Vector-Borne Diseases in Arab Countries

Abdulla Salem Bin Ghouth, Ali Mohammad Batarfi,Adnan Ali Melkat, and Samirah Elrahman

ContentsIntroduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2Vector-Borne Diseases in Arab Countries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3Brief Epidemiological Description of the Most Important Vector-BorneDiseases in EMRO/WHO Region . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3Malaria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3Dengue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5Dengue in the WHO Eastern Mediterranean Region . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6Schistosomiasis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6Leishmaniasis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7Filariasis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8Crimean-Congo Hemorrhagic Fever (CCHF) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9Onchocerciasis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9Yellow Fever . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10Plague . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10Murine Typhus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11Relapsing Fever . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11Chikungunya . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12West Nile Fever . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12Rift Valley Fever . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

A. S. B. Ghouth (*) · A. M. Batarfi · A. A. MelkatHadramout University, Yemen, Yemene-mail: abinghouth2007@yahoo.com; ambatarfi@yahoo.com

S. Elrahman

e-mail: samhamid2002@yahoo.co.uk

© Springer Nature Switzerland AG 2019I. Laher (ed.), Handbook of Healthcare in the Arab World,https://doi.org/10.1007/978-3-319-74365-3_57-1

1

AbstractVector as a term is universally applied to hematophagous mosquitoes, and we usethis definition in this chapter to describe epidemiology of vector-borne diseases inArab countries.

About 15 vector-borne diseases (VBDs) are common in the Arab countries withgreat variations from one country to another. They are malaria, dengue, schistoso-miasis, leishmaniasis (visceral and cutaneous), lymphatic filariasis, Crimean-Congo hemorrhagic fever (CCHF), onchocerciasis, yellow fever, plague, murinetyphus, relapsing fever, chikungunya, West Nile virus, and Rift Valley fever.

Understanding the epidemiology of each VBD makes the coordination towardregional control possible. In this chapter, the authors presented the epidemiolog-ical distribution of the most common 15 VBDs in Arab countries. The resultsshow that there are two diseases of complex epidemiology (malaria and schisto-somiasis), but their distribution was limited in certain countries including Sudan.A lot of neglected tropical diseases including emerging diseases like dengue andCrimean-Congo hemorrhagic fever (CCHF) and chikungunya are common.Leishmaniasis, either visceral or cutaneous, is spread in most of the Arab coun-tries, while Sudan bears the most burden of the VBDs in the Arab world.

KeywordsVector-borne diseases · Arab countries · Epidemiology

Introduction

Vectors are living organisms that can transmit infectious diseases between humans orfrom animals to humans. Many of these vectors are bloodsucking insects that ingestdisease-producing microorganisms during a blood meal from an infected host(human or animal) and later inject them into a new host during their next bloodmeal. Mosquitoes are the best-known disease vectors. Others include some speciesof ticks, flies, sandflies, fleas, bugs, and freshwater snails (WHO 2014) (Table 1).

Many parasites and pathogens responsible for some of the most important diseasesin humans, agriculture, and nature are routinely described as “vector-borne.”However,different definitions of a vector are used in different fields. For instance, the term isuniversally applied to hematophagous mosquitoes (Wilson et al. 2017), and we usethis definition in this chapter to describe epidemiology of vector-borne diseases inArab countries.

Vector-borne diseases are illnesses caused by pathogens and parasites in humanpopulations and account for more than 17% of all infectious diseases (http://www.emro.who.int/egy/programmes/neglected-tropical-diseases.html). More than onebillion people are infected every year, and more than one million people die fromvector-borne diseases such as malaria, dengue, schistosomiasis, leishmaniasis,Chagas disease, yellow fever, lymphatic filariasis, and onchocerciasis (WHO 2014).

2 A. S. B. Ghouth et al.

One sixth of the illness and disability suffered worldwide is due to vector-bornediseases, with more than half the world’s population currently estimated to be at riskof these diseases (World Health Organization 2004).

Vector-Borne Diseases in Arab Countries

About 15 vector-borne diseases are common in the Arab countries with great varia-tions from one country to another (Table 2).

Brief Epidemiological Description of the Most Important Vector-Borne Diseases in EMRO/WHO Region

All Arab countries except Algeria and Mauritania are members of the EMRO regionof the WHO so this section will descript the main epidemiological feature of malariaas a disease and the main epidemiological features in these countries.

Malaria

Malaria is a parasitic disease that triggers fever, chills, and a flu-like illness. Symptomsusually appear after a period of 7 days or more after infection from a mosquito bite(WHO 2014).

