Specific vaccines
Diphtheria, Pertussis and Tetanus
Also known as "DTP" or "Triple vaccine", the combination of three vaccines has been used for decades and has had periods of ups and downs in terms of acceptability.
Diphtheria is a serious bacterial infection of the respiratory tract which can also affect the heart. Largely because of the vaccine, it is now very rare. Many doctors today have never seen a case of diphtheria, but the the disease has not been entirely eradicated. It could certainly stage a comeback if vaccination coverage falls.
Tetanus is a bacterial infection, usually of dirty, deep wounds. The bacteria produce a toxin which attacks the nervous system. Unlike many other diseases for which there are vaccines, tetanus can never be eradicated, as the bacteria is found everywhere in the environment.
Pertussis is better known as "whooping cough". If vaccination safety has been a major concern for you, then you probably have heard some bad things about the whooping cough vaccine.
Whooping Cough
Before the Pertussis vaccine came into common use, whooping cough used to be a common childhood illness with high rates of mortality and permanent damage in survivors. Few sights can be more pitiable than that of a young child staying up all night coughing, vomiting, turning blue in the face for lack of breath, and bleeding into the whites of the eyes. After the advent of the vaccine the incidents of whooping cough fell dramatically, so much so that people began to wonder if the world would soon be rid of the bacteria and the vaccine no longer necessary, then some time in the 70's, a scientific paper was published which suggested a possible link between the whooping cough vaccine and permanent brain damage. Although the link was tenuous at best, the story was seized by the media which naturally emphasized the sensational "vaccine killed my baby" aspect. The belief that the Pertussis vaccine was highly dangerous spread like wild fire. Parents and even doctors believed the benefit of the vaccine was no longer worth the risk and the number of immunised children fell sharply. Many doctors fought in vain to keep the immunisation rate up, but quoting statistics like "the risk is only 1 in 200 000 cases" did not help. Many people could not relate this number to real life and the spectre of permanent brain damage overcame the fear of whooping cough itself.
The fact that the Pertussis component of the DTP vaccine was the main cause of the common but mild side effects from DTP (fever, some inflammation at the injection site) also led many people to leave it out of the routine vaccination schedule.
The inevitable consequence of the fall in vaccination coverage was that cases of whooping cough shot up. With startling rapidity in all countries where the vaccine suffered from a bad reputation, whooping cough changed from a rare "textbook" disease to a common illness. Cases of children brain and lungs damaged by the disease soon outstripped the number of cases of "possible" vaccine damaged children.
After very careful scrutiny of the evidence lasting years, researchers concluded that the link between the vaccine and brain damage was so tenuous that it was highly doubtful that it exists at all. Certainly the risk from the disease is very much higher than the risk from the vaccine, as many victims of whooping cough and their families found to their sorrow. It has taken many years of public relation to re-establish the reputation of the vaccine as essential and safe. Acceptance rate is now very good in most parts of the world and cases of whooping cough have reduced to very low levels again. But even now, in many communities where the relationship between the population and the health care authority is poor (in my experience this tends to happen in economically depressed areas) some parents are still refusing the whooping cough vaccine. Worse still, in some (European) countries which are perhaps rather more obsessive about personal rights and freedom of choice than public safety, whooping cough is excluded from routine vaccination. Such communities and such countries are condemned to repeat history's painful lessons.
Currently, in most parts of the world now, the DTP is the basic vaccine that all children receive routinely if they have any access to health care at all. There are many different immunisation schedule in used in different countries but basically three doses are given by or before the age of six months and one or two booster doses from 1.5 to 5 years of age. About 10% of recipients develop a moderate fever lasting less than 24 hours. Occasional painful swelling at the injection site is seen which is more likely if the injection was given "into" the skin rather than muscle. Serious side effects such as high fever with convulsion or large painful swellings are rare and may preclude further vaccination with DTP or with Pertussis vaccine alone.
