The West of England P&I Club has published a new Loss Prevention Bulletin “Malaria – Practical Guidance for Seafarers”, containing advice on the measures that should be taken to minimise the risk of catching theMalaria disease.
Malaria is a potentially life threatening illness responsible for hundreds of thousands of fatalities every year, and the West of England P&I Club continues to encounter claims where crewmembers have contracted this mosquito borne infectious disease.
The illness can disrupt the blood supply to vital organs. According to World Health Organisation (WHO) estimates, malaria was responsible for the deaths of approximately 438,000 people in 2015. The plasmodium (P.) parasite which causes malaria is spread by the bite of infected female Anopheles mosquitoes and cannot be transmitted directly between humans
Preventative measures
Actions that can be taken to protect a crewmember from contracting malaria fall into two categories; practical considerations and anti-malaria treatments.
- Practical considerations
When considering practical steps that can be taken to prevent being bitten an understanding of what attracts mosquitoes is useful; mosquitoes are looking for a human or animal on which to feed, therefore they are attracted by carbon dioxide in exhaled breath, body heat, lactic acid present on human skin and movement indicating that a person or animal is alive. Dark colours and dark clothing contrasting with the background can also help show them that a human or animal is moving. Mosquitoes are not attracted to light; rather they may be attracted to the heat emitted by a light. The female Anopheles mosquito responsible for carrying the parasite causing malaria, feed and therefore bite mainly between dusk and dawn, therefore, so far as possible, remain inside at these times.
When proceeding outside between dusk and dawn cover up bare skin with light coloured loose fitting clothing; mosquitoes are attracted to dark clothing and can in some cases bite through tight clothing. A suitable insect repellent should be applied to any exposed skin, ideally containing DEET (Ndiethylmetatoluamide), whist following the manufacturer’s instructions and re-applying regularly as sweat will reduce its effectiveness over time. When sun screen is also being used, this should be applied first.
On vessels visiting ports in malaria affected areas the accommodation air conditioning should be in use and all doors, windows, ports and, where practicable, vents should be fully and properly closed. Where mesh screen doors are fitted on accesses these should also be closed. If mosquitoes are spotted inside the accommodation these should be killed, ideally using knockdown insecticide spray. Where air conditioning is not available, then screen doors should be fitted and in use. Bed nets should also be used, ensuring that they are well tucked in and mosquitoes are not present within the net prior to going to sleep. Bed nets should be soaked in a suitable insecticide every six months and regularly inspected for holes and tears.
The spraying of internal areas with indoor residual insecticide should also be considered, this can be effective for over three months depending on the insecticide used and the type of surface on which it is sprayed. In some areas mosquitoes have developed resistance to some insecticides, therefore it will need to be confirmed that the proposed insecticide is effective in the region where it is to be used. Since mosquitoes prefer to breed in stagnant water, higher concentrations of mosquitoes may be expected in and around still water areas, even small puddles of rainwater. Areas of standing water on the deck should be brushed away, and any water that has collected, for example, on top of lubricating oil drums, in buckets or in save-alls should be removed to discourage mosquito activity. In some areas malaria transmission may be seasonal; it may be more prevalent during and immediately after the rainy season.
- Anti-malaria treatments
Prior to proceeding to a Malaria affected area, it is recommended that a risk assessment be conducted as, even in areas where malaria exists, the risk may be very low and the taking of prophylactic anti-malaria drugs may not be deemed necessary, and expert advice should be sought in this regard. The situation in any given port may, however, change, for example in Mumbai when construction works were underway in the port, this led to numerous pools of water being present and a subsequent increase in the number of cases of malaria, therefore risk assessments should be periodically revisited and updated.
Anti-malaria drugs can help prevent as well as treat malaria. The recommended anti-malaria prescription may consist of one of more different drugs and its composition will depend on the area visited. Advice should therefore be sought from medical professionals to determine the most effective course of tablets which should be taken by crewmembers travelling to a particular affected area.
A course of anti-malaria tablets should be taken in accordance with the manufacturers’ instructions. Usually the course of tables will start prior to travelling, be taken for the duration of the visit to a malaria affected area, and then taken for one or more weeks after leaving. It is important that the treatment periods prior to and after being in a malaria affected area and the recommended dosages are strictly adhered to. Often people will forget to take their tablets after leaving an affected area, or they will consider that as they have not fallen ill while in a malaria zone, that it is safe to stop taking their tablets early.
This is a potentially fatal fallacy and the full course of recommended anti-malarial treatment should always be completed. The areas visited will dictate the recommended anti-malaria treatment as the P. falciparum parasite is resistant to chloroquine in many areas, and resistance to artemisinin is found in a number of South East Asian countries. Common anti-malaria treatments involve Mefloquine (Larium), Doxycycline and / or Atovaquone / Proguanil (Malarone). The situation is reminiscent of thehepatitis C treatment. However, a number of these drugs may cause side effects which should also be considered when evaluating the most suitable therapy for a given area:
• Mefloquine (Larium) – dizziness, headache, insomnia, nightmares, anxiety, depression, panic attacks and hallucinations. Although an effective drug, due to the various side effects it is deemed by medical experts to be an inappropriate drug for seafarers.
• Doxycycline – sunburn due to light sensitivity, upset stomach, heartburn and thrush.
• Atovaquone / Proguanil (Malarone) – upset stomach, headaches, rashes and mouth ulcers.
When considering the foregoing anti-malaria treatments, medical professionals recommend that Atovaquone / Proguanil (Malarone) should be the primary drug to be considered for use by seafarers.
Some anti-malaria drugs may also affect a person’s ability to operate machinery. Therefore when selecting the anti-malaria regime it should be ensured that these will not affect the crew’s ability to carry out their work safely. It should, however, be considered that anti-malaria medicines are not 100% effective; therefore these should be taken as well as ensuring practical measures are in place to mitigate the possibility of crewmembers being bitten. As anti-malaria treatments do not guarantee immunity from contracting malaria, it is important that any flu like symptoms that develop even when a full schedule of anti-malarial treatment has been completed, even some time after departing from a malaria area, be referred for medical attention. Anti malarial drugs should be sourced from trusted suppliers, as studies have shown that fake anti-malarial drugs are commonplace in some countries, in particular in South East Asia.
At present there is no vaccine against malaria, although research and testing of possible vaccines is ongoing.
Further information may be found by reading the bulletin below
Source & Image credit: West of England P&I Club