Malaria is caused by Plasmodium parasites transmitted through the bites of femaleAnophelesmosquitoes, which are active mainly between dusk and dawn. Five parasitespecies cause malaria in humans, and Plasmodium falciparum and P. vivax are themost common. P. falciparum is the most dangerous, with the highest rates of compli-cations and mortality. This deadly form of malaria is a serious public health concern inmost countries in sub-Saharan Africa. Anopheline mosquitoes are the only vectors of

Table 1 Vectors and the diseases that they can transmit (WHO 2014)

Vector Diseases

Mosquitoes:

Aedes aegypti Dengue, yellow fever, chikungunya, Zika virus

Aedes albopictus Chikungunya, dengue, West Nile virus

Culexquinquefasciatus

Lymphatic filariasis

Anopheles Malaria

Sandflies Leishmaniasis

Triatomine bugs Chagas disease

Ticks Crimean-Congo hemorrhagic fever (CCHF), tick-borne encephalitis,typhus, Lyme disease

Fleas Plague, murine typhus

Vector-Borne Diseases in Arab Countries 3

Table

2Vector-bo

rnediseases

insomeArabcoun

tries(A

letal.2

017;

Gou

ld20

08;Cuo

mo)

Diseases

Algeria

Bahrain

Djib

outi

Egypt

Iraq

Jordan

Kuw

ait

Lebanon

Libya

Morocco

Mauritania

Oman

Qatar

Saudi

Arabia

Som

alia

Sudan

Syria

Tunisia

UAE

Yem

en

Malaria

++

++

++

++

Dengue

++

++

++

WestNile

virus

++

++

++

++

++

++

++

+

Cutaneous

leishm

aniasis

++

++

++

++

++

++

++

Visceral

leishm

aniasis

++

++

++

++

++

++

++

Schistosomiasis

++

++

++

++

++

+

Onchocerciasis

++

+

Bancroftian

filariasis

++

+

CCHF(A

letal.

2017

)+

++

++

++

++

++

+

Tick-borne

relapsingfever

++

++

+

Louse-borne

relapsingfever

++

++

Plaque

++

++

++

++

++

Murinetyphus

++

++

++

++

Chikungunya

(Gould

2008

)+

++

Yellow

fever

(Gould

2008

)+

4 A. S. B. Ghouth et al.

the Plasmodium parasites. Each of the 60 known species of Anopheles that cantransmit malaria has its own biological and ecological peculiarities. Disease transmis-sion is more intense where the mosquito species has a long lifespan and a habit ofbiting only humans, for example, An. gambiae (WHO 2014).

Burdens of malaria in Arab countries are in Sudan, Yemen, Somalia, and Dji-bouti. Saudi Arabia is in the road for malaria elimination, while Oman reported zeroindigenous malaria cases in 2017. Morocco and the United Arab Emirates weredeclared malaria-free. The other Arab countries are not risk of malaria as the diseasesis not a common health problem (Table 3).

Dengue

Dengue fever is a severe, flu-like illness. Symptoms include high fever, severeheadaches, muscle and joint pains, nausea, vomiting, swollen glands, or rash.Dengue itself is rarely fatal, but severe dengue is a potentially fatal complication,with symptoms including low temperature, severe abdominal pains, rapid breathing,bleeding gums, and blood in vomit. There are four known serotypes of dengue virus(DEN 1 to 4). Recovery from infection by one provides lifelong immunity againstthat particular serotype. However, subsequent infections by other serotypes increasethe risk of developing severe dengue (WHO 2014).

Table 3 The main malaria control measures in the most affected countries in 2017 (WHO 2017)

Country Insecticide–treated mosquito nets Indoor residual spraying

Chemoprevention

ITNs/LLINsaredistributedfree of charge

ITNs/LLINsaredistributedto all agegroups

ITNs/LLINsdistributedthrough masscampaigns toall age groups

IRS isrecommendedby malariacontrolprogram

DDT is usedfor IRS

IPTp usedto preventmalaria duringpregnancy

Seasonalmalariachemoprevention

Algeria

Saudi

Arabia

Mauritania

Sudan

Somalia

Djibouti

Yemen

Actually implemented Not implemented

Vector-Borne Diseases in Arab Countries 5

The Aedes aegypti mosquito is the primary vector of dengue. The virus istransmitted to humans through the bites of infected female mosquitoes. Once aninfected mosquito has incubated the virus for 4–10 days, it can transmit the virus forthe rest of its life. Infected humans are the main carriers and multipliers of the virus,serving as a source of the virus for uninfected mosquitoes. Patients who are alreadyinfected with the dengue virus can transmit the infection (for 4–5 days; maximum12) via Aedes mosquitoes once their first symptoms appear. The Ae. aegypti mos-quito lives in urban habitats and breeds mostly in man-made containers. This speciesis a daytime feeder; its peak biting periods are early in the morning and in theevening before dusk. Female Ae. aegypti bite multiple people during each feedingperiod. Aedes albopictus, a secondary dengue vector in Asia, has spread to NorthAmerica and Europe largely due to the international trade in used tires (a breedinghabitat), timber, and other goods such as “lucky bamboo” (a decorative house plantthat is marketed worldwide). This mosquito species can survive in cooler temperateregions of Europe. Ae. albopictus has a wide geographical distribution, is particu-larly resilient, and can survive in both rural and urban environments. The mosquito’seggs are highly resistant and can remain viable throughout the dry season. It is also adaytime feeder (WHO 2014).

