`
`Use of DDT in vector control?
`
`Many countries rely on the use of DDT for the
`control of both malaria and visceral leishmaniasis.
`
`Recently, however, it has been suggested that there
`is an association between use of DDT and the occur-
`
`rence of human cancers;"-° a report on the presence
`of DDT in breast milk has appeared;°' and two gener-
`al reviews on the use of DDT in vector control have
`
`been carried out.‘’ The WHO Study Group on Vector
`Control
`for Malaria and other Mosquito-bome
`Diseases, which met in Geneva on 16-24 November
`1993, was asked as a specific additional
`task to
`review the current situation in the light of these
`recent developments. For this purpose, two expert
`toxicologists were invited to participate.’ Based on
`the discussions of all the participants at the meeting,
`the conclusions of the Study Group with regard to
`the use of DDT for vector control are summarized
`below.
`
`0 The information presented does not provide suffi-
`cient and convincing evidence for the adverse effects
`of DDT exposure as a result of indoor residual
`spraying as carried out in malaria control activities.
`
`0 There is therefore, at this stage, no justification on
`toxicological or epidemiological grounds for chang-
`ing current policy towards indoor spraying of DDT
`for vector-bome disease control.9
`
`0 DDT may therefore be used for vector control,
`provided that all the following conditions are met:
`
`3 Based on: Vector control for malaria and other mosquito-borne
`diseases (Annex 1). Geneva, World Health Organization (WHO
`Technical Flepon Series), in press.
`‘’ Garabrant DH et al. DDT and related compounds and risk of
`pancreatic cancer. Journal of the National Cancer Institute,
`1992, 84: 764-771.
`° Woltt MS et al. Blood levels of organochlorine residues and
`risk of breast cancer. Journal of the National Cancer Institute,
`1993, 85: 648-652.
`4 Bouwrnan H et al. Levels of DDT and metabolites in breast
`milk from Kwa-Zulu mothers after DDT application for malaria
`control. Bulletin of the World Health Organization, 1990. 68:
`761-768.
`9 Prepared by: Dr C. F. Curtis, Department of Medical Parasito-
`logy, London School of Hygiene and Tropical Medicine, London,
`England; and Professor J. Mouchet,
`lnstitut
`trancais de Re-
`cherche Scientitique pour
`le Développement en Cooperation
`(ORSTOM), Paris, France.
`' Dr W.N. Aldridge, The Roben’s Institute, Kings Worthy, Hants,
`England; and Professor M. Lotti, Institute of Occupational Medi-
`cine, University ot Padua, Padua, ltaly.
`9 The place of DDT in operations against malaria and other vec-
`tor-borne diseases. in: Executive Board Forty—seventh Session,
`Geneva, 19-29 January 1971, Part ll. Report on the proposed
`programme and budget estimates for 1972. Geneva, World
`Health Organization, 1971 (Official Records of the World Health
`Organization, No. 190): 176-182.
`Reprint No. 5632
`
`- it is used only for indoor spraying;
`- it is effective;
`
`is manufactured according to the
`—- the material
`specifications issued by WHO;” and
`
`— the necessary safety precautions are taken in its
`use and disposal.
`
`o In considering whether to use DDT, governments
`should take into consideration the following addi-
`tional factors:
`
`- the costs involved in the use of insecticides
`
`(DDT or alternatives);
`— the role of insecticides in focal or selective
`
`vector control, as specified in the Global Malaria
`Control Strategy;"/
`
`-— the availability of alternative vector control
`methods, including alternative insecticides (in View
`of the availability of alternative insecticides for
`indoor residual spraying, some of which may com-
`pete with DDT in terms of their epidemiological
`impact, public acceptability, logistic suitability and
`compliance with specifications issued by WHO,
`DDT no longer merits being considered the only
`insecticide of choice);
`
`-— the implications for insecticide resistance, inclu-
`ding possible cross—resistance to some alternative
`insecticides; and
`
`— the changing public attitude to pesticide use,
`including public health applications.
`
`0 In view of the paucity of data suggesting adverse
`effects of indoor house-spraying, further epidemi-
`ological investigation using rigorous scientific proto-
`cols is to be encouraged.
`0 Further studies should also be carried out on the
`
`following:
`— examination of the health effects of DDT in
`
`breast milk on breast-fed infants,
`resulting behavioural changes;
`
`including any
`
`— thorough investigation of any suspected associa-
`tion between the use of DDT in routine malaria
`control activities and an increased incidence of
`
`cancer(s); and
`
`” Specifications for pesticides used in public health —- insecti-
`cides: DDT. Unpublished document WHO/CTD/WHOPES/93,
`1993 (Specifications WHO/SIT/1.R7 and WHO/SIF/1.R7).
