Ascariasis
Independent evaluation of the Nigrosin-Eosin modification of the Kato-Katz technique. (1/215)
A new modified quantitative Kato-Katz thick-smear technique for the detection of helminth eggs in faeces preserves hookworm eggs unaltered for a long time, while with the classic Kato-Katz technique, they disappear after approximately 2 h in tropical climates and thus slides must be read within hours after sample collection. For an independent comparison of these two laboratory techniques, faecal smears from 263 school children were examined in two surveys and prevalence, intensity of infection and costs of surveys calculated. There was no statistical difference between the methods in detecting prevalence and stratification of the sample in different classes of intensity. While there was no statistical difference for the arithmetic mean of the epg for T. trichiura and only a small difference for A. lumbricoides (P=0.04), we observed a highly significant difference for hookworm mean intensities of infections (P<0.001). From the public health viewpoint both methods provided similar results, but due to its simplicity and widespread use the classical Kato-Katz technique remains first choice for community investigation of soil-transmitted nematodes. However, the Nigrosin-Eosin approach has several advantages and can be a valuable alternative in certain circumstances. (+info)Evidence for an improvement in cognitive function following treatment of Schistosoma japonicum infection in Chinese primary schoolchildren. (2/215)
A double-blind, placebo-controlled, treatment trial was conducted in Sichuan, China to investigate the unique and combined effects on the cognitive function (working memory) of children after treating geohelminth infections with albendazole and treating Schistosoma japonicum infection with praziquantel. One hundred eighty-one children 5-16 years of age participated. At baseline, the praziquantel and placebo groups were similar in all background characteristics. Three months after praziquantel treatment, there was a significant reduction in the prevalence and intensity of S. japonicum infection. There were significant age group by praziquantel treatment interaction effects in three of the five cognitive tests, Fluency, Picture Search, and Free Recall, with effects being strongest in the youngest children (5-7 years old). Exploratory analysis within the youngest children showed a significant positive main effect of treatment on Fluency (P < 0.001), after controlling for sex, anthropometric, and parasitic and iron status. There was also a treatment by height-for-age interaction (P = 0.03) and a treatment by iron status interaction (P = 0.024) on Fluency. There was a treatment by S. japonicum intensity interaction (P < 0.001) on Free Recall, but the main effect of treatment on Picture Search was not significant (P = 0.058). Younger children and those who are physically the most vulnerable are likely to benefit the most from the treatment of S. japonicum infection in terms of improved performance on tests of working memory. (+info)A controlled evaluation of two school-based anthelminthic chemotherapy regimens on intensity of intestinal helminth infections. (3/215)
BACKGROUND: School-based deworming programmes have been promoted as a cost-effective strategy for control of nematode infection in developing countries. While numerous efficacy studies have been conducted, there is little information on actual programme effectiveness in areas of intense transmission. METHODS: A randomized trial of a school-based deworming programme was conducted in 12 primary schools on Pemba Island, Zanzibar. Four schools each were randomized to control, twice a year deworming with single dose mebendazole or three times a year deworming. Baseline and 12-month follow-up data on helminth infection using the Kato-Katz technique, demographic information and nutritional status were collected on 3028 children from March 1994 to May 1995. RESULTS: Intensity of infection measured as eggs per gram of faeces (epg) declined significantly for Ascaris lumbricoides, Trichuris trichiura and hookworm infections in both treatment groups. A. lumbricoides infection intensity declined 63.1% and 96.7% in the twice and three times per year treatment groups compared to the controls. T. trichiura infection intensity declined 40.4% and 75.9% respectively and hookworm intensity declined 35.3% and 57.2% respectively compared to control schools. CONCLUSIONS: These results suggest that school-based programmes can be a cost-effective approach for controlling the intensity of intestinal helminth infection even in environments where transmission is high. (+info)Assessment of combined ivermectin and albendazole for treatment of intestinal helminth and Wuchereria bancrofti infections in Haitian schoolchildren. (4/215)
This randomized, placebo-controlled trial investigated the efficacy and nutritional benefit of combining chemotherapeutic treatment for intestinal helminths (albendazole) and lymphatic filariasis (ivermectin). Children were infected with Ascaris (29.2%), Trichuris (42.2%), and hookworm (6.9%), with 54.7% of children having one or more of these parasites. Wuchereria bancrofti microfilaria were found in 13.3% of the children. Children were randomly assigned to treatment with placebo, albendazole, ivermectin, or combined therapy. Combination treatment reduced the prevalence of Trichuris infections significantly more than either drug alone. Combination therapy also significantly reduced the prevalence and density of W. bancrofti microfilaremia compared with placebo or ivermectin alone. Only combination therapy resulted in significantly greater gains in height (hookworm-infected children) or weight (Trichuris-infected children) compared with the placebo group. Combined albendazole and ivermectin was a more efficacious treatment for intestinal helminth and W. bancrofti infections in children and resulted in nutritional benefits not found with either drug alone. (+info)Tumor necrosis factor alpha is a critical component of interleukin 13-mediated protective T helper cell type 2 responses during helminth infection. (5/215)
