#449 Travel Medicine, Malaria, Traveler’s Diarrhea, Yellow Fever, and more! with Dr. Boghuma Titanji

July 16, 2024 | By Beth “Garbs” Gasperlin

Audio

Video

Get your patients ready to globetrot with our fantastic review of Travel Medicine with the esteemed Dr. Boghuma Titanji (@Boghuma)!  We cover malaria, anti-malarial chemoprophylaxis, basics of treatment and management of traveler’s diarrhea, yellow fever, and vaccination guidance!

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Show Segments

• Intro
• Case 1 – Defining travel medicine
• How to approach a travel clinic visit
• Malaria basics, transmission and burden
• Chemoprophylaxis for malaria
• Basic guidance for mosquito avoidance and travel
• Harm reduction, pregnancy and STI prevention, PrEP and doxyPEP
• Case 2 – Traveler’s diarrhea
• Food safety
• When to treat traveler’s diarrhea
• Case 3 – Yellow fever vaccine
• General vaccination guidance
• Take home points
• Outro

Travel Medicine Pearls

1. Always review CDC Yellow Book, UK’s Fit for Travel, and the WHO Disease Outbreaks News when preparing for a travel medicine visit!
2. Usually atovaquone-proguanil (Brand name: Malarone) is the drug of choice for malarial chemoprophylaxis.  However, it cannot be used in patients who are breastfeeding  or in patients with renal impairment, it is not recommended in pregnancy and should be used with caution if patients are taking warfarin (CDC 2017). 
3. Counseling pearl: Adults living in endemic regions have partial ‘immunity’ to malaria (Hviid 2005). However, living outside of an endemic region for 6 months will cause that immunity to wane, per Dr. Titanji (Langhorne 2008). 
4. Offer refills for patients’ existing medications (and make sure to send enough to last the trip!). Assume (without judgment) that patients may be having intercourse while traveling. Travel visits are an opportunity to offer contraceptives, condoms, and PrEP. Dr. Titanji recommends also considering offering doxy PEP for patients who meet criteria ( doxyPEP is currently only approved for MSM and transgender /m→F). 
5.  If a patient will be eating a lot of street food or have other risk factors, Dr. Titanji generally provides a treatment course of azithromycin for patients to take if they develop moderate traveler’s diarrhea. It is also recommended to obtain and take oral rehydration salts (CDC 2024).

Travel Medicine Show Notes

What is travel medicine?

Travel medicine pertains to any of the diseases and ailments one might encounter when they are traveling globally.  Recommendations in a travel medicine appointment involve understanding both the destinations to be encountered and the patient’s specific medical history, age, and needs.  It is important to understand how the patient is traveling (locations, environments, activities), as well as how long they are planning to be traveling. 

Some important resources to reference include CDC Yellow Book, UK’s Fit for Travel, and the WHO Disease Outbreaks News. 

Malaria Basics

Dr. Titanji says that if a patient returns from a part of the world where malaria is endemic with a fever – the differential is malaria, malaria, malaria! The burden of malaria is still globally significant. Annually, there are still hundreds of thousands of deaths and most of these are occurring in Africa (WHO 2023). 

Malaria is caused by parasites. There are 5 subtypes  – Plasmodium falciparum, Plasmodium vivax, Plasmodium ovale, Plasmodium malariae, and Plasmodium knowlesi(WHO 2023).  The most deadly is P. falciparum, which is largely prevalent in sub-Saharan Africa but also seen in southeast Asia. 

Choosing Malaria Chemoprophylaxis

There are a range of options to prevent malaria. It is important to know how soon they are departing, their preference for daily versus weekly medication, and any specific comorbidities. Pregnancy status is important. Location of travel  determines which species of Plasmodium you need to cover and which types of resistance patterns exist. When reviewing the CDC Yellow Book and NHS Fit for Travel will indicate which type of malaria circulates in the country of interest. 

One of the most common frontline medications is atovaquone-proguanil (brand name: Malarone).  Atovaquone-proguanil is a daily medicine that only needs to be started 1-2 days prior to travel. It must be continued for 7 days after return. However, it cannot be used in breastfeeding  or in patients with renal impairment (CDC 2017). It is not recommended in pregnancy. It also might prolong INR and should be used with caution if patients are taking warfarin (CDC 2017). 