`" A global strategy for malaria control. Geneva, World Health
`Organization, 1993.
`/ Implementation of the Global Malaria Control Strategy. Report
`of a WHO Study Group on the Implementation of the Global
`Plan of Action for Malaria Control 1993-2000. Geneva, World
`Health Organization, 1993 (WHO Technical Report Series.
`No. 839).
`
`Bulletin ol the World Health Organization, 1995, 73 (4): 547-551
`
`© World Health Organization 1995
`
`547
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`
`— clarification of the significance of the reduction
`in muscarinic receptor density caused by DDT.
`
`Control of epidemic meningococcal
`disease
`
`Meningococcal disease occurs in two clinical forms:
`meningococcal meningitis and meningococcal septi-
`caemia. Of these,
`the former
`is commoner, but
`responds well to treatment. In contrast, meningococ-
`cal septicaemia, although less common, is fatal, even
`when actively treated. Meningococcal meningitis is
`the only form that causes epidemics. These can occur
`anywhere in the world; however,
`the largest occur
`mainly in the semi-arid areas of sub-Saharan Africa
`(African meningitis belt). Apart
`from epidemics,
`meningococcal meningitis
`occurs
`sporadically
`throughout the world, with seasonal variations, and
`accounts for a variable proportion of endemic bac-
`terial meningitis.
`A 7l-page booklet containing practical guide-
`lines on the control of meningococcal disease for
`health personnel and health authorities, at any level,
`has recently been prepared by a WHO Working
`Group.“ The five chapters cover a range of topics,
`the most important of which are outlined below.
`
`0 The magnitude of the problem.‘ review of epidem-
`ics of meningococcal disease since 1970 (periodicity
`and seasonality of the epidemics, epidemic patterns);
`conditions
`favouring epidemics
`(serogroups
`and
`serotypes,
`immunity,
`and demographic
`factors);
`and meningococcal meningitis as part ,of bacterial
`meningitis (endemic meningococcal disease, other
`causes of bacterial meningitis).
`
`o The disease: how to recognize and confirm
`meningococcal disease (signs and symptoms, physi-
`cal examination, lumbar puncture and cerebrospinal
`fluid (CSF) examination, differential diagnosis); how
`to manage patients with meningococcal disease (anti-
`microbial
`therapy,
`supportive therapy,
`simplified
`management under difficult conditions); how to pre-
`vent meningococcal disease (vaccination, chemo-
`prophylaxis).
`
`: How to detect and confirm an outbreak or epi-
`demic of meningococcal disease: epidemic versus
`endemic disease; plarming and implementing an
`early warning system (collecting and reporting infor-
`mation, regular data review, deciding when an epi-
`demic is occurring); rapid assessment of a suspected
`epidemic of meningococcal disease (investigation of
`suspected cases).
`
`o How to plan for and respond to an epidemic:
`national/provincial crisis committee;
`informing the
`public; planning an appropriate emergency response
`(vaccination, chemoprophylaxis, general measures);
`sustaining the control programme and ensuring
`follow-up; and documenting the epidemic.
`
`o Interepidemic prophylaxis: containment around a
`patient with meningococcal disease in non-epidemic
`conditions; routine vaccination; and regulations for
`travellers.
`
`A list of 84 references to the original literature is
`included,
`together with 10 annexes that provide
`information on the following:
`
`-- Gram and methylene blue staining;
`
`-— latex agglutination tests;
`
`—— injecting oily chloramphenicol;
`— vaccines;
`
`-— public domain software
`investigations;
`
`for epidemiological
`
`— materials for field investigations;
`
`—— materials for diagnosing Neisseria meningitidis;
`
`-— preparing trans-isolate medium;
`
`— sources of kits for mass vaccination campaigns;
`and
`
`— organizing a vaccination campaign.
`
`Single copies of this booklet can be obtained
`from the Programme on Bacterial, Viral Diseases
`and Immunology, Division of Communicable Dis-
`eases, World Health Organization, 1211 Geneva 27,
`Switzerland.
