Child Healthcare: Parasites

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Child Healthcare addresses all the common and important clinical problems in children, including:immunisation history and examination growth and nutrition acute and chronic infections parasites skin …

Child Healthcare addresses all the common and important clinical problems in children, including:immunisation history and examination growth and nutrition acute and chronic infections parasites skin conditions difficulties in the home and society.

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  • 1. 11 Parasites Children with AIDS may be infected with Objectives unusual parasites not normally seen in healthy children (e.g. Toxoplasmosis). When you have completed this unit you should be able to: 11-2 Which are the common intestinal • Diagnose and manage children with parasites? intestinal worms. In Southern Africa the common intestinal • Diagnose and treat giardiasis. parasites are: • Diagnose and treat amoebiasis. • Diagnose and treat bilharzia. • Roundworms • Diagnose and manage children with • Whipworms malaria. • Pinworms • Hookworms • GiardiaINTRODUCTION • • Tapeworms Amoebae11-1 What are parasites? ROUNDWORMSThese are small creatures (animals) whichinvade and infect (infest) the body. They maybe either: 11-3 What is a roundworm?• External parasites which live on or in the Roundworms are the most common parasites skin, e.g. scabies and sandworms. found in the gut of children. The worms are• Internal parasites which live in the body. pink and smooth and measure about 25 cm Many internal parasites live in the bowel long. They look like pale garden earth worms. (i.e. intestinal parasites such as worms). Other parasites live in the blood (e.g. Roundworms produce thousands of eggs a day malaria) or other organs such as the which are passed in the child’s stool (faeces). bladder wall (e.g. bilharzia). The eggs have a very characteristic shape and can be easily recognised if a sample of stool is examined under a microscope.
  • 2. PARASITES 183Roundworms are common in children (undernutrition). Roundworms alsobetween the ages of 1 and 5 years. decrease the child’s appetite. • A large bunch (bolus) of worms can cause colic (cramping abdominal pain) and even Roundworms are the most common bowel total small bowel obstruction. The mass parasite in many poor countries. of worms may be palpable on abdominal examination. NOTE The roundworm is Ascaris lumbricoides. • Migrating worms can get stuck in the bile Infection with roundworms is called ascariasis. duct, resulting in acute, severe pain over the liver (biliary colic).11-4 How do children get roundworms? NOTE Roundworms can also cause bowelIf human faeces are not disposed of in a perforation, volvulus, intussusception, colangitishygienic way, or if sewerage sludge is used as and pancreatic duct obstruction. With heavya garden fertiliser, children can swallow and infections, bunches of roundworms can beget infected by roundworm eggs. Roundworm seen in a plain abdominal X-ray. Do not give mebendazole or albendazole if acute abdominaleggs can survive in soil for years. Playing or pain is present as treatment increases the worms’crawling in contaminated soil or eating raw tendency to migrate and may precipitate bowelvegetables that have not been washed may obstruction. Surgery must be considered if thereresult in infection. High prevalence rates are are signs of obstruction.common in communities with poor sanitation.This is a major public health problem in many 11-6 How can roundworms cause chestparts of South Africa. problems?Roundworm eggs hatch in the child’s small The larvae (which hatch out of the eggs in thebowel, and the newly hatched larvae then pass gut) can causes respiratory symptoms and signsthrough the bowel wall into the bloodstream during the time that they are migrating throughand are carried to the alveoli of the lungs. the lungs. Children with roundworm larvae inFrom here they make their way up the bronchi the lungs present with a dry cough or wheeze.and trachea then get swallowed. In the smallbowel the roundworm larvae mature into adult NOTE A high eosinophil count in the peripheral blood (10% or more) is typical. Chest X-ray mayworms where they can live for 2 years. show a pneumonitis.11-5 Do roundworms in the gut cause 11-7 How are roundworms treated?clinical problems? Roundworm infection can be treated withMany children with roundworms appear either:healthy and have no symptoms. Often theonly way the parents know that their children • Mebendazole orally 100 mg (i.e. 1 tablet)have roundworms, is when worms are seen in twice a day for 3 days if below 5 years andthe stool. Sometimes worms can be vomited. 500 mg as a single dose if 5 years or older.When the child is ill with a fever, roundworms • Albendazole as a single dose 200 mg (2may make their way up the child’s oesophagus tablets) for children below 2 years and 400and come out of the nose. mg for children of 2 years or more.Large numbers of worms in the bowel cancause problems: 11-8 How can infection with roundworms be prevented?• Vague abdominal pain or discomfort• The amount of food they use • By safely disposing of human faeces can contribute to malnutrition (adequate sanitation), e.g. water borne sewerage or correctly built pit latrines