In vivo manipulation of cytokine and/or cytokine receptor expression has previously shown that resistance to infection with the caecum-dwelling helminth Trichuris muris is dependent on interleukin (IL)-4 and IL-13 while susceptibility is associated with a T helper cell type 1 (Th1) cytokine response. Using gene-targeted mice deficient in tumor necrosis factor (TNF) receptor signaling and anti-TNF-alpha monoclonal antibody treatment, we have extended these studies to reveal a critical role for TNF-alpha in regulation of Th2 cytokine-mediated host protection. In vivo blockade of TNF-alpha in normally resistant mice, although not altering IL-4, IL-5, or IL-13 production in the draining lymph node, significantly delayed worm expulsion for the duration of treatment. IL-13-mediated worm expulsion in IL-4 knockout (KO) mice was also shown to be TNF-alpha dependent, and could be enhanced by administration of recombinant TNF-alpha. Furthermore, TNF receptor KO mice failed to expel T. muris, producing high levels of parasite-specific immunoglobulin G2a and the generation of a predominantly Th1 response, suggesting that the absence of TNF function from the onset of infection dramatically alters the phenotype of the response. These results provide the first demonstration of the role of TNF-alpha in regulating Th2 cytokine-mediated responses at mucosal sites, and have implications for the design of rational therapies against helminth infection and allergy. (+info)Parenteral nutrition in the management of a dog with lymphocytic-plasmacytic enteritis and severe protein-losing enteropathy. (6/215)
Management of lymphocytic-plasmacytic enteritis in a dog with whipworm infestation, hypoproteinemia, and ascites is described. Short-term parenteral nutrition hastened normalization of serum proteins, resolution of diarrhea, and weight gain. A description of the potential benefits, limitations, and possible complications of parenteral nutrition in refractory inflammatory bowel disease is given. (+info)Anti-IL-9 vaccination prevents worm expulsion and blood eosinophilia in Trichuris muris-infected mice. (7/215)
Production of neutralizing anti-IL-9 antibodies was induced in mice by immunization with mouse IL-9 coupled to ovalbumin. In the six mouse strains tested, a strong and long-lasting anti-IL-9 response developed with seric inhibitory titers of 10(-3) to 10(-5), as measured in an in vitro IL-9-dependent cell proliferation assay. In vivo, this immunization completely abrogated the increase in mast-cell protease-1 levels as well as the eosinophilia observed in mice after implantation of an IL-9-secreting tumor. We took advantage of this method to assess the role of IL-9 in infections with nematode Trichuris muris, where IL-9 production correlates with the resistant phenotype. C57BL/6 mice, which normally expel the parasite, became susceptible after anti-IL-9 immunization, demonstrating that IL-9 plays a critical role in this model. In addition, neutralization of IL-9 also inhibited parasite-induced blood eosinophilia. Taken together, the present data demonstrate the potency of our strategy to antagonize IL-9 in vivo and shows that this cytokine plays a major role in resistance against T. muris infection. (+info)Peripheral cytokine responses to Trichuris muris reflect those occurring locally at the site of infection. (8/215)
The study of human cellular immune responses to parasite infection under field conditions is very complex. Often, the only practical site from which to sample the cellular responses is the peripheral blood. Sampling peripheral blood lymphocytes (PBL) relies on the assumption that these peripheral responses accurately reflect the immune responses acting locally at the site of infection. This is a particularly important point for the human intestinal helminth Trichuris trichiura, which solely inhabits the cecum and large intestine and so will stimulate a localized immune response. Using the well-defined model of T. trichiura, T. muris in the mouse, we have demonstrated that the dominant cytokine responses of the mesenteric lymph nodes (MLN) can be detected by sampling PBL. Resistant mice which mount a type 2 cytokine response in their MLN had PBL producing interleukin-4 (IL-4), IL-5, and IL-9, with negligible levels of gamma interferon (IFN-gamma). Conversely, susceptible mice which mount a type 1 cytokine response in their MLN had PBL producing IFN-gamma and negligible levels of type 2 cytokines. We have also shown that the PBL are capable of mounting a functional immune response against T. muris. PBL from immune mice were capable of transferring immunity to T. muris-infected severe combined immunodeficient (C.B-17 scid/scid) mice. Sampling PBL responses is therefore a viable option for monitoring human intestinal immune responses during T. trichiura infection in the field. (+info)Trichuriasis is a parasitic infection caused by the nematode (roundworm) Trichuris trichiura, also known as the whipworm. This infection primarily affects the large intestine (cecum and colon). The main symptoms of trichuriasis include diarrhea, abdominal pain, and weight loss. In heavy infections, there can be severe complications such as anemia, growth retardation, and rectal prolapse. Trichuriasis is typically transmitted through the ingestion of contaminated soil containing Trichuris trichiura eggs, often through poor hygiene practices or exposure to contaminated food and water.
"Trichuris" is a genus of parasitic roundworms that are known to infect the intestines of various mammals, including humans. The species that commonly infects humans is called "Trichuris trichiura," which is also known as the human whipworm. These worms are named for their long, thin shape that resembles a whip.
