**6. References**

194 Current Topics in Tropical Medicine

to a host in order to inhibit haemostasis, inflammation and innate and adaptive immune responses but ticks are able to modulate their host's local haemostatic reactions (Carvalho et

As happens with other ticks in which salivary gland proteins are immunogenic (Sanders et al., 1996), our results have shown that *H. lusitanicum* has proteins (antigens) that stimulate the production of immunoglobulins in humans as well as the finding of a significant high prevalence in bitten patients by ticks respect to the control group (see in Tables 1 and 2). It would be very interesting to conduct an epidemiological study, in those sera that have positive results, if at any time have had a history of febrile illness of unknown etiology with

As occurs with other genus or species of ticks capable to induce high responses, *H. lusitanicum* could share antigens with other ticks. It is easy to found that antigens can cross react with the antigens of a closely related species. This fact has been observed in several studies that have realized cross-resistance studies between *Dermacentor andersoni* and *Dermacentor variabilis* (McTier et al., 1981), *Hyalomma anatolicum anatolicum* and *Boophilus microplus* (Parmar et al., 1996), *H. a. anatolicum, Hyalomma dromedari* and *Boophilus microplus* (Kumar & Kondal., 1999) as well as between a series of other tick species (Brown & Askenase., 1984; Jaansen van Vuuren et al., 1992). In fact, the homology among several tick species suggests that possibly common antigen(s) may be suitable for a vaccine against some

By other hand, though ticks are well known blood suckers, blood sources between males and females seem to be different and gene expressions in fedding males and females are also different (Aljamali et al., 2009). In fact the male blood meals may be digested and nutrients can be used for spermatogenesis. The host blood meal is necessary for egg production in female ticks (Sanders et al., 1996). As occurs with partially fed female *Ixodes ricinus* (Linnaeus, 1758), female and male *Amblyomma variegatum* (Fabricius, 1794) and *Rhipicephalus appendiculatus* Neumann, 1901 in which have been observed that exist species- and sex-specific differences in the effects of tick salivary gland antigens on human lymphocyte proliferation, our results, as can be seen in Table III, have demonstrated that exist differences in the human antibodies response against male and female *H. lusitanicum* antigens. This fact makes that both could be considered as

Since for each tick-borne disease there may be one or several vectors (Lane, 1994), perhaps this ixodid could be implicated as a vector susceptible of parasitizing humans. In this sense, other studies would in a future provide us about the frequency and which life cycle stages of this tick can infest humans as well as its role in the transmission of human pathogens as happened with those studies in which *Dermacentor marginatus* was recently demonstrated to be the vector in the transmission of *Rickettsia slovaca*, that causes the TIBOLA/DEBONEL disease in humans (Rehacek, 1984; Lakos., 1997; Raoult et al., 1997;

Until date, each tick species has preferred environmental conditions and biotopes that determine the geographical distribution of the ticks and the risk areas fro tick borne diseases, but day to day more research studies are going on in order to elucidate a higher diversity of ixodid tick species infesting humans potentially transmisors of underdiagnosed

al., 2010)

or without rash.

different ticks.

susceptible to bite humans.

Ibarra et al., 2006).

diseases.


Screening of the Prevalence of Antibodies to the Tick

9788448602369, Madrid.

890, ISSN 1080-6040.

(December), pp. 589-593, ISSN 1776-1042.

Vol. 53, Nº 4 (April), pp. 241-256, ISSN 1612-4642.

Sciences Association, ISBN 978-1851532575, London.

0168-8162.

0042-4900.

2951.

8923.

0132-8077.

Kaufman.

210, ISSN 0168-8162.

Vol. 5, Nº 2, pp. 47-56. ISSN 0169-4758.

International, ISBN : 0-851-98968-3.

*Hyalomma lusitanicum* in a Province of Northern Spain 197

Encinas, A.; Oleaga, A. & Pérez, R. (1999). Garrapatas duras. En: Cordero del Campillo *et al.*,

Estrada-Peña, A. & Jongejan, F. (1999). Ticks feeding on humans: a review of records on

Fernández-Soto, P.; Encinas-Grandes, A. & Pérez-Sánchez, R. (2003). *Rickettsia aeschlimannii*

Gibbs, E. P.J. (2005). Emerging zoonotic epidemics in the interconnected global

Giménez-Pardo, C. & Martínez-Grueiro, M. M. (2008). Some hydrolase activities from the

Gortázar, C.; Ferroglio, E.; Höfle, U.; Frölich, K.; Vicente, J. (2007). Diseases shared between

Habela, M.; Rol, J. A.; Antón, J. M.; Pena, J.; Cordero, E.; van Ham, I. & Jorge, E.