Dengue in the WHO Eastern Mediterranean Region

Outbreaks of dengue have been documented in the Eastern Mediterranean Region,possibly as early as 1799 in Egypt (Messina et al. 2015). The frequency of reportedoutbreaks continues to increase, with outbreaks, for example, in Sudan (1985, DEN-1and DEN-2) (25) and in Djibouti (1991, DEN-2) (Amazigo 2006). Recent outbreaks ofsuspected dengue have been recorded in Saudi Arabia, Sudan, and Yemen, 2005–2006(Messina et al. 2015). Yemen is also affected by the increasing frequency andgeographic spread of epidemic dengue, and the number of cases has risen since themajor DEN-3 epidemic that occurred in the western Al-Hudaydah governorate in2005. In 2008, dengue affected the southern province of Shabwa. Since the first case ofDHF died in Jeddah in 1993, Saudi Arabia has reported three major epidemics: aDEN-2 epidemic in 1994 with 469 cases of dengue, a DEN-1 epidemic in 2006 with1269 cases of dengue (WHO 2009). In Somalia infections of DENV-1, DENV-2,DENV-3, and coinfections of DENV-1/2 and DENV-2/3 serotypes were identified inthe Magdieshou outbreak in 2011 (Kyobe Bosa et al. 2014) (Fig. 1).

Schistosomiasis

Schistosomiasis is a parasitic disease caused by trematodes of the genus Schistosoma.Urinary schistosomiasis is a disease caused by Schistosoma haematobium of tropicaland intertropical zones. The disease is endemic in several areas in Africa, Madagascar,and the Middle East. The route of infection for humans is skin exposure to parasite-

6 A. S. B. Ghouth et al.

infested freshwater during routine occupational, recreational, or domestic activities(Colley et al. 2014).

The parasitic transmission cycle starts when people with urinary schistosomiasiscontaminate freshwater sources with urine that contains parasite eggs. Under specificenvironmental conditions, the eggs hatch, and the released miracidia penetrate specificfreshwater snails, the intermediate hosts. Cercariae, the infective form, are released bythe snails and can penetrate the skin of a human host upon exposure to fresh water. Intheir human hosts, adult Schistosoma live 3–10 years, but in some cases, they can livefor 40 years. The disease caused by S. haematobium is characterized by chronicurogenital complications due to the presence of eggs in tissues (Bamgbola 2014). Inendemic areas, the infection in people can remain subclinical for a long period but stillcauses progressive damage to the urogenital tract (Eurobian Center for DiseaseControl and Prevention).

Leishmaniasis

The leishmaniases are a group of diseases caused by protozoan parasites from >20Leishmania species that are transmitted to humans by the bite of infected femalephlebotomine sandflies (98 of which are of medical importance). There are four mainforms of the disease: visceral leishmaniasis (VL, also known as kala-azar), post-kala-azar dermal leishmaniasis (PKDL), cutaneous leishmaniasis (CL), and mucocutaneousleishmaniasis (MCL). While cutaneous leishmaniasis is the most common form of thedisease, visceral leishmaniasis is the most serious and can be fatal if untreated (WHO).

1994: 673 suspected cases,DEN-2:

Djibauti (1991-1992, DEN-2)Somalia (1982, 1993, DEN-2)

Al-Hudaydah, Mukkala, Shaabwa(1994, DEN-3, no data);

Al-Hudaydah, Yemen(September 2000, DEN-2, 653 suspected cases, 80 deaths (CFR = 12%));

Al-Hudaydah, Yemen(March 2004, 45 suspected cases, 2 deaths);

Al-Hudaydah, Mukkala(March 2005, 403 suspected cases, 2 deaths);

Sudan (No data)

289 confirmed cases6 confirmed cases2 confirmed cases

15 confirmed cases0 confirmed cases

0 confirmed cases0 confirmed cases

3 confirmed cases

1995: 136 suspected cases,1996: 57 suspected cases,1997: 62 suspected cases,1998: 31 suspected cases,1999: 26 suspected cases,2000: 17 suspected cases,2001: 7 suspected cases,2005: 32 suspected (confirmed)

Fig. 1 Outbreaks of dengue fever in the WHO Eastern Mediterranean Region, 1994–2005 (WHO2009)

Vector-Borne Diseases in Arab Countries 7

Leishmaniasis is a major health problem worldwide, with several countries reportingcases of leishmaniasis resulting in loss of human life or a lifelong stigma because ofbodily scars. The Middle East is endemic for cutaneous leishmaniasis, with countrieslike Syria reporting very high incidence of the disease (WHO). Leishmaniasis isendemic in Iraq, where both forms of the disease, cutaneous and visceral, are found,while cutaneous leishmaniasis is the most common form of the disease present in SaudiArabia and Jordan (Salam et al. 2014). Although other Arab countries reported eitherforms of leishmaniasis like Yemen and Morocco, Tunisia but three Arab countries arewithin the ten top countries in the global burden of cutaneous leishmaniasis; they areAlgeria, Syria, and Sudan, while 90% of visceral leishmaniasis in the world occurred insix countries, including Sudan (WHO).

Filariasis

Lymphatic filariasis (LF), also known as elephantiasis, is a major disease of tropicaland subtropical regions worldwide. LF is endemic in 80 countries, and it is estimatedthat 120 million people are infected, with one third of them suffering from chronicmanifestation of the disease. One billion more individuals are at risk of acquiring theinfection (Ottesen 2002).

