Ascaris lumbricoides
Classification
Kingdom: Animalia
Phylum: Nematoda
Class: Chromadorea
Order: Ascaridida
Family: Ascarididae
Genus: Ascaris
Species: A. lumbricoides
Introduction
Ascaris lumbricoides, Linnaeus, 1758 and Ascaris suum, Goeze, 1782 are parasitic nematode (Family Ascarididae) infections of humans. Ascaris lumbricoides is one of the most frequent intestinal parasites that cause Ascariasis in children under the age of five in developing nations with poor sanitation (Schulze et al., 2005; Steinberg et al., 2003). In endemic locations, worm infection affects about 30% of adults and 60-70 per cent of children (Khuroo et al., 1989). The majority of cases, however, are asymptomatic; yet, in cases when the worm burden is substantial, catastrophic problems such as intestinal blockage or perforation can occur, necessitating immediate surgical intervention (Agrawal et al., 2016). Though microbiologic diagnosis of Ascaris lumbricoides infection is possible (Arora et al., 2005), X-ray and ultrasonography are rapid, safe, and non-invasive methods for early diagnosis (Mehta et al., 2010; Mani et al., 1997).
Description
1.The intestinal nematode Ascaris lumbricoides belongs to the Ascaridodea superfamily and is a round worm.
2. Ascaris worms are a huge, heavy infection that can cause obstruction or perforation of the intestine, as well as obstruction of the bile ducts and pancreatic ducts in infants (Braids, 1986).
3. The intestinal nematode species Ascaris lumbricoides, Trichuris, and Hookworm are cylindrical, unsegmented helminths with pointy ends.
4. Their length can range from a few millimetres to over a metre. The sexes are normally separated, with the female being larger than the male. They have a thick, smooth exterior cuticle and a hollow with a fully functioning digestive tract, including a mouth, intestine, and anus.
5. They spend several days in the alveoli before ascending the respiratory tree to the epiglottis and descending into the oesophagus. Their maturation occurs in the intestine, and after mating, the female produces a huge number of eggs that are passed into the faeces (Ukoli, 1991; Cheesbrough, 1987).
6. It is most prevalent in places with poor sanitation, where untreated human faeces are used for fertilisation or (as fertilisers) (Cheesbrough, 1987).
7. Man is infected by the ascariasis etiological agent. Infectious eggs can be found in contaminated food, water, or on faecal-contaminated hands. The larvae hatch in the circulation after being consumed, and they are taken to the heart and lungs (Andrade et al., 2001).
8. Though a few worms may cause no symptoms, severe infections are dangerous, as anybody who has seen marasmic toddlers with swollen bellies after being starved of 80 to 100 worms knows (Denhams et al., 1985). A.lumbricoides is a widespread parasite in both temperate and tropical zones, however, it is more abundant in warm temperate countries with poor sanitation.
9. According to Harold et al. (1983), Ascaris can affect people of all ages, although it is most common in pre-school and elementary school children aged 5 to 9, who are more likely to be exposed to contaminated soil than adults.
10. Due to soil contamination and inadequate cleanliness, the parasite is most prevalent in the impoverished classes in both urban and rural settings. Infected youngsters represent the primary source of soil pollution by indiscriminate defecation in dooryards and earthen-floored houses, where the resistant eggs stay viable for lengthy periods.
11. Ascaris is controlled by providing and using proper latrines, which prevents soil from becoming faecally polluted. Using untreated human faeces as fertiliser is not recommended.
12. Individuals who have been treated for their infection are part of a carefully monitored programme. It can also be controlled by washing hands before eating, avoiding raw vegetables, green salads, and fruits that may contain Ascaris eggs from contaminated soil, and avoiding eating uncooked vegetables, green salads, and fruits (Seo, 1983).
Symptoms
During the larvae’s migration through the liver and lungs, the patient may have signs of pneumonitis, such as cough and low-grade fever. With eosinophilia, this can be accompanied by wheezing and coughing. Adult worms travel actively through the colon, causing intestinal obstruction, vomiting, and abdominal pain, although infections can often go unnoticed. A high worm burden in children can cause serious nutritional problems.