Hillyard, P. D. (1996). Ticks of north-west Europe. Synopses of the British fauna. Ed. Barnes

Ibarra, V.; Oteo, J. A.; Portillo, A, Santibáñez, S.; Blanco, J. R.; Metola, L.; Eiros, J. M.; .

Jansen van Vuuren, A.M.; Crause, J.C.; Vershoor, J.A.; Spickett, A.M. & Neitz, A.N. (1992).

Kettle, D.S. (1995). Medical and veterinary entomology. 2th ed. Cambridge: CAB

Kolonin, G.V. (2009). Fauna of Ixodid ticks of the world (*Acari, Ixodidae*). Moscow, ISSN

Kumar, S. & Kondal, J.K. (1999): Lack of immunological cross-reactivity of 36 kDa secretory

editores. *Parasitología Veterinaria.*, McGraw-Hill Interamericana; pp. 420-429, ISBN

human biting *Ixodoidea* with special reference to pathogen transmission. *Experimental and Applied Acarology,* Vol. 23, Nº 9 (September), pp. 685-715, ISSN

in Spain: molecular evidence in *Hyalomma marginatum* and five other tick species that feed on humans. *Emerging and Infectious Diseases*, Vol. 9, Nº 7 (July), pp. 889-

community. *Veterinary Records*, Vol. 26, Nº 22 (November), pp. 673-679, ISSN

tick *Hyalomma lusitanicum* Koch, 1844 (*Ixodoidea*: *Ixodida*). *Parasite*, Vol. 15, Nº 4

wildlife and livestock: a European perspective*. European Journal of Wildlife Research*,

(1999). Epidemiology of mediterranean theileriosis in Extremadura region, Spain. *Parassitologia,* Vol. 41, Suppl 1 (September), pp. 47-51, ISSN 0048-

KRS & Crothers JH: The Linnean Society of London and the Estuarine and Coastal

&, Sanz, M. (2006). *Rickettsia slovaca* infection: DEBONEL/TIBOLA. *Annals of the New York Academy of Science.* Vol. 1078 (October), pp. 206-214, ISSN 0077-

The identification of a shared immunogen present in the salivary glands and gut of ixodid and argasid ticks. *Experimental and Applied Acarology* Vol. 15, Nº 3, pp. 205-

W. (1989). Tick-host interaction: A synthesis of current concepts *Parasitology Today*

salivary glands antigen of *Hyalomma anatolicum anatolicum* with *Hyalomma* 


Briones, V.; Téllez, S.; Ballesteros, C.; González, S.; Bordes, I.; Domínguez L *et al.* (2002).

Brossard, M. & Wikel, S. K. (2004). Tick immunobiology. *Parasitology*, Vol. 129, Suppl 1, pp.

Brown, S.J & Askenase, P.W. (1984). Analysis of host components mediating immune

Carvalho, W. A.; Maruyama, S. R.; Franzin, A. M.; Abatepaulo, A. R.; Anderson,

Chomel, B. (1998). New emerging zoonoses: a challenge and an opportunity for the

Cleaveland, S.; Laurenso, M. K. & Taylor, H. (2001). Diseases of human and their domestic

Cordero del Campillo, M.; Castañón Ordóñez, L. & Reguera Feo, A. (1994). *Índice-Catálogo de* 

Cunningham, A.A. (2005). A walk on the wild side emerging wildlife diseases. *British* 

Daszak, P.; Cunningham, A. A. & Hyatt, A. D. (2000). Emerging infectious diseases of

Daszak, P. & Cunningham, A. A. (2003). Anthropogenic change, biodiversity loss, and a new

Domínguez, G. (2004). North Spain (Burgos) wild mammals ectoparasites. *Parasite*, Vol. 11,

Encinas-Grandes, A. (1986). Ticks of the province of Salamanca (Central/NW/Spain).

Vol. 21, Nº 1 (March), pp. 1-14, ISSN 0147-9571.

