Travel: Advice for Pregnant Women going to areas that have Malaria
2016/51 - Gillian Pearce
How to give advice to pregnant women who are travelling to areas where there is malaria, is a challenge. Women have asked me for advice and as a community midwife advising them that it was not advisable to go because of the risk of getting malaria to them and their unborn baby was not always acceptable. There were sometimes cultural reasons for travelling, many Asian women travel to see their families in India and Pakistan during the second trimester, whilst others were visiting Africa. It is then important to give advice which is acceptable to them so that they could make an informed choice in regards to their travel arrangements.
The travel scholarship allowed me to meet people and discuss their research and seek the answers to the questions that pregnant women asked me. This gave me different avenues to explore so that I would be able to give them the relevant advice. I have utilised the travel scholarship to combine information from different scientific areas such as entomology, parasitology, tropical medicine, veterinary research and how it can all impact on a pregnant woman.
In order to understand malaria, it is important to understand how the mosquito functions. The mosquito is the host for the sexual cycle of the plasmodium. There are four species of Plasmodium that can cause malaria in humans. They are Plasmodium falciparum, Plasmodium ovale, Plasmodium vivax and Plasmodium malariae. However, there is a fifth plasmodium that has been identified to cause malaria in humans which is Plasmodium knowlesi. It has been found in parts of Malaysia such as Sarawak and Sabah. This currently appears to be a result of zoonosis as it normally infects macaque monkeys who are the main hosts. The aspect of research that I found interesting is the change in perception as all the plasmodium species except Plasmodium falciparum have previously been considered benign but Plasmodium vivax which is the main malarial parasite outside of Africa within the last decade has been noted to have an impact on pregnancy. It causes severe anaemia and low birth weight babies.
Meeting Rotarians from different professions at the Rotary Convention in Seoul resulted in useful discussions on preventative measures and why mosquitoes are attracted to humans which I then followed up with a literature review from looking at entomology trials on how mosquitoes identify their food source from using wind tunnels and introducing different attractants from odour, colour and/ or heat. Literature search has identified that female Anopheline Mosquitoes are attracted to humans by odour, sight and heat. To using the outcomes from the research and applying it to the physiological changes in pregnancy helped to identify possible causes for pregnant women being more prone to acquiring a malarial infection. The increase in the metabolic rate in pregnancy leads to more carbon dioxide and heat being produced and this could be one of the reasons that pregnant women are at higher risk of getting malaria than non-pregnant women or men. The other reason could be that pregnant women need to urinate more at night and they need to leave the safety of insecticide treated bednets. The research by a vet in Kamuli, Uganda has identified that the rate of malarial infection falls by 75% providing everyone in a village uses a treated bednet.
Malaria in pregnancy has a significant impact on the woman and the fetus. Plasmodium falciparum sequesters in the placenta. The infected erythrocytes become sticky and stick to the syncytiotrophoblastic membrane causing the membranes to thicken. This interferes with the transfer of nutrients and waste products across the placental barrier. This can result in low birth weight baby, miscarriage and stillbirth. The inflammation of the placenta during the 18to 20 weeks’ gestation can impact on the remodelling of the uterine spiral arteries and this is a possible precursor to pre-eclampsia. Malaria causes anaemia and can result in a maternal death.
Plasmodium vivax has previously been considered benign but it does cause severe anaemia resulting in low birth weight babies. It can cause maternal death as plasmodium vivax sequesters in the lungs and this can lead to acute lung injury or adult respiratory distress syndrome.
Understanding how malaria can impact in pregnancy and what measures a pregnant woman can take to reduce the risk of being bitten.The main preventative advice is to take antimalarial chemoprophylaxis however this is limited to malarone, mefloquine and chloroquine and proguanil. Primaquine and doxycycline are contraindicated in pregnancy. There are limitations on antimalarial chemoprophylaxis as the information is limited because drug trials are not done in pregnancy. It is also important to consider other preventative measures to reduce mosquito bites such as treated bednets, insect repellents, clothing and environment.
The travel scholarship allowed me to put information together that could be used to assist pregnant women about the choices they have if they wish to travel to a country that has malaria or if they decide not to go.