`
`Yellow fever in 1992 and 1993’
`
`The total numbers of cases of yellow fever in 1992
`and 1993 were relatively low, but noteworthy in that
`the first outbreak recorded in Kenya since 1943 was
`documented. A total of 295 cases were reported to
`WHO for 1992, with 102 deaths (case—fatality rate
`(CFR), 35%). These included 176 cases and 21 deaths
`(CFR, 12%)
`from Africa, and 119 cases and 81
`deaths (CFR, 68%) from South America. In 1993, a
`total of 218 cases and 38 deaths (CFR, 17%) were
`reported from Africa, and 175 cases with 79 deaths
`(CFR, 45%) were documented from South America,
`for a grand total of 393 cases and 117 deaths (CFR,
`30%). A summary of the number of yellow fever
`cases and deaths reported to WHO by Member States
`for the period 1989-93 is shown in Table 1.
`
`“ Control of epidemic meningococcal disease: WHO practical
`guidelines. Lyon, Edition Foundation Marcel Mérieux, 1995.
`
`’ Based on: Yellow fever in 1992 and 1993. Weekly epidemio-
`logical record, 1995, 70(10): 65-70.
`
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`Country/area
`Africa
`Cameroon
`Ghana
`
`Kenya
`Nigeria
`
`Total
`South America‘’
`Bolivia
`Brazil
`Colombia
`Ecuador
`Peru
`
`Total
`
`—-
`—
`
`--
`3 270
`
`3 270
`
`107
`9
`1
`—-
`120
`
`237
`
`—-
`—
`
`--
`618
`
`618 (19)‘
`
`87
`3
`1
`--
`100
`
`191 (81)
`
`809 (23)
`
`173
`—
`
`—
`4 075
`
`4 248
`
`118
`—
`
`—
`223
`
`341 (8)
`
`38
`1
`7
`6
`17
`
`50
`2
`7
`12
`17
`
`as
`
`—
`—
`
`—
`2 561
`
`2 561
`
`91
`1 5
`4
`14
`27
`
`—-
`—
`
`—
`661
`
`661 (26)
`
`54
`8
`4
`9
`15
`
`69 (78)
`
`151
`
`90 (so)
`
`Table 1: Yellow fever: number of cases and deaths (case-fatality rate) notified to WHO, 1989-93
`1989
`1990
`1991
`1992
`
`1993
`
`WHO News and activities
`
`Cases
`
`Deaths
`
`Cases
`
`Deaths
`
`Cases
`
`Deaths
`
`Cases Deaths
`
`Cases Deaths
`
`—
`—
`
`27
`149
`
`176
`
`22
`1 2
`2
`1 6
`67
`
`119
`
`295
`
`-
`—
`
`1 3
`8
`
`21 (12)
`
`18
`8
`2
`1 3
`40
`
`81 (68)
`
`102 (35)
`
`39
`
`27
`152
`
`218
`
`18
`66
`1
`1
`89
`
`175
`
`393
`
`15
`
`15
`8
`
`38 (17)
`
`14
`1 7
`1
`-
`47
`
`79 (45)
`
`117 (30)
`
`Grand total
`
`3 507
`
`4 336
`
`410 (9)
`
`2 712
`
`751 (28)
`
`3 Figures in parentheses are percentages.
`" The case previously reponed in French Guiana in 1990 has been deleted.
`
`Africa
`
`In a dramatic decrease in the number of cases repor-
`ted compared with previous years, only Kenya and
`Nigeria reported yellow fever in 1992, while Ghana
`experienced a limited outbreak in 1993 that con-
`tinued into 1994.
`
`In 1993, an outbreak of yellow fever
`Ghana.
`occurred in the Upper West Region, with 39 cases
`and 15 deaths (CFR, 38%)!" The outbreak began in
`October 1993 and cases were still being reported in
`December. Transmission appeared to be limited to
`the Jiripa District. Yellow fever was confirmed sero-
`logically. Of 37 cases where age and sex were
`reported, 15 (40%) were under 15 years of age, and 9
`(24%) were females. An immunization campaign
`was begun in December 1993 and continued into
`1994; it appears to have controlled the outbreak.
`
`Kenya. The first yellow fever outbreak reported from
`Kenya since 1943 began in September 1992 and con-
`tinued through March 1993. The outbreak was limit-
`ed to the Baringo and Elgeyo Marakwet Districts in
`the Kerio Valley, north-west of Nairobi. A total of
`54 cases and 28 deaths (CFR, 52%) were recorded.
`Eighteen of the cases (33%) were among people
`aged S19 years and 19 cases (35%) were females.
`Epidemiological
`investigations
`indicated that
`the
`outbreak was consistent with jungle yellow fever.
`The virus was isolated from clinical specimens of ill
`
`'" Yellow fever, Ghana. Weekly epidemiological record, 1994,
`69(6): 44; and 1994, 69(10): 76.
