Schistosomiasis is an infectious disease that infects the human body and causes severe illness. The disease usually affects people living in rural areas and is spread through contact with infected water. Women and children are most susceptible to infection due to poor hygiene and contact with dirty water. It is also spread through migration to urban areas, especially in developing countries. The disease is also being spread through eco-tourism, as travelers often visit infected areas. In some severe cases, the disease can be life-threatening and cause paralysis.
Symptoms
Schistosomiasis is a parasitic disease caused by the schistosoma parasite. It can infect humans and other animals when they come in contact with contaminated water. This disease is particularly dangerous for women who perform household tasks in contaminated water. The disease can also affect children who do not practice good hygiene. Therefore, it is very important to boil drinking water for at least one minute before consumption. It is also essential to avoid unfiltered lakes or rivers because the water can carry the infection.
Symptoms of Schistosomiases can appear as soon as one to two days after acquiring an infection. However, most people have no symptoms during the initial stage of infection. However, if the infection is left untreated, the eggs of the parasite can develop into adults and migrate to various parts of the body, including the lungs, the bladder, and the lymph nodes.
In children, chronic schistosomiasis may cause intestinal symptoms, particularly colicky abdominal pain and bloody diarrhea. In some children, schistosomiasis can develop into hepatosplenomegaly. The schistosomes eggs may also escape into the lungs and cause symptoms of pulmonary hypertension and cor pulmonalemor.
A chest X-ray or ultrasound may be needed to confirm a diagnosis of schistosomiasis. Live schistosome eggs may be found in the lungs during an ultrasound, and they can also affect the heart and liver. A cystoscopy or colonoscopy may also be necessary to confirm the diagnosis. Fortunately, a good treatment regimen can help prevent chronic Schistosomiasis and treat its associated complications.
Chronic schistosomiasis often causes abdominal pain, abdominal swelling, and urinary tract swelling. In more severe cases, it can lead to damage to organs and the nervous system. In severe cases, eggs may lodge in the brain, causing paralysis and seizures.
Transmission
The transmission of SCHISTOSOMATOSIS occurs through contact with animals such as cattle, sheep, and goats. This parasite produces schistosomes that live as adult worms in the intestines and bladder. These worms can also be transmitted from one animal to another by the transfer of schistosome eggs.
Schistosoma species have specific snail intermediate hosts, which determine the geographic distribution of the disease. In general, the expansion of the disease is associated with the development of freshwater resources. In addition, snails are spread from one area to another through migration along contiguous waterways or introduction into new bodies of freshwater on the feet of aquatic birds.
Schistosoma species often hybridise, and the prevalence of schistosomiasis in livestock and human populations is high. The parasites in animals can cause zoonotic transmission between livestock and humans. A study in northern Senegal surveyed livestock and human populations, and found widespread schistosomiasis. It also found that hybrids between S haematobium and S bovis were common. In contrast, sympatric livestock were not infected.
Infection by schistosomes can be transmitted to humans by contact with infected animals, untreated human feces, and urine. Schistosome eggs are released into an aquatic environment, where they develop into free-swimming larvae. Unlike the schistosome eggs, the parasites produced by infected snails are called cercariae, which penetrate the skin and are infectious to humans.
The WHO has published a roadmap for schistosomiasis control and elimination. It sets goals to reduce morbidity by 2020 and to eliminate it as a public health problem by 2025. This means that we must identify the specific causes of transmission of schistosomes, develop new treatment methods, and stop the spread of the parasite.
Diagnosis
The most accurate way of diagnosing schistosomiasis is to look for the presence of ova and parasites on stool and urine specimens. The type of specimen depends on the suspected schistosome and location. The classical Kato-Katz test has low sensitivity in areas of low transmission but high specificity. It uses purified S. mansoni eggs incubated with the patient’s serum for 48 hours at 37degC.
Diagnosis of schistosomiasis can be difficult. A microscopic examination of the stool or urine specimen may be helpful. Depending on the species, repeated examinations may be necessary. Symptoms of schistosomiasis can vary in severity, and may occur a few days or several months after primary infection.
