Glossary

Medical Conditions


Amoebiasis - Parasite (Entamoeba histolytica) caused gastroenteritis most commonly affecting young to middle-aged adults. Often a problem for travellers to countries with poor sanitation.

Symptoms include : diarrhoea (may contain blood), stomach cramps, fever.


Avitaminosis - Chronic / long-term vitamin deficiency (sometimes due to a defect in metabolic conversion, such as tryptophan to niacin).

Deficiency caused conditions include : night blindness (vitamin A), beriberi (thiamine), pellagra (niacin), megaloblastic anemia (vitamin B12), scurvy (vitamin C), rickets / osteomalacia (vitamin D) and impaired blood clotting (vitamin K).


Beriberi - Thiamine (vitamin B1) is essential for digestion, metabolism and communication between nerves and muscles. Water-soluble vitamins like thiamine are not stored in fat and quickly pass through the body. Deficiency can occur within 14 days to a month if a proper diet is not maintained. Chronic deficiency at any age can affect the heart, muscles, gastrointestinal or nervous systems. Early signs and symptoms are abdominal discomfort, apathy, depression, fatigue, hoarseness, irritability, loss of appetite, memory loss, nausea, poor concentration, sleeping problems and weight loss. If left untreated, thiamine deficiency progresses to beriberi after approximately three months. A Sri Lankan word, beriberi means “I can’t, I can’t,” illustrating the condition's nature. Beriberi takes two forms : wet and dry.

Wet beriberi affects the cardiovascular (heart) system and causes body fluid retention and heart damage. Signs and symptoms : rapid heart rate, dilation of blood vessels, swelling of extremities due to fluid build up (especially in the legs), warm / moist skin, fluid in the lungs, shortness of breath at night / with activity, heart enlargement and eventually failure.

Dry beriberi affects the nervous and muscular systems. Generally caused by low calorie intake and sometimes called cerebral beriberi if the brain or central nervous system is affected. Signs and symptoms : decreased / exaggerated reflexes, difficulty standing / walking, drooping eyelids, inability to sense vibrations, involuntary / cyclical eye movements (nystagmus), language difficulties, muscle wasting (leading to loss of function or paralysis of the legs and arms), pain / tingling / numbness in hands and feet, vision changes, vomiting, mental confusion, seizures, coma and death.

Risk factors include : (a) processed diets such as white rice; thiamine is often removed during processing / boiling (or destroyed by overcooking), (b) chronic vomiting, appetite loss or diarrhea resulting in malnourishment / thiamine deficiency and (c) the body requires more energy (and therefore thiamine) to combat severe diseases such as malaria.

In most cases, symptoms of wet and dry beriberi overlap, and prolonged thiamine deficiency may result in paralysis, heart failure and death. With treatment, symptoms may show rapid improvement in the first 12 hours. Most neurological symptoms are completely reversed and heart function normalizes in the first few days. Over time, heart swelling and further damage can be controlled and may also be reversed. Memory problems may take months to respond and, depending on severity, recovery may be incomplete. Lack of treatment may result in permanent neurological damage or death.


Cholera - Disease caused by the bacterium Vibrio cholerae which is naturally found in brackish rivers and coastal waters. Cholera is common in many parts of the world, especially the Indian subcontinent and sub-Saharan Africa. People typically contract cholera after ingesting drinking water (surface / well water) or food contaminated with feces containing Vibrio cholerae. Raw or undercooked shellfish often transmit the bacteria too. Other sources include contaminated raw fruits and vegetables. Also, grains (e.g., rice, millet) contaminated after they are cooked and allowed to remain at room temperature for several hours.

Risk factors : (a) malnutrition, (b) reduced (hydrochlorhydria) or nonexistent (achlorhydria) stomach acid, (c) untreated Helicobacter pylori infection (stomach ulcer), (d) exposure to fecal matter from an infected person in the same housing, (e) immune system problems and (f) people with type O blood are much more likely to develop cholera (reason unknown).