Doxycycline is another well-tolerated option, that is also a daily medicine started 1-2 days prior to departure. It  can be helpful if a patient will be exposed to rickettsial infections as well. Unfortunately, it also should not be used in pregnancy or breastfeeding. Another downside is it should be continued for 4 weeks upon return to a non-endemic country (CDC 2013). Dr. Titanji also counsels patients regarding increased risk of severe sunburn. 

Primaquine is another daily prophylaxis option. It can cause hemolytic anemia in G6PD deficiency so it cannot be safely used unless we know a patient does not have this condition (CDC 2017). Primaquine can eradicate liver hypnozoites so Dr. Titanji will use it to treat patients if  upon return there is concern for exposure to P. ovale or P. vivax (ie: less than perfect adherence while traveling to their prophylaxis). 

Counseling pearl: Adults living in endemic regions have partial ‘immunity’ to malaria (Hviid, 2005). However, living outside of an endemic region for 6 months will cause that immunity to wane, per Dr. Titanji (Langhorne 2008). 

Weekly medicines include mefloquine and chloroquine. Both are safe in pregnancy and breastfeeding. Mefloquine must be started at about 1-2 weeks prior to entering an endemic location. Chloroquine-resistance limits the use of this medication for malaria prophylaxis, but it can be safe to use in areas where there is no P. falciparum. Both agents need to be continued for 4 weeks. Mefloquine cannot be used in patients with seizure disorders, cardiac arrhythmias (CDC 2017). Dr. Titanji says mefloquine should not be used in patients with psychiatric history, as there can be neuropsychiatric side effects including severe nightmares.  A common side effect for chloroquine is tinnitus. Chloroquine should also not be used in patients with arrhythmias. If a patient is on hydroxychloroquine for another condition and they are traveling to an non-falciparum region, they will not need an additional agent for malaria chemoprophylaxis. 

One new agent is tafenoquine. It is started daily three days prior to travel, and then taken weekly when traveling and for 1 week upon return. It also cannot be used in G6PD deficiency or pregnancy (CDC 2022).  It is not widely available, per Dr. Titanji. 

In Dr. Titanji’s practice, she sometimes sends patients at high-risk for malaria with a course of treatment with artemether-lumefantrine (Brand name: Coartem). 

Tips and Counseling for Travel Lifestyle Guidance

If you’re going to the tropics, the mosquitos are out and biting all day long. Dr. Titanji recommends using mosquito repellents and utilizing insecticide-treated bed nets to avoid getting bitten.  She also recommends wearing clothes with good coverage if you’re outside with heavy exposure risk (ie: hiking). 

Offer refills for patients’ existing medications (and make sure to send enough to last the trip!) Assume (without judgment) that patients may be having intercourse while traveling. Travel visits are an opportunity to offer contraceptives, condoms, and PrEP. Dr. Titanji recommends also considering offering doxy PEP for patients who meet criteria ( doxyPEP is currently only approved for MSM and transgender /M→F). You may also suggest that patients investigate appropriate travel insurance in case there are any unforeseen medical issues. 

Food Safety and Traveler’s Diarrhea

Exploring local cuisine is a great way to experience a new culture and Dr. Titanji has plenty of tips for doing so safely!  If you’re traveling to a location with concerns for water sanitation, Dr. Titanji recommends patients use bottled water for all purposes including brushing teeth. If you want to enjoy fresh fruit and vegetables, it should be washed thoroughly with boiled tap water or with bottled water.  Generally speaking, it is also advised to avoid raw foods (CDC 2022). 

Culprits for traveler’s diarrhea include enteropathogenic E. coli, Campylobacter, and Shigella. Salmonella can also cause severe diarrhea. Viruses include norovirus, astrovirus, enterovirus. 

Parasites such as Giardia, Entamoeba histolytica, and Cryptosporidium can also cause diarrhea (CDC 2024). Cholera is causing outbreaks, but it is still not the most common source for traveler’s diarrhea (WHO 2024). Persons who are doing humanitarian work or medical aid work are at greatest exposure risk for cholera. 