Whole cell v acellular whooping cough vaccine
In recent years a new type of Pertussis vaccine has been introduced which does not contain whole bacterial cells. Instead it contains one or two proteins which are component parts of the whooping cough bacteria. Many trials have been carried out and the acellular vaccine as replaced the older type entirely in some countries such as Japan. Evidence strongly suggests that the acellular vaccine has less side effect that the common whole cell vaccine, and the efficacy is "acceptable". It seems however that the whole cell vaccine remains more effective that the acellular vaccine at inducing long lasting immunity. Many questions remain unanswered about the relative merits of the two vaccine types. Which vaccine your child receive will likely depend on the bias or attitude of your local health department. If you are given the choice however, you may prefer your child to have the acellular vaccine if whooping cough is rare in your country. On the other hand if whooping cough is a common disease as it is in Scandinavia and third world countries the whole cell vaccine will provide a greater degree of protection.
Polio
Poliomyelitis is a viral infection of the gut which spreads to the central nervous system. With the widespread use of the vaccine it has become a rare illness. In many countries there are no cases resulting from the wild virus (except in immigrants) but a few cases have been found which are caused by the live (oral) polio vaccine.
Polio vaccines
There are two main types of polio vaccines: live oral vaccine and "inactivated" vaccine for injection. Until very recently the oral vaccine is the type most favoured around the world with the exception of a few European countries, notably France and Sweden. Although rare, cases of polio disease caused by the oral vaccine in recipients or close contacts now outnumber cases caused by the wild virus in many countries. The alternative injectable killed vaccine has proven to be effective and safer, there would seem to be no good reason not to use the killed vaccine at least for the first two doses, except perhaps in countries where cost is a major factor. In the US it is now routine to use injectable polio vaccine for the first two doses and live vaccine for subsequent doses. Other countries will probably follow the US lead. In the mean time, the French and Swedes who had been right all along about the choice of superior vaccine continue to use the killed vaccine exclusively.
In Thailand, both types of vaccine are available, but the oral vaccine is in very much more common use than the injectable. This is probably partly due to cost, only one manufacturer (Merieux) markets the killed vaccine in Thailand therefore the cost of the live vaccine is not comparable to the oral. Public health has not traditionally been a priority area for Thai politicians therefore when or if Thailand will improve its national vaccination policy is anybody's guess.
Vaccination schedule
The polio vaccine (either type) is given at the same time as the DPT vaccine at 2,4,6, 18months and 4-7 years. The injectable vaccine is mainly available mixed with the DPT as "Tetracoq", or mixed with DTP and HIb (PentactHib, Pentacoq, or other names).
Which one to use?
If cost is not a factor, for most countries it is probably best to use both types sequentially, starting with the injectable for two doses, and the oral thereafter. This has the advantage of both safety and increased level of antibody in the gut. Some countries, such as France, choose to use the injectable exclusively and this is quite reasonable for countries in which the reappearance of the wild type virus is unlikely.
Recommendation
For children, the MMR vaccine is now mandatory in most countries with effective health policies. It should be given to all previously unimmunised children aged 11 months and over, irrespective of whether the child is thought to have previous suffered from these diseases or not. Adults who know themselves to be umimmune, particularly women of child-bearing age, should also receive this vaccine.
Measles, Mumps and Rubella
These viral infectious diseases were once common childhood illnesses world-wide. They were often regarded and minor, self-limiting illnesses and indeed in previously healthy children, these diseases are usually not severe and get better without any specific treatment and with no long-term complication. Infection with these viruses confer life-long immunity. With improvement in the standard of living and general hygiene in developed countries, these diseases became less common in children. Ironically it is the adults nowadays who are at higher risks from these diseases if they did not contract the viruses as children and reached adulthood before the vaccine entered general use. Measles and mumps can be severe and debilitating in adults. Mumps in adult males can involve the testes and lead to sterility. Rubella is virtually always a mild infection but in pregnant women, the fetus can be severely damaged.
In some countries now, particularly the USA, these diseases have become very rare, so much so that some doctors may finish their training without seeing a single case. In parts of developing countries they are still common. Measles can be severe or even fatal in weakened, malnourished children.