The bacteria infect the intestine and produce a strong toxin called CTX which binds to the intestinal walls. Normal sodium and chloride flow is disrupted which induces the body to secrete enormous amounts of water into the intestines and cause diarrhea. The incubation period is from less than a day up to five days. Most people do not experience symptoms after they are infected, or have only a mild illness similar to influenza but continue to shed the bacteria in their stool for 7 to 14 days and remain infectious during that time. About 1 in 20 patients develop severe cholera (cholera gravis) with profuse, watery diarrhea as the major symptom. Often, this diarrhea is flecked with mucus and dead cells and has a watery milk appearance (often with a fishy odor). Vomiting is also common, and may persist for hours at a time. The diarrhea and vomiting can rid the body of a litre of fluid per hour. This rapid loss can lead to dehydration and death within two to three hours. Less severe cases can lead to death between 24 and 48 hours after symptoms first appear. The disease itself is usually highly treatable and responds well to oral rehydration. However, it quickly can become fatal if left untreated (up to 50 percent).

Signs of dehydration include: dry mouth, extreme thirst, irregular heartbeat (arrhythmia), irritability, lethargy, low blood pressure (hypotension), muscle cramps, reduced urine output, shriveled skin and sunken eyes. Severe dehydration is life-threatening and may lead to a condition known as hypovolemic shock. This occurs when low blood volume causes a drop in blood pressure that prevents enough oxygen from reaching the tissues. Without proper treatment, this type of shock can lead to death within minutes.

Potentially fatal complications include : (a) low blood sugar (hypoglycemia) causing seizures, unconsciousness and death, (b) low levels of potassium (hypokalemia) interfering with heart and nerve function, (c) kidney failure affecting filtering of blood (allowing fluids and wastes to build up in the body) and (d) some patients developing an intestinal ileus (blockage).


Conjunctivitis - Inflammation of the conjunctiva, the tissue that lines the inside of the eyelid that helps keep the eyelid and eyeball moist. The condition (also called pinkeye) is caused by a virus, bacteria, irritating substances, allergens or sexually transmitted diseases (STDs) such as chlamydia and gonorrhea. Pinkeye caused by bacteria, viruses, and STDs can spread easily from person to person. Patients recover fully from the illness. Eyes can become re-infected.

Symptoms : blurred vision, burning eyes, eye discharge (green or white), increased sensitivity to light, itchy eyes, large amount of tears, redness in the white of the eye / inner eyelid and yellow discharge that crusts over the eyelashes.

Preventing the spread of the disease : avoiding sharing common articles such as unwashed food utensils / cups, not touching or rubbing the infected eye(s) and washing hands often with soap and warm water.

Treatment : a) antibiotics as eyedrops, ointments, or pills (bacterial conjunctivitis), b) allowed to run its course (viral conjunctivitis), c) irrigating the eye (irritating substances), d) temporarily by applying a cold compress on closed eyes or with antihistamines (allergens) and e) ophthalmia neonatorum is usually spread during birth as the infant passes through an infected mother's birth canal. Newborns are usually given eye drops immediately to treat any possible infection (STDs).


Coral ear - Inflammation of the ear canal caused by water entering and activating fungal spores. The resulting secondary bacterial infection and inflammation can be very painful. It usually starts after swimming and was a very common complaint in the New Guinea theatre of war. Treatment with antibiotic eardrops is very effective.


Coryza - Word that describes head cold symptoms such as inflammation of mucous membranes lining the nasal cavity which can give the symptoms of nasal congestion and loss of smell. The source can be an infection, allergy, spicy food, cold wind or tender neck muscles.


Dengue fever - An infectious disease caused by any one of four types of dengue virus: DEN-1, DEN-2, DEN-3 and DEN-4 carried by infected striped Aedes aegypti (rarely Aedes albopictus) mosquitoes which feed during the day. Dengue is not contagious from person to person. Also called "break-bone" fever because it sometimes causes severe joint and muscle pain that feels like bones are breaking. Infection can be by at least two if not all four types at different times during the lifetime, but only once by the same type. Dengue fever is found mostly during and shortly after the rainy season in tropical and subtropical areas of Africa, Southeast Asia, China, India, Middle East, Caribbean, Central and South America, Australia and the South and Central Pacific.

