121
chloroquine and where mefloquine has not yet been used. Selection by drug pressure in the host may have happened during the prolonged prophylaxis (more than 3 months) and during treatment. However, even if selection of a resistant strain did take place by drug pressure under subtherapeutic doses, we cannot overlook another factor that could compound drug pressure-namely, selection by "therapeutic escape". This case raised questions about prolonged prophylaxis, or treatment with the same drug afterwards, especially in areas where mefloquine has been little used. Department of Parasitology, Tropical Medicine, and Public Health, INSERM Unit 313; and Paediatrics Service,
Groupe