The MMR vaccine
This vaccine contains live attenuated strains of all three viruses. It provides 95% protection. Cases of measles infection in vaccinated children are sometimes seen, but they tend to be much milder than normal. The immunity lasts about 16 years. A single dose only of the vaccine is required and should be given after the age of 11 months. Vaccination before this age provides incomplete protection and will need to be repeated. Major side effects are rare but fever following vaccination is moderately common and occurs about seven days after vaccination. The fever usually last less than 24 hours, but occasionally can be quite high.
Allergy to the vaccine is rare. Individuals known to be allergic to neomycin or kanamycin (both are uncommon antibiotics in general use) or those who has had severe allergic reaction to eggs cannot receive the vaccine.
Recommendation
For children, the MMR vaccine is now mandatory in most countries with effective health policies. It should be given to all previously unimmunised children aged 11 months and over, irrespective of whether the child is thought to have previous suffered from these diseases or not. Adults who know themselves to be umimmune, particularly women of child-bearing age, should also receive this vaccine.
Thailand differs from most other countries in that measles (only) vaccine is usually given to nine month old babies, and the MMR given at 15 months. The reasoning behind this seems to be that most measles cases in Thailand are seen in babies less than a year old. I personally doubt that this two-injection schedule is better than single-injection schedule used in other countries provided the population uptake of the vaccine is good.
Tuberculosis: BCG Immunization
Tuberculosis is caused by the tubercle bacteria. Most cases involve the lungs but any part of the body can be affected. It is most commonly spread by coughing and sneezing. Characteristics of the disease include chronic coughs, often with green sputum, night fever, weight loss, or in children, failure to grow at a normal rate. TB used to be the disease of the poor and underprivileged. In many parts of the world, as general living conditions improved, TB was on the decline. With the advent of AIDS, TB is once again on the increase world-wide. TB has always been common in Thailand, but recently there has been an alarming increase in the number of new cases, affecting all social classes. What is even more worrying is the increase in drug resistance of the TB bacteria. Established TB is very difficult to treat, involving months of taking multiple medications. Unless a breakthrough is made soon in the fight against TB, we may well see the day when there is no antibiotic strong enough to treat TB.
The BCG vaccine
This vaccine contains live bacteria, a harmless strain related to the TB bacteria. It gives about 70% protection, and although this is not as good a level of protection as one may wish, it is still far better than nothing and makes this vaccine absolutely essential. It is a very safe vaccine if given with care by qualified persons. Adverse effects including abscesses and large scars are mainly due to faulty techniques. Very severe adverse effects are virtually unknown.
Who needs BCG vaccine?
In Thailand, all individuals not previously immunized with this vaccine, and who has a negative tuberculin skin test should be immunized. This applies especially to all newborn infants and expatriate residents.
Administration
The BCG vaccine is given by an "intradermal injection", as opposed to what is commonly known as a hypodermic injection. An intradermal injection requires some skill to perform properly. The best sites for the injection are over the hip bone around the back and on the outside of the upper arm. For the upper arm, the selection of the exact site is important as the higher up it is on the arm, the bigger the scar tends to be. Some people, in order to hide the scar, select a site near the tip of the shoulder. This is inadvisable as scaring at the tip of the shoulder can produce a very large scar. The best site on the arm is the over the lowest part of the deltoid muscle, about halfway down between the shoulder and the elbow.
Localized reaction to BCG vaccine
Unlike other vaccines in common usage, the BCG causes a prolonged localized reaction which ends in scarring. Although the localized redness and swelling are usually small and painless, it usually last several weeks or even a few months. Some discharge of pus is common, but large abscesses with a lot of pus are only caused by faulty techniques. Swimming and other physical activities are permitted, although you may need a water-proof plaster for swimming if the injection site is discharging.
The tuberculin skin test
This is a test for immunity against TB. It can also indicate a possible active TB infection but it is inadequate for this purpose on its own. Unimmunised Asian adults often have immunity against TB due to previous infection which may have been very mild and resolved unnoticed. Unimmunised Westerners are much less likely to have any immunity. The skin test is required for adults before receiving the vaccine as vaccination of immune persons can produce a severe reaction as well as being unnecessary.