`
`and fatal cases, and from captured mosquitos.
`Molecular characterization of the isolated viruses
`
`indicated that they were similar in genetic composi-
`tion to those previously isolated from humans and
`mosquitos during past outbreaks of yellow fever in
`East Africa, and genetically distinct from isolates
`from specimens collected in West Africa or South
`America. The outbreak was halted following a mass
`immunization campaign, during which nearly 1 mil-
`lion doses of yellow fever vaccine were administered
`to residents of the areas at risk.
`
`Nigeria. Only 149 cases and 8 deaths (CFR, 5%)
`were reported from Nigeria in 1992, unlike the situa-
`tion in recent years when several
`thousand cases
`were documented. In 1993, 152 cases were reported,
`with eight deaths (CFR, 5%). No information was
`provided on the specific dates of onset,
`locations,
`age or sex of the reported cases for either year.
`
`EPI: yellow fever vaccine in Africa. Since 1989,
`WHO/EPI has recommended that yellow fever vac~
`cine be included in the childhood immunization pro-
`grammes of the 33 countries in Africa at risk for the
`disease. Today, 17 of the 33 countries have a nation-
`al policy to this effect. Up to August 1994, yellow
`fever immunization coverage data had been reported
`to WHO by 15 of the 17 countries. Burkina Faso, the
`Gambia, and Mauritania have achieved coverage
`above 50% for children by their first birthday. How-
`ever, for all 33 African countries at risk for yellow
`fever, vaccine coverage levels only reached 7% in
`1993, compared with 11% in 1992.
`
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`
`The African countries at risk are among the
`most impoverished countries in the world. Although
`yellow fever vaccine is available to developing coun-
`tries at less than US$ 0.25 per close, this price is still
`a barrier to many countries at risk. Donors are
`encouraged to provide assistance to help the African
`countries at risk prevent the deadly disease through
`routine immunization.
`
`South America
`
`In 1992, a total of 119 cases and 81 deaths (CFR,
`68%) were officially reported from South America:
`22 cases and 18 deaths (CFR, 82%) were reported
`from Bolivia; 12 cases and 8 deaths (CFR, 67%) from
`Brazil; 2 cases and 2 deaths (CFR, 100%) from
`Colombia; 16 cases and 13 deaths (CFR, 81%) from
`Ecuador and 67 cases and 40 deaths (CFR, 60%)
`from Peru.
`
`In 1993, 18 cases and 14 deaths (CFR, 78%) were
`reported from Bolivia, 66 cases and 17 deaths (CFR,
`26%) from Brazil; one fatal case from Colombia; one
`non-fatal case from Ecuador; and 89 cases with 47
`deaths (CFR, 53%) from Peru. Thus, a total of 175
`cases were reported, with 79 deaths (CFR, 45%).
`
`Bolivia. All 22 cases that occurred during 1992 were
`among adult males aged 16-70 years. A total of 16
`cases were reported from La Paz Department, 1 case
`from Cochabamba, and 5 cases from Santa Cruz.
`Eighteen of the 22 cases were fatal,
`including all
`those from La Paz, the case in Cochabamba, and one
`of the cases in Santa Cruz. Cases occurred through-
`out the year. Of the 18 cases reported in 1993, 14
`were from La Paz and 4 from Santa Cruz: 13 of the
`
`14 patients from La Paz and 1 of the cases from
`Santa Cruz died. Three cases involved females aged
`6 months, 30 years, and 70 years. The youngest and
`the oldest were among the fatal cases. The 15 male
`cases were aged 7-57 years; 12 died.
`
`Brazil. Of 12 cases reported in 1992, all were among
`young adult males except one, a 21-year-old woman
`who died on 1 January 1992 in Sidrolandia, Mato
`Grosso do Sul State. The male cases were aged
`18-39 years (1 was aged <20 years; 4 were aged
`20-29 years; 6 were aged 30-39 years). A total of
`eight cases were reported from Mato Grosso do Sul
`State, two from Mato Grosso, and one each from
`Amazonas and Roraima. Six cases occurred in Janu-
`
`ary, one in February,
`November.
`
`three in March and two in
`
`In 1993, an outbreak of yellow fever occurred
`between March and May around the Municipality of
`Mirador in the State of Maranhao. Of the 66 cases
`
`reported, 44 were from this location, and an addi-
`tional 11 were from Barra do Corda in the same
`
`state. A total of 17 deaths were reported (CFR,
`26%), but only three were from Mirador and four
`from Barra do Corda.
