Malaria and the Dental Hygienist

Malaria is a parasitic disease of the blood that is transmitted to animals, including humans, by infectious mosquitoes. Advances in tropical medicine research and vector eradication efforts have provided data about mosquito breeding habitat, effective avoidance behaviors, and anti-malarial drugs. Regardless of these advances, malaria remains a significant global public health problem.^1-3 Currently, more than 50% of the global population is at risk of malaria infection (Figure 1).^1,2 Each year approximately 500 million clinical malaria episodes occur with more than 1 million resultant deaths.^1-3 Most of the morbidity and mortality affect vulnerable populations such as children younger than age 5, pregnant women, and those who are HIV positive or have tuberculosis.²

Malaria infections are spreading into previously uninfected geographical regions due to a myriad of factors including a growing population and increased drug resistance.² Given the increasing threat of malaria infection, health care providers— regardless of discipline—need to collaborate to eliminate global malaria. Dental hygienists have a role in recognizing and managing the oral implications of malaria.

TRANSMISSION

Although malaria parasites can be transmitted by blood transfusions and contaminated needles or syringes, parasites are typically transmitted through the bite of the female Anopheles mosquito.² During the bite, the mosquito takes a blood meal and injects parasites into the new host’s bloodstream via the saliva.² Anopheles spp. transmits four species of human-specific parasites belonging to the genus Plasmodium.² Each of these species (P. falciparum, P. vivax, P. ovale, and P. malaria) enter the human body in a similar fashion but differ in their liver duration periods, the symptoms they produce, the drug therapies they respond to, and their resulting mortality rates.² P. falciparum has the highest mortality rate and accounts for 80% of all human malarial infections.^1,2

Upon entering the body, these parasites receive chemical cues that allow them to rapidly enter cells of the host’s liver. Without causing any pathology to the liver, the Plasmodium parasite multiplies and develops into a blood stage once again.^2,3 Depending on the species, it will remain in the liver for 6 days to 1 year before reentering the bloodstream.³ Through recognition of cell surface receptors, the parasites invade the nutrient-rich red blood cells. In this stage, the parasites are able to grow and multiply rapidly, invading new red blood cells every 48 hours to 72 hours until the host literally contains billions of parasites. Consequently, the swollen red blood cells burst and the parasites and their toxic metabolic byproducts are released into the host’s bloodstream, inducing many of the symptoms of clinical malaria.³

SYSTEMIC SYMPTOMS

People with malaria typically do not have persistent symptoms but rather cyclic periods of fever, chills, and sweating. Signs and symptoms of malaria infection correspond to the synchronous invasion and bursting of parasite-infected red blood cells. During this cyclical infection process, the host’s body temperature rises and fever results. After the red blood cells burst, body temperature drops, inducing the chills that characterize a malaria infection. In severe cases of malaria there is acute spread of the disease to the brain.^2,4,5 Cerebral malaria causes impaired consciousness, seizures, coma, and death.^2,4 Pregnant women and their unborn children are more vulnerable to the disease due to an already compromised immune system and because maternal malaria increases the risk of spontaneous abortion, stillbirth, premature delivery, and low birth weight.⁵ Other reported symptoms include jaundice, anemia, sweating, fatigue, headache, dizziness, nausea, vomiting, abdominal cramps, chipped or broken teeth (in cerebral malaria), loss of appetite, dry cough, muscle or joint pain, and back ache.^2,5

AT RISK POPULATIONS

Individuals most at risk of malaria infection are those who live in or travel to countries where there are malaria-infected people and malariainfected mosquitoes. Malaria is widely present in Central and South America, sub-Saharan Africa, the Indian subcontinent, Southeast Asia, the Middle East, and Oceania.⁶ Specific risk assessment depends on an individual’s travel itinerary, local weather conditions, the presence of the Plasmodium species and abundance of Anopheles mosquitoes in the area, and the level of malaria drug resistance in a geographical region.^2,4

Malaria infection can also be brought into an area by an infected person, which is known as imported malaria. Malaria can be imported by refugees, migrant workers, international business professionals, and tourists.⁷ In the United States, most malaria infections originate due to travel in areas with active malaria transmission, exposure to infected blood products, by congenital transmission, or through exposure to mosquito transmission.⁴ Concurrent conditions associated with malaria include HIV, mycobacterium infections, malnutrition, and anemia.^2,5

ORAL MANIFESTATIONS

Oral symptoms are due to the systemic effects of the disease as well as the side effects of prescribed medications and traditional treatments. High fevers seen in individuals with malaria cause xerostomia and dehydration.² Clinical signs may include oral dryness; tongue sticking to palate; difficulty with mastication, swallowing, or speech; impaired taste; thirst; licking of lips; and burning and soreness of the mucosa and tongue.⁸ A lack of saliva and its associated immunoglobulins, electrolytes, and protective benefits can contribute to discomfort, difficulty eating and swallowing, and increased risk of caries. Untreated xerostomia increases oral biofilm development, which causes gum disease, tooth loss, and caries.⁸