  • 3. 184 PARASITES• By washing raw vegetables before they are 11-11 What are the clinical features of eaten whipworm infection?• By washing hands before preparing or Whipworms usually infect children over 5 eating meals years of age. If the infection is light there are• By preventing children from eating soil usually no symptoms or signs. Heavy infection• By routinely deworming children can cause:11-9 When is deworming recommended? • Loose stools containing blood.Deworming every 6 months is recommended • Rectal prolapse may occur with very heavyfor children between the ages of 2 and 5 infections. With prolapse, the worms mayyears in communities with poor hygiene and be seen attached to the rectal mucosa.inadequate sanitation (poor toilet facilities). • Iron deficiency anaemia due to chronicThis should be done even if there is no history blood loss in the stool. This may be severe.of roundworms in the stool. Medication is • Malnutritionusually given at the local primary care clinicor in schools. Deworming has been found to Whipworm infection can cause iron deficiencyimprove the learning capacity and growth of anaemia.school children.Mebendazole is the drug of choice. 11-12 What is the treatment of whipwormAlbendazole is more expensive. The dose infection?for deworming is the same as for treatingroundworms. Both these drugs are highly 1. Prevention through good hand hygiene,effective for roundworms. washing raw vegetables and the correct disposal of human faeces (as with prevention of roundworms) Regular deworming of young children is 2. Mebendazole or albendazole, as given for recommended in communities where roundworms roundworms are common. 3. Treat iron deficiency anaemia with oral iron. PINWORMSWHIPWORMS 11-13 What are pinworms?11-10 What are whipworms? Pinworm infection is very common. They areWhipworms commonly infect the bowel small, thin worms (about 4 cm long). Pinwormsof children in Southern Africa. They are are especially common where children sleepshort, thin worms (about 4 cm) that attach or play together in crowded conditions. Adultthemselves to the mucosa of the large bowel female worms pass out the anus at night to laywhere they cause bleeding. It is rare to see the eggs on the perineum. Eggs are swallowed fromworms in the stool. contaminated fingers, clothing or bed linen.As with roundworms, eggs are ingested Pinworms are common even where hygiene(swallowed) with soil. The eggs hatch in the and sanitation are of a high standard. They arechild’s gut and the larvae attach to the bowel also known as threadworms.wall. Unlike roundworms, the larvae do not NOTE The pinworm is Enterobius vermicularis.migrate through the lungs. NOTE The whipworm is Trichuris trichura. The eggs in the stool have a typical ‘tea tray’ appearance.
  • 4. PARASITES 18511-14 What are the clinical features of 11-18 What are the clinical features ofpinworm infection? hookworm infection?Perianal itching and scratching at night. This Usually, there are no symptoms unless theremay cause loss of sleep. Secondary infection is heavy infection. The child may have anof the scratched skin is common. In girls the unusually large appetite and want to eat sand.worms may enter the vulva causing irritation In severe cases there may be signs of ironand vaginal discharge (vaginitis). deficiency anaemia. Pinworm infection presents with perianal itching 11-19 How is hookworm infection diagnosed? and scratching, especially at night. Worms and their eggs may be found in the stools.11-15 How is pinworm infectiondiagnosed? 11-20 What is the treatment of hookwormThe clinical diagnosis can be confirmed by the infection?parent finding the small worms on the skinaround the anus at night. A piece of sticky tape Mebendazole or albendazole, as for(Sellotape) should be placed against the anus roundworm infection.and surrounding skin during the night and then NOTE Pyrantel (Combantrin) orally 10 mg/kg as aimmediately removed. In this way eggs can be single dose may also be used.collected and identified under a microscope.11-16 What is the treatment of pinworms? TAPEWORMSMebendazole or albendazole, as used forroundworms 11-21 What are tapeworms? The common tapeworms that infect theHOOKWORMS human gut are the pork and, to a lesser degree, the beef tapeworm. They are very long (up to 5 metres) segmented worms that grow11-17 What are hookworms? in the small bowel of humans after eating uncooked or partially cooked meat, which isHookworms commonly occur in warm, contaminated with tapeworm cysts. Tapewormmoist climates such as northern KwaZulu- segments filled with eggs are excreted inNatal and the Mozambique coast. With human stools and later may be swallowedpoor sanitation, hookworm eggs in the stool by animals (pigs or cows). The eggs hatchcontaminate the soil and hatch rapidly. They in the animal’s gut and are carried in thethen infect the feet of barefoot children. Once bloodstream to the muscles of the animalsthe skin is penetrated, hookworms behave like where they become tapeworm cysts. Eatingroundworms as they enter the bloodstream infected, uncooked meat of these animalsand travel via the lungs to get into the small completes the life cycle of the tapeworm whenbowel. The worms attach to the bowel mucosa the eggs hatch, resulting in adult worms livingand cause bleeding. in the human gut. NOTE There are two types of hookworm, Ancylostoma duodenale and Necator americanus. Most tapeworms result from eating poorly cooked pork which is infected with tapeworm cysts.