`
`Colombia. In 1992, two fatal cases of yellow fever
`involving young men were reported in Florencia,
`Caqueta Province, and Puerto Asis, Putumayo Prov-
`ince. No additional epidemiological information was
`reported for these cases. In 1993 one fatal case was
`reported in Zaragoza, Antioquia Province.
`
`Ecuador. Epidemiological information was available
`for 11 of the 16 cases reported in 1992. All were
`among young men, with seven aged less than 20
`years, two aged 20-29 years, and two aged 40-49
`years. The dates of onset were May (3 cases) and
`June (8 cases), and the localities affected were Pasta-
`za Province (4 cases), Napo (3 cases), and Sucumbi-
`os (3 cases); no information was provided for one
`case. In 1993 one case was reported but no epidemi-
`ological information was given.
`
`Peru. Peru accounted for the largest number of cases
`notified in the American Region in 1992 and 1993.
`In 1992, 67 cases were reported, of which 40 were
`fatal (CFR, 60%) and in 1993, 89 cases and 47
`deaths (CFR, 53%). Throughout 1992, a total of
`1-12 cases were notified monthly. A total of 35
`cases were from seven provinces in the Department
`of San Martin. The remaining 32 cases were reported
`in 13 provinces in seven departments. A total of 56
`of the 67 cases were in patients over 15 years of age,
`and 43 were aged 20-40 years.
`Of the 89 cases notified in Peru in 1993, a total
`of 80 were from the Departments of San Martin (32),
`Junfn (28) and Ayacucho (20). The highest number
`of cases in San Martin Department were reported
`from Huallaga Province (17 cases), in Junin Depart-
`ment from Chanchamayo Province (21 cases), and in
`Ayacucho Department from Lucanas Province (12
`cases). Six other provinces in San Martin, two in
`Junin and 12 in Ayacucho reported cases, and the
`remaining nine cases were scattered over six prov-
`inces in five departments. Seventeen of the 89 cases
`were in females, 15 cases were 15 years of age, and
`three were >60 years of age.
`
`Conclusion
`
`The risk of yellow fever in many tropical and sub-
`tropical areas of Africa and South America continues
`to be significant. The disease remains enzootic in
`these areas in a jungle cycle, with transmission
`occurring primarily among non-human primates,
`with forest-dwelling mosquitos serving as vectors.
`Humans are infected when they enter into areas of
`active transmission and are fed upon by infectious
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`mosquitos. A greater risk for human epidemic trans~
`mission occurs when viraemic persons enter urban
`centres where they may be fed upon by competent
`domestic mosquito vectors, especially Aedes aegypti.
`The re-infestation of many tropical and subtropical
`cities by this mosquito species is of grave concern in
`the light of historical urban yellow fever outbreaks,
`and the realization that both human and vector mos-
`
`quito population densities are now much greater than
`when urban yellow fever was last commonplace.
`
`Nutritional value of Antarctic krill"
`
`A healthy diet requires a proper balance of carbohy-
`drates, proteins, fats (and oils), fibre and minerals, as
`well as other nutrients. Nutritionally, Antarctic krill
`(Euphausia superba) appears to be a food appropria-
`te for inclusion in a healthy diet;
`it contains equal
`proportions of polyunsaturated, monounsaturated,
`and saturated fatty acids, with the last-mentioned
`accounting for less than 6% of the total energy
`content; and it has a high protein content (63.7% of
`dry weight of the meat).
`Of the more than 70 species of euphausiid crus-
`taceans that are present
`in the ecosystem of the
`south-westem Atlantic Ocean, the largest is Antarc-
`tic krill, which can reach up S—6 cm in length. Ant-
`arctic krill occurs throughout the circumpolar zone,
`but is especially abundant in the waters surrounding
`the South Shetland Isles. The total estimated reserves
`
`of the crustacean are enormous (500—250O million
`tonnes) and an annual catch of only 10% of this bio-
`mass would be equivalent to the world’s total yearly
`fish catch. Work on its use as a foodstuff for human
`
`consumption has been carried out in several coun-
`
`" Summary of an article submitted by B.A. Grillo, W. Alallon,
`and P. Louisot. Copies of the full article can be obtained upon
`request
`from Dr Grillo, Bvar. Espana 2575/402, Montevideo
`11300, Uruguay.
`
`WHO News and activities
`
`tries, e.g., Russian Federation, Poland, Japan, Chile,
`and Uruguay.