The incubation period ranges from three to fifteen (usually five to eight) days. Symptoms include chills, severe headache, loss of appetite, low backache, nausea, pain upon moving the eyes, rash, reddening of the eyes, severe dizziness, vomiting, severe joint and muscle pain. The temperature rises quickly as high as 40° degrees Celsius, with relative low heart rate (bradycardia) and low blood pressure (hypotension). A flushing or pale pink rash comes over the face and then disappears. The glands (lymph nodes) in the neck and groin are often swollen. The dengue rash is bright red petechiae (1 to 2mm spots caused by broken capillary blood vessels) and usually appears first on the lower limbs and the chest 3 to 4 days after the fever begins (subsiding after 1 to 2 days); sometimes spreading to cover most of the body. The palms and soles may be bright red and swollen. A second rash can appear a few days later.

Symptoms of dengue hemorrhagic fever include all of the symptoms of classic dengue and marked damage to blood and lymph vessels with bleeding from the nose, gums, or under the skin, causing purplish bruises. This form can cause death.

Symptoms of dengue shock syndrome include all of the symptoms of classic dengue and dengue hemorrhagic fever. In addition, leaking of blood vessels, massive bleeding, shock from very low blood pressure, weak rapid pulse, cold / clammy skin, restlessness, vomiting blood, bloody diarrhea and coma. This is the most severe form of dengue.

Complications : dengue hemorrhagic fever and dengue shock syndrome can result in vascular (blood vessel) and liver damage.

There is no specific treatment for classic dengue fever, and most people recover within 2 weeks. Some, especially adults, may be tired and/or depressed for several weeks to months afterwards. Recovery is assisted with bed rest, drinking lots of fluids and fever reducing medications.


Dysentery - An infection of the colon (used to be called flux or bloody flux) caused by two main types of organisms. The most common is bacillary dysentery, or shigellosis, caused mostly by (a) Shigella dysenteriae (the most severe form), (b) Shigella flexneri, (c) Shigella boydii and (d) Shigella sonnei (the mildest form). Also, campylobacteriosis from Campylobacter species and salmonellosis from Salmonella enterica. The less common type is amoebic dysentery, or amoebiasis, (also called traveller's dysentery or Montezuma's revenge) which is caused by the parasite Entamoeba histolytica. It can cause liver infection and abscesses but most people with amoebiasis do not experience any symptoms and may carry the parasite for years.

The organisms invade the cells lining the large intestine, multiply and produce bloody, mucus-laden diarrhea. These microbes are passed through the stools, so contact with infected stool can transmit the disease to another person. They are spread through (a) person-to-person contact, (b) eating food contaminated by infected food handlers who do not wash their hands or when it is harvested from fields contaminated / fertilized with sewage, (c) drinking or swimming in water contaminated with sewage or having someone with dysentery bathe in it and (d) infected flies or cockroaches that come into contact with food.

The main symptom of dysentery is mild to severe diarrhea that may contain blood or mucus. Uncontrolled dehydration due to the diarrhea can make dysentery a fatal disease. Other symptoms may include abdominal pain / cramping / tenderness, fatigue, fever / chills, painful bowel movements (tenesmus), unexplained weight loss, nausea and vomiting. Shigellosis symptoms may appear within one to three days of exposure and may last for a week or more. Severe straining during bowel movements may cause rectal prolapse (the protrusion of part of the rectum through the anus). Additional complications may occur when dysentery toxins reach other body systems. Patients with shigellosis are susceptible to secondary bacterial infections of the blood and kidneys. Shigellosis patients with a specific gene are more likely to develop Reiter’s syndrome that may include arthritis (joint inflammation) and possibly inflammation of the urinary tract and eyes. In people with amoebiasis symptoms, the disease may spread from the large intestine to the liver, where it may cause abscesses. It may also eventually spread to the lungs and other organs.

Treatment includes replacing lost fluids and electrolytes to avoid dehydration (eg. intravenous (I.V.) fluids). Refeeding must allow for temporary lactose intolerance (can last for years). Patients usually recover fully from the illness.


Hookworm - Infestation affecting the small intestine and lungs caused by infestation with Necator americanus or Ancylostoma duodenale in humans. The disease is widespread in the moist tropics and subtropics. Walking barefoot in soil contaminated with faeces (the source of hookworm eggs and larvae) is the most common method of exposure.