  • 5. 186 PARASITES NOTE The pork tapeworm is Taenia solium and the are a common cause of fits in children that live beef tapeworm is Taenia saginata. in rural areas where toilets are not available. Good sanitation, safe water, hand-washing11-22 How is tapeworm infection and washed vegetables will reduce the risk ofdiagnosed? neurocycticercosis.Small segments of the worm are seen in thestool or may be found in the bed. Often there Swallowed pork tapeworm eggs from humanare no other symptoms. However, tapeworms faeces result in tapeworm cysts in the brain.can cause abdominal discomfort, failure tothrive and loss of appetite. NOTE The tapeworm cysts (cysticerci) are best identified in the brain by MRI or CT scanning.11-23 What is the treatment of tapeworm With time they become calcified and can beinfection? seen on X-ray. Cysts may also occur in muscles. Antibody tests are of little help. Treatment ofMebendazole orally 100 mg twice daily for 7 neurocysticercosis in hospital is with steroids anddays. Praziquantel.11-24 How can tapeworm infection beprevented? HYDATID DISEASEIf possible, animals should be slaughtered in aregistered abattoir where all meat is inspected 11-26 What is hydatid disease?to ensure that it is not infected by tapewormcysts. Cooking meat well kills the cysts. This is caused by the dog tapeworm whichTherefore, avoid eating raw or partially cooked can occur in the gut of dogs. Eggs, which aremeat. Meat lightly cooked on an open fire may passed in the dog’s stool, may be swallowedstill contain live tapeworm cysts. by sheep and goats, resulting in tapeworm cysts in their muscles. Other dogs can thenHuman stools must be disposed of safely be infected with tapeworms by eating the rawso that it cannot be eaten by pigs. This will meat of these sheep or goats.prevent the pigs from becoming infectedwith tapeworm cysts. Parts of the Eastern If eggs of the dog tapeworm are swallowed byCape of South Africa are particularly heavily humans instead, the eggs hatch in the humancontaminated with tapeworm eggs. gut and are carried by the bloodstream to the liver or lung where they form large cysts (hydatid cysts). These large cysts may cause In villages, pigs must be prevented from eating clinical problems (hydatid disease) and will human faeces. have to be removed surgically. Dogs should be dewormed regularly and11-25 Can tapeworm cysts enter the brain? they should not be allowed to eat raw meat,Yes. Sometimes the eggs of the pork tapeworm, especially mutton or goat meat which iswhich have been passed in human faeces, are infected with the cysts of the dog tapeworm.swallowed by other humans (instead of by pigs) Prevent children eating soil as it may bein food or water contaminated by infected contaminated with dog tapeworm eggs.human faeces. The eggs hatch in the child’s Always wash hands before eating. Also washgut and are then carried by the bloodstream vegetables well.into all parts of the body including the brain.In the brain they form many small tape worm Hydatid disease results when children swallowcysts (neurocysticercosis) which cause fits the eggs of the dog tapeworm.(convulsions). Tapeworm cysts in the brain
  • 6. PARASITES 187Treatment is with mebendazole or albendazole 11-29 What is the treatment of giardiadaily for 6 weeks. infection? NOTE The dog tapeworm is Echinococcus Metronidazole (Flagyl) 500 mg (under 4 years) granulosus. or 800 mg (4 years or older) daily for 3 days.The prevention, diagnosis and treatment of It is best to avoid infection with giardia bysandworm infection is discussed in Unit 12. not drinking contaminated water or eating unwashed vegetables or salad.GIARDIASIS AMOEBIASIS11-27 What is giardiasis? 11-30 What is amoebiasis?Giardiasis is an infection with a single-celled Amoebiasis is an infection caused by a single-organism (protozoa) called giardia. The cysts celled organism (protozoa) called an amoebaof giardia are swallowed in contaminated food which infects the large bowel. Amoebaeor water. Giardia lives in the small bowel and are passed in the stool from where they cancysts are passed in the stool. The cysts in human contaminate food or water causing infection instools contaminate the soil and nearby water. others. Therefore, the provision of toilets and NOTE Giardia lamblia is the cause of giardiasis. a safe water supply are important to prevent amoebiasis.11-28 What are the clinical features of NOTE Entamoeba histolytica is the amoeba whichgiardia infection? causes amoebiasis.Giardiasis is usually