Lymphatic filariasis is a mosquito-borne parasitic disease caused by three nematodeworms of the family Filariidae: Wuchereria bancrofti, Brugia malayi, and B. timori.Wuchereria bancrofti is responsible for 90% of worldwide infections, with 9% causedby B. malayi in Southeast and Eastern Asia, whereas 1% results from infection with

Fig. 2 Global distribution of lymphatic filariasis; Egypt, Sudan, and Somalia are the most affectedArabic countries (CDC)

8 A. S. B. Ghouth et al.

B. timori in the Pacific region (Michael and Bundy 1997). The disease is transmittedby Anopheles, Culex, and to a lesser extent by Aedes andMansoniamosquito species.

The disease is known to be focally endemic in three Arabic countries: Egypt,Sudan, and the Republic of Yemen, whereas the LF situation in Djibouti, Oman,Saudi Arabia, and Somalia is currently uncertain. However, clinical cases have beenreported in Oman, Saudi Arabia, and Somalia (El and Ramzy1 2003) (Fig. 2).

Crimean-Congo Hemorrhagic Fever (CCHF)

Crimean-Congo hemorrhagic fever (CCHF) is a vector-borne viral disease, widelydistributed in different regions of the world. The fever is caused by the CCHF virus(CCHFV), which belongs to the Nairovirus genus and Bunyaviridae family. Thevirus is clustered in seven genotypes, which are Africa-1, Africa-2, Africa-3,Europe-1, Europe-2, Asia-1, and Asia-2. The virus is highly pathogenic in nature,easily transmissible, and has a high case fatality rate of 10–40%. The reservoir andvector of CCHFVare the ticks of the Hyalomma genus. Therefore, the circulation ofthis virus depends upon the distribution of the ticks. The virus can be transmittedfrom tick to animal, animal to human, and human to human. The major symptomsinclude headache, high fever, abdominal pain, myalgia, hypotension, and flushedface. As the disease progresses, severe symptoms start appearing, which includepetechiae, ecchymosis, epistaxis, bleeding gums, and emesis (Aslam et al. 2016).

Historical evidence points to the probable description of CCHF by a physician inTajikistan in 1100 AD in a patient with hemorrhagic manifestations (Al-Abri et al.2017; Hoogstraal 1979; Maltezou and Papa 2011). In recent times, the disease wasfirst recognized during an outbreak in Crimea in 1944; however, it later becameevident that the causative agent was identical to a virus isolated from a patient inCongo in 1956, and the name CCHF was adopted (Messina et al. 2015). The diseaseis endemic in many regions, such as Africa, Asia, Eastern Europe, and the MiddleEast (Messina et al. 2015). The known distribution of CCHFV covers the greatestgeographic range of any tick-borne virus, and there are reports of viral isolationand/or disease from more than 30 countries across four regions: Africa (DemocraticRepublic of Congo, Uganda, Mauritania, Nigeria, South Africa, Senegal, Sudan),Asia (China, Kazakhstan, Tajikistan, Uzbekistan, Afghanistan, Pakistan, India),Europe (Russia, Bulgaria, Kosovo, Turkey, Greece, Spain), and the Middle East(Iraq, Iran, Kuwait, Saudi Arabia, Oman, the United Arab Emirates (UAE)) (WorldHealth Organization 2013).

Onchocerciasis

Onchocerciasis is caused by worms,Onchocerca volvulus. The adult worms measurenearly a meter long and live in coiled mating pairs in nodules under the skin.Reproducing adult females spawn about 2000 immature worms every day. Thesetiny juvenile worms migrate throughout the skin and eyes, causing the various

Vector-Borne Diseases in Arab Countries 9

symptoms of the disease. Although they are damaging, these immature wormscannot mature to adulthood without being transmitted by a blackfly of the genusSimulium. This fly breeds in rapidly flowing streams and rivers and thus the name“river blindness.” The most important vector is Simulium damnosum sensu lato,which has a wide range throughout Africa and the Middle East (Amazigo 2006).

Onchocerciasis used to be endemic in some 30 countries in Africa (includingSudan) where over 99% of all cases in the world were found (Zouré et al. 2014;World Health Organization 1995). In Yemen, the disease, locally termed as sowda, isunique in its clinicopathologic pattern, being of the localized, non-blinding, hyper-reactive onchocercal skin disease (Abdul-Ghani et al. 2016).

Yellow Fever

Yellow fever (YF) is a viral disease, endemic to tropical regions of Africa and theAmericas. YF principally affects humans and nonhuman primates and is transmittedvia the bite of infected mosquitoes. The agent of YF, yellow fever virus (YFV), cancause devastating epidemics of potentially fatal, hemorrhagic disease (Gardner andRyman 2010). Yellow fever virus is the prototypic member of the genus Flavivirus,family Flaviviridae, flavus being Latin for yellow. The three genera in this familycontain a large number of major human and veterinary pathogens (Gould andSolomon 2008), including dengue (DENV), Japanese encephalitis (JEV), and WestNile (WNV) viruses in the Flavivirus genus (Gardner and Ryman 2010).

