TRENDS in Parasitology Vol.18 No.6 June 2002

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ParaSite

Not a simple problem

after all

World Class Parasites: Volume 1 The African

Trypanosomes

edited by Samuel J. Black and J. Richard Seed,Kluwer Academic Press, 2001. £80.74 (hbk)(192 pages) ISBN 0 79237 512 2

The demise of thecolonial system hasnot brought thebirth of a new brightfuture for Africa.During the pastseveral decades,Africa has sufferedfrom anarchy,famine and tribalwarfare. The public

health system is in disarray and the regionis plagued with epidemics, old and new. The diseases once thought to be undercontrol are resurging. Sleeping sickness,caused by the subspecies of Trypanosoma brucei in sub-Saharanregions, is often overshadowed by AIDSand malaria. Nagana, a trypanosomiasisof cattle, is caused by related organismsand remains a serious impediment toeconomic development in Africa.

The African Trypanosomes, written by renowned authors and edited bySamuel J. Black and J. Richard Seed,contains twelve chapters, which addressthe economic problems and describeapproaches to control and preventtrypanosomiasis. This book represents the first volume of the new series WorldClass Parasites – intended to cover recenttrends and advances in the research ofparasites with a high impact onsocioeconomics. The editors estimate that300 000–500 000 people in Africa areaffected by trypanosomiasis, which can befatal if not treated. The situation is worsenow than just a few decades ago andcorresponds to the situation in the 1930s.The paradox is that, at the same time, inthe developed world, more efforts andresources than ever are being devoted tofinding rational ways to combat Africantrypanosomiasis.

The book opens with a chapter writtenby David H. Molyneux, who gives hispersonal view on the failure of science

and the public health system to prevent orstop the epidemics. This chapter is trulyremarkable and the book deserves areader’s attention just for this alone.Molyneux noticed that trypanosomeresearch had: ‘yielded an excess of scientificpapers but no new drug’. However, sciencecan still be ‘given a final opportunity tosolve what ought to be a simple problemgiven the major differences betweentrypanosomes and mammalian cells’. Even though the simplicity thesis could bedebatable, it is impossible to disagree with Molyneux on his main point: ‘anefficient use of the resources availabletoday and a focus on the disease controlwould make a difference even in theabsence of a magic bullet yet to bedelivered by the drug design and vaccinedevelopment programs’.

Accurate information is crucial forsuccess because part of the solutionproposed by Molyneux lies in the realm of rational decision-making. Chapters twoand three describe the development ofinformation systems to support the Program Against AfricanTrypanosomiasis (PAAT), the predictedimpact of climate and social factors onvector distribution, and the disease risk toyear 2050. Both chapters would benefitfrom color maps instead of black andwhite ones. The following chapter isdevoted to vector control and describes aninnovative strategy to reduce diseasetransmission through replacement oftrypanosome-susceptible tsetse withengineered trypanosome-refractoryvectors. A reader with a practical mindwould also be interested in an evaluationof more traditional strategies based onattractants and traps, but they have notbeen covered here. The diagnosis andchemotherapy chapters highlight the factthat the absence of effective diagnostictests and drugs in the field mostly reflects the lack of incentives for thepharmaceutical industry to proceed with validation and production ratherthan the difficulties to develop these toolsin the laboratory.

Several chapters are devoted totrypanosome immunology and cell biology,including the new paradigm of hostresistance, trypanotolerance mechanismsin some breeds of West African cattle, the discovery of a bloodstreamtrypanosome-released factor affecting

cell division, and the endocytosis system. The trypanosome genome organizationand the ongoing sequencing efforts arealso covered, ending with a generaldiscussion on the rational approaches tovaccine development.

In the ideal world, the book would also include additional chapters onconventional vector control, mechanismsof human resistance to trypanosomes, and trypanosome metabolism andintracellular transport as mentioned by the editors as glaring omissions. But would there be African trypanosomesin the ideal world?

Dmitri Maslov

Dept of Biology, University of California, 3401 Watkins Drive, Riverside, CA 92521,USA.e-mail: maslov@ucrac1.ucr.edu

Essential guide to travel

medicine

Health Information for the International

Traveler, 2001–2002

by The Centers for Disease Control andPrevention, 2001. US$25.00 (pbk) (257 pages)

Health Information for theInternational Traveler,2001–2002 is the biannualupdate of the gold-standard reference bookfor travel medicine, whichis written by physicians

and scientists from the Travelers’HealthSection of The Centers for Disease Controland Prevention (CDC). The book isdesigned for health care providers whoprovide pre-travel advice on theprevention of infectious diseases. An online version of the text from thisbook is also updated periodically athttp://www.cdc.gov/travel and the hardcopy is available for purchase fromhttp://bookstore.phf.org

The book does not attempt anexhaustive coverage of the different topics in travel-related infections, but covers essential information in areader-friendly approach. A useful list of websites including addresses of travel medicine clinics, in addition to

TRENDS in Parasitology Vol.18 No.6 June 2002

http://parasites.trends.com 1471-4922/02/$ – see front matter © 2002 Elsevier Science Ltd. All rights reserved. PII: S1471-4922(02)02327-9

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international disease surveillance reports, is provided in the introduction.The book is not only informative and organized but, as a result of itsorigination at the CDC, it represents ade facto official policy for travel medicinein the USA.