`The cholesterol
`
`level of Antarctic krill is low
`
`(ca. 30 mg per 100 g), while the level of polyunsatu-
`rated fatty acids of the n—-3 series (principally octa-
`decatetraeonic
`acid,
`eicosapentaenoic
`acid,
`and
`docosahexaenoic acid) is high (1.47 g per 100 g). The
`total level of polyunsaturated fatty acids is similar to
`that of tuna, salmon, anchovy, and herring.
`Noteworthy is the high selenium content of Ant-
`arctic krill (3.41 pg/g), a trace element that is a co-
`factor for glutathione peroxidase. Other trace ele-
`ments present include zinc (43.7 pg/g) and copper
`(4.77 pg/g), both of which play a role in the action of
`superoxide dismutase.
`Studies on rabbits indicated that replacement of
`10% of their basal diet with krill produced a reduc-
`tion (P<0.05) in formation of atheromatous plaque;
`also,
`the levels of aortic and pulmonary plaque
`caused by a hypercholesterolaemic diet were reduced
`in rabbits that were fed krill.
`
`Controlled studies on humans suggest that con-
`sumption of 25 g per day of Antarctic krill meat for
`7 days could significantly reduce platelet aggregation
`and increase plasma levels of eicosapentaenoic acid
`and docosahexaenoic acid. Furthermore, a krill diet
`may have a pronounced anti—atherogenic effect, as
`indicated by the marked reduction or elimination of
`the atherogenic potential
`it produces on the blood
`plasma of patients with cardiac insufficiency,
`in-
`ducing an in—vitro reduction in the incorporation of
`cholesterol into the subendothelial cells of the aorta.
`
`The organoleptic properties appear to be retained
`in krill meal stored for up to 6 months at tempera-
`tures below 20 °C and for over 8 months at tempera-
`tures of 4—8 °C. The authors report that Antarctic
`krill meat has no hepatotoxic effects and that it may
`have beneficial effects on chronic diseases such as
`
`atherosclerosis. Other products that can be derived
`from Antarctic krill, e.g., chitosans from the shell,
`astaxanthins, proteolytic
`and lipolytic
`enzymes,
`together with exploitation of its high fluorine con-
`tent, represent novel areas for research.
`
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`Notes et activités OMS
`
`Utilisation du DDT dans la lutte
`
`antivectoriellea
`
`De nombreux pays utilisent le DDT dans la lutte
`contre le paludisme et contre la leishmaniose viscé-
`rale. Toutefois, 1’hypothese d’une association entre
`1’utilisation du DDT et la survenue de cancers chez
`
`l’homme a été récemment avancée;°"’ un rapport sur
`la présence de DDT dans le lait matemel a été
`public,“ et deux mises au point générales sur l’utili-
`sation du DDT dans la lutte antivectorielle ont été
`
`réaliséesf’ Le Groupe d’étude de l’OMS sur le palu-
`disme et les autres maladies transmises par les mous-
`tiques, qui
`s’est
`réuni a Geneve du 16 au 24
`novembre 1993, était charge, entre autres questions,
`d’examiner la situation actuclle a la lumiere des pro-
`gres récents réalisés dans ce domaine. Deux experts
`toxicologues ont été, a cette fin, invites a participer
`aux travaux du Groupe.’ Les conclusions du Groupe
`d’étude concemant l’utilisation du DDT dans la lutte
`antivectorielle, résultant des discussions entre l’en-
`semble des participants, sont résumées ci-dessous.
`
`o L’information présentée n’offre pas de preuves
`suffisantes ni convaincantes des effets indésirables
`
`dc l’exposition au DDT resultant des pulvérisations a
`effet rémanent a l’intérieur des habitations telles
`
`qu’e1les sont pratiquées dans le cadre de la lutte anti-
`paludique.
`
`o Dans l’état actuel des connaissances, rien ne justi-
`fie,
`tant sur le plan toxicologique qu’épidémiolo-
`
`5 D'apres: Vector control for malaria and other mosquito-borne
`diseases (Annexe 1). Geneva, Organisation mondiale de la
`Santé (OMS, Série de Rapports techniques), sous presse (ver-
`sion frangaise en preparation).
`‘’ Garabrant DH et al. DDT and related compounds and risk of
`pancreatic cancer. Journal of the National Cancer Institute,
`1992, 84: 764-771.
`° Wolff Ms et al. Blood levels of organochlorine residues and
`risk of breast cancer. Journal of the National Cancer Institute,
`1993, 85: 648-652.
`‘ Bouwman H et al. Levels of DDT and metabolites in breast
`milk from Kwa-Zulu mothers after DDT application for malaria
`control. Bulletin de I’Organisation mondiale de la Santé, 1990,
`68: 761-768.