asymptomatic. However,with heavy infection the child develops loose, 11-31 What are the clinical features offoul-smelling, watery stools. Abdominal amoebiasis?cramps and vomiting are common. Usually Mild infection is asymptomatic. However,the infection resolves in a few days but it may heavy infection causes abdominal discomfortbecome chronic. Chronic giardiasis may cause and dysentery with blood and mucus in thechronic diarrhoea with malabsorption leading stools. Amoebae can also cause abscesses into failure to thrive and malnutrition. the liver. This presents with an enlarged tenderIt is difficult to confirm the diagnosis by liver. Severe bowel infection can result infinding cysts in the stool. Therefore, diagnosis perforation and peritonitis.is usually suspected from the clinical history Amoebae can be seen microscopically inand confirmed when the symptoms and signs warm stool. A blood test for antibodies againstdisappear after treatment. amoebae is useful in identifying patients with amoebiasis. Giardiasis can cause chronic diarrhoea and failure to thrive. 11-32 What is the treatment of amoebiasis? Metronidazole (Flagyl) 200 mg 3 times daily NOTE Giardia is a common cause of ‘travellers’ for 5 days. All children with severe dysentery diarrhoea’. or suspected liver abscess must be referred urgently. A large liver abscess may need to be aspirated.
  • 7. 188 PARASITESClean water, washing hands before eating, parasites in communities where they areavoiding unwashed vegetables and salads, and common.the safe disposal of human faeces prevents It is important that parents are aware of theamoebiasis. clinical features of infection with intestinal parasites and can recognise the worms if they11-33 How can infection with many types are seen.of intestinal parasite be prevented?The same basic steps are needed to preventmost intestinal parasites: BILHARZIA1. The safe disposal of faeces is most important, e.g. water flush toilets or 11-35 What is bilharzia? correctly-made pit toilets (VIP toilets). Never pass urine or stool near a stream or Bilharzia (schistosomiasis) is a disease caused dam. by the bilharzia parasite. About 2 million people2. Hands should always be washed before are infected with bilharzia in South Africa. preparing and eating food. They should There are 2 forms of bilharzia. One affects also be washed before eating. the bowel while the other affects the bladder.3. Always use a clean, safe source of water for Bilharzia of the bladder is the most common drinking and washing. form of bilharzia in children in South Africa.4. Always wash raw vegetables or salads Eggs of the bladder parasite are passed in the before eating. urine. If the urine reaches a source of water,5. Avoid eating meat which has not been the parasite can infect and multiply in a special thoroughly cooked. snail often found in pools, dams, reservoirs,6. Prevent pigs from eating human faeces. canals or slow flowing streams. Parasites7. Do not leave dog faeces lying around. released from the snail can penetrate the skinPublic awareness campaigns are an important of humans. From here the parasites enter themethod of reducing the number of infected bloodstream and are carried to the bladder.children. Methods of preventing infection Sometimes they may also reach other organs.with intestinal parasites should be taught and In the bladder wall the parasites causepractised at schools. inflammation, bleeding and eventually scarring. Damage can extend to the rest of the Safe toilets and clean water will prevent infection urinary tract, resulting in urinary obstruction with most intestinal parasites. with chronic renal failure. NOTE Bilharzia (schistosomiasis) is caused by either Schistosoma haemotobium (bladder parasite) or11-34 What is the treatment of intestinal Schistosoma mansoni (bowel parasite).parasites?Most intestinal parasites can be effectively Bilharzia of the bladder is common in Southtreated with oral mebendazole or albendazole.Some require a single dose (roundworms, Africa.whipworms and pinworms) but others need adaily dose for a number of days (tapeworms). 11-36 What are the clinical features ofGiardia and Amoeba infections should be bilharzia of the bladder?treated with metronidazole (Flagyl). At the time of infection an itchy, papular rashRegular treatment of children (e.g. deworming may occur at the site where the parasites enterfor roundworms) is advised for some intestinal the skin (called ‘swimmers’ itch’). This may be followed a few weeks later by a flu-like illness.
