Waquaruddin Ahmad  ( PMRC Research Centre, Jinnah Postgraduate Medical Centre, Karachi. )

The International Health Regulations were adopted by the 22nd World Health Assembly in 1969¹ with the purpose to prevent the inter­national spread of disease and in the context of international travel, to do so with the minimum of inconvenience to the passenger. This requires international collaboration in the detection, reduction or elimination of the sources from which infection spreads rather than attempt to prevent the introduction of disease by legalistic barriers which, over the years, have proved inef­fective.
Based on epidemiological studies it was found that introduction of Cholera in any country cannot be prevented by Cholera Vaccine. The 26th World Health Assembly (WHA) in 1973 amended the regulations so that Cholera Vacci­nation certificate should not be required by any traveller.²
WHA declaredon8th May 1980,that Smal­ipox has been eradicated,therefore smallpox vacci­nation is no longer required; it may even be dangerous in some cases.³
YELLOW  FEVER  VACCINATION  CERTI­ FICATE
A yellow fever vaccination certificate is now the only one that should be required in inter­national travel. Yellow fever is endemic in Africa and South-America. For the traveller’s own protection and the countries visited, travellers who enter areas where the yellow fever virus is endemic should be vaccinated.
The vaccination certificate is valid only if it conforms with the model recommended by International Health Regulation and the vaccine has been approved by WHO and administered at an approved Yellow Fever Vaccination Centre.⁴
The validity period of international certi­ficate of vaccination against yellow fever is 10 years, beginning 10 days after vaccination. If a person is revaccinated before the end of the validity of certificate, the validity is extended for a further 10 years from the date of revacci­nation.
MALARIA
Malaria is a mosquito-borne disease closely associated with international travel and there is a high risk of acquiring the infection in endemic areas. Vaccination does not yet exist in a practi­cable form; individual travellers can and should protect themselves when visiting endemic countries.
In many countries where malaria is endemic, the main towns are often free of disease; While there is usually much less risk of malaria at altitudes greater than 1500 meters the disease can occur in certain climatic conditions as high as 3000 meters or above. Risk of infection may also vary with the season of the year.⁵
Protective measures should be taken by the travellers while visiting endemic areas £e.,sleeping in air-conditioned or properly screened rooms, using anti-fly spray to kill any mosquito in the screen, using mosquito nets around the bed at night, wearing sufficient clothing to protect whole body, arms and legs from mosquito bites, avoiding dark colours which attract mosquitos, smearing an insect repellent (diethyl-m-toluamide) on parts of the body not covered by clothing and drug prophylaxis.
Travellers should be made aware that no drug can guarantee malaria suppression and medical advice should be obtained immediately if fever occurs while under,or after having treated, malaria prophylaxis.
It would be preferable to start drug pro­phylaxis one week before departure to assess the individual’s tolerance to the drug, at the latest it should be given on the day of arrival in the malarious area. Chemoprophylaxis should be continued for 6 weeks after leaving endemic area to control incubating infections with falciparum malaria, but orale or vivax malaria may break through even after that period.
CHEMOPROPHYLAXIS FOR MALARIA⁵
Remarks
Drugs and Dosages
Where no resistance of P. quine exists falciparum to chloro­Where resistance of P. falciparum to chloroquine is not widespread and predominantly of low degree
If fever occurs, one or more treatment dose of 500 mg sulfodonin /25 mg pyriniithamine or 500 mg sulfaline/25 mg pyrimithamine should be taken Where highly chioroquine-resistant P. falciparum occurs.
(South—East Africa and Latin America)
Proguanil 200 mg (base) daily ch1oroquine 300 mg Dapsone/pyrimithaniine
(base) weekly+I tablet weekly
In no circumstances should the dose of depsone/pyrimithamine exceed 1 tablet weekly.
All dosages refer to 50 - 70 Kg. adults, for persons heavier than 70 Kg. doses may be increased. The recommendations given here are applicable only to non-immune travellers visiting endemic areas for not more than 6 months.