Plague

Plague is a zoonotic disease caused by the gram-negative bacterium Yersinia pestis(Dennis et al.). Humans are extremely susceptible to plague and may be infected eitherdirectly or indirectly. Indirect transmission through the bite of a flea is the mostcommon route of transmission between plague-infected rodents and humans.Human infection most frequently occurs when an epizootic develops among syn-anthropic rats in centers of human population, following contact with infected wildrodents. Commensally rat fleas, including plague-infected fleas, leave the bodies ofrats killed by plague seeking a blood meal from another host and may bite humanbeings. Humans who contract the disease may subsequently become infective to otherpeople (Tikhomirov 1999).

According to the World Health Organization (WHO) reports published in 2009(World Health Organization 2009) and 2016 (Bertherat 2016), >95% of the 15,396cases reported worldwide during 2004–2014 occurred in Africa, especially in theDemocratic Republic of the Congo (DRC, 8,379 cases), Madagascar (5,583 cases),Uganda (436 cases), and Tanzania (World Health Organization 1983, Abedi et al2018).

Natural foci of plague are known to exist in broad areas of Africa. These includeareas in the Democratic Republic of the Congo, Kenya, Lesotho, Libya, Madagascar,

10 A. S. B. Ghouth et al.

Mauritania, Mozambique, Namibia, Senegal, South Africa, Tanzania, Uganda, andprobably Egypt. In Asia, Endemic foci are found in Cambodia, China, India, Indone-sia, Iran, Mongolia, Myanmar, Nepal, Vietnam, and the southern part of the ArabianPeninsula, the Yemen-Saudi Arabian border, and in Saudi Arabia (Tikhomirov 1999).

Plague is one of three epidemic diseases still subject to the International HealthRegulations and notifiable to the World Health Organization (1983). Recently,Madagascar in Africa reported a fatal plague outbreak in August 2017 (WHO/AFRO).

Murine Typhus

Murine typhus, also called endemic typhus or flea-borne typhus, is a disease causedby a bacterium “Rickettsia typhi.”Murine typhus is spread to people through contactwith infected fleas. People get sick with murine typhus when infected flea feces arerubbed into cuts or scrapes in the skin. In most areas of the world, rats are the mainanimal host for fleas infected with murine typhus. Murine typhus occurs in tropicaland subtropical climates around the world where rats and their fleas live (Murinetyphus). Currently there have been reports of the presence of Rickettsia typhi inAmerica in countries like Brazil in 2005, which reports the presence of rickettsialantibodies to Rickettsia typhi in a rural community as well as other Rickettsia andRickettsia rickettsii, causal agent of Rocky Mountain spotted fever (da Costa et al.2005); a similar study was conducted in Argentina also founding these antibodies ina healthy population of a community rural (Ripoll et al. 1999). The importance aboutthese studies is the presence of R. typhi in the population which has already beeninfected possibly being misdiagnosed (Peniche Lara et al. 2012). In Arab countries,murine typhus seems to be frequent in Tunisia (Znazen et al. 2013) and maybe inAlgeria and Egypt (Angelakis et al. 2010).

Relapsing Fever

Relapsing fever is characterized by recurring episodes of fever and nonspecificsymptoms (e.g., headache, myalgia, arthralgia, shaking chills, and abdominal com-plaints). The illness is caused by infection with Borrelia species that vary theirsurface antigens, lending to repeated spirochetemias and stimulation of the immunesystem by each new antigen and a febrile response by the patient (Goubau 1984;Dennis and Hayes 2005). These Borrelia (spirochetes) are transmitted to humans byexposure to the bite of an infected Ornithodoros tick (TBRF) or contact with thehemolymph of an infected human body louse (Pediculus humanus) (louse-bornerelapsing fever [LBRF] or epidemic relapsing fever) (Southern and Sanford 1969).LBRF is caused by infection with Borrelia recurrentis. These spirochetes areintroduced by crushing the louse (e.g., when scratching), which releases the insect’sinfected hemolymph and contaminates abraded or normal skin and mucous mem-branes (Dworkin et al. 2008). In Arab countries, louse-borne relapsing fever

Vector-Borne Diseases in Arab Countries 11

occurred in Sudan (Ahmed et al. 1980). It remains endemic and seasonally epidemicin the highlands of Sudan and Somalia and the hilly areas of Yemen (Warrell 2017).

Chikungunya

Chikungunya virus (CHIKV) is an alphavirus whose principal vectors are the Aedesaegypti and Aedes albopictus mosquitoes. In the Middle East and North Africa(MENA), the epidemiology of CHIKV remains poorly characterized despite recentreports of outbreaks and novel transmission in the Arabian Peninsula. Autochthonoustransmission was identified in eight countries in the Arab region (Djibouti, Egypt, Iraq,Kuwait, Saudi Arabia, Somalia, Sudan, and Yemen). Recently, CHIKVoutbreaks werereported from Djibouti, Sudan, and Yemen (Humphrey et al. 2017).