Traveler’s diarrhea is graded based on severity, volume, and level of impact on the person’s daily activities. Moderate traveler’s diarrhea would cause a patient to need to change their schedule based on how sick they are, whereas severe traveler’s diarrhea would be so sick that you would not be able to leave your lodgings (CDC 2024).  Any blood diarrhea (dysentery) would indicate severe traveler’s diarrhea.  It is currently recommended to treat moderate and severe traveler’s diarrhea. If a patient will be eating a lot of street food or have other risk factors, Dr. Titanji generally provides a treatment course of azithromycin for patients to take if they develop moderate traveler’s diarrhea (CDC 2024).  Ciprofloxicin and levofloxacin may be considered, however are not first-line in areas with increased fluoroquinolone resistance (Fernandes 2019). 

Patients having severe diarrhea should seek medical evaluation in addition to starting antibiotics, per Dr. Titanji.  Oral rehydration salts are also an incredibly important part of treating patients with traveler’s diarrhea (CDC 2024).  They are widely available in global pharmacies because they are an essential WHO medication. She recommends patients obtain those and consume to stay on top of fluid losses (Fernandes 2019).

Dr. Titanji’s quick way to think through timing of symptoms and etiology:

– Bacterial toxin mediated  – Diarrhea after 1-6 hrs

-Viral infections and non-toxin mediated bacteria – Diarrhea after 1-2 days

-Parasitic infections – Diarrhea after 1-2 weeks

Prophylaxis should be considered in immunosuppressed patients, solid organ transplant recipients, or those older than 65 with multiple comorbidities (CDC 2024).  Rifaximin is the recommended option (Fernandes 2019, CDC 2024), although there can be insurance coverage challenges. Bismuth salicylate can also prevent traveler’s diarrhea but the dose is quite high. 

Vaccination Recommendations

Always review the handy CDC Yellow Book and NHS Fit for Travel  to understand the specific vaccine recommendations.  Get patients up-to-date with the standard vaccines, including MMR, Tdap, seasonal Covid and seasonal flu. Generally, parts of sub-Saharan Africa and parts of South America are areas where a patient might require the yellow fever vaccine. It is a live vaccine, so it is contraindicated in patients who are immunocompromised. 

Blood donation and organ donation should not occur if you’ve recently received yellow fever vaccine (Gould 2023). In elderly patients,  there an elevated risk for yellow fever vaccine-associated viscerotropic disease (YEL-AVD), and yellow fever vaccine-associated neurologic disease (YEL-AND) from vaccination which can be quite severe and even cause death(CDC 2021).  As with all our counseling, vaccination should be approached in a shared-decision making manner. Some, but not all countries, will accept a waiver based on age, per Dr. Titanji. 

Patients do not need a specific certificate notating the yellow vaccine, they just require appropriate vaccination documentation (ie: immunization record with administration information). Dr. Titanji recommends having patients shop around for pricing if there are issues with coverage for travel vaccination. She reports most locations will be quite upfront with how much the vaccines might cost. 

Rabies, typhoid, cholera, Japanese encephalitis vaccinations may be considered in certain instances, but Dr. Titanji does not routinely recommend unless the patient has specific risk factors based on their travel activities. The dengue vaccine exists as well, but is only approved in children and adolescents living in dengue areas with previous confirmed dengue (CDC, 2024). Serologies for dengue are also somewhat limited. She is hopeful for new dengue vaccinations coming down the pike. 

Important pearl: patients need to obtain vaccination in advance of travel, some of which require several months between doses. 

Links

1. CDC Yellow Book
2. UK’s Fit for Travel
3. WHO Disease Outbreaks News

Goal

Listeners will have more comfort navigating travel medicine office visits. 

Learning objectives

After listening to this episode listeners will…

1. Review malaria risks and understand the importance of prophylaxis and mitigation strategies.
2. Describe multiple different antimalarial regimens.
3. Recognize appropriate vaccination needs for travelers, including the yellow fever vaccine.

Disclosures

Dr. Titanji reports no relevant financial disclosures. The Curbsiders report no relevant financial disclosures. 

Citation

Garbitelli B, Titanji B, Williams PN, Watto MF. “Travel Medicine, Malaria, Traveler’s Diarrhea, Yellow Fever, and more! with Dr. Boghuma Titanji ”. The Curbsiders Internal Medicine Podcast. thecurbsiders.com/category/curbsiders-podcast July 15, 2024.