`
`9 Par: Dr C.F. Curtis, Department of Medical Parasitology, Lon-
`don School oi Hygiene and Tropical Medicine, Londres, Angle-
`terre, et Protesseur J. Mouchet,
`lnstitut francais de Recherche
`Scientifique pour le Développernent en Cooperation (ORSTOM),
`Paris, France.
`' Dr W.N. Aldridge, The Roben‘s institute, Kings Worthy, Hants,
`Angleterre, et Professeur M. Lotti,
`lnstitul de Médecine do Tra-
`vail, Université de Padoue, Padoue, Italie.
`9 Place du DDT dans Ies operations contre Ie paludisme et
`autres maladies transmises par des vecteurs. In: Conseil execu-
`tif, Quarante-septieme session, Geneve, 19-29 janvier 1971,
`
`Tiré a part N° 5633
`
`gique, de modifier la politique en vigueur en matiere
`de pulvérisations de DDT a l’intérieur des habita-
`tions dans le cadre de la lutte contre les maladies
`transmisesrpar des vecteurs.9 _
`_
`.
`0 Le DD peut donc étre utilisé dans la lutte anti-
`vectorielle, a condition que toutes les conditions sui-
`vantes soient rempliest
`
`— i1 ne doit étre utilise que pour les pulvérisations a
`l’intérieur des habitations;
`
`— i1 doit étre efficace;
`
`— le produit doit étre fabriqué conformément aux
`normes publiées par 1’OMS;"
`—— les mesures de sécurité nécessaires doivent étre
`
`prises lors de son utilisation et de son elimina-
`tion.
`
`0 Lorsqu’ils envisagent d’uti1iser le DDT, les gou-
`vemements devraient tenir compte des facteurs sup-
`plémentaires suivants:
`
`— cofit de 1’emploi d’insecticides (DDT ou insecti-
`cides de remplacement);
`— role des insecticides dans la lutte antivectorielle
`
`ciblée ou sélective, comme il est spécifié ‘dans la
`Stratégie mondiale de lutte antipaludique;"/
`— existence d’autres méthodes de lutte antivecto-
`
`rielle, y compris avec des insecticides de rempla-
`cement (étant donné l’existence d’autres insecti-
`cides utilisables pour les pulvérisations 51 effet
`rémanent £1 l’intérieur des habitations, dont cer-
`tains peuvent concurrencer le DDT sur le plan de
`l’impact épidémiologique, de 1’acceptabilite’ par
`le public, de 1’intérét logistique et de la confor-
`mité aux normes publiées par l’OMS, le DDT ne
`mérite plus d’étre considéré comme l’insecticide
`de choix);
`
`——- conséquences sur le plan de la resistance aux
`insecticides, y compris une éventuelle resistance
`croisée avec certains insecticides de remplace—
`ment;
`
`Partie ll. Rapport sur Ie projet de programme at de budget pour
`1972. Geneve, Organisation mondiale de la Santé, 1971 (Actes
`otficiels de l’Organisation mondiale de la Santé, N° 190):
`176-182.
`
`" Specifications for pesticides used in public health — insecti-
`cides: DDT. Document non publié WHO/CTD/WHOPES/93,
`1993. Normes WHO/SlT/1.R7 et WHO/SIF/1.Ft7.
`
`’ Stratégie mondiale de lutte antipaludique. Genéve, Organisa-
`tion mondiale de la Santé. 1994.
`I" Miss en oeuvre de la strategie mondiale de lutte antipaludique.
`Rapport d'un groupe d’étude de l’OMS sur la mise en oeuvre do
`plan mondial d'action pour
`la
`lutte
`contre
`Ie paiudisme
`1993-2000. Genéve, Organisation mondiale de la Santé, 1993
`(OMS, Série de Rappons techniques, N° 839).
`
`Bulletin de I’Organisation mondiale de la same, 1995, 73 (4): 553-558
`
`© Organisation mondiale de la Santé 1995
`
`553
`
`000006
`
`AKER877|TC00739752
`
`000006
`
`
`
`Notes et actlvltés OMS
`
`—- évolution de l’attitude du public vis-a—vis de
`l’utilisation des pesticides, y compris dans le
`domaine de la santé publique.
`
`o Etant donné la minceur des données évoquant un
`éventuel effet indésirable des pulvérisations a effet
`rémanent a l’intérieur des habitations,
`il convient
`d’encourager de nouvelles recherches épidémiolo-
`giques
`reposant
`sur des protocoles
`scientifiques
`rigoureux.