Chikungunya virus (CHIKV) is an alphavirus of the Togaviridae family which istransmitted by Aedes mosquitoes and causes epidemic arthritis or arthralgia togetherwith fever and rash (Rougeron et al. 2015). Since its discovery in 1952, CHIKV wasresponsible for sporadic and infrequent outbreaks. However, since 2005, globalchikungunya outbreaks have occurred, inducing some fatalities and associated withsevere and chronic morbidity. Chikungunya is thus considered as an importantre-emerging public health problem in both tropical and temperate countries, where thedistribution of the Aedes mosquito vectors continues to expand (Rougeron et al. 2015).

West Nile Fever

West Nile virus (WNV) is a neurotropic human pathogen that is the causative agentof West Nile fever and encephalitis (Colpitts et al. 2012). Others reported on theoccurrence of West Nile virus fever in Tunisia, the United Arab Emirates, SaudiArabia, Qatar, Jordan (Malik et al. 2013), and Morocco (Negev et al. 2015). Thevirus has also spread to dengue-endemic countries such as Sudan, Yemen, Djibouti,and Somalia.

Rift Valley Fever

Rift Valley fever (RVF) is a zoonotic disease and humans become infected throughcontact with tissues of infected animals or mosquito bites. Infection in humans isusually associated with mild to moderately severe influenza-like illness, but severecomplications such as retinal damage and blindness, encephalitis, or hemorrhagicdisease occur in about 1% of patients (FAO).

Outbreaks were reported exclusively from sub-Saharan Africa until 1977–1978,when infections in 18,000 persons and 598 deaths were reported in Egypt (El-Akkad1978; Meegan 1979). In 1987, after dam construction on the Senegal River causedflooding in the lower Senegal River area, a major epidemic, which caused200 human deaths, occurred for the first time in Mauritania (Digoutte and Peters

12 A. S. B. Ghouth et al.

1989). In 2001, epidemic of RVF in southwestern Saudi Arabia and the neighboringnorthwestern regions of Yemen represented the first occurrence of this diseaseoutside of Africa (Madani et al. 2003). In East Africa, epidemics have been associ-ated with above average rainfall favouring the breeding of the mosquito vectors ofRVF. This has been the case in late 2006 and early 2007, when El Niño-drivenrainfalls dramatically affected the Horn of Africa, with subsequent flooding and RVFoutbreaks in Kenya, Somalia and Tanzania. In mid-October 2007, Rift Valley fevercases in humans were detected in the Kosti District, White Nile state of Sudan(FAO).

There is a relationship between transmission of RV virus and the trade of livestock,and it is expected that there is a large trade flux of livestock moving from the Africaneastern region to the Arabian Peninsula, Saudi Arabia and Yemen in particular. Sudanand Somalia are the two countries of the Horn of Africa with the biggest volume oflivestock exports (cattle, sheep, and goats) (FAO) (Fig. 3).

Conclusions

A lot of vector-borne diseases are endemic in Arab countries, and there were nospecific policies and strategies to control their spread except the global strategies tocompact malaria. Leishmaniasis is the most VBD spread in most Arab countries.Dengue is an emerging challenge, while schistosomiasis and Crimean-Congo hem-orrhagic fever (CCHF) are still endemic in some countries. Most of the VBDs areendemic is Sudan, while Algeria and Tunisia are the least Arab countries forendemicity of VBDs.

Fig. 3 Map summarizing the main trade movements of livestock (cattle and small ruminants) in theregion from the Horn of Africa at risk of RFV (FAO)

Vector-Borne Diseases in Arab Countries 13

The limitation of this work is that there were limited studies addressing the epide-miology of VBDs in Arab countries especially about what is called “neglected tropicaldiseases,” and accordingly authors looking for further studies strengthen the nationalsurveillance activities and regional coordination and partnership toward control andelimination of VBDs in Arab countries within a global strategy.

References

Abdul-Ghani R, Mahdy MA, Beier JC (2016) Onchocerciasis in Yemen: time to take action againsta neglected tropical parasitic disease. Acta Trop 162:133–141

Abedi A, Shako J, Gaudart J, Sudre B, Ilunga B, Shamamba S et al (2018) Ecologic features ofplague outbreak areas, Democratic Republic of the Congo, 2004–2014. Emerg Infect Dis24(2):210–220. https://doi.org/10.3201/eid2402.160122

Ahmed MA, Abdel Wahab SM, Abdel Malik MO, Abdel Gadir AM, Salih SY, Omer A, Al HassanAM (1980) Louse-borne relapsing fever in the Sudan. A historical review and a clinico-pathological study. Trop Geogr Med 32(2):106–111

Al-Abri SS et al (2017) Current status of Crimean-Congo haemorrhagic fever in the World HealthOrganization Eastern Mediterranean Region: issues, challenges, and future directions. IntJ Infect Dis 58:82–89

Amazigo U (2006) Onchocerciasis. In: Jamison DT (ed) Disease and mortality in Sub-SaharanAfrica, 2nd edn. The International Bank for Reconstruction and Development/The World Bank,Washington, DC

Angelakis E et al (2010) Murine typhus as a cause of fever in travelers from Tunisia andMediterranean Areas. J Travel Med 17:310–315

Aslam S, Latif MS, Daud M et al (2016) Crimean-Congo hemorrhagic fever: risk factors andcontrol measures for the infection abatement. Biomed Rep 4(1):15–20. https://doi.org/10.3892/br.2015.545