Xerostomia symptoms can be minimized with over-the-counter products such as saliva substitutes, saliva stimulants, dentifrices, spray, gels, lozenges, mouthrinses, and a few behavior modifications. Since xerostomia places patients at an elevated risk of caries, prescription 1.1% NaF toothpaste at 5,000 ppm is particularly effective since it contains a built-in cleaning system and can be used once daily to promote tooth remineralization.⁸ Products containing amorphous calcium phosphate (ACP), casein phosphopeptide-ACP (CPP-ACP), and calcium sodium phosphosilicate may help remineralize enamel in patients who have xerostomia.⁸ Chewing xylitol-containing gum and/or consuming xylitol-containing lozenges to stimulate the salivary glands and inhibit the growth of Streptococcus mutans can also be helpful. Patients may find relief in sucking on ice chips or frequently sipping water throughout the day.⁸ Patients should also refrain from consuming alcohol and caffeinated beverages because both have a dehydrating effect on the body.

Malaria infection can cause severe anemia, which manifests as pallor of the tongue and buccal mucosa in the oral cavity.³ There are several causes of anemia in malaria patients, therefore, several oral manifestations of anemia exist.⁹ The following conditions may be found in patients who have malaria-induced anemia: mucosal pallor, angular cheilitis, erythema, atrotemphy of the oral mucosa, and loss of filiform and fungiform papillae on the dorsum of the tongue.⁹ Mucosa and other oral variations of anemia can occur when the malaria infection suppresses bone marrow stem cells, prohibiting the production of red blood cells and when nutritional deficiencies exist, for example, iron, folic acid, or vitamin B12, prohibiting the normal development of red blood cells.⁹ Once the anemia diagnosis is made, the dental hygienist can provide nutritional counseling on iron-rich foods and accurately record sites of pallor or other changes in the mouth.

Malnutrition and anorexia may also be present in patients who have acute malaria, which predispose them to malodor and coated tongue.² Dental hygienists should accurately record oral findings of these conditions and refer to a physician for further diagnosis. These oral manifestations will clear once the causative malnutrition or anorexia is treated. Nutritional counseling can also be provided as needed.

Patients with cerebral malaria experience episodes of febrile convulsions, which may cause trauma to the teeth and surrounding structures.² In some cultures, objects may be forced into the mouth to prevent clenching of the teeth or hot teas and bovine urine are used to treat the seizures.² These unusual treatments can cause chemical stomatitis and other oral lesions.² In these instances, dental hygienists need to provide education to patients and caregivers about the cause of the lesion; provide palliative care, such as use of appropriate and recommended healing agents on active lesions, eg, antibiotic ointments, anti-fungal, or burn creams; and properly cover or protect lesion sites by avoiding finger and tongue contact to reduce cross-contamination.¹⁰ For lesions caused by burns, the severity of the burn first needs to be determined. For small first degree and second degree burns, dental hygienists can apply cold compresses but no ice.¹⁰ Blisters from burns should not be opened. If blisters do open on their own, they should be gently cleaned with a mild antiseptic and covered with gauze or sterile bandage.¹⁰ Third degree burns should be managed by a physician and monitored for infection.¹⁰ Any oozing should be clear—yellow or greenish discharge and redness around the burn can be a sign of infection.¹⁰ In all instances dental hygienists should accurately record lesions, including the size, shape, color, history, and consistency of the lesion, and refer the patient to the proper health care provider based on collective data.

Oral candidiasis or thrush is an infection of yeast fungus found in immunocompromised patients; individuals taking certain medications, mainly antibiotics; pregnant women; and newborn babies.¹⁰ Clinical symptoms include white, cream-colored, or yellow spots in the mouth, most often first evident on the dorsal part of the tongue.^9,10 The spots are slightly raised and asymptomatic. The lesions do not slough and if scraped will bleed slightly.^9,10 Oral candidiasis lesions should resolve with topical and/or systemic antifungal treatments.^9,10

Cancrum oris or noma is a gangrenous infection of the mouth that mostly affects already malnourished and ill children, most commonly from 1 year to 4 years of age.^2,11 Malaria, measles, diarrhea, tuberculosis, and necrotizing ulcerative gingivitis are common diseases that weaken the immune system and can precede noma.¹¹ Therefore, patients with malaria infection should have an intra- and extra-oral examination to determine if clinical signs of noma exist. Some documented initial signs are extraoral tenderness, swelling, and localized increased temperature of an initial noma lesion, mild crusting of lips/corner of mouth, swollen lymph nodes, and an intraoral ulcer of buccal mucosa to mirror extraoral swelling.^11-13 A defining characteristic is a bluish tint to the tissues surrounding the noma lesion and crater-like erosion.^11,13 Patients with noma may have trismus or difficulty opening the mouth due to swelling and pain.^11,13 A panoramic radiograph should be taken to determine if any loss of primary teeth or damage to permanent tooth buds is present and to view any bony or fibrous alkalosis of the temporomandibular joint.^12,13 All of these structures in and around the oral cavity can be affected by the necrotizing progression of noma.