Hepatitis B
This is an infection of the liver caused by the hepatitis B virus. Transmission is mainly via infected blood and contaminated needles. Transmission through sexual intercourse and human bites are also possible but not common. In the past, infections caused by transfusion with infected blood were common, but most countries including Thailand now have effective screening of donated blood for hepatitis B and other diseases. Hepatitis caused by blood transfusion is still possible, but usually caused by hepatitis viruses other than hepatitis B, and is all together rare. The people most at risk from hepatitis B infection are doctors and nurses, and intravenous drug abusers.
Hepatitis B is found world wide but in the Far East it very much more common than in the West. In the Asian subcontinent it is moderately common. Many people in the Far East become carriers; ie they carry the virus in their bloodstream all the time but have little or no symptom. Because of prolonged close contact, hepatitis B is often transmitted in the Far East within families and in schools without the parties involved being aware of the infecting event. Large numbers of Asian adults show evidence of previous exposure to the virus in the form of specific antibodies in their blood, without knowing that they were ever infected.
The symptoms of hepatitis B often start with vague general malaise, nausea, vomiting and abdominal pain. Later jaundice follows. There may also be fever. The degree of severity range from virtually unnoticeable to fatal fulminating liver failure (1% mortality rate). Most cases recover fully in a few weeks, the sufferer then may or may not become a carrier. Affected children are more likely than adults to become carriers.
The hepatitis B vaccine
This vaccine provides good protection against the disease, and very rarely cause any side effect. A course of vaccination consists of three doses at 0 - 1 - 6 month intervals. At the present time booster doses are not considered necessary although many doctors continue to advise boosters every five years. Adults, especially Asians, need blood tests for immunity before and after a course of vaccination. About 10% of adult recipients of the vaccine fail to develop any immunity, but they may respond to additional courses of the vaccine. Blood tests are not normally carried out in children, although it may be advisable if there is a known carrier in the family.
Recommendation
In most countries where hepatitis B is uncommon eg in the UK and most of Europe, hepatitis B vaccines are mainly given to people at special risks only (health workers, frequent travellers, those with "risky" lifestyles). In the USA hepatitis B vaccination has recently been added to the schedule of immunisation of all children.
In the Far East, hepatitis B vaccine has for some years been routinely given to all children in many countries. The comprehensiveness of the coverage varies from country to country according to the priority given to health care by each respective government. For Western travellers to the Far East, click here.
Hepatitis A
This disease is caused by a virus and is transmitted mainly through contaminated food and drink. There is an incubation period of up to 40 days. The disease is often mild, especially in children. In adults the symptoms can be quite debilitating. Diarrhoea is the main feature of clinically significant cases, along with nausea, vomiting, loss of appetite. Occasional cases can have jaundice.
Incubation period: when you catch a virus or a bacteria, initially the number or organisms are usually too small to cause immediate problems. The micro-organisms need time to "incubate"- to grow and multiply in sufficient quantity before you feel the effect of the disease. Incubation ed time to "incubate"- to grow and multiply in sufficient quantity before you feel the effect of the disease. Incubation period varies for different diseases. Bacterial infections have shorter incubation period, often five days or a week. Viral infections can incubate for a long time, eg. two weeks for chicken pox, upto four weeks or more for hepatitis A, months for AIDS. If you ever wonder who you got a cold from, think back about two weeks.
Hepatitis A is found world-wide. Here in the Far East it is very common, and few people reach adulthood without contracting it , although most people have no recollection of catching it while they were young.
Hepatitis A vaccine
This is a relatively new vaccine (and therefore expensive!). It provides effective prevention of hepatitis A but it is not yet routinely used. This situation may change in the future if the price comes down enough. Side effects are mild: mainly limited to some aching at the injection site for a day. The course of vaccination consists of three injections over six months. Full protection is not attained at least until the third dose is given. If immediate protection from hepatitis A is required, you may need a dose of "normal immunoglobulin" or HNIG. This used to be advocated for travellers from the West to the East. It is not a vaccine and therefore only provides "passive" immunity lasting about three months, but it is effective from the time of injection. HNIG often causes vague feverish illness lasting a few days. Another problem with HNIG is that further doses given to provide continuing protection are more likely to produce allergy or more severe side effects. In most cases the vaccine is to be preferred to HNIG. They can be administered simultaneously.
