Between 1969 and 1999, 12 countries reported a total of 87 cases of malaria in people living near an airport. France heads the list, with 26 cases, followed by Belgium, 16, and the United Kingdom, 14 cases. These "airport malaria" cases, occurring in or near airports, are distinguished from other cases of imported malaria among persons who contract the infection during a stay in a malarious area and subsequently fall ill. The occurrence of a relatively large number of cases of airport malaria in Paris and Brussels reflects the large number of flights arriving from Central and West Africa. At least five deaths have resulted; all cases occurred among people with no immunity to the disease. Long delays in achieving the correct diagnosis frequently resulted in-patients developing severe or complicated malaria. Five cases of airport malaria occurred in Switzerland in 1990; in at least one case, 31 days elapsed before a correct diagnosis was made

"A serious consequence of the transport of infected mosquitoes aboard aircraft has been the numerous cases of "airport malaria" reported from Europe, North America and elsewhere," say the authors of the report. Airport malaria is particularly dangerous in that physicians generally have little reason to suspect it. This is especially true if there has been no recent travel to areas where malaria is endemic. Diagnosis may, therefore, be protracted and death may occur before a correct diagnosis is made and adequate treatment provided."

In some instances, mosquito species have been established in countries in which they have not previously been reported. The study quotes the introduction – probably by ship rather than aircraft - into Brazil in 1930 of a species of mosquito that was a major vector of malaria. "The importation and subsequent establishment of this highly efficient vector led to an epidemic of malaria involving some 300 000 cases and 16 000 deaths. A costly campaign was successfully conducted to eradicate the vector from Brazil."

The authors of the Bulletin study are Dr Norman Gratz, former Director of the Division of Vector Biology and Control, WHO, Dr Robert Steffen, of the University Travel Clinic, Institute for Social and Preventive Medicine, Zurich University, and Dr William Cocksedge, a communicable diseases specialist at WHO. "There is an important on-going need for the disinsection of aircraft coming from airports in tropical disease endemic areas into non-endemic areas," they say.

"Malaria-carrying mosquitoes may enter the passenger cabin before take-off or during stopovers or may survive the trip in the luggage hold. Whatever its mode of travel, imported malaria is frequently fatal, due to late diagnosis by physicians not primed to the risk of malaria. The cost of treating it can exceed US$ 2700 per case, which far outweighs the cost of disinsection of aircraft with periodic application of a residual insecticide, such as permethrin, plus aerosol spraying either just before passengers board or just before take-off."

Many countries already insist that arriving aircraft be disinsected, especially if they have come from areas where vector-borne diseases are endemic. It is common for an arriving aircraft to be sprayed by the health services of the country of destination if there is any doubt as to whether treatment has been applied earlier in the flight. The latest WHO recommendations for aircraft disinsection were published in 1998.

• The first reported occurrence of insects in an aircraft was in 1928 when a quarantine inspector boarded the dirigible Graf Zeppelin on its arrival in the USA: 10 species of insects were discovered on plants carried by passengers.

Also in this month's Bulletin

Preventing mother-to-child transmission of HIV in developing countries might soon be technically feasible, judging from the results of recent trials of zidovudine and nevirapine in Thailand and Uganda. These results raise hopes but also many questions. Given the cost of such drugs, would developing countries not be better advised to put their money into the distribution of condoms and health education to prevent HIV infection in adults, particularly pregnant women? Should bolstering basic health services and thereby reducing child mortality not be a top priority for resources? Would the availability of such treatment not increase the prevalence of high-risk behaviour and the number of HIV-infected children? The overriding consideration should be to safeguard the rights of women to adequate health care and social support, including proper counselling.

Over the last four decades, health analysts have been devising indices or measures of health that aim to summarize a population's health. A valuable health measure is one that can be used, among other things, to compare the levels of health enjoyed by different populations, to monitor changes in a population's health, to quantify health inequalities within a population and to assess the impact of non-fatal health problems on a population's overall health. None of the measures currently available fulfils all the criteria but decision-makers should not wait before using those that come closest to the ideal.

In India cervical cancer is the leading malignancy in women, with about 90 000 new cases reported annually. In more than 90% of these cases, the lesions are in an advanced stage by the time the patient seeks medical care. In industrialized countries, mass cytological screening has largely brought the problem under control, at a cost prohibitive for most developing countries. A study using a new type of elongated magnifying glass that illuminates and magnifies the cervix - the "magnivisualizer - detected 77% of cases of confirmed early cervical cancer. The method, which is inexpensive and practicable in a primary health care setting, offers a valid method of screening for cervical cancer in countries that cannot afford cytological screening.

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