Diagnosis of schistosomiasis has historically been difficult because of the difficulty of detecting the parasite eggs in stool or urine. Although this is still the primary method, the sensitivity of this test decreases in adulthood. However, it is now possible to detect parasite eggs using DNA from the parasite.
Schistosomiasis is a major public health problem with significant economic and public health implications. Mass chemotherapy campaigns have reduced the intensity of the infection, and conventional diagnostic methods are no longer as effective. Because of this, it is crucial to use a more sensitive and more specific method in clinical settings and epidemiological studies.
PCR-based multiplex PCR is one of the most powerful and sensitive methods for diagnosing schistosomal infections. The sensitivity and specificity ranges from 94.9 percent to 100 percent. Diagnosis of schistosomiasis is essential for effective control and eradication of the disease.
Treatment
Schistosomiasis and strongyloidiasis have high rates of infection and mortality. They are common among international travelers, immigrants, and refugees from countries where the parasite is endemic. In particular, the Lost Boys and Girls of Sudan, who were resettled in the United States in the early 2000s, have been diagnosed with strongyloidiasis. They also reported chronic abdominal pain. However, current policies for refugees from endemic areas have not adequately addressed these parasites.
Specific treatment for schistosomiasis reduces the prevalence of the disease and the morbidity and mortality caused by infection. This treatment has limitations, however, because it does not control transmission of the disease. However, it has been proven effective in reducing disease morbidity in remote areas.
Acute schistosomiasis usually has a 14 to 84-day incubation period. Symptoms of acute infection include fever, rash, and headache. Acute infection can also lead to hepato and splenomegaly. In contrast, chronic disease is characterized by host-induced immune responses to the schistosome eggs. This inflammation results in bowel wall ulceration, hyperplasia, polyposis, and liver fibrosis.
A new drug called ARA has been shown to be effective in the treatment of schistosomiasis. In a laboratory study, pure ARA reduced worm burden in mice seven days after infection with S. mansoni, while a high-dose of the drug reduced worm burden by 55% in mice 20 days after infection.
In most cases, a single course of treatment is curative. However, in some patients, repeated treatments are necessary. This is because the immune response is weaker in a lightly infected person. Further, repeat treatment increases the effectiveness of the drug.
Prevention
In the long term, prevention of SCHISTOSOMATOSIS involves improving access to clean water and sanitation, as well as improving hygiene practices. There are many WASH interventions that are proven effective in reducing the risk of STH infection, and these often involve several components such as hygiene education and promotion of safe water practices. Improvements in these areas are associated with a reduction of the risk of STH infection by as much as 33%, according to pooled meta-analyses.
Treatment for acute schistosomiasis includes treating the acute symptoms and stabilizing the patient. Prehospital care should include schistosomiasis as a differential diagnosis. Urine and stool samples should be sent for parasitology testing to look for eggs that indicate schistosomiasis.
Acute schistosomiasis symptoms include fever, general malaise, abdominal tenderness, and nonproductive cough. In severe cases, a person may experience a painful and life-threatening clinical course. Infection can also affect the esophagus and spleen.
The current global strategy to prevent schistosomiasis is not based on theoretical modeling but on field-based schistosomiasis control programs. These programs are based on local knowledge of the disease and endemicity and require on-the-ground planning and coordination. Additionally, they require daily supervision and local community involvement.
In schistosomiasis-endemic countries, people should avoid contact with water that has been contaminated. Although swimming in oceans and chlorinated pools is safe, it is important to boil water to kill cercariae. Freshwater from lakes and canals can also be contaminated. Hence, if someone has been exposed to contaminated water, they should wash themselves thoroughly and consult with a healthcare provider.
The infection of humans by schistosomes is a neglected tropical disease that can lead to serious morbidity and mortality. According to the World Health Organization, schistosomiasis affects 207 million people worldwide. Out of these, 97.2 million of them need treatment.
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