Recommedation for travellers
If you are travelling to Asia. Africa, or South America it is recommended that you have either the vaccine or HNIG. If you are a frequent traveller or you are an expatriate worker, then the vaccine is recommended over HNIG. Remember to get immunised well before you embark on your journey. Travellers to Europe, North America and Australasia do not need to be immunised.
Recommedation for residents of Asia and other regions with high risk: if you are not already immune then the vaccine is to be recommended. For adults a prior blood test for immunity is advised. For children a blood test is not really necessary. Immunisation is by three intramuscular injections at 0 - 1- 6 month intervals.
Haemophilus Influenzae (Hib)
The name Haemophilus influenzae refers to a species of bacteria which is a common cause of respiratory tract infections. There are a number of subtypes of this species and it is the type b which can be particularly virulent in children. Despite its name, Haemophilus influenzae has nothing to do with influenza, which is caused by several kinds of virus. Haemophilus influenzae type b (Hib) is a common cause of meningitis in young children. Meningitis is an infection and inflammation of the lining of the brain. It is a very serious disease with high risk of permanent brain injury or death. Hib can also cause epiglottitis, an uncommon infection of the top part of the windpipe. Epiglottitis is also very serious and potentially fatal. Children under the age of two are at particularly high risk from Hib meningitis. Between ages two and four the risks are lower but still significant. Over the age of four Hib infection is rare.
Hib is said to be more common in western countries but it is probably found world-wide. In Thailand it is found more commonly in overcrowded communities and some privately run infant day care nurseries.
Hib vaccine
Hib vaccine has been used widely from the late eighties in Europe and North America. Trials have shown the modern vaccine to be highly effective in preventing Hib infection and there has been no report of serious side effects. Hib vaccine is now well established as a routine vaccine for all children under four in Europe, North America and Australasia. The vaccine has only recently been introduced to the far east and due to a number of factors such as lack of good epidemiological data and cost, the role of this vaccine in Asia has not been well defined.
Recommendation
The Hib vaccine has become one of the essential vaccines for children, along with the other "routine" vaccines. All children under four should receive this vaccine. The vaccine is often given together with the DPT/polio vaccines, and sometimes can be physically mixed with the DPT vaccine, thus reducing the number of injections required. There are different types of Hib vaccines on the market. All are roughly equally good, but it is important to use the same brand for the whole course of injection. Depending on the type, two to three doses are given before the age of six months, and a booster is given at 13 months of age or over. Previously unimmunised children over one year of age only need one dose.
The vaccine can cause minor redness and swelling at the site of injection in upto 10% of cases with the first dose. Other side effects have not been reported.
Japanese B encephalitis
This is a viral infection of the brain transmitted by mosquito bites. The disease is found in the Far East, including Thailand. Cases are uncommon and mainly occur in rural, agricultural areas where pig-farming and rice growing coexist. Incidences of infection peak during the rainy season. Most cases are mild and produce no lasting ill effects but young children have an increased risk of developing brain inflammation, which may lead to permanent brain damage or death.
The Japanese B encephalitis vaccine
The vaccine provides effective protection against this infection. There are two brands in use in Thailand: Biken and Kaketsuken, both of Japanese origin and probably equally effective. These vaccines can be difficult to find outside of the East Asian region, and because they are still fairly new, may not yet be licensed for use in some countries.
Side effects appear to be very uncommon.
A course of immunisation consists of three doses at 0 - 1/2- 12 months intervals. Immunity takes about one month to develop.
In Thailand, you should take good precautions against mosquito bites whether or not you are vaccinated with this or any other vaccine.
Recommendation
For short term visitors (less than one month), unless you plan to visit rural non-touristy areas you do not really need this vaccine. If you an expatriate worker with children then your children should have the vaccine, but adults working in cities do not need it. For permanent residents of far eastern countries, the vaccine is routinely recommended for all children.