Bamgbola OF (2014) Urinary schistosomiasis. Pediatr Nephrol 29(11):2113–2120Bertherat E (2016) Plague around the world, 2010–2015. Wkly Epidemiol Rec 91:89–93CDC. Lymphatic Filariais: epidemiology and risk factors. Available at: https://www.cdc.gov/para

sites/lymphaticfilariasis/epi.html. Accessed inColley DG, Bustinduy AL, Secor WE, King CH (2014) Human schistosomiasis. Lancet 383(9936):

2253–2264Colpitts TM, Conway MJ, Montgomery RR, Fikrig E (2012) West Nile virus: biology, transmission,

and human infection. Clin Microbiol Rev 25(4):635–648. https://doi.org/10.1128/CMR.00045-12Cuomo MJ. Vector borne disease ecology of the Middle East. Tulane University. PowerPoint

presentation. Available at: www.phsource.us/.../MiddleEast_Vector-Borne_Disease_Ecology.pdf. Accessed in 12 Mar 2018

da Costa PS, Brigatte ME, Greco DB (2005) Antibodies to Rickettsia rickettsii, Rickettsia typhi,Coxiella burnetii, Bartonella henselae, Bartonella quintana, and Ehrlichia chafeensis amonghealthy population in Minas Gerais, Brazil. Mem Inst Oswaldo Cruz 100(8):853–859

Dennis DT, Hayes EB (2005) Relapsing fever. In: Braunwald E, Hauser SL, Fauci AS (eds)Harrison’s principles of internal medicine, 16th edn. McGraw-Hill, New York, pp 991–995

Dennis DT, Gage KL, Gratz N, Poland JD, Tikhomirov E. Plague manual: epidemiology, distribu-tion, surveillance and control [cited 2017 Nov 22]. http://www.who.int/csr/resources/publications/plague/WHO_CDS_CSR_EDC_99_2_EN/en/

Digoutte JP, Peters CJ (1989) General aspects of the 1987 Rift Valley fever epidemic in Mauritania.Res Virol 140:27–30

Dworkin MS et al (2008) Tick-Borne relapsing fever. Infect Dis Clin North Am 22(3):449–468.https://doi.org/10.1016/j.idc.2008.03.006

14 A. S. B. Ghouth et al.

El Setouhy M, Ramzy RM (2003) Lymphatic filariasis in the Eastern Mediterranean Region: currentstatus and prospects for elimination. EMHJ 9(4):534–541

El-Akkad AM (1978) Rift Valley fever outbreak in Egypt, October–December 1977. J Egypt PublicHealth Assoc 53:137–146

Eurobian Center for Disease Control and Prevention. Risk of importation and spread of EVD withmigrants to the EU, Oct 2015. Available at: http://ecdc.europa.eu/.../risk-malaria-vector-borne-diseases. Accessed on 12 Mar 2018

FAO. Rift Valley Fever could spread with movement of animals from East Africa. Available at:www.fao.org/docs/eims/upload/236966/ew_africa_dec07_rvf.pdf. Accessed in 16 Mar 2018

Gardner CG, Ryman KD (2010) Yellow fever: a reemerging threat. Clin Lab Med 30(1):237–260Goubau PF (1984) Relapsing fevers. A review. Ann Soc Belg Med Trop 64:335–364Gould LH (2008) An outbreak of yellow fever with concurrent chikungunya virus transmission in

South Kordofan, Sudan, 2005. Trans R Soc Trop Med Hyg 102(12):1247–1254Gould EA, Solomon T (2008) Pathogenic flaviviruses. Lancet 371(9611):500–509Hoogstraal H (1979) The epidemiology of tick-borne Crimean-Congo hemorrhagic fever in Asia,

Europe, and Africa. J Med Entomol 15:307–417. https://www.ncbi.nlm.nih.gov/pubmed/113533

Humphrey JM, Cleton NB, Reusken CBEM, Glesby MJ, Koopmans MPG, Abu-Raddad LJ (2017)Urban Chikungunya in the Middle East and North Africa: a systematic review (Powers AM,ed.). PLoS Negl Trop Dis 11(6):e0005707. https://doi.org/10.1371/journal.pntd.0005707

Kyobe Bosa H, Montgomery JM, Kimuli I, Lutwama JJ (2014) Dengue fever outbreak in Moga-dishu, Somalia 2011: co-circulation of three dengue virus serotypes. Int J Infect Dis 21(S1):3.https://doi.org/10.1016/j.ijid.2014.03.412

Madani TA et al (2003) Rift Valley fever epidemic in Saudi Arabia: epidemiological, clinical, andlaboratory characteristics. Clin Infect Dis 37(8):1084–1092

Malik MR et al (2013) Novel coronavirus infection in the Eastern Mediterranean Region: time toact. East Mediterr Health J 19(supplement 1). http://www.emro.who.int/emhj-volume-19-2013/volume-19-supplement-1-coronavirus/

Maltezou HC, Papa A (2011) Crimean-Congo hemorrhagic fever: epidemiological trends andcontroversies in treatment. BMC Med 9:131