`
`0 De nouvelles études devraient également étre rea-
`lisées dans les domaines suivants:
`
`— examen des effets du DDT present dans le lait
`matemel sur la santé des nourrissons allaités au
`
`sein, y compris d’éventuels effets comportemen-
`taux;
`
`—— étude approfondie de toute association éventuelle
`entre l’utilisation du DDT dans les activités cou-
`
`rantes de lutte antipaludique et une incidence
`accrue des cancers;
`
`— élucidation de la signification de la réduction de
`la densité des récepteurs aux muscariniques due
`au DDT.
`
`Lutte contre les épidémies de
`méningite a méningocoque
`
`La méningococcie se présente sous deux forrnes cli-
`niques: la méningite it méningocoque et la septice-
`mie a méningocoque. La premiere forme est la plus
`commune, mais elle répond bien au traitement. En
`revanche, la septicémie a méningocoque, moins fré-
`quente, est mortelle, méme quand elle est traitée acti-
`vement. La méningite a méningocoque est la seule
`forme qui provoque des épidémies. Celles-ci peuvent
`éclater dans n’importe quelle partie du monde;
`cependant,
`les plus grandes épidémies surviennent
`principalement dans la zone semi-aride de l’Afrique
`subsaharienne (“ceinture africaine de la méningite”).
`En dehors des épidérnies, la méningite a méningo-
`coque sévit sous forme de cas sporadiques dans
`l’ensemble du monde, avec des variations saison-
`nieres, et représente une part plus ou moins impor-
`tantes des méningites bactériennes endémiques.
`Un Groupe de travail de l’OMS a récemment
`préparé un guide de 72 pages contenant des indica-
`tions pratiques pour la lutte contre les méningococ-
`cies, 5 l’intention des personnels de santé et des
`autorités sanitaires, a tous les niveaux/‘ Ses cinq cha-
`pitres couvrent divers sujets dont les plus importants
`sont les suivants:
`
`" Lutte contre les épidémies de méningite a méningocaque:
`guide pratique OMS. Lyon, Edition Fondation Marcel Mérieux,
`1995.
`
`554
`
`o Ampleur du probléme: revue des épidémies obser-
`vées depuis les années 70 (périodicité et variations
`saisonniéres des épidémies, caractéristiques des épi-
`démies); conditions favorisant les épidémies (séro—
`groupes et sérotypes,
`imrnunité, facteurs démogra-
`phiques); place de la méningite a méningocoque
`parmi
`les méningites bactériennes
`(méningite a
`méningocoque endémique, autres causes de méningi-
`te bactérienne).
`
`0 La maladies comment reconnaitre et confirmer
`
`une méningococcie (symptémes, examen clinique,
`ponction lombaire et examen du liquide céphalo-
`rachidien (LCR), diagnostic différentiel); comment
`prendre en charge les malades (traitement antibio-
`tique,
`traitement symptomatique, prise en charge
`simplifiée dans des conditions défavorables); com-
`ment prévenir les méningococcies (vaccination, chi-
`mioprophylaxie).
`
`0 Comment détecter et confirmer une épidémie de
`méningite ct me’m'ngocoque.' épidémie ou endémie?
`planification et mise en oeuvre d’un systeme d’alerte
`précoce (collecte et transmission dc l’inforrnation,
`analyse réguliere des données, comment determiner
`l’émergence d’une épidémie);
`évaluation rapide
`d’une alerte a l’épidémie (investigation des cas sus-
`pects).
`
`0 Comment plamfier et gérer la réponse d une épi-
`démie: comité de crise national ou provincial; infor-
`mation du public; organisation d’une réponse urgente
`appropriée (vaccination, chimioprophylaxie, mesures
`générales);
`réalisation et suivi du programme de
`lutte; rapport sur 1’épidémie.
`
`o Prophylaxie interépidémique: prévention autour
`d’un cas de méningococcie, en dehors d’une epide-
`mie; vaccination de
`routine;
`réglementation et
`recommandations pour les Voyageurs.
`
`L’ouvrage contient une liste de 84 references a
`des articles originaux et 10 annexes qui donnent des
`informations sur les points suivants:
`—— coloration de Gram et coloration au bleu de
`
`méthyléne;
`
`—— test d’agg1utination au latex;
`
`—— chloramphénicol injectable en solution huileuse;
`
`— laboratoires producteurs de vaccins;
`
`— logiciels informatiques destinés aux investiga-
`tions épidémiologiques;
`
`—- matériel nécessaire pour Pinvest