6		Flying and Health

Health and Flying 6

Caffeine is a diuretic and can increase the risk of dehydration, particularly when relative humidity is low. Caffeine is found in the blood only 10 minutes after ingestion and has a halflife of approximately 4 hours.

Regular intakes of caffeine over a long period can lead to:

•Ulcers and other digestive disorders.

•Increased risk of cardiac arrest.

•Hypertension.

•Personality disorders.

•Chronic muscle tension.

•Insomnia.

•Disorientation.

•Hyperactiveness (especially in children).

The withdrawal symptoms (normally 12 - 16 hours after last dose) are:

•Irritability.

•Sluggishness.

•Headaches.

•Depression.

•Drowsiness.

•Lethargy.

•Occasional nausea and vomiting (in the more serious case).

The approximate contents of caffeine sources are shown below:

	Caffeine content (mg)
Cup of brewed coffee	80 - 135
Cup of instant coffee	65 - 100
Cup of decaffeinated coffee	3	- 4
Cup of espresso coffee	100
Cup of black tea	30	- 70
Average 12 oz can of Cola	30	- 60
Bar of dark chocolate	30
Average cold relief tablet	30
Can of 7Up		0

It is recommended that the absolute maximum caffeine limit of approximately 250 - 300 mg (2 - 3 cups of coffee) a day should be rigorously respected by aircrew.

Psychiatric Illnesses

Serious forms of psychiatric illness associated with loss of insight or contact with reality - a psychosis such as bipolar disorder (manic depression) or schizophrenia - will always result in the permanent loss of a flying licence.

106

Flying and Health		6

There are less serious mental states of the neurotic type - anxiety states, phobic states, depression, or obsessional disorders which are treatable by drugs or counselling. Whilst these disorders are active or under treatment they, too, will be a bar to flying.

After successful treatment, however, when in good health and off all drug treatment most pilots will be able to return to flying duties.

TropicalDiseasesandMedicalHazards(includingHepatitisandDiabetes)

Aircrew are responsible for arranging their own vaccinations against the communicable diseases. If travelling for the first time to areas where these may be found, a medical brief should be arranged prior to travel. Although the list below covers the most important medical hazards which may be encountered, it is far from complete.

Note: Approximately two thirds of the cabin air in modern airliners is recirculated which can in itself cause health problems such as Legionnaires disease and be associated with the spread of other infections/diseases.

Malaria

Malaria is still considered as one of the world’s biggest killers. It is responsible for the death of about 1 million infants and children every year in Africa.

The symptoms include recurrent cyclic fever, uncontrolled shivering and delirium and must be treated in hospital.

Over the years, too much reliance has been placed on antimalarial tablets which are providing less and less protection. The only sure way to stop catching malaria is to avoid being bitten by the mosquitoes which carry the protozoa responsible for the disease. The individual should wear long trousers and long sleeves in the evening, when the insects are active. When in air conditioned rooms, avoid opening the windows and always spray the room before retiring. If mosquito nets are provided - use them.

Should antimalarial prophylaxis be taken, the treatment should generally start a week before departure to an area where malaria is endemic and continue throughout the stay and for 4 weeks after leaving. Advice from an aviation medical specialist should be sought as to the choice of prophylactic drugs to be taken.

Tuberculosis

Tuberculosis (an airborne contagion) has made a dramatic return. This potentially fatal disease was virtually extinct in the developed world and was believed to be under control in other countries. However, in recent years there has been a great upsurge in the disease in many parts of Africa and other developing areas and it now compares with Malaria as a killer disease.

It is passed by airborne water droplets (normally through coughing or sneezing). The organism may lie dormant for several years before symptoms appear. These include a hacking cough, anorexia, chest pain, shortness of breath, fever and sweating. Hospitalization is necessary.

Smallpox

Smallpox is an acute viral infection. Although the World Health Organization confirmed in May 1980 that the disease had been eradicated, cases have reappeared.

Flying and Health 6

107

6		Flying and Health

Health and Flying 6

Cholera

Cholera is contracted through food or water which has been contaminated by the faeces of infected persons. Outbreaks thus reflect poor sanitary and hygiene conditions.

