Travel & EndemicNewsletter
FEBRUARY 2024

DENGUE

Prioritization of Vaccines for Travelers:
A Post-COVID-19 Era Update
A literature search on the epidemiology of travel-related VPD and synthesized data for eachdisease with a focus on symptomatic cases and on the impact of the respective infection
among travellers, considering the hospitalization rate, disease sequela and case fatality rate.
The data summarized may provide a tool for travel health professionals to prioritize
preventive strategies for their clients against VPD. Updated assessments on incidence andimpact are ever more important since new vaccines with travel indications (e.g. dengue) havebeen licensed or are undergoing regulatory review.
Conclusions:• Yellow fever has become more relevant for travelers given the recent trends inepidemiology, with an estimated risk of 1 case per 1,000 person-months in West Africa and1 case per 10,000 person-months in South America.
• Hepatitis A has decreased globally with the improvement of vaccination programs andsanitation, although regional risk exists (highest in Africa).
• Dengue is a new VPD that is considered to occur more frequently than animal bites but
less frequently than inﬂuenza.
• VPD risks are observed in travelers going to areas other than low- and middle-income
countries (e.g., inﬂuenza, COVID-19, and tick-borne encephalitis).
• Incidence of VPD is one metric that should be considered in pretravel counseling andshared clinical decision-making. Other important considerations are acute impact of agiven infection, health system coverage, cost of vaccine to a traveler, potential cumulative
exposure of the traveler, and potential for long-term disability associated with an infection.

More at academic.oup.com

VACCINESDEVELOPMENT
Live, Attenuated, Tetravalent Butantan–Dengue Vaccine inChildren and Adults• Butantan–Dengue Vaccine (Butantan-DV) is an investigational, single-dose, live, attenuated,
tetravalent vaccine against dengue disease, but data on its overall efficacy are needed. In an ongoingphase 3, double-blind trial in Brazil, participants were randomly assigned to receive Butantan-DV orplacebo, with stratification according to age. The objectives of the trial were to evaluate overall vaccine
efficacy against symptomatic, virologically confirmed dengue of any serotype occurring more than 28
days after vaccination.
• Conclusions:
A single dose of Butantan-DV prevented symptomatic DENV-1 and DENV-2, regardless of dengue
serostatus at baseline, through 2 years of follow-up.

More at nejm.org

ZIKA &DENGUE

Inﬂuence of previous Zika virus infection on acute dengue episode
The co-circulation of ﬂaviviruses in tropical regions has led to the hypothesis that immunity
generated by a previous dengue infection could promote severe disease outcomes insubsequent infections by heterologous serotypes. This study investigated the inﬂuence ofantibodies generated by previous Zika infection on the clinical outcomes of dengue infection.
In this study, the prior Zika virus infection was associated with a higher frequency of more
severe forms in subsequent dengue. Preliminary ﬁndings did not suggest that themechanism is the same one triggered in secondary dengue, known as antibody-dependentenhancement.

More at journals.plos.org* About the Impact of prior dengue virus infection on Zika virus infectionduring pregnancy in marmosets you can read here (was published in the September 23
Travel & Endemic Newsletter edition)

DISEASE
OUTBREAKS
ZIKA

Thailand reports more than 300% increase in Zika infections in2023
Zika has surged to levels not seen since before thepandemic in Thailand, with more than 750 people
infected and at least 13 babies born with birthdefects in 2023.
The pathogen has long circulated in the southeast
Asian nation, but cases jumped by almost 300 percent last year as the virus, carried by the Aedes
aegypti mosquito, resurfaced following severalyears of limited transmission.
A coordinated effort, combining data sharing,
integrated control programs, communityengagement, and innovative methods, is essential tocurb the spread of arboviruses like Zika and protect
public health in Thailand.

More at telegraph.co.uk

Source:ministry of publichealth thailand

ZIKA In Mali
The Mali Ministry of Health (MOH) reported 12 conﬁrmed Zika cases in December 23 from theBarnako region.

More at outbreaknewstoday.substack.com

ZIKA In Singapore

There were 22 Zika cases in Singapore in the ﬁrst half of 2023. A total of 15 cases were foundin a cluster at Kovan. The cluster is now closed and is currently under surveillance.

More at channelnewsasia.com

DENGUESouth America dengue spike: South America is seeing a surge in cases of themosquito-borne disease dengue during the southern hemisphere summer.
Argentina has seen a sharp spike in the disease that’s endemic in much of Latin
America. Brazil this month has started spraying insecticide from trucks as the disease
rips through previously unaffected regions. hospitals in Paraguay have set up nightclinics to attend to the sick due to elevated dengue activity.

More at gulf-times.com

Dengue cases in Brazil nearly triple: High rainfall and temperatures associatedwith El Niño phenomenon and climate change have caused cases of dengue fever inBrazil to triple in the ﬁrst few weeks of 2024. Health officials predict record casenumbers this year of between 1.7 million and 5 million. Brazil will become the ﬁrst
country in the world to offer a dengue vaccine through the public health system.