The text is divided into six sections:‘Vaccine recommendations’; ‘Yellow fever vaccine requirements and malariarisk by country’; ‘Disease-specificrecommendations’; ‘Health hints for theinternational traveler’; ‘Geographicdistribution of potential health hazards totravelers’and ‘Advising the traveler withspecial needs’. Foldout tabs divide eachsection, which helps to pull the book off the shelf and find the requiredinformation quickly.

In ‘Disease-specific recommendations’,I learnt that the risk of a new variant ofCreutzfeldt–Jakob disease is estimated tobe one case per 10 billion servings of beefin the UK, that the tsetse (vector ofAfrican trypanosomiasis) are attracted todark and contrasting colors and movingautomobiles, and that immunoglobulinfails to prevent hepatitis E duringoutbreaks. If you were not convinced of thevalue of personal protective measuresagainst insects then this section can also make a cynic convert: the risk ofacquiring leishmaniasis from a sandflybite is at its greatest between dusk anddawn in rural or peri-urban areas,whereas Aedes aegypti (vector of Dengue

fever) lives in and around houses in urban areas and bites during the day.Malaria contracted from the bite of aninfected Anopheles mosquito can beacquired from dusk to dawn in rural areas as well as urban locations insub-Saharan Africa.

The malaria prophylaxis section has achecklist of issues to address withtravelers before departure, which includes the risk of malaria in thedestination, personal protectivemeasures, chemoprophylaxis, how torecognize the symptoms of malaria andwhat to do if malaria has been acquired,and special recommendations forpregnancy and young children. Severaltables are present, summarizing the drugs approved in the USA for malariaprophylaxis and self-treatment, andinclude adult and pediatric dosages and comments on toxicity andcontraindications. The CDC continuallyupdates the text and provides moredetailed information on malariaprevention at http://www.cdc.gov/travel A well-balanced discussion of the pros and cons of mefloquine, doxycycline andMalarone for chemoprophylaxis is alsogiven. Finally, prevention of accidentaland potentially fatal ingestion of malaria medications by young children iscovered emphatically.

‘Vaccine recommendations’providesinformation on vaccine certificaterequirements for travelers from the USA

going abroad, standard childhood vaccinerecommendations of the US Public HealthService, timing of vaccines afteradministration of immunoglobulin,‘catch-up’ immunization schedules forchildren who are inadequatelyimmunized, and travel-specific vaccinessuch as yellow fever, hepatitis A andtyphoid. ‘Health hints’ covers subjectssuch as the prevention of diarrhealdiseases, use of insect repellents, websites for the results from the biannual CDC inspections of cruise ships for food and water safety, and asummary of the WHO Blood TransfusionGuidelines. Pregnancy, breast-feeding and travel, special precautions for theHIV-infected traveler and a pleasingdiscussion of the medical issues ofinternational adoption are presented inthe final section of the book in the specialneeds section.

This is a fun book to sit down and read.A travel clinic in the USA would notfunction without this reference book, butwould also likely supplement the bookwith computerized databases providingprintouts of county-specific informationfor the traveler.

William A. Petri, Jr

Division of Infectious Diseases, PO Box 801340, University of Virginia HealthSystem, Charlottesville, VA 22908-1340,USA.e-mail: wap3g@virginia.edu

Corrigendum

In the Research Update article‘Updating the DALYs for diarrhoeal

disease’ by R.L. Guerrant et al.(Trends Parasitol. 18, 191–193, 2002),

the address for the 49th AnnualMeeting of American Society ofTropical Medicine and Hygiene

was given incorrectly in the footnote * on p. 191.

The address read Atlanta, GA, USA,and it should have read

Houston, TX, USA.

The authors and Trends in Parasitology would like to

apologize for any confusion thatmay have resulted from this error.

PII: S1471-4922(02)02326-7

Cestode Zoonoses: Echinococcosis and Cystericosis

An Emergent and Global Problem

edited by Philip Craig and Zbigniew Pawlowski, IOS Press, 2002. (€100, £60) (xii + 395 pages) ISBN 158603 220 8

Cestode Zoonoses: Echinococcosis and Cystericosis – An Emergentand Global Problem is a collection of results presented at the NATO Advanced Research Workshop on Cestode Zoonoses:

Echinococcosis and Cystericosis – An Emergent and Global Problem, held 10–13 September 2000, in Poznan, Poland.

Cestode zoonoses, tapeworm infections of animals that aretransmittable to humans, are being increasingly recognised as a public health

problem in Europe, Central Asia, the Middle East, sub-Saharan Africa, LatinAmerica and USA. This book provides an update and a comprehensive reviewof the recent advances in the study and control of these parasitic tapeworms.

There are four main sections: ‘Disease status, re-emergence and spread’; ‘Tools and methods for diagnostic, transmission and epidemiological studies’;

‘Wild-life ecology and transmission of Echinococcus’ and ‘Approaches forcontrol’, which cover different sessions from the workshop.