356, Nº 1411 (July), pp. 991-999, ISSN 0080-4622.

(January), pp. 443-449, ISSN 0036-8075.

*Acarology VI*, Vol 2. Ellis Horwood, Chichester, ISBN 9780130054890. Bueno, R; Moreno, J.; Oltra, M.T. & Jiménez, R. (2009). Artrópodos con interés vectorial en la

27, ISSN 0212-0054.

161-176, ISSN 0031-1820.

214, ISSN: 2173-9110 .

9788477194033, León.

41, ISSN 0022-3395.

pp. 262-272, ISSN 1776-1042.

4894.

9999.

4150.

Enfermedades transmisibles de los mamíferos silvestres. *Quercus*, Vol. 198, pp. 22-

resistance to ticks, p.1040-1050. In: D. A Griffiths and C. E Browman (eds).

salud pública en España. *Revista Española de Salud Pública*, Vol. 83, Nº 2, pp. 201-

J.M.; Ferreira, B. R.; Ribeiro, J.M.; Moré, D.D.; Augusto Mendes Maia, A.; Valenzuela, J. G.; Garcia, G. R. & de Miranda Santos, I. K. (2010). *Rhipicephalus*  (Boophilus) *microplus*: clotting time in tick-infested skin varies according to local inflammation and gene expression patterns in tick salivary glands. *Experimental Parasitology,* Vol. 124, Nº 4 (April), pp. 428-435, ISSN 0014-

veterinary profession. *Comparative Immunology, Microbiology and Infectious Diseases*,

mammals: pathogen characteristics, host range and the risk of emergence. *Philosophical Transactionc Royal Society Londondon. Series B, Biological Sciences.*, Vol.

*Zooparásitos Ibéricos*, p. 650. Universidad de León, Spain, ISBN

*Medical Journal*, Vol. 331, Nº 7527 (November), pp. 1214-1215, ISSN 2007-

wildlife threats to biodiversity and human health. *Science*, Vol. 287, Nº 5452

agenda for emerging diseases. *Journal of Parasitology*, Vol. 89 Suppl (April), pp. 37-

Prevalence and parasitization Intensity in dogs and domestic ungulates. *Annales de Parasitologie Humaine et Comparée*, Vol. 61, Nº1 (January), pp. 95-107, ISSN 0003-


Screening of the Prevalence of Antibodies to the Tick

8758.

5683.

Burgos.

6040.

0022-2585.

0066-4170.

ISBN 978-0125104517, Orlando.

(July), pp. 67-74, ISSN 0002-9637.

0233.

1820.

2951.

London.

*Hyalomma lusitanicum* in a Province of Northern Spain 199

Rehacek, J. (1984). *Rickettsia slovaca*, the organism and its ecology. *Acta Scientiarum* 

Rolníková, T.; Kazimírová, M.; Buc, M. (2003). Modulation of human lymphocyte

Román, J; Román, L.; Ansola, L.M;, Palma, C. & Ventosa, R. (1996). Atlas de las aves

Rumer, L.; Graser, E.; Hillebrand, T.; Talaska, T.; Dautel, H.; Mediannikov, O.; Roy-

Sanders, M,L.; Scott, A. L.; Glass, G.E. & Schwartz, B.S. (1996). Salivary gland changes and

Sauer, J.R.; McSwain, J.L.; Bowman, A.S. &. Essenberg, R.C. (1995). Tick salivary gland

Simpson, V. R. (2002). Wild animals as reservoirs of infectious diseases in the UK.

Sonenshine, D.; Lane, R. S. & Nicholson, W. L. (2002). Ticks (Ixodida). In: Mullen G &

Toledo, A.; Olmeda, S.; Escudero, R.; Jado,I.; Valcárcel, F.; Casado-Nistal,M.; Rodríguez-

Valenzuela, J. G.( 2004). Exploring tick saliva: from biochemistryto"sialomes" and

Viseras, J. & García-Fernández, P. (1999). Studies on theileriosis in Southern Spain.

Wall, R. & Shearer, D. (1997). *Veterinary Entomology: Arthropods Ectoparasites of* 

Wall, R. (2007). Ectoparasites: Future challenges in a changing world. *Veterinary Parasitology*, Vol. 148, Nº 1 (August), pp. 62-74, ISSN 0304-4017.

