Angiostrongyliasis: A Parasitic Threat to the Nervous System

Angiostrongyliasis is a parasitic infection caused by roundworms of the Angiostrongylus genus, primarily Angiostrongylus cantonensis, or rat lungworm. This zoonotic disease affects the central nervous system, leading to eosinophilic meningitis—a rare but severe condition involving inflammation of the brain and spinal cord membranes.

Humans acquire the infection by consuming raw or undercooked intermediate hosts such as snails, slugs, freshwater prawns, or crabs. Contaminated vegetables, fruits, and water are additional sources. After ingestion, infective larvae migrate to the brain, triggering a cascade of neurological symptoms.

Symptoms typically emerge within one to four weeks and range from mild to severe. Patients often experience intense headaches, neck stiffness, nausea, and vomiting. Neurological symptoms, including numbness, tingling, and hypersensitivity, are common. Severe cases can progress to paralysis, coma, or even death. Although fatalities are rare, the infection's neurological complications can lead to long-term disability.

Diagnosing angiostrongyliasis is challenging due to its nonspecific symptoms. Clinicians rely on a combination of patient history—particularly exposure to potential infection sources—and the presence of elevated eosinophils in cerebrospinal fluid. Advanced imaging techniques like MRI can help identify inflammation in the central nervous system, but definitive diagnosis requires specialized laboratory tests, including PCR for parasite DNA.

Currently, no specific antiparasitic drug is approved for treating angiostrongyliasis. Management focuses on alleviating symptoms. Corticosteroids help reduce inflammation, while pain relievers address severe headaches. In some cases, lumbar punctures are performed to relieve intracranial pressure. Experimental treatments, such as albendazole and other anthelmintics, have shown promise but require further study.

Preventive measures are critical. Thoroughly washing and cooking food, especially leafy vegetables, and avoiding raw or undercooked snails and slugs are essential. Public health education in endemic regions, including Southeast Asia, the Pacific Islands, and parts of the Americas, plays a pivotal role in reducing infection rates.

In conclusion, angiostrongyliasis poses a significant public health threat in endemic areas. Heightened awareness, rigorous hygiene practices, and research into effective treatments are vital for mitigating its impact.
Angiostrongyliasis: A Parasitic Threat to the Nervous System

New Species Of Infectious Disease Found In Amazon

New Species Of Infectious Disease Found In Amazon
While investigating the tropical disease leptospirosis in the Peruvian Amazon, an infectious disease specialist from the University of California, San Diego School of Medicine has uncovered new, emerging bacteria that may be responsible for up to 40 percent of cases of the disease. Patients with severe forms of leptospirosis have jaundice, renal failure and lung hemorrhage, with high fatality rates.

Joseph Vinetz, M.D., professor of medicine in UC San Diego's Division of Infectious Diseases working in collaboration with colleagues from Universidad Peruana Cayetano Heredia in Lima, Peru, and others headed the study that led to discovery of the new species in the family of pathogens, Leptospira, which is spread from animals to humans. The findings will be published in the April 1 issue of the Public Library of Science (PLoS) journal Neglected Tropical Diseases.

Leptospirosis is a severe, water-borne disease transmitted from animals to humans, with tens of millions of human cases worldwide each year. Fatality rates can range as high as 20 to 25 percent in some regions, and it is particularly prevalent in tropical countries where poor people live under highly crowded condition, or in rural areas where people are exposed to water contaminated by the urine of Leptospira-infected animals such as rats.

The new species reflects Amazonian biodiversity, according to Vinetz, and the pathogen has apparently evolved to become an important cause of leptospirosis in the Peruvian Amazon region of Iquitos. There, Vinetz leads an international team of physicians from the U.S. and Peru in an NIH-funded training program studying malaria, leptospirosis and other infectious diseases that impact disadvantaged populations in developing countries.

The researchers found that the new species, Leptospira licerasiae cultured from a very small number of patients, as well as eight rats is significantly different from other forms of the bacteria at a genomic level and has novel biological features.

"This strain has fundamentally different characteristics," said Vinetz, adding that the next step is to sequence its genome. "We think that hundreds of patients are infected with this pathogen, which is so unique that antibodies for the disease don't react to the regular tests for leptospirosis."

In testing 881 patients in a prospective clinical study of fever, the researchers found that 41 percent of them had antibodies that reacted only to this new strain of the bacteria, showing a much higher incidence of leptospirosis than previously suspected.

"This observation is relevant to other regions of the world where leptospirosis is likely to be common, because it's necessary to identify the right strain of the Lepstospira in order to make the correct diagnosis," Vinetz said.

Since isolation of the new Leptospira in people was rare despite the high prevalence of antibodies to this strain of the bacteria in the Amazonian population, Vinetz theorizes that the individuals with positive cultures may have a previously undiscovered immune system defect, making them more susceptible to the disease.
Source: http://www.medicalnewstoday.com
New Species Of Infectious Disease Found In Amazon