Symptoms include vomiting, cramps and diarrhoea resulting in dangerous loss of body fluids. Liquid loss may be as much as 19 litres a day. Once fluids have been replaced, antibiotics may be given to stop the bacteria. A vaccine is available but is of questionable benefit.

Drinking only boiled or bottled water and eating only cooked food are the best preventative measures. It is noteworthy that aircrew should always check that the seal is intact before drinking from a bottle of water at hotels or restaurants. In many developing countries bottles are refilled and thus may contain contaminated water.

Yellow Fever

Yellow fever is an acute destructive disease usually found in tropical regions and is caused by a virus transmitted by infected mosquitos. The virus has an incubation period of 3 to 8 days. Symptoms include fever, liver damage (with accompanying jaundice) and intestinal disorders. Treatment consists of maintaining the blood volume and transfusions may be necessary. Vaccination confers immunity for 10 years.

Tetanus

Tetanus is an infection which is transmitted through spores via a puncture of the skin and attacks the central nervous system. The most characteristic symptom of tetanus is lockjaw. After the initial vaccination (3 over a 12 month period) revaccination every ten years is necessary.

Typhoid Fever

Typhoid is contacted through infected milk, water or food and affects the large intestine. Symptoms include high fever, headache, constipation which soon changes to diarrhoea and a rash which usually appears on the chest and abdomen. The disease is serious and can be fatal. The vaccine does not provide complete protection and a booster is required after two years.

Hepatitis

Hepatitis is a virus that affects the liver, causing its enlargement and can sometimes result in liver failure. Symptoms include fever, chills, headache, decreased appetite, tenderness in the upper right abdomen, dark urine, light-coloured faeces and yellow skin or eyes. Left untreated, the victim can fall into a coma and die. Of the six forms, the three most common are discussed briefly below.

Hepatitis A

Hepatitis A is primarily spread through food and water contamination. Undercooked or raw shellfish and seafood, along with raw vegetables are likely sources. Symptoms develop about one month after exposure to the virus.

It has been reported that Hepatitis A can also be transmitted through sexual contact and drug use (needle exchange).

Gamma globulin is used as a vaccine but can be of limited protection and short-lived.

Hepatitis B

Hepatitis B is more serious than Hepatitis A, resulting in chronic liver disease. It is spread through blood transfer rather than by eating. It is transmitted primarily via intravenous drug

108

Flying and Health		6

use (needle exchange), sexual contact and blood transfusion. Tattooing and immunisation with improperly sterilised syringes are also common causes. Vaccination is possible.

Hepatitis C

Hepatitis C is transmitted primarily through intravenous drug use and shared needles, maternal transmission and possibly some forms of sexual contact. Vaccines exist.

Diabetes

There are two types of Diabetes : types 1 and 2

Type 1

Often referred to as juvenile diabetes, this type is normally found in the young. Either there is a deficiency of insulin or a lack of production of insulin by the pancreas. People with type 1 diabetes therefore require regular insulin injections to manage their glucose/sugar levels.

Type 2

Usually effects adults and pilots are not immune to this condition. It is caused by either the pancreas not producing enough insulin to maintain a normal blood glucose level or, more usually, when the body is unable to effectively use the insulin (insulin resistant). Research is continuing to look more closely into how insulin resistance develops. It is thought that the principle causes of insulin resistance is obesity, poor diet and sedentary lifestyles.

Both types can be as a result of family history.

Symptoms

These include :

•Thirst

•Frequent urination

•Blurry vision

•Irritability

•Tingling or numbness in the hands or feet

•Frequent skin, bladder or gum infections

•Wounds that do not heal

•Extreme unexplained fatigue

In most cases of type 2 diabetes, there are no symptoms. In such cases, people can live for months, even years, without knowing they have the disease. This form of diabetes comes on so gradually that symptoms may not even be recognized.

Type 2 diabetes can potentially be avoided through diet and exercise and treatment includes diet modification and control, regular exercise, home blood glucose testing and, in some cases, oral medication and/or insulin injections

Complications

Complications may be numerous and include :

•Hypertension

•Tearing of the retina of the eyes which can lead to blindness

•Neuropathy (loss of feeling or numbness – especially of the lower limbs and feet)

•Blocked arteries with associated chances of heart attacks and strokes

•Kidney failure

•Hypoglycaemia caused by taking too much insulin and possible coma

Flying and Health 6

109