Typhoid
Typhoid is a disease caused by the bacterium "Salmonella typhi". The typhoid bacteria is just one of thousands of types of Salmonella bacteria. Most kinds of Salmonella cause gastroenteritis (diarrhoea and vomiting) but the typhoid bacteria invades the bloodstream causing high fever and severe malaise. Diarrhoea is not a prominent feature of typhoid, and indeed constipation is common in early sufferers.
Like many other infectious diseases, typhoid is more common in undeveloped or developing countries although it turns up in all parts of the world. The incidence of typhoid varies proportionately with the standard of food hygiene in different countries. It is not very common in most parts of Thailand. In some African countries it is very common.
The typhoid vaccines
There are three types of typhoid vaccine in common use. Unfortunately none of them are very good. The degree of protection provided varies between 60% to 80%. The current thinking is that typhoid vaccination is useful for countries where typhoid is very common. It's usefulness is doubtful for countries like Thailand where it is not very common.
Whole cell typhoid vaccine
This was the most commonly used typhoid vaccine and it has been around the longest. It is also the most troublesome, frequently causing very uncomfortable if not dangerous side effects. It is predictably the cheapest of the three types and until relatively recently it was the only one available in Thailand. A course of vaccination consists of two doses.
Vi antigen typhoid vaccine
Containing only a component part of the bacteria, this vaccine provides comparable degree of protection to the whole-cell type but with much less troublesome side effects. Only one dose is required for a course of vaccination.
Oral typhoid vaccine
This is a live vaccine, ie. it contains live bacteria. Three capsules are taken, one each on alternate days and care must be taken to store them properly. Taking antibiotics also interferes with this vaccine. The vaccine does provide some protection but there are some experts who believe it is not good enough to warrant routine use. Side effects are not very common but there may be nausea, vomiting, or a rash.
Recommendations
Residents of developed countries do not routinely require typhoid vaccine. Residents of countries with high incidence of typhoid should be vaccinated with one of the injectable vaccines. Protection lasts only for about three years therefore the need for continuation of vaccination should be regularly reviewed. Routine 3-yearly vaccination with the whole cell vaccine would probably cause too much side effect to be tolerated by most people. The Vi vaccine is better for this reason but the adverse effect of repeated courses is not yet fully assessed. Oral typhoid vaccine is probably not good enough to be useful.
Residents of countries where typhoid is only occasionally seen, like Thailand and travellers to Thailand may wish to be vaccinated for their peace of mind but it must be understood that the vaccines provide incomplete or even uncertain protection.
Your best defence against typhoid remains good nutritional hygiene; ie. avoiding uncooked food or cooked cold food, and avoiding eating "este stalls which look unlikely to have proper food preparation facilities. Gastronomically adventurous tourists should take note not to eat as the locals do even if a food stall appears highly popular.
Vaccination of children against typhoid
For children aged 5 and over, the recommendations and dosages are the same as for adults. Children aged 2 to 5 years are unlikely to be able to swallow the oral vaccine. Chewing the capsules release the caustic content into the mouth which can be very irritating as well as render the vaccine ineffective. The Vi antigen vaccine has been studied mainly in older children but probably would work well in children aged two or above. The vaccines have not been well studied in very young children but in any case infants who only take milk and well prepared baby foods are at low risk unless a parent or close relative is a carrier of typhoid.
Cholera
Cholera is a disease characterised by profuse watery diarrhoea which if left untreated can rapidly lead to shock. The cholera bacteria is frequently found in contaminated water supply. In Thailand epidemics or isolated cases of severe cholera are rare, but milder cases of infection by the cholera bacteria producing moderate diarrhoea are found sporadically, and are not confined to certain population groups or social class.
Cholera is not difficult to treat once recognised, and the mortality rate is only 1% for treated cases.
The cholera vaccine
Many years ago, vaccination with cholera vaccine was common practice and many older people will remember needing a health pass with evidence of cholera vaccination for international travel. In many Thai schools mass cholera immunisations were dreaded yearly events. Alas, it was all wasted effort and an example of overeaction and blind faith in technology, possibly with political motives thrown in for good measure. The cholera vaccine was then and remains now next to useless. It provides less than 50% protection for about three months which in practice translates to no useful protection.
