Walk around tropical Asia’s foreign cemeteries, from Calcutta and Penang to Macau and Hong Kong, and what becomes apparent is the extreme youth of many buried within them, and the sudden deaths of relative newcomers to tropical lands. Young people recently arrived from temperate territories, late teens and early 20s being a particularly dangerous ages, were rapidly felled by tropi­cal diseases. Until advances in micro­biology in the mid-19th century demonstrated links between filth and disease, little existed in the way of prevention.

If newcomers survived their first “cycle of Cathay” (as the initial 10 years were termed) in reasonable health, they were considered “salted” and thus fairly likely to last until retirement. Cemetery monuments confirm this fact; mortality spikes are discernible among the relatively young and – presum­ably – recently arrived. Death rates tail off in the middle years and then climb back steadily from the late 50s onwards.

When death came calling: how the plague swept through Hong Kong

The most common debilitating tropical illnesses and often the deadliest, were amoebic and bacillary dysentery. Neither strain had any cure. In many places, native herbal remedies were used; some relieved the fevers and aches that accompanied an acute bout while others stopped the constant diarrhoea that typically characterised the illness. Eventually, experience demonstrated that getting a patient as cool as possible dramatically lowered fevers and – some­times, if the individual was robust enough – could destroy the internal parasite altogether. Ice baths were occasionally deployed as a “cure-or-kill” measure, this drastic medical use being one of the less well known reasons for the large-scale import­ation of ice into tropical lands throughout the 19th century.

As well as ice packs, transferring patients to higher altitudes helped to lower the body temperature. Hill stations grew up across tropical Asia in the 18th century, partially in response to the ongoing ravages of dysentery. In Bengal, Malaya, Sumatra and Java, where the average lowlands temperature varied little throughout the year, going into the mountains for a rest cure was sometimes the last resort. What were known as “con­valescent bungalows” dotted the upper slopes of hill stations. These facilities were often either owned or heavily subsidised by local trading firms for the use of their European staff.

Lengthy sea voyages into temperate zones were also undertaken.

How nets, coils, insecticides and Indian tonic water were used to deal with malaria

Once the causes of diseases were scienti­fically established, and while effective cures remained to be discovered, scrupulous avoidance of contaminated water and foodstuffs was essential. The late 19th century saw disease-prevention work in public health around the world, targeting illnesses ranging from those carried by mosquitos, such as malaria and dengue, to water- and food-borne maladies such as typhoid, cholera and dysentery.

Humorous rhymes with under­lying solemn messages were repeated to Asia newcomers and conveyed their stark yet sensible warnings down the generations:
Luscious fruits and salads green, Harbour filthy germs unseen! Travellers in the East must not, Eat anything, unless it’s hot!

In many places across tropical Asia – India and Indonesia, in particular – this remains prudent advice.

Remedies for various tropical com­plaints were developed during the 1930s and medical advancements accelerated during the second world war. Penicillin, sulfa drugs, malarial prophylactics such as Atabrine, May and Baker’s pills (popu­larly known as M&B) and Mepacrine for various strains of dysentery had by the 1950s significantly lengthened life expectancy in tropical territories.

Despite these advances, Hong Kong, ever the exception, retained its thoroughly justified reputation for inexcusable levels of disease, public filth and insanitation throughout the 20th century and – with the Sars outbreak in 2003 – on into the 21st.