More at laprensalatina.com

Costa Rica’s Dengue Cases: As 2024 unfolds, Costa Rica ﬁnds itself grappling withan unwelcome guest that refuses to leave – dengue fever. This mosquito-borne menace
has been a thorn in the side of this tropical paradise for years, impacting both locals andtourists alike. With over 1,000 cases conﬁrmed early in the year, the situation is buzzing
with concern.

More at costaricantimes.com

Peru increase in dengue cases: The Peru Ministry of Health (Minsa) issued an
epidemiological alert on January 31 due to an increase in dengue fever across thecountry.

More at outbreaknewstoday.substack.com

MEASLES

Measles outbreaks in U.S. and across England:

The sudden outbreak of measles has sounded alarm bells among experts in the US,
Europe and several parts of Asia.
The World Health Organization (WHO) recently announced a 30-fold increase inmeasles cases across Europe and has called for urgent action to close immunity gaps
through vaccination. The number of cases in the European region has skyrocketed to42,200 in 2023, compared to 941 in 2022.
The Center for Disease Control and Prevention (CDC) has issued a health alert as
measles cases are on the rise. The CDC explains that the outbreaks are mostly amongchildren who have not been vaccinated.
Also, CDC recommends vaccination before traveling abroad.

More at healthline.com

A map of U.S. states showing those (shaded red) thathave had cases of measles recorded by health officials
this year as of February 6, 2024, and the locations of thecases.© Newsweek/Getty

International health officials have reported elevated measles activity in multiple
areas in England, especially West. Local health officials have urged the public to
get their measles vaccinations up to date to prevent disease transmission.
More at crisis24.garda.com
The UK Health Security Agency (UKHSA) has declared a national incident.
More at healthline.com
Kazakhstan has seen the highest number of measles cases, with 13,677 recorded
in 2023, 65% of which were in children under ﬁve.
More at weforum.org

Sri Lanka experiencing an imported Measles outbreak
Sri Lanka is currently experiencing an imported Measles outbreak since May 2023.
considerable number of cases are reported to date predominantly among vaccine
refusal communities and subsequently spreading to those who were partiallyvaccinated (between 9 months - 3 years) or not eligible for MMR vaccination
through routine immunization programme (< 9 months of age). As a response
measure to this situation, the Ministry of Health has launched a Supplementary
Immunization Activity (SIA) on 6th January 2024, targeting vulnerable children (6 –9 months of age) in selected high-risk districts.
More at epid.gov.lk

Measles outbreak in Israel among unvaccinated individuals

The Health Ministry knows of 20 reported cases of the disease in recent months,
two in the Haifa area, six in the north, 10 in Tel Aviv, one in Netanya, and one in
Jerusalem all contracted measles.
More at jpost.com
Due to the increase in the incidence of measles in the world together with thestate of emergency in Israel and the extensive evacuation of citizens, there isconcern of measles outbreaks in additional centers. Therefore, The Ministry of
Health issued national interim guidelines for raising awareness, preventative andtreatment guidelines in the various medical settings and health bureaus.
The guidelines are based on current recommendations of the American
Association of Pediatricians (RedBook) with adjustments for Israel, according torecommendations Advisory Committee on Infectious Diseases and Vaccines.
Link to Guidlines

POLIO

Kenya declares polio outbreak
Kenya conﬁrmed a polio outbreak, raising concerns about the contagious disease's
resurgence in the country after a decade, prompting the government in Nairobi toannounce the launch of emergency vaccination campaigns in high-risk areas,targeting more than 7.5 million children in affected counties.
Fourteen cases of polio have been conﬁrmed as of Jan. 27. All cases have been
detected in Garissa County, which is located in northeastern Kenya, as well as in
the capital Nairobi. Kenya successfully eradicated wild poliovirus in 2014 and was
declared polio-free.
More at aa.com.tr

CHOLERA OUTBREAK• After decades of progress against cholera, the disease has seen a global upsurge
since 2021. In 2023 over half of the countries reporting cases were from Africa.
• Door-to-door vaccination starts to ﬁght Zimbabwe cholera outbreak. Zimbabwe
launched a cholera vaccination campaign to immunise over 2 million people
against the waterborne disease. Cholera had killed 452 people and infected a
total of 20,446 in the southern African country as of Jan 24, since the outbreakstarted in February 2023, according to health ministry statistics. About half ofthe cases have involved children.
More at dunyanews.tv

Somalia Floods Trigger Cholera Outbreak

The IRC (International Rescue Committee) said: “The outbreak presents a grave
public health crisis, with the majority of cases being severe and affecting the mostvulnerable population.”
More at news.yahoo.com

Zambia Battles Worst Outbreak In Decades

Zambia is among the latest to battle its worst outbreak in decades and it'svaccination rollout is under pressure as stocks face increased global demand.
More at bbc.com