The larvae emerge from passed eggs within 24 hours and molt once to an infective larval stage in another 24 hours. After molting, larvae are able to penetrate intact skin, where an itchy rash called ground itch may develop. The larvae migrate to the lungs via the bloodstream, enter the airways and cause coughing. After travelling up the windpipe, the off-white larvae are swallowed and attach to the wall of the small intestine to feed on the host's blood. A N. americanus adult consumes approximately 0.3 mL of blood / day and the A duodenale consumes approximately 0.5 mL of blood / day. Males are 8 to 11 mm, and females are 10 to 13 mm in length. Eggs start to be excreted in the faeces 6 to 8 weeks later. The lifespan is up to 5 years for N. americanus and up to one year for A. duodenale.

Symptoms include abdominal tenderness, blood in the stool, bloody sputum, coughing, diarrhea, fatigue, fever, itchy rash (at point of entry; usually the feet), loss of appetite, nausea, pale conjunctiva and pallor (anaemia related), tachycardia (anaemia related) and vomiting. There may be no symptoms at all and most people have no symptoms once the intestines are infected.

Complications : anemia (secondary to loss of iron into the gut), ascites (abdominal fluid retention), nutritional deficiencies and severe protein loss.

Complete recovery occurs if treatment is given before serious complications develop. The infection is easily eradicated with treatment.


Malaria - A serious disease (also called Paludism, Plasmodium Infection or Jungle Fever) that can be fatal and is most often found in areas with low altitudes, warm temperatures and high humidity. These offer the best breeding conditions for the mosquitoes that spread the disease. The disease is endemic to more than 100 tropical and subtropical countries and infects 300 million to 500 million people each year according to the World Health Organization (WHO). Of those infected, WHO estimates more than 1 million die each year. Benign Tertian malaria was referred to as Malaria BT in World War 2.

There are five species of Plasmodium parasites that infect people and cause malaria. Each affects the body in different ways and more than one may be present at a time. (a) Plasmodium falciparum causes the most malaria-related deaths. Symptoms develop suddenly and can be severe. It is found throughout much of Africa, Southeast Asia, Oceania (the islands of the Pacific Ocean) and South America. (b) Plasmodium vivax, the most widespread, is found throughout tropical Asia, Central America, the Middle East and India. After infection, it may become dormant within the liver for intervals of up to two years. Even with treatment, this species may cause relapses for several years. (c) Plasmodium malariae symptoms are usually mild but may take years or decades to appear. It is found in parts of Africa and Asia. This species is also known to cause a severe kidney disease known as nephrotic syndrome. (d) Plasmodium ovale infection is rare and mainly occurs in West Africa. It can remain dormant in the liver for years. (e) Plasmodium knowlesi was once believed to only infect monkeys but human infections have been reported in Malaysia and Thailand. It causes more severe disease than Plasmodium malariae.

The life cycle of the single-cell Plasmodium parasites depends on moving between mosquito and human hosts. The parasite moves from an infected person to a mosquito while the insect is feeding. Inside the mosquito, it moves from the gut to the saliva where it can infect the next person bitten. Following a bite, Plasmodium moves through the bloodstream to the person’s liver. Depending on the species, it may stay dormant or begin to multiply inside the liver cells. If the parasite multiplies, it eventually causes the infected cell to burst. The offspring then move into the bloodstream where they infect red blood cells and can also be transmitted through additional mosquito bites. Within red blood cells, the parasites consume proteins and hemoglobin and continue to multiply. Eventually the cell ruptures and the parasites move on to infect others. This cycle continues and causes relapses of symptoms every two to three days. It only stops with medical treatment or a response from the body’s immune system. Repeated infection allows the body to develop partial immunity or resistance to the disease but this immunity fades without continued exposure to the parasite.

After an incubation period of 10 to 16 days, the disease typically progresses from chills (possibly with headache, nausea and vomiting) to fever to profuse sweating. Other possible symptoms include muscle aches, fatigue, anemia and jaundice (yellowing of the skin). Depending on the species, symptoms may fade but will usually recur. Those caused by Plasmodium falciparum often continue and may cause severe complications, for example, kidney failure, coma and death. The disease is called cerebral malaria when it affects the brain and central nervous system and can be fatal without treatment. Early diagnosis of malaria is important for proper treatment and anyone suffering from flu-like symptoms within a year of visiting an area where malaria is endemic should consult their physician. Doxycycline works against all types of malaria and may be used by people traveling to Thailand, Myanmar or Cambodia.