  • 8. PARASITES 189Mild bladder infection with bilharzia MALARIAparasites is often asymptomatic. With moresevere infection, the classical sign is terminalhaematuria (blood seen in the urine towards 11-40 What is malaria?the end of micturition). Malaria is a serious illness caused by a malaria parasite which is transmitted to humans by a Bilharzia of the bladder usually presents with special type of mosquito. When a mosquito terminal haematuria. bites an infected person, human blood containing malaria parasites is taken in by the NOTE Bilharzia of the bowel may cause dysentery. mosquito. The mosquito becomes infected (but not ill) and can then bite and infect other11-37 How is the diagnosis of bilharzia of humans. In the human, the malaria parasitethe bladder confirmed? infects both red cells and the liver. Infection of the red cells causes haemolysis, resultingBy finding the typical bilharzia eggs in the in anaemia. It also causes the red cells to stickurine under a microscope. It is best to collect together which obstructs small blood vessels.urine around midday when most eggs are Malaria is a common cause of chronic illnessreleased. A blood test for antibodies to the and death in many low lying regions whereparasite is also available. malaria mosquitoes occur. NOTE Eosiniphilia in the blood is usually present with bilharzia. Malaria is an important cause of death in many parts of southern Africa.11-38 What is the treatment of bilharzia?Praziquantel 40 mg/kg orally as a single As falciparum malaria is by far the mostdose. This treatment can be given at a clinic. common form of malaria in South Africa, otherUnfortunately, children who live in a bilharzia rarer forms of malaria will not be considered.region may have to be treated repeatedly for NOTE Almost all malaria in Southern Africa isbilharzia. caused by Plasmodium falciparum which is transmitted by female Anopheles mosquitoes11-39 How can bilharzia be prevented? (the vector of malaria).Every effort must be made to prevent bilharziainfection. Never pass urine into a stream or 11-41 What are the clinical signs ofpool of water. Standing or slow-moving water malaria?such as farm dams and irrigation furrows are The patient develops an acute illness withthe home of the bilharzias snail, especially fever, shivering rigors and flu-like symptomsin the eastern areas of South Africa and in 1 to 2 weeks after being bitten by an infectedZimbabwe. Fast-moving streams are usually mosquito. Headache, nausea and body painssafe. Swimming or bathing in infected water are common in uncomplicated (mild) malaria.must be avoided as this is the common way of The symptoms and signs of malaria are verygetting bilharzias. Efforts are being made to non-specific, making the clinical diagnosiskill the snails in high risk areas. difficult to confirm or exclude. Severe headache, repeated vomiting and Do not swim in standing water where there are drowsiness suggest the development of severe bilharzia snails. malaria. Mild malaria may become severe and even fatal within hours. NOTE Infection of other organs such as the liver (jaundice), gut (diarrhoea), lungs (respiratory
  • 9. 190 PARASITES distress) and kidneys (oliguria with renal failure) • Is passing urine may occur. Massive haemolysis (blackwater fever) • Is not vomiting repeatedly, and is able to causes anaemia, with dark urine. take oral medicationAnyone who develops fever in a malaria • Has no signs of organ failurearea, or within 2 weeks of leaving a malaria NOTE In uncomplicated malaria the parasite countarea, must be suspected of having malaria. on a thin blood smear is less than 5%, i.e. lessThinking of malaria is the most important than 5% of red cells containing malaria parasites.step in the clinical diagnosis. As the clinical In severe malaria the patient may have any ofsymptoms and signs of malaria are very varied, the following:it is always important to confirm the clinicalsuspicion. There are often no clinical signs at • Signs of cerebral malariapresentation. • Breathing difficulty • Hypoglycaemia, jaundice or severe anaemia (Hb less than 5 g/dl) Suspect malaria in anyone with a flu-like illness • Repeated vomiting, apparent dehydration who lives in or has recently visited a malaria or little urine passed