Cholera vaccines are still available and their primary use now is not for protection but for dealing with red tape at those few immigration control points in the world which still insist on proof of cholera vaccination
Chicken pox
Chicken pox is an infection caused by the virus Herpes zoster, also known as Varicella zoster. In children it is a mild if unsightly illness lasting seven days. There may be associated fever and itchiness which are rarely severe. Most children recover from chicken pox uneventfully, and the marks left behind fade away with time. Infection with chicken pox confers life-long immunity, although the virus may re-emerge in adulthood as the disease "shingles" which is painful skin condition. Chicken pox in adults is potentially much more serious. Adults can become severely debilitated from the disease, and there may be complications such as pneumonia. It is not uncommon for adults to be admitted to hospital for chicken pox.
As the incidence of chicken pox and other communicable diseases decline in many developed countries, many people are reaching adulthood without contracting chicken pox, and these are the people who are at significant risk. In Thailand it is still rare to find an unimmune adult.
Treatment of chicken pox
In children, very little treatment is need, some paracetamol for the fever, and occasionally some medicine to reduce the itchiness are all that is required. The child may eat anything and wash as normal. The only precaution to take is to avoid spreading the virus to other children or adults. There has been a tendency however to overtreat chicken pox with unnecessary pills and potions. Some of this is due to parental anxiety, the need to do something for a "sick" child even though nothing needs doing. Unfortunately many doctors perhaps too busy to explain, reenforce this belief by prescribing all manners of things from the bland to the dangerous. Such irresponsible practice is sadly not uncommon in Thailand, but in many cases it is just what the customer wants.
A much better case for treatment of chicken pox can be made for adults. There is a "cure" for chicken pox in the form of the drug acyclovir. The drug kills the virus, one of the very few drugs in use that actually kills any virus. It works and it is a very safe drug. It can shorten the period of illness of chicken pox from 7 down to 5 days, and reduce the number of skin lesions. More importantly it can prevent the severe complications which sometime occur in adults. Acyclovir is expensive. Clear instructions for its use need to be given by the prescriber for it to be effective, and these must be strictly followed.
Chicken pox vaccine
Chicken pox vaccine has been used for some time in Japan. In the US it is becoming a "routine" vaccine. In Thailand it has recently become available but the cost for most people is prohibitively high, and so it is unlikely that the vaccine will become part of the normal vaccination schedule in this country in the near future. The chicken pox vaccine is a live vaccine. It can be given to unimmune adults and children over the age of 1. Children under 12 need only one dose injected subcutaneously, adults need 2 doses one month apart.
The main question people often ask is why immunise against a disease that is "not dangerous". There are two main reasons: severe and dangerous complications may be rare but can happen, especially in adults, and secondly, the vaccine is not known to cause later eruption of shingles, unlike naturally acquired immunity to chicken pox.
Safety and effectiveness
Although the chicken pox vaccine is relatively new outside of Japan, many studies have shown that is highly effective, giving immunity lasting at least 20 years and probably longer. Severe side effects are almost unknown. Minor side effects include development of a few spots six days after receiving the vaccine, but this seems to happen only in 2 to 3 percent of recipients.
Recommendation
Vaccination is highly recommended for unimmune adults, especially in Thailand and other countries where the disease is very common. Personnally I would recommend that children are immunised a few months after their first birthday, although in Thailand the local "experts" sometime recommend that children are immunised after the age of 10 if they had not managed to get infected naturally before then.
Rabies
Rabies is basically a viral infection of the central nervous system. It is virtually always fatal. Rabies is contracted through being bitten by rabid animals. Transmission from saliva is also possible via the mouth or eyes, but not through intact skin. Rabies is found in all parts of Thailand, although in Bangkok it is not very common.
If you are bitten...