Mokkas - Small mites of the scabies family that burrowed under the soldiers' skin. A road clearing on Bulldog-Wau Road, New Guinea at the twenty three mile point was known as Mokka's Roost as it was infested with them.


Pellagra - Vitamin B3 deficiency disease (Italian word for “rough skin”) caused by dietary lack of niacin (B3) and protein (especially proteins containing the essential amino acid tryptophan). Tryptophan can be converted into niacin, so foods with tryptophan but without niacin (eg. milk), prevent pellagra. However, if dietary tryptophan is diverted into protein production, niacin deficiency may still result. Tryptophan is found in soybeans, meat, poultry, fish and eggs.

The condition is common where the main food staple is maize (corn) since untreated corn is a poor source of both niacin (vitamin B3) and tryptophan. Alkali treatment of the corn with lime (nixtamalization) corrects the niacin deficiency.

Symptoms include : aggression, alopecia (hair loss), ataxia (shaky gait), confusion, dermatitis, diarrhea, edema, emotional disturbances, insomnia, odours intolerance (leading to nausea and vomiting), paralysis of extremities, peripheral neuritis, restlessness, skin lesions (red), smooth / beefy red glossitis, sunlight hypersensitivity, weakness and eventually dementia.

Untreated, the disease can kill within four to five years. Treatment is with niacin (usually as niacinamide).


P.U.O. - Pyrexia (fever) of unknown origin or cause.


Sandfly fever - Virus transmitted by the female bite of the midge Phlebotomus papataci. The midges breed in rubble, cracks in walls and dugouts. Bites occur during the night and early morning. Also called Pappataci Fever or Phlebotomus Fever, it is endemic to Mediterranean lowlands of tropical and subtropical countries which have long periods of hot and dry weather. It is not fatal and has no serious long term effects.

The incubation period ranges from three to six days before symptoms suddenly appear. Body temperature rises abruptly to between 102 and 104 degrees Farenheit for two to four days (sometimes longer).

Symptoms include : anorexia, chills, conjunctival infection, general aching of the limbs and back, malaise, nausea, severe frontal and retro-orbital headache, sore eyes and very painful eye movement. Sometimes occipital pain, stiffness in the neck, throat congestion and vomiting. Depression, weakness and weight loss are common effects that can last for weeks.


Scabies - Small mites that burrow under the skin (for example, Mokkas).


Septic arthritis - Infection and inflammation of a joint (arthritis) usually caused by bacteria but viral, mycobacterial, and fungal arthritis occur occasionally. The protective synovial membrane of the joint must be bypassed before infection can happen either by bacteria carried by the bloodstream or an injury / condition that penetrates into the joint. Several joints can be affected at the same time.

Bacteria that can cause the condition are : (a) Staphylococcus aureus (most common cause in adults), (b) Streptococci (2nd most common cause), (c) Neisseria gonorrhoea (young adults) and (d) Escherichia coli (the elderly, IV drug users and the seriously ill).

Treatment is intravenous antibiotics, analgesia (pain relief) and washout/aspiration of the joint.


Tropical ulcers - Lesions caused by a variety of microorganisms and in many instances by the bites of insects and pyogenic infections. They frequently develop on existing abrasions, sores or even scratches. Tropical ulcers (also called Aden Ulcers, Jungle Rot, Malabar Ulcers or Tropical Phagedena) are seen throughout the tropics and subtropics; particularly during the rainy season.

Ulcers can occur on any exposed parts of the body after minor trauma. However, the vast majority of the tropical ulcers occur below the knee (especially around the ankle). Lesions begin as inflammatory papules that progress to vesicles and rupture to form an ulcer. Tropical ulcers are very painful.

Risk factors include : poor health, indequate footwear, malnutrition, poor hygiene and untreated ankle / leg skin breaks.

Complications include : chronic ulceration, deep tissue invasion (often involving bone and potentially leading to amputation) and infection (for example, Tetanus and osteitis).

Treatment with Penicillin is usually sufficient in the early stages.