region. • A shocked appearance NOTE In severe malaria the parasite count is well11-42 How is the diagnosis of malaria over 5% (hyperparasitaemia). The higher theconfirmed? count, the more severe the malaria. Metabolic acidosis may occur.1. Seeing the malaria parasites within red cells in a stained thick blood smear is 11-44 What is cerebral malaria? the traditional ways of confirming the diagnosis. Repeated smears may be needed This is the most dangerous complication of before malaria is excluded as the smear severe malaria as the brain is affected and can may be negative early in the infection. lead to rapid death. Young children, pregnant2. A blood test to detect malaria proteins women and people who are HIV infected are (rapid antigen test) is also useful in making particularly susceptible to cerebral malaria. a rapid diagnosis. It is very reliable and Each year many children die of cerebral available at primary care facilities in malaria in Africa. malarial areas of South Africa. Signs of cerebral malaria must always be3. It is very important to confirm the viewed with great concern: diagnosis of malaria as soon as possible. • Depressed level of consciousness, i.e. drowsy, unable to stand, confused or Most deaths due to malaria are caused by delayed unconscious diagnosis or late treatment. • ConvulsionsRemember that many other serious conditionsmay present with the same symptoms and signs Confusion is an important sign of potentially fatalas malaria, e.g. bacterial meningitis. Children cerebral malaria.may also have malaria plus another infection. NOTE In cerebral malaria the large numbers of parasites obstruct the normal blood flow to the11-43 How can you tell whether malaria is brain.uncomplicated or severe?In uncomplicated malaria the patient:• Has mild symptoms• Is fully alert and able to stand and walk
  • 10. PARASITES 19111-45 How is uncomplicated malaria In future intravenous artesunate will probablytreated? replace quinine as it is safer. Rectal artesunate is also an effective emergency treatment.Early and accurate diagnosis with urgenttreatment using the correct drugs is the key NOTE A loading dose of quinine 20 mg/kg dilutedto successful management. It is important in 5% dextrose water (10 ml/kg) must always beto differentiate uncomplicated from severe given as a slow infusion over 4 hours and never as a bolus. This is followed by 10 mg/kg 8 hourlymalaria. If possible all patients with malaria are intravenously. Change to oral quinine as soon asreferred to a hospital or clinic where the staff possible.are experience in treating malaria. They mustbe closely followed up for the first few days. Using a combination of drugs for bothPatients with confirmed malaria are usually uncomplicated and severe malaria is moretreated with coartemether (Coartem). Coartem effective and less likely to result in resistance inis a combination of two potent, rapidly acting the community than monotherapy (one druganti-malarial drugs which are well tolerated. only). The patient should improve clinically within 48 hours and the fever should settleFor uncomplicated malaria, one dose of within 5 days.Coartem should be taken immediately, thenagain after 8 hours, followed by a twice daily 11-47 How is malaria prevented?dose for the next 2 days. Each dose is 1 tabletif 10–14 kg, 2 tablets if 15–24 kg, 3 tablets if 1. Pregnant women and young children should25–34 kg and 4 tablets if 35 kg or more. Best not enter a malaria areas if at all possible.taken with food. 2. Mosquitoes usually bite in the early evening and early morning. Therefore, stayDrug resistance is a major problem with indoors with screens over windows andmalarial treatment. Most strains of malaria doors or wear light coloured clothes, longare now resistant to chloroquine alone or in sleeves and trousers with shoes and sockscombination with other drugs. Paracetamol in the evenings and early mornings.is best for reducing the fever. Make sure the 3. Use a bed net impregnated with insecticidepatient is taking enough fluids. (pyrethroid) at night.Uncomplicated malaria can also be treated with 4. Use insect repellent on the skin and clothesoral quinine. However, there are some serious or burn repellent coils or pads or sprays atside effects of quinine, e.g. myocardial