Meegan JM (1979) Rift Valley fever epizootic in Egypt: description of the epizootic and virologicalstudies. Trans R Soc Trop Med Hyg 73:618–623

Messina JP, Pigott DM, Golding N, Duda KA, Brownstein JS, Weiss DJ et al (2015) The globaldistribution of Crimean-Congo hemorrhagic fever. Trans R Soc Trop Med Hyg 109:503–513

Michael E, Bundy DAP (1997) Global mapping of lymphatic filariasis. Parasitol Today 13:472–476Murine typhus. Available at: https://www.cdc.gov/typhus/murine/index.html. Accessed in 16 Mar 2018Negev M, Paz S, Clermont A et al (2015) Impacts of climate change on vector borne diseases in the

Mediterranean Basin – implications for preparedness and adaptation policy (ToscanoW, ed.). IntJ Environ Res Public Health 12(6):6745–6770. https://doi.org/10.3390/ijerph120606745

Ottesen EA (2002) Major progress toward eliminating lymphatic filariasis. N Engl J Med347:1885–1886

Peniche Lara G, Dzul-Rosado KR, Zavala Velázquez JE, Zavala-Castro J (2012) Murine Typhus:clinical and epidemiological aspects. Colombia Médica: CM 43(2):175–180

Ripoll CM, Remondegui CE, Ordonez G, Arazamendi R, Fusaro H, Hyman MJ et al (1999)Evidence of rickettsial spotted fever and ehrlichial infections in a subtropical territory ofJujuy, Argentina. Am J Trop Med Hyg 61:350–354

Rougeron V, Sam I-C, Caron M, Nkoghe D, Leroy E, Roques P (2015) Chikungunya, a paradigm ofneglected tropical disease that emerged to be a new health global risk. J Clin Virol 64:144–152

Salam N, Al-Shaqha WM, Azzi A (2014) Leishmaniasis in the Middle East: incidence andepidemiology (Ghedin E, ed.). PLoS Negl Trop Dis 8(10):e3208. https://doi.org/10.1371/jour-nal.pntd.0003208

Southern PM, Sanford JP (1969) Relapsing fever: a clinical and microbiological review. Medicine48:129–149

Vector-Borne Diseases in Arab Countries 15

Tikhomirov E (1999) Epidemiology and distribution of plague. In: Dennis DT, Gage KL (eds)Plague manual epidemiology, distribution, surveillance and control. WHO/CDS/CSR/EDC/99.2, pp 11–39

Warrell DA (2017) International medicine: major tropical syndromes: systemic infections: relapsingfever. In: Cohen J, Powderly WG, Opal SM (eds) Infectious diseases, 4th edn. Elsevier,Amsterdam

WHO (2009) Dengue: guidelines for diagnosis, treatment, prevention and control. World HealthOrganization, Geneva. New Edition. Available from: https://www.ncbi.nlm.nih.gov/books/NBK143159/

WHO (2014) A global brief of vector borne diseases: an overview. Available at: https://www.who.int/campaigns/world-health-day/2014/global-brief/en/. Accessed 20 Nov 2017

WHO. Leishmaniasis in high-burden countries: an epidemiological update based on data reported in2014. Weekly epidemiological record

WHO (2017) World Malaria report. World Health Organization, GenevaWHO/AFRO. Plaque outbreak in Madagascar: external situation report 14. December 2017.

Available at: http://www.afro.who.int/health-topics/plague/plague-outbreak-situation-reportsWilson AJ et al (2017) What is a vector? Philos Trans R Soc B 372:20160085. https://doi.org/

10.1098/rstb.2016.0085World Health Organization (1983) International Health Regulations (1969). Third annotated edi-

tion. World Health Organization, GenevaWorld Health Organization (1995) Onchocerciasis and its control. In: Report of a WHO expert

committee on onchocerciasis control. World Health Organization, Geneva, pp 1–104World Health Organization (2004) The world health report 2004 – changing history. World Health

Organization, GenevaWorld Health Organization (2009) Human plague: review of regional morbidity and mortality,

2004–2009. Wkly Epidemiol Rec 85:40–45World Health Organization (2013) Surveillance, forecasting and response, Crimean- Congo

haemorrhagic fever (CCHF) in Pakistan. WHO, Geneva. Available at: http://www.emro.who.int/surveillance-forecasting-response/outbreaks/ cchf-pakistan-june-2013.html. Accessed 21 Nov 2016

Znazen A, Hammami B, Mustapha AB, Chaari S, Lahiani D, Maaloul I, Jemaa MB, Hammami A(2013) Murine typhus in Tunisia: a neglected cause of fever as a single symptom. Med MalInfect 43(6):226–229. https://doi.org/10.1016/j.medmal.2013.02.007. Epub 2013 Apr 22

Zouré HG et al (2014) The geographic distribution of onchocerciasis in the 20 participatingcountries of the African Program for Onchocerciasis Control: (2) pre-control endemicity levelsand estimated number infected. Parasit Vectors 7(326):2–15. Available at: http://www.parasitesandvectors.com/content/7/1/326

16 A. S. B. Ghouth et al.