Typhoid fever - Salmonella typhi bacteria caused disease (also called Salmonella Typhi Infection, Typhoid or Enteric Fever) spread by contaminated foods, water or fluids. Healthy people can become infected after consuming food or beverages handled by a person who is shedding the bacteria (e.g., if that person’s hands are not thoroughly washed after coming into contact with feces). Sewage containing Salmonella typhi may also contaminate water used for drinking or washing food. The bacteria quickly multiply in the body and spread from the intestines to the bloodstream. They may affect the liver, lymph nodes, spleen and gallbladder. The incubation period is usually one to three weeks after exposure. In some cases, symptoms may take as long as two months to appear.

The bacteria only live in humans and sometimes continue to live on in people even after recovery. About 5 percent of people who contract the illness become carriers and may exhibit no signs of illness. Carriers as well as people actively infected with typhoid fever shed the bacteria in their stool. Occasionally, bacteria may also be present in the urine.

Sustained fever is the primary symptom and typically runs as high as 39 to 40 degrees Celsius. During the second week of the fever, some patients also develop a flat, rose-colored rash that appears mostly on the abdomen and lower chest in the form of spots approximately 6mm in diameter. They usually go away without treatment after a few days. The illness usually resolves in 2 to 4 weeks with treatment. Left untreated, typhoid fever can be fatal or may last for weeks or months.

Other symptoms include : abdominal tenderness, bloody stools, chills, confusion, constipation (then diarrhea), difficulty concentrating, fluctuating mood, hallucinations, lethargy, loss of appetite, nosebleed, severe headache, weakness, weight loss and general discomfort, uneasiness, or ill feeling (malaise). As the disease progresses, fever may increase, diarrhea may become prominent and patients may become profoundly fatigued, agitated and delirious.

Up to 20 percent of patients with untreated typhoid fever may die from complications which include : intestinal hemorrhage (bleeding), intestinal perforation, kidney failure and inflammation of the lining inside the abdomen (peritonitis).


Typhus - An infectious disease (also known as historic typhus, European typhus, jail, war, petechial, hospital, putrid, famine, camp or ship fever). It is currently prevalent in mountainous regions of Africa, South America and Asia. Typhus is a Greek word meaning "cloudy" or "misty" and refers to the patient's lethargic state of mind.

Typhus is spread by : (a) human lice infected with Rickettsia prowazekii (epidemic typhus) and (b) fleas on rats infected with Rickettsia typhi (murine or endemic typhus). Scrub typhus is spread by harvest mites (on humans or rodents) infected with Orientia tsutsugamushi and is actually classed in the spotted fever group (despite the word "typhus" in the title). The information below refers to epidemic typhus only (which is a life-threatening illness even for young, previously healthy persons).

The human body louse Pediculus humanus corporis acquires Rickettsiae prowazckii while feeding on people who are infected. A person infested with infected lice contracts typhus when the lice or the Rickettsiae prowazckii present in the louse feces are rubbed into itchy lice bite wounds or other skin abrasions. Epidemics commonly occur in cold climates where people live in overcrowded unsanitary conditions with few opportunities to change their clothes or bathe. Typhus eventually kills the louse but the bacteria can survive in the dried louse feces for many days.

Symptoms appear suddenly after a one to two week incubation period and include : intense headache, chills, sustained high fever (up to 39 degrees Celsius), coughing, severe muscle pain, sensitivity to light, stupor and delirium. A rash develops on the fourth to seventh day of disease. It first appears on the upper trunk and then becomes generalized, involving the whole body except the face, palms, and soles. The early rash is a light rose color and fades when you press on it. Later, the rash becomes a dull red and does not fade. People with severe typhus may also develop petechiae (1 to 2mm red or purple spots caused by broken capillary blood vessels). Stupor to coma usually is next, particularly in untreated patients. In patients with severe disease, hypotension (low blood pressure) and kidney failure are common. Symptoms usually last 2 - 3 weeks.

Intravenous fluids and oxygen may be necessary. Without treatment, death may occur in 10 - 60% of patients. When treatment is promptly received, the patient is expected to fully recover. Complications may include kidney problems, pneumonia and central nervous system damage. Persistence of Rickettsia prowazekii after recovery can cause a relapse with milder symptoms (Brill-Zinsser disease).