HEPATITIS E

A deadly Hepatitis E outbreak in South Sudan

Doctors Without Borders/Médecins Sans Frontières (MSF) announced that sinceApril 2023, they have treated 501 cases of Hepatitis E at the MSF hospital in Old
Fangak, Jonglei state. In addition, 19 deaths were reported, primarily in women.
This has prompted MSF to launch a mass vaccination campaign in collaboration
with the Ministry of Health to safeguard women and girls of reproductive age, who
are at greatest risk of death from the disease.
More at doctorswithoutborders.org

A spike in hepatitis E infections in Finland
The National Institute of Health and Welfare (THL) is investigating the reasons forthe increase.
In January 24, 19 people fell ill due to a hepatitis E infection in different parts ofthe country. In 2023, only one hepatitis E infection was reported.
More at foodsafetynews.com

MALARIA

Assessing the daily natural history of asymptomatic
Plasmodium infections in adults and older children in Katakwi, Uganda
This longitudinal cohort study aimed to classify the natural history of Low-density
asymptomatic Plasmodium infections in a high transmission area.
Participants were healthy, malaria-asymptomatic, afebrile, adults (age 18–59 years) and olderchildren (age 8–17 years) in Katakwi District, Uganda, who were negative for Plasmodium
infection on rapid diagnostic tests.
This study evaluated infection proﬁles and dynamics of asymptomatic, low-density
Plasmodium infections using dried blood spots (DBSs) self-collected by participants daily for
29 days. About a third of all DBSs collected were positive for Plasmodium and 60% of allparticipants had a Plasmodium infection identiﬁed during the study. This results highlight thepitfalls of single timepoint measurements for Plasmodium infection status, especially inareas with high prevalence of low-density infections. The ﬁndings indicate that more
frequent sampling might be needed to better understand the different types of trajectories
in endemic areas and the frequency at which these infections occur, and to assess theeffect of these dynamics on transmission and elimination efforts.

More at thelancet.com

Treatment Failure in a UK Malaria Patient
A traveler, who returned to the UK from Uganda in 2022with Plasmodium falciparum malaria, twice failed
treatment with full courses ofartemether-lumefantrine. Parasites from the patient
exhibited signiﬁcantly reduced susceptibility to andlumefantrine. Genotyping identiﬁed the presence of
pfk13 mutations encoding L145V and A675V. Parasites
with reduced susceptibility to both artemisinin andlumefantrine may be emerging in Uganda.

More at academic.oup.com

Similar Malaria treatment failure report from Israel, waspublished in the December 23 edition.

More at academic.oup.com

Effect of primaquine dose on the risk of recurrence in patientswith uncomplicated Plasmodium vivax
A systematic review and individual patient datameta-analysis to investigate the efficacy and tolerabilityof different primaquine dosing regimens to prevent P
vivax recurrence.
23 studies with patient-level data from 6879 patientsfrom 16 countries were included in the efficacyanalysis. The results show the beneﬁt of high total
dose (7 mg/kg) compared with low total dose (3·5mg/kg) primaquine to reduce vivax recurrences acrossmost vivax-endemic regions. The increase in the daily
dose of primaquine (from 0·25 mg/kg per day to 0·5–1mg/kg per day) resulted in a small increase ingastrointestinal adverse events.
The implications of all the available evidence are that High total dose primaquine (7 mg/kg)
might halve the risk of P vivax recurrences in most vivax-endemic regions over 180 days offollow-up. Increased daily doses need to be balanced against increased risk ofgastrointestinal side-effects and haemolysis in vulnerable patients.

More at academic.oup.com

WHO Certiﬁed Cape Verde as Malaria Free country
With this signiﬁcant achievment, Cape Verde joins the ranks of 43 countries and 1 territorythat WHO has awarded this certiﬁcation. Cape Verde is the third country to be certiﬁed in
the WHO African region, joining Mauritius and Algeria.
Malaria elimination certiﬁcation is granted by the WHO when a country has:shown that malaria transmission by Anopheles mosquitoes has been interrupted nationwide
for at least three consecutive years demonstrated the capacity to prevent there-establishment of malaria transmission Malaria burden is the highest on the African
continent, which accounted for approximately 95% of global malaria cases and 96% ofrelated deaths in 2021.
Malaria prevention measures are not required for travellers to Cape Verde, although insect
bites should be avoided as other vector-borne infections may be present.

More at afro.who.int

UPCOMING
CONGRESSESTHE ANNUAL MEETING OF
THE ISRAEL SOCIETY FOR
PARASITOLOGY,PROTOZOOLOGY AND
TROPICAL DISEASES

06 March 2024
ADELIS Conference center
Tel Aviv, Israel
Click for Registration

Contact | lital.hertz@sanoﬁ.com
Scientiﬁc Editor | Prof. Eli Schwartz
MAT-IL-2400067