Side effects of chioroquine in prophylac­tic doses are rare and usually restricted to mild gastric discomfort, pruritus, longterm adminis­tration carries the risk of retinopathy. Sulfadoxin may cause drag fever, photo dermatitis, jaundice, toxic epidermic necrolysis, agranulocytosis and Steven—Johnson syndrome. Daprone/ Pyrimi­thamine may cause methaemoglobinaemia and agranulocytosis.
Pregnancy is not a contra-indication to the use of chioroquine or proguanil. In the recom­mended doses, any of these drugs can safely be taken at all stages of pregnancy. The real danger in pregnancy lies less in drug prophylaxis than in the malaria itself.
It is advisable not to give sulfadoxin, sulfone or daprone combinations to children below 1 year of age; similarly these drugs are not recommended during pregnancy.
RISK OF MALARIA EXIST IN FOLLO­WING COUNTRIES
Afghanistan, Algeria, Angola, Bangladesh, Belize, Benin, Bhutan, Boliva, Brazil, Burkina
Faso, Burma, Burundi, Cameroon, Central African Republic, Chad, China, Columbia, Congo, Cote
D’Voire, Democratic Kampuchea, Democratic Yemen, Djibouti, Egypt, El Salvador, Equatorial
Guinea, Ethiopia, Gabon, Gambia Ghana, Guati­mala, Guinea, Guinea, Bissaea Guyana, Haiti, Hon­duras, India, Indonesia, Iran, Iraq, Kenya. LaosPeople’s Democratic Republic, Liberia, Libyan
Arab Jamahuriya, Madagascar, Malawi, Malaysia, Maldives, Mali, Mauritania, Mauritius, Mexico.
Mozambique, Namibia Nepal, Netherland’s  Antilles, Nicaragua, Niger, Nigeria, Oman,
Pakistan, Panama, Papua New Guinae, Paraguay, Peru, Phillipines, Rwanda, Sao Tome & Principe,
Saudi Arabia, Senegal, Sierra Leone, Solomon
Islands, Somalia, South Mrica, Sri Lanka, Sudan,
Surinam, Swaziland, Syrian Arab Republic, Thailand, Togo, Uganda, United Arab Emirates. United
Republic of Tanzania, Vietnam, Zaire, Zambia, Zimbabwe.
CHOLERA VACCINATION IS REQUIRED
IN FOLLOWING COUNTRIES
Albania, India, Lesotho, Madagascar, Malta, New Caledonia and Dependencies, Pakistan, Pitcairns, Somalia, Sn Lanka.
Following countries require no vaccination for any traveller:
Andorra, Argentina, Austria, Belgium, Bermuda, Botswana, British Virgin Islands, Bulgaria, Canada, Cayman Islands, Chile, Comoros, Cook Islands, Costa Rica, Cuba, Cyprus, Czech­oslovakia, Democratic People’s Republic of Korea, Denmark, Dominican Republic, Ecuador, Fal­kiand Islands, Faroe Islands, Finland, France,
German Democratic Republic, Federal Republic of Germany, Gibraltar, Greenland, Guam, Hong Kong, Hungary, Iceland, Ireland, Israel, Italy, Japan, Jordan, Kuwait, Liechtenstein, Luxem­bourg, Macao, Monaco, Mongolia, Morocco, Netherlands, New Zealand, Northern Mariana Islands, Norway, Pacific Islands—Trust territory of the U.S.A., Poland, Puerto Rico, Republic of Korea, Romania, Saint Helena, Saint Pierre anti Miquelon, San Marino, Seychelles, Spain, Sweden, Switzerland, Turkey, U.S.S.R., U.K., U.S.A., Uruguay, Vanuata, Venezuela, Virgin Islands, Wake Island, Yugoslavia.

1. International Health Regulation (1969): Third annotated edition. Geneva, World Health Or­ganization, 1983, pp. 79.
2. Resolution WHA 26.55.
3. Resolution WHA 34. 13.
4. Yellow fever vaccinating centres for international travel. Situation as on 1 January 1985. Geneva, W.H.O., 1985.
5. Vaccination certificate requirement and Health Advice for International Travel. WHO, 1987, pp.47.