toxicity. night. NOTE The dose of oral quinine is 10 mg/kg 8 hourly 5. Antimalarial drug prophylaxis is for 7 days PLUS clindamycin 5 mg/kg 8 hourly for 7 recommended for short visits to a malaria days or doxycycline (if over 8 years of age) 4 mg/kg area. immediately then 2 mg/kg daily for 7 days. 6. By reducing the number of mosquitoes.The quinine tablets are very bitter but can be Preventing mosquito bites is more effectivecrushed and taken with jam, or mashed banana. than prophylaxis. Usually both are needed.11-46 How is severe malaria treated? Preventing mosquito bites is the most effectiveSevere malaria is usually treated with way of avoiding malaria.intravenous quinine PLUS oral doxycycline(if over 8 years) or clindamycin (oral, 11-48 What malaria prophylaxis isintramuscular or intravenous in younger recommended?children). Intravenous drugs must bestarted immediately and the patient urgently Malaria prophylaxis is needed by all who enterreferred to hospital. Look for and manage a malaria area (a region where malaria occurs),hypoglycaemia, shock or convulsions. even if it is only a one day visit. The risk of
  • 11. 192 PARASITESbecoming infected by malaria is particularly CASE STUDY 1high in the rainy season when mosquitoes arecommon. Full compliance is very important. A mother brings her 5-year-old son to theHowever, prophylaxis is never 100% effective. clinic because he has passed 2 roundworms1. Malanil or malarone (atovaquone plus with his stool. He is generally well but the proguanil) for children of 10 kg or more. It mother complains that he scratches his anus at is well tolerated but expensive. night which keeps him awake.2. Mefloquine (Larium) for children of 5 kg or more. 1. How do children get roundworms?3. Doxycycline for older children (over 8 years). They ingest the roundworm eggs after playing in sand or soil. If human faeces are notIt is best for all children under 5 years, disposed of correctly they can contaminateespecially children under 5 kg, not to enter a soil in the village, garden or playground. Eggsmalaria area as they are at high risk for severe can survive for years in soil and may alsoinfection. Chloroquine alone, chloroquine contaminate pools of water or raw vegetables.with proguanil, and Coartem should not be This is a common public health problem.used for prophylaxis. NOTE Malanil daily ¼ tablet if 5–20 kg, ½ tablet 2. Can roundworms cause clinical if 21–30 kg, ¾ tablet if 31–45 kg and 1 tablet if problems? over 45 kg starting one day before entering and stopping one week after leaving a malaria area. Usually not. However, with heavy infections Mefloquine weekly ¼ tablet if 5–20 kg, ½ tablet children may complain of abdominal if 21–30 kg, ¾ tablet if 31–45 kg and 1 tablet if pain or discomfort and lose their appetite. over 45 kg starting one week before entering and Roundworms can cause bowel obstruction or stopping 4 weeks after leaving a malaria area. block a bile duct. The larvae of roundworms Doxycycline 100 mg daily starting 1 day before pass through the lungs and can cause entering and stopping 4 weeks after leaving a coughing and wheezing. malaria area.Seasonal Intermittent Treatment of children 3. How should this child be treated?in malaria regions decreases the incidence ofclinical malaria. With a single oral dose of mebendazole or albendazole. The mother should be told how to avoid reinfection.11-49 How can the number of mosquitoesbe reduced? 4. Is routine deworming recommended for1. By reducing the mosquito population all children? with the use of controlled spraying around homes with insecticides. This is done by A deworming programme is recommended in state-employed teams. regions where roundworms are common.2. By reducing pools of water where mosquitoes can breed. 5. What is a common cause of perianal itch at night in children? NOTE Malarial mosquitoes have become resistant to many insecticides. The controlled use of DDT Pinworms. These are short worms that infect is very effective but remains controversial due to the gut and leave the anus at night, causing the risk of environmental pollution and dangers irritation to the skin around the anus. They to other animals and possibly the newborn infant. can also cause a vaginal discharge in girls.