*Naturalium Academiae Scientiarum Bohemoslovacae* ,Vol. 18, No 2 pp. 1-50, ISSN 0032-

proliferation by salivary gland extracts of ixodid ticks (*Acari: Ixodidae*): effect of feeding stage and sex. *Folia Parasitologica*, Vol. 50, Nº 4, pp. 305-12, ISSN 0015-

nidificantes en la provincia de Burgos. Ed. Aldecoa, ISBN 978-84-7009-485-9,

Chowdhury, P.; Sheshukova, O.; Donoso Mantke, O. & Niedrig, M. (2011). *Rickettsia aeschlimannii* in *Hyalomma marginatum* ticks, Germany. *Emerging Infectious Diseases* , Vol. 17, Nº 2 (February), pp. 325-325, ISSN 1080-

host antibody responses associated with feeding of male lone star ticks (*Acari:Ixodidae*). *Journal of Medical Entomology,* Vol. 33, Nº 4 (July), pp. 628-34, ISSN:

physiology. *Annual Review of Entomology*, Vol. 40, (January), pp. 245-267, ISSN:

*The Veterinary Journal*, Vol. 163, Nº 2 (March), pp. 128-146, ISSN: 1090-

Durden L, editors. *Medical and Veterinary Entomology*, Elsevier Science, pp. 517-557,

Vargas, M.; Gil, H. & Anda, P. (2009). Tick-borne zoonotic bacteria in ticks collected from central Spain. *American Journal of Tropical Medicine and Hygiene*, Vol. 81, Nº 1

functional genomics. *Parasitology*. Vol. 129, Suppl, pp. S83-S94, ISSN 0031-

*Parassitologia*, Vol. 41, Suppl 1 (September), pp. 111-115, ISSN 0048-

*Veterinary importance*. 1th edition, Chapman & Hall, ISBN 978-0412615108,

*dromedary* and *Boophilus microplus* ticks*. Zentralblatt für Veterinärmedizin. Reihe* B. Vol. 46, Nº 6 (august), pp. 405-410, ISSN 0514-7166.


Lane, S. L. (1994). Competence of ticks as vectors of microbial agents with an emphasis on

Lakos, A. (1997). Tick-borne lymphadenopathy, a new rickettsial disease. *The Lance*t. Vol.

Lindgren, E.; Talleklint, L.; Polfeldt, T. (2000). Impact of climate change on the northern

Lledó, L.; Giménez-Pardo, C.; Domínguez-Peñafiel, G; Sousa, R.; Gegundez-Cámara, M.I.;

López-Vélez, R. & Molina, R. (2005). Cambio climático en España y riesgo de enfermedades

Matsumoto, K.; Parola, P.; Brouqui, P. & Raoult,D. (2004). *Rickettsia aeschlimannii* in

McTier, T.L.; George, T.E. & Benett, S.N. (1981). Resistance and cross-resistance of guinea

Morse, S. S. (1995). Factors in the emergence of infectious diseases. *Emerging Infectious* 

Parmar, A.; Grewal A.S. & Dhillon P. (1996). Immunological cross-reactivity between

Pérez-Sánchez, R.; Oleaga-Pérez, A. & Encinas-Grandes, A. (1992). Analysis of the specificity

Punda-Polic, V.; Petrovec, M.; Trilar, T.; Duh, D.; Bradaric, N.; Klismanic, Z. & Basic-Zupanc,

Raoult, D.; Berbis, P.; Roux, V.; Xu, W. & Maurin, M. (1997). A new tick-transmitted disease

*Diseases,* Vol. 1, No. 1 (January-March), pp. 7-15, ISSN 1080-6040.

*de Salud Pública*, Vol. 79, Nº 2, pp. 177-190, ISSN 1135-5727.

*Diseases*, Vol. 23, Nº 9 (August), pp. 732-734, ISSN 0934-9723.

(December), pp. 813-832, ISSN: 1937-2345.

(March), pp. 201-216, ISSN 0141-9838.

pp. 169-176, ISSN 0168-8162.

Vol. 46, Nº 6 (august), pp. 405-410, ISSN 0514-7166.

350, Nº 4 (October), pp. 1006, ISSN 0140-6736.

York.

3667.

123, ISSN 0091-6765.

ISSN 0165-2427.

6736.