ORAL TREATMENT

There is no vaccine against malaria; individuals can only practice preventive behaviors and take recommended drugs to aid in preventing and/or managing malaria infection. Avoidance behaviors include: using indoor/outdoor residual sprays, eliminating water breeding grounds, using personal protection, using insecticidetreated bed nets, and avoiding mosquito biting prime times—particularly dusk and dawn.¹⁴ Suppression includes using antimalarial drugs. The drugs do not prevent initial infection through a mosquito bite (as a topical spray should) but instead prevent the development of malaria parasites in the blood.¹⁴

The seriousness of malaria is exacerbated by the spread of drug-resistant parasites.¹⁴ Therefore, recommended antimalaria medicines may be different due to availability, travel destinations, and durations or individual tolerance of the drug. See Table 1 for more information about the clinical implications of commonly prescribed anti-malarial medications.

PREVENTIONS STRATEGIES

Dental hygienists should emphasize to patients receiving treatment for malaria that they must precisely follow anti-malaria treatment therapy doses and schedules, including advising against cutting pills in half or using only until symptoms disappear. When patients do not take the prescribed antimalarials as recommended, they increase the risk of treatment failure and potentially induce parasite resistance to the drugs. All medications must be used as prescribed.

Dental hygienists can also bring awareness to malaria transmission through contaminated needles by promoting prevention strategies. Needles should never be reused, manipulated, or bent, and should be disposed of and handled in order to prevent injury and cross contamination.¹⁰ Health care workers should use the “scoop method” when recapping needles by using one hand to slide the needle end into the needle cap. Used needles should always be disposed of in a designated puncture-resistant sharps container.^10,12

Because malaria is a worldwide disease affecting millions of people, more research is needed to further explore the oral signs and symptoms of malaria and associated diseases. Dental hygienists are well suited to aid in the research of malaria infections, their oral implications, and effective mouth care for individuals who have malaria.

As our society becomes more and more global, an increased awareness of the oral implications of malaria is necessary for managing oral manifestations of malaria and ultimately improving care for at risk populations.

REFERENCES

1. Breman JG, Holloway CN. Malaria surveillance counts. Am J Trop Med Hyg. 2007;77:36-47.
2. Owotade FJ, Greenspan JS. Malaria and oral health. Oral Dis. 2008;14:302-307.
3. Carlson JC, Byrd BD, Omlin FX. Field assessments in western Kenya link malaria vectors to environmentally disturbed habitats during the dry season. BMC Public Health. 2004;4:1471-1483.
4. Causer LM, Newman RD, Barber AM. Malaria surveillance—2000. MMWR Surveill Summ. 2002;51(SS05);9-21.
5. Lagerberg RE. Malaria in pregnancy: A literature review. J Midwifery Womens Health. 2008;53:209-215.
6. Centers for Disease Control and Prevention. Malaria Facts. Available at: www.cdc.gov/malaria/facts.htm. Accessed November 2, 2009.
7. Roll Back Malaria. Malaria in Africa. Available at: www.rollbackmalaria.org/cmc_upload/0/000/015/370/RBMInfosheet_3.htm. Accessed November 2, 2009.
8. Bartels CL. Xerostomia Information for Dentists. Available from: www.oralcancerfoundation.org/dental/xerostomia.htm. Accessed November 2, 2009.
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10. Wilkens E. Clinical Practice of the Dental Hygienist. 8th Ed. Philadelphia: Lippincott Williams and Wilkens; 1999:69-70,345-346,504- 508,702-766,915.
11. Enwonwu CO. Noma—the ulcer of extreme poverty. N Engl J Med. 2006;354: 221-224.
12. Darby M, Walsh M. Dental Hygiene Theory and Practice. Philadelphia: W.B. Saunders Company; 1995:219220, 674-676.
13. Auluck A, Pai KM. Noma: Life cycle of a devastating sore—case report and literature review. J Can Dent Assoc. 2005;71:757.
14. Barnes K, Watkins WM, White NJ. Antimalarial dosing regimens and drug resistance. Trends Parasitol. 2008;24:127-134.
15. Wynn R, Meiller T, Crossley H. Drug Information Handbook for Dentistry. 12th ed. Hudson, Ohio: Lexi-Comp Inc: 2006; 161-162, 320-321, 975-977, 1424-1425.
16. Pickett F. Terezhalmy G. Dental Drug Refer ence with Clinical Implications. Philadelphia Lippincott Williams & Wilkins; 2006:297-298, 367-370.
17. Mosby’s Dental Drug Reference. 8th ed. Philadelphia: Mosby Elsevier; 2008:288-290,434-436.

From Dimensions of Dental Hygiene. December 2009; 7(12): 40-43.