...or if you/your children come in contact with a rabid animal, you need immediate treatment. If you are bitten by any mammal you need treatment, regardless of whether the animal is someone's pet, or if it has been previously immunised by the vet, or if it appears quite healthy. The only possible exception to the rule might be if the animal is your own pet and you know for definite that it never gets out of the house to mingle with any other animal and the animal is perfectly well and it only bit because it was provoked. The treatment required depends upon the site and nature of the wound and may range from simple vaccination to injections with antibody serum and surgery. If there is good evidence that the biting animal is rabid, it needs to be destroyed and the carcass examined by a pathologist for evidence of rabies. If it is more likely that the animal is well, it should be observed for signs of illness for two weeks, in which time if it is rabid it will die, and if it is not it will remain well. This information may affect the schedule of vaccination.
Rabies vaccine
The best type of rabies vaccine is made from cultured human cells and is called "HDCV". There are several brands available. The vaccine is effective and has few side effects. Depending on circumstances, up to six doses may be required over a period of six months for treatment after contact, this is "post exposure" treatment.
Pre-exposure vaccination?
It is not normal practice to vaccinate against rabies before exposure has occured. This is partly because rabies is not all that common, and if you get bitten you would normally have time to get effective treatment to prevent development of the disease. There are a few circumstances where rabies vaccine may be given as a precaution:
- Travelling or habitation in remote areas with difficult access to medical care
- Work which involves frequent contact with animals
If maintenance of immunity is required, booster doses are needed every 2 to 3 years.
Meningococcal meningitis
This is an infection of the "lining" of the brain caused by a small bacteria: the meningococcus, of which there are types a, b, c, d. The disease is severe and life-threatening. Even a short delay in treatment may lead to inexorable deterioration and death. Parts of the world where meningococcal meningitis is relatively common include the "meningitis belt" of Africa, Mecca in Saudi Arabia, and parts of the Indian subcontinent. Meningococcal meningitis is sporadically seen in the UK. In Thailand it is rare.
Meningococcal vaccine
The killed vaccine only provides protection against meningococcus groups a and c. For immunisation of adults and children from two months of age, a single dose is required.
Recommendations
Travellers to areas where the disease is common should be immunised. The meningitis belt of Africa includes most countries in the sub-saharan and central African areas stretching from the east to the west coast. In Europe and in some African countries the predominant bacteria is group b, for which there is no effective vaccine. Travellers to Saudi Arabia for the Haj are required to have meningococcal immunisation.
Protect yourself against mosquito bites!
If you are visiting the far east, you will get bitten by mosquitoes. A few bites will not harm you other than producing itchy raised spots, but if you get many bites you risk catching some very unpleasant diseases; including malaria, dengue fever and Japanese B encephalitis.
To protect yourself and your family, take the following precautions:
- If you sleep in an un-air-conditioned room make sure the windows have good mosquito screens or get hold of a mosquito net; (looks like a tent with sides made of thin white cloth, either with strings for tying the corners to projections from the wall, or with wire skeleton)
- If you will be out in the open at night eg dining al fresco, use some insect repellant lotion before you go out. Lotions are widely available in supermarkets and drug stores. If you don't like the idea of putting chemicals on your children's skin, put it on their socks or clothes or wristband instead.
- Wear long-sleeved shirt/blouse and long trousers when you go out at night. Socks also help deter mosquitoes but some will still bite you through your clothes so don't forget the insect repellant lotion.
- Insecticide sprays are sometimes a necessary evil. Get ones that are specifically for flying insects rather than ants and cockroaches. Spray in all the dark corners of the room, under beds and wardrobes etc. Close doors and windows to allow the spray to work for an hour or so, then air the room well (of course you will have already checked that the mosquito screens are in place and serviceable).
- Insect traps using blue neon lights work, but not very well. Don't put to much faith in them.
- Insecticide coils that need to be lit and insecticide-impregnated pads that need to be heated also work, but may not be very effective if there is a strong draught.
- If you are the adventurous type and you plan to visit remote forested areas or remote islands- get anti-malarial prophylaxis at least a month before you leave home, and follow your doctor's instruction religiously. Remember that you will need to continue with the medication for a few weeks after you get back home. Some anti-malarial drugs are not suitable for pregnant or lactating women.
- Remember also that if you catch something from a mosquito, it may be some weeks before you fall sick. Visit your doctor promptly if you get sick within a few months after visiting risk areas.
- Just a note for those who do not already know: AIDS is not transmitted by mosquitoes.
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