  • 12. PARASITES 1936. How can the diagnosis be confirmed? 5. Can tapeworms affect the brain?A strip of Sellotape should be stuck onto the Yes. If eggs of the pork tapeworm are passedchild’s skin over and next to the anus and then in human faeces and then later get swallowedimmediately removed. Pinworm eggs will stick by another human rather than a pig, theyto the Sellotape. These can then be seen under can hatch in the gut of that person and thena microscope. The treatment is the same as for travel in the bloodstream to the brain whereroundworms. they form many small cysts. This is called neurocysticercosis and usually presents with convulsions. Neurocysticercosis is common inCASE STUDY 2 communities where there are pigs and human faeces are not disposed of safely.A malnourished child from a rural villagepresents at the local clinic after passing a piece 6. What problems can be caused by the dogof tapeworm in her stool. Pigs run free and eat tapeworm?human faeces. There are also a number of dogs If eggs of the dog tapeworm are ingestedin the village. by humans they hatch in the gut, enter the bloodstream and are carried to organs such as1. What are the common types of the liver and lungs where they grow into largetapeworms in children? (hydatid) cysts. Therefore it is important thatThe pork or beef tapeworms. Pig tapeworms children do not play in areas where dog faecesare more common. are left to mix with the soil or pools of water. Hydatid disease can be treated with oral daily2. What is the clinical presentation of mebendazole or albendazole for 6 weeks.tapeworms? Large cysts may have to be removed surgically.Infected children are often asymptomatic.However, tapeworms can cause poor appetite,abdominal discomfort and weight loss. This CASE STUDY 3child’s malnutrition may be partly explainedby the tapeworm. A month after returning from holiday on a farm in the Eastern Cape, a 14-year-old child3. How did this child get infected with a presents with a 3-week story of loose stools,tapeworm? and terminal haematuria for 2 days. While on holiday he swam in a farm dam.Probably by eating uncooked or partiallycooked pork. Tapeworm eggs get passed in the 1. What is the common cause of terminalstool and then may be eaten by pigs if toilets haematuria?are not available. The eggs hatch in the pig’sgut and then travel in the bloodstream to the Blood in the urine towards the end ofmuscles where they form cysts. If these cysts in micturition is typical of bilharzia. The bilharziathe meat are eaten by humans, they hatch out parasite settles in the wall of the bladder wherein the gut to form a tapeworm. it causes inflammation and bleeding.4. What is used to treat intestinal 2. When did the infection probably occur?tapeworms? When he swam in the farm dam. The specialOral mebendazole twice daily for 7 days. bilharzia snail is common in the eastern parts of South Africa where it lives in standing or slow-moving water such as farm dams or
  • 13. 194 PARASITESirrigation furrows. If someone with bilharzia indicates severe, probably cerebral malaria.passes urine into the water the snails can Malaria can progress from uncomplicated tobecome infected. The parasites released from severe within hours if not treated.the snails can then penetrate the skin ofanyone walking or playing in the water. 3. How can the diagnosis be confirmed? By examining a blood smear or performing a3. Can bilharzia be treated? malaria rapid antigen test.Yes. It can be treated very effectively withpraziquantel. It is best to first confirm the 4. What is the correct treatment?diagnosis by seeing bilharzia parasites ina urine sample collected around midday. She must be admitted to hospital urgently asChronic bilharzia infection can lead to damage cerebral malaria can be fatal. She needs to beof the urinary system causing renal failure. treated with intravenous quinine plus either doxycycline or clindamycin. Uncomplicated malaria can be adequately treated with oral4. What is the probable cause of the Coartem provided the clinical diagnosis hasdiarrhoea for the past 3 weeks? been confirmed.The child may have a bowel infection withgiardia, which causes diarrhoea. Although it 5. How can malaria be prevented while onis often acute it may last for weeks or months. holiday?Giardia is common where a safe water supplyand adequate toilets are not present. The only way to confidently avoid malaria is not to enter a malaria area. However, malaria can usually be avoided by making efforts not5. Which drug is used to treat giardiasis? to be bitten by mosquitoes and by takingMetronidazole (Flagyl). malaria prophylaxis. Insecticide impregnated bed nets are very effective. Also keeping indoors after sunset with mosquito screens onCASE STUDY 4 the door and windows. Wear long trousers and sleeves, and shoes and socks if going out in theTwo weeks after returning from a malaria area, evening or early morning, when mosquitoesa 10-year-old child presents with headache, are most active.shivering and vomiting. The mother gave hersome paracetamol for the fever. A few hours 6. What malaria prophylaxis should belater the child becomes confused and cannot taken?stand up. The family did not take malarial The choice is atovaquone and proguanilprophylaxis because they planned to be in the (Malanil) for children of 10kg or more, orarea for 2 days only. mefloquine (Larium) for children of 5 kg or more. Children over 8 years can also use1. Do you think this child has malaria? doxycycline. The medication must be takenYes. Malaria has an incubation period of 1 to correctly, including for the correct period after2 weeks and presents with fever and a flu-like leaving the malaria area. Prophylaxis must beillness. taken even for a one day visit.2. How severe is the infection?At presentation it was uncomplicated, withfever and vomiting. However, within hoursshe was confused and could not stand. This