, young children, or adults may die from the acute disease due to severe inflammation/infection of the heart muscle (myocarditis) or brain (meningoencephalitis). The acute phase also can be severe in people with weakened immune systems.
If symptoms develop during the acute phase, they usually resolve spontaneously within three to eight weeks in approximately 90% of individuals.Although the symptoms resolve, even with treatment the infection persists and enters a chronic phase. Of individuals with chronic Chagas disease, 60–80% will never develop symptoms (called indeterminate chronic Chagas disease), while the remaining 20–40% will develop life-threatening heart and/or digestive disorders during their lifetime (called determinate chronic Chagas disease). In 10% of individuals, the disease progresses directly from the acute form to a symptomatic clinical form of chronic Chagas disease
Prevention And Treatment
There are two approaches to therapy, both of which can be life saving:
- antiparasitic treatment, to kill the parasite; and
- symptomatic treatment, to manage the symptoms and signs of infection.
Antiparasitic treatment is most effective early in the course of infection but is not limited to cases in the acute phase. In the United States, this type of treatment is available through CDC. Your health care provider can talk with CDC staff about whether and how you should be treated. Most people do not need to be hospitalized during treatment.
Symptomatic treatment may help people who have cardiac or intestinal problems from Chagas disease. For example, pacemakers and medications for irregular heartbeats may be life saving for some patients with chronic cardiac disease.
To kill the parasite, Chagas disease can be treated with benznidazole and also nifurtimox. Both medicines are almost 100% effective in curing the disease if given soon after infection at the onset of the acute phase. However, the efficacy of both diminishes the longer a person has been infected. Treatment is also indicated for those in whom the infection has been reactivated (for example due to immunosuppression), for infants with congenital infection and for patients during the early chronic phase. Infected adults, especially those with no symptoms, should be offered treatment. The potential benefits of medication in preventing or delaying the development of Chagas disease should be weighed against the long duration of treatment (up to 2 months) and possible adverse reactions (occurring in up to 40% of treated patients).
Benznidazole and nifurtimox should not be taken by pregnant women or by people with kidney or liver failure. Nifurtimox is also contraindicated for people with a background of neurological or psychiatric disorders.
Additionally, specific treatment for cardiac or digestive manifestations may be required.
