Strongyloidiasis is a human parasitic infection caused by Strongyloides stercoralis, which is a roundworm or nematode. Strongyloidiasis is found in warm climates and this infection is observed in subtropical and tropical countries. Strongyloidiasis is one of the neglected tropical diseases and efforts are being made worldwide to eradicate this infection. This infection also commonly occurs in rural areas. In many cases, strongyloidiasis produces no symptoms. Symptoms commonly experienced due to this intestinal worm mainly include skin symptoms, diarrhea , abdominal pain and weight loss . In patients who need certain medications, such as immunosuppressants or corticosteroids, Strongyloidiasis can lead to hyperinfection syndrome, which, if left untreated, can cause the patient to die. Blood and stool tests may confirm the diagnosis of strongyloidiasis. Treatment of strongyloidiasis consists of ivermectin medication.
Symptoms of Strongyloidiasis
Many patients with strongyloidiasis may have no symptoms. Symptoms when present consist of:
- Pain or burning in the upper abdomen.
- Cough .
- The patient may have diarrhea or alternate with constipation and diarrhea.
- Development of red hives near the anus.
- Vomiting .
- Weight loss.
There are 5 forms of strongyloidiasis. When the patient initially acquires this infection, he may have respiratory symptoms (Löffler’s syndrome). Strongyloidiasis then becomes chronic where the patient will mainly experience digestive symptoms. If the patient has reinfection where larvae migrate through the body, then the patient will have skin, respiratory and digestive symptoms. Finally, if the patient has hyperinfection syndrome, the symptoms will be from multiple organ systems.
Causes of Strongyloidiasis
The cause of strongyloidiasis is a parasite, Strongyloides stercoralis, which mainly infects humans. Strongyloides stercoralis is commonly found in subtropical and tropical climates; However, it can sometimes also be found in more temperate climates, including Appalachia and parts of the southern United States. After the patient has contacted Strongyloides stercoralis, the infection follows the worm’s life cycle, which consists of the following steps:
In the first stage, these tiny worms penetrate the patient’s skin and enter the bloodstream. Then the worms migrate through the bloodstream, pass through the right side of the heart and move into the lungs. The parasites then migrate from the lungs to the patient’s trachea and mouth. The patient may unknowingly swallow these worms from where they reach the stomach and move to the small intestine. They then lay eggs that hatch and produce larvae. These larvae are expelled from the body by the patient’s feces. These larvae can cause infection in the body by penetrating the skin around the anus, where they develop into mature worms and can infect someone else. In rare cases, worms, instead of passing through the body through the feces, may penetrate the patient’s intestines like larvae.
Risk Factors for Strongyloidiasis
- Individuals living or traveling to Africa, South America and other tropical regions are most at risk for strongyloiasis.
- People who do not practice good personal hygiene are more likely to get strungiloidiasis.
- Individuals who live or travel to rural areas and areas with poor sanitation without proper public health services are at greater risk for strongyloiasis.
- Individuals with weakened immune systems, such as those suffering from AIDS or HIV , are at a higher risk of getting strongyloidiasis.
Diagnosis of Strongyloidiasis
The following tests can be performed to diagnose a Strongyloides stercoralis infection:
- Stool testing is done to look for Strongyloides stercoralis larvae in the stool. This test may need to be repeated for accurate diagnosis of Strongyloides.
- Microscopic examination of stool and duodenal specimens are the most common methods for diagnosing strongyloidiasis. In a duodenal aspiration, fluid is removed from the first section of the small intestine, which is then sent to the laboratory for examination under the microscope by Strongyloides stercoralis.
- Airway or lung fluid can be taken and sputum culture can be done to look for Strongyloides stercoralis.
- Blood testing, which includes differential whole blood count (CBC), helps rule out other causes of symptoms or other infections.
- A blood antigen test can also be done to check antigens for Strongyloides stercoralis. This test is done when doctors cannot find the parasite in stool specimens or a duodenal aspiration but suspect the patient has this infection.
- Treatment for Strongyloidiasis mainly consists of eliminating the worms. Ivermectin is the drug of choice for the treatment of strongyloidiasis. This medicine is given as a single dose and works by killing worms in the small intestine.
- Two courses of albendazole may also be taken about 10 days apart. Alternatively, albendazole may also be taken twice a day for two or three days.
- Se o paciente tiver estrongilidíase generalizada, a medicação deve ser tomada por mais tempo ou será repetida.
Prevenção de Estrongiloidíase
Não é possível prevenir sempre a Estrongiloidíase; no entanto, usar instalações sanitárias e manter uma boa higiene pessoal ao viajar para áreas tropicais ou quentes reduzirá o risco de contrair a estrongiloidíase.
Complicações da estrongiloidíase
O paciente pode ter as seguintes complicações da Estrongiloidíase:
- Desnutrição: O paciente sofre de desnutrição quando os intestinos não são capazes de absorver adequadamente os nutrientes dos alimentos devido à estrongiloidíase.
- Pneumonia Eosinofílica: O paciente desenvolve Pneumonia Eosinofílica quando há inchaço dos pulmões devido ao aumento de eosinófilos. O aumento dos eosinófilos ocorre quando os vermes entram nos pulmões e o corpo produz mais eosinófilos como resultado.
- Estrongiloidíase disseminada: Existe uma ampla distribuição do parasita no corpo envolvendo múltiplos órgãos. Isso acontece quando o paciente está tomando medicamentos imunossupressores ou se o paciente tem um sistema imunológico fraco devido a um vírus. A estrongiloidíase disseminada também pode ocorrer quando o Strongyloides stercoralis altera seu ciclo de vida ao entrar nos intestinos e reentrar na circulação sanguínea. O paciente apresenta os seguintes sintomas: dor e inchaço no abdômen, choque, septicemia, complicações neurológicas e pulmonares.
Prognóstico da Estrongiloidíase
The prognosis of strongyloidiasis is good as long as the appropriate treatment of the patient is started. With proper treatment, the patient can have a complete recovery after the parasites have been completely eliminated. In some patients, treatment may need to be repeated.
However, the prognosis is not good if the patient has a weak immune system with widespread or severe infection. If diagnosis and treatment are delayed in such patients, then Strongyloidiasis can cause death of the patient.