On holidays men are more likely to get malaria and sexually transmitted diseases whereas women suffer from stomach problems, Swiss research has found.
The study, by Zurich University, is the first one ever to give a broad profile of travel-based infectious diseases from a gender point of view.
“What we see very clearly is that men are much more likely to have vector-borne diseases, such as malaria, leishmaniasis or rickettsia which are transmitted by mosquitoes or ticks or other vectors,” said study leader Patricia Schlagenhauf, from the university’s Centre for Travel Medicine.
“Women are more likely to have gastro-intestinal illnesses such as acute diarrhoea and irritable bowel syndrome and to have respiratory tract infections,” she told swissinfo.ch.
Schlagenhauf and her team looked at the patient records of almost 59,000 international travellers from 44 travel medicine clinics around the world. This data is included in the GeoSentinel data network which tracks travel-related illnesses.
The findings were published in the latest edition of the Clinical Infectious Diseases journal.
Of mosquitoes and men
The exact reason for the differences between the sexes is not clear. One explanation is that men are simply more prone to malaria and other mosquito-borne diseases, said Schlagenhauf.
“We think this is due to the fact that they’re more attractive to mosquitoes, because mosquitoes find their victims using smell and particularly the anopheles mosquito, which is the transmitter of malaria, has a very finely tuned sense of smell specifically for humans,” she explained.
“Men produce more carbon dioxide and tend to sweat more and that makes them more attractive to mosquitoes than women.”
As for sexually transmitted diseases, just over one per cent of the men visited a travel clinic for this reason, with males being one third more likely to do so than females. The researchers said that past studies had shown that men were more apt than women to have sex with someone they met abroad.
As for women, they may be biologically more susceptible to the pathogens that cause gastrointestinal illnesses, said Schlagenhauf. Or they simply go to the doctor more often for these complaints.
The team also looked into how often people consulted medics and found that more women came to pre- and post-travel advice sessions than men. But more men were hospitalised post-travel.
“This could be that men’s infections or diseases are more serious or it could be that maybe the healthcare system takes men more seriously,” said Schlagenhauf.
The research scientist said there were some practical messages from the study.
“When seeing people before travel, it’s good to see them not just as travellers, but maybe as male or female travellers, and then to perhaps place more emphasis on certain things,” she said.
“It doesn’t mean that women won’t get malaria, but it means that perhaps you should spend more time with the men explaining about mosquito bite protection, the use of repellents, and how those repellents are water soluble so if men are sweating a lot they need to keep reapplying.”
Self medication, safe sex
Women should take medication with them when travelling, so that they can treat conditions such as urinary tract infections themselves as treatment might not be locally available.
The study also found that women tended to report more adverse events, like reactions to certain medicines like anti-malarial drugs.
“Perhaps the pre-travel advice session should look at this more closely, for example, in the cases where low-weight women are receiving the same anti-malarial dosage as a very heavy man. There perhaps the use of a split dose should be considered, or time should be taken to discuss possible adverse events,” Schlagenhauf said.
Schlagenhauf will investigate the STD data more fully in a second paper. But she observed that safe sex advice is often missing in a lot of pre-travel advice sessions.
“It’s because it’s a difficult theme to tackle, but it seems that this is really an important topic that needs more effort, for men in particular.”
Isobel Leybold-Johnson in Zurich, swissinfo.ch
“Sex and Gender Differences in Travel-Associated Disease” was published in the March 15 edition of the American Journal Clinical Infectious Diseases
For the study, Schlagenhauf and her team looked at GeoSentinel records for 58,908 patients who visited the 44 clinics worldwide between 1997-2007. GeoSentinel is a network of travel and tropical medicine experts worldwide and is funded by the International Society of Travel Medicine.
The variable used was biological sex, but the study also considered gender factors to do with behaviour.
The Centre of Travel Medicine at Zurich University’s Institute for Social and Preventative Medicine is a World Health Organization collaborating centre for travel health and helps the international body form guidelines. This is important as travel is becoming increasingly important, said Schlagenhauf.
Malaria: is caused by a parasite called plasmodium, which is transmitted via the bites of infected mosquitoes. Symptoms include fever, headache, and vomiting, and usually appear between 10 and 15 days after the bite. If not treated, it can quickly become life-threatening by disrupting the blood supply to vital organs. In many parts of the world, the parasites have developed resistance to a number of malaria medicines.
Leishmaniasis: is caused by parasitic protozoa of the genus Leishmania. Humans are infected via the bite of phlebotomine sandflies, which breed in forest areas, caves, or the burrows of small rodents. There are four types, with three types causing varying degrees of lesions and one type having a fatality rate as high as 100% within 2 years if left untreated.
Rickettsia: is a kind of bacteria which is carried as parasites by many ticks, fleas, and lice. It can cause diseases such as typhus, rickettsialpox, African tick bite fever and Rocky Mountain spotted fever.
(Source: WHO, Wikipedia )