The life cycle of Trichuris involves ingestion of eggs containing infective larvae through contaminated food or water. Once inside the human body, the larvae hatch and migrate to the large intestine, where they mature into adult worms that live in the caecum and colon. Adult female worms lay thousands of eggs every day, which are passed in the feces and can survive in the environment for years, waiting to infect a new host.
Infections with Trichuris trichiura can cause symptoms such as diarrhea, abdominal pain, bloating, and weight loss. In severe cases, it can lead to anemia, malnutrition, and impaired growth in children. Treatment for trichuriasis typically involves medication that kills the adult worms, such as albendazole or mebendazole.
Ascariasis is a medical condition caused by infection with the parasitic roundworm Ascaris lumbricoides. This type of worm infection, also known as intestinal ascariasis, occurs when people ingest contaminated soil, food, or water that contains Ascaris eggs. Once inside the body, these eggs hatch into larvae, which then migrate through the tissues and eventually reach the small intestine, where they mature into adult worms.
The adult worms can grow to be several inches long and live in the small intestine, where they feed on partially digested food. Female worms can produce thousands of eggs per day, which are then passed out of the body in feces. If these eggs hatch and infect other people, the cycle of infection continues.
Symptoms of ascariasis can vary depending on the severity of the infection. Mild infections may not cause any symptoms, while more severe infections can lead to abdominal pain, nausea, vomiting, diarrhea, and weight loss. In some cases, the worms can cause intestinal blockages or migrate to other parts of the body, leading to potentially serious complications.
Treatment for ascariasis typically involves medication to kill the adult worms and prevent them from producing more eggs. Preventive measures include good hygiene practices, such as washing hands thoroughly after using the bathroom and before eating, and avoiding contact with contaminated soil or water.
Helminthiasis is a medical condition characterized by the infection and infestation of body tissues and organs by helminths, which are parasitic worms. These worms can be classified into three main groups: nematodes (roundworms), cestodes (tapeworms), and trematodes (flukes).
Helminthiasis infections can occur through various modes of transmission, such as ingestion of contaminated food or water, skin contact with contaminated soil, or direct contact with an infected person or animal. The severity of the infection depends on several factors, including the type and number of worms involved, the duration of the infestation, and the overall health status of the host.
Common symptoms of helminthiasis include abdominal pain, diarrhea, nausea, vomiting, weight loss, anemia, and nutritional deficiencies. In severe cases, the infection can lead to organ damage or failure, impaired growth and development in children, and even death.
Diagnosis of helminthiasis typically involves microscopic examination of stool samples to identify the presence and type of worms. Treatment usually consists of administering anthelmintic drugs that are effective against specific types of worms. Preventive measures include improving sanitation and hygiene, avoiding contact with contaminated soil or water, and practicing safe food handling and preparation.
A "Parasite Egg Count" is a laboratory measurement used to estimate the number of parasitic eggs present in a fecal sample. It is commonly used in veterinary and human medicine to diagnose and monitor parasitic infections, such as those caused by roundworms, hookworms, tapeworms, and other intestinal helminths (parasitic worms).
The most common method for measuring parasite egg counts is the McMaster technique. This involves mixing a known volume of feces with a flotation solution, which causes the eggs to float to the top of the mixture. A small sample of this mixture is then placed on a special counting chamber and examined under a microscope. The number of eggs present in the sample is then multiplied by a dilution factor to estimate the total number of eggs per gram (EPG) of feces.
Parasite egg counts can provide valuable information about the severity of an infection, as well as the effectiveness of treatment. However, it is important to note that not all parasitic infections produce visible eggs in the feces, and some parasites may only shed eggs intermittently. Therefore, a negative egg count does not always rule out the presence of a parasitic infection.
Parasitic intestinal diseases are disorders caused by microscopic parasites that invade the gastrointestinal tract, specifically the small intestine. These parasites include protozoa (single-celled organisms) and helminths (parasitic worms). The most common protozoan parasites that cause intestinal disease are Giardia lamblia, Cryptosporidium parvum, and Entamoeba histolytica. Common helminthic parasites include roundworms (Ascaris lumbricoides), tapeworms (Taenia saginata and Taenia solium), hookworms (Ancylostoma duodenale and Necator americanus), and pinworms (Enterobius vermicularis).
Parasitic intestinal diseases can cause a variety of symptoms, including diarrhea, abdominal pain, bloating, nausea, vomiting, fatigue, and weight loss. The severity and duration of the symptoms depend on the type of parasite, the number of organisms present, and the immune status of the host.
Transmission of these parasites can occur through various routes, including contaminated food and water, person-to-person contact, and contact with contaminated soil or feces. Preventive measures include practicing good hygiene, washing hands thoroughly after using the toilet and before handling food, cooking food thoroughly, and avoiding consumption of raw or undercooked meat, poultry, or seafood.
Treatment of parasitic intestinal diseases typically involves the use of antiparasitic medications that target the specific parasite causing the infection. In some cases, supportive care such as fluid replacement and symptom management may also be necessary.