Laboratory Diagnosis
Ascaris lumbricoides adults can be found in faeces or vomit, but they must be distinguished from segmented earthworms, which are frequently recovered as a contaminant from toilets. It’s the biggest nematode discovered in humans’ intestines. The male has a coiled tail with protruding spicules and measures 15cm in length with a diameter of 3-4mm. The female is 25cm long, with a 5mm diameter and a straight pointed back end. One dorsal and two ventral lips can be found in the mouth. The typical bile stained eggs can be seen on microscopic analysis of stool deposits following concentration. Unfertilized ova have a brick form and a bumpy surface. They’re 85-95 metres long and 43-47 metres wide. The fertilised ova are oval, thick-walled, and have an irregular bumpy surface, measuring 45 to 75 metres by 35 to 50 metres. If too much iodine is used in the moist preparation, eggs might become difficult to distinguish from detritus because they retain the stain. Decortication is another possibility with Ova.
Strategies for control of Ascaris
There are three basic tactics for controlling soil-transmitted helminths (STHs) in human hosts: improving sanitation, health education, and anthelminthic treatment (chemotherapy) to reduce parasite intensity (and thus morbidity). Ascaris infection management techniques are influenced by a variety of parasite life cycle traits and epidemiological patterns. Re-infection rates are affected by the rates at which ova are produced, as well as their durability and survivability in the soil. As a result, providing sanitation for the safe disposal of human faeces is critical to the long-term control and eradication of A. lumbricoides infection. Sanitation seeks to stop the spread of worms, prevent re-infection, and reduce worm burdens over time.
The joint method of integrated control of schistosomiasis and STHs was supported by the WHO. The goal of antihelminthic drug therapy programmes is to reduce morbidity rather than eradicate helminths, which is not a realistic goal. Due to high re-infection rates in endemic areas, systematic treatment is required regularly. Within 11 months, A. lumbricoides had reached 55 per cent of pre-treatment rates. There are several types of therapy programmes: universal, selective, and focused. Children, as previously stated, have higher worm burdens and are hence considered a good candidate for focused treatment. Albonico et al., WHO recommends targeted therapy two to three times a year for school-age children with a prevalence of more than 70% and once a year for school-age children with a prevalence of 50 to 70%, respectively. WHO recommends a fast assessment of STH prevalence and intensity in roughly fifty children in five to ten schools per area to determine the best chemotherapeutic method and frequency for a given location. Sturrock et al. proved, in response to WHO guidelines, that examining four to five schools in a given area, focusing on age cohorts most likely to be infected, is a cost-effective technique for identifying communities that require mass treatment. For communities where STH prevalence reaches 20%, universal medication administration is recommended, while places with a prevalence of more than 50% are considered high risk. The cost of treatment at a certain interval is $0.02 to 0.03 per individual, however, the frequency of chemotherapy is governed by prevalence. Polyparasitism must also be taken into account while developing chemotherapeutic tactics, as there is a risk that helminth infections will affect the outcome of other infectious diseases that are considered pandemics. The geographical overlap between A. lumbricoides with diseases like HIV, malaria, and tuberculosis, like other STH, raises the potential of causative linkages between these infections. However, a conclusive answer as to whether Ascaris provides protection or is antagonistic to microparasite infection has yet to be determined.
TOP QUESTIONS
Question: What is Ascaris lumbricoides’s common name?
Ans: The Human Roundworm
Question: What’s the difference between Ascaris lumbricoides males and females?
Ans: The male has a coiled tail with protruding spicules and measures 15 cm in length with a diameter of 3-4 mm. The female is 25 cm long, with a 5 mm diameter and a straight pointed back end.
Question: What are the different symptoms that Ascaris lumbricoides cause?
ANS: The patient may have signs of pneumonitis, such as cough and low-grade fever. With eosinophilia, this can be accompanied by wheezing and coughing. Adult worms travel actively through the colon, causing intestinal obstruction, vomiting, and abdominal pain.
Question: How does the Ascaris lumbricoides disease spread?
Ans: Man is infected by the ascariasis etiological agent. Infectious eggs can be found in contaminated food, water, or on faecal-contaminated hands.