*dromedary* and *Boophilus microplus* ticks*. Zentralblatt für Veterinärmedizin. Reihe* B.

*Borrellia burgdorferi,* p*.* 45-67. In: Sonen Shine, DE, Mather, TN. (eds), *Ecological dynamics of tick-borne zoonoses*, Oxford University Press, ISBN 978-0195073133, New

latitude limit and population density of the disease transmitting European tick *Ixodes ricinus*. *Environmental Health Perspectives*, Vol. 108, Nº 2 (February), pp. 119-

Casado, N. & Criado-Fornelio, A. (2010). Molecular detection of Hemoprotozoa and *Rickettsiae* sp in arthropods from wild animals in the Burgos province, Spain. *Vector-Borne and Zoonotic Diseases*, Vol. 10, Nº 8 (October), pp. 735-738, ISSN 1530-

infecciosas y parasitarias transmitidas por artrópodos y roedores. *Revista Española* 

*Hyalomma* ticks from Corsica. *European Journal of Clinical Microbiology and Infectious* 

pigs to *Dermacentor andersoni* Stiles, *D. variabilis* (Say), *Amblyomma americanum* (Linnaeus) and *Ixodes scapularis* (Say). *Journal of Parasitology*, Vol. 67, Nº 6

salivary gland proteins of *Hyalomma anatolicum anatolicum* and *Boophilus microplus* ticks. *Veterinary Immunology and Immunopathology,* Vol.1, Nº 3-4 (June), pp. 345-352,

of the salivary antigens of *Ornithodoros erraticus* for the purpose of serological detection of swine farms harbouring the parasite. *Parasite Immunology*, Vol. 14, Nº 2

T. (2002). Detection and identification of spotted fever group rickettsiae in ticks collected in southern Croatia. *Experimental and Applied Acarology*, Vol. 28, Nº 1-4,

due to *Rickettsia slovaca*. *The Lancet*, Vol. 350, Nº 12 (July), pp. 112-113, ISSN 0140-


**14** 

**Amoebiasis in the Tropics:** 

A. Samie1, A. ElBakri2 and Ra'ed AbuOdeh2

*University of Sharjah, Sharjah,* 

*2United Arab Emirates* 

*1South Africa* 

**Epidemiology and Pathogenesis** 

*1Molecular Parasitology and Opportunistic Infection Program, Department of Microbiology, University of Venda, Private Bag X5050 Thohoyandou 0950 2Medical Laboratory Technology Department, College of Health Sciences,* 

*Entamoeba histolytica* is a protozoan parasite that causes amebic dysentery and liver abscess. The disease is common in tropical regions of the world where hygiene and sanitation is often approximate. The epidemiology of *E. histolytica* has been studied around the world. However, there is a dearth of comprehensive literature on the epidemiology of this pathogen as well as its pathogenicity in the tropical and underdeveloped regions of the world where the disease is actually more common. Epidemiological figures in many endemic tropical countries are often overestimated because of inaccurate identification. Accurate data on the prevalence of the pathogenic strain(s) of *E. histolytica* in those regions will allow for the effective cure of patients with anti-amoebic drugs thus preventing the

With the advents of HIV and AIDS, several organisms have been identified as potential opportunistic pathogens. However, it is not clear whether amoebiasis is an opportunistic infection or not. Up to date, very little data has been published on the occurrence of *E. histolytica* in relation to HIV and AIDS. In developed countries amebiasis tends to be more common in older patients and occurs mostly among men who have sex with men or in institutions. However, in tropical regions, the epidemiology of amoebiasis is completely different and is more common among the general population and particularly among patients attending health care centers with diarrhea. Therefore, it is important to understand the epidemiology of this pathogen in tropical areas where it is responsible for most

The recent reclassification of *E. histolytica* into different species now including the pathogenic *Entamoeba histolytica* and the non pathogenic *Entamoeba dispar* and *Entamoeba moshkovskii* has further added to the complexity of the epidemiology of amoebiasis since these three species cannot be differentiated by microscopy that is the most commonly used diagnostic method particularly in tropical countries where resources are limited, but can only be differentiated by the use of molecular methods such as the polymerase chain reaction based methodologies. Recent development of simpler but more sensitive methods

development of resistant types and reducing management costs.

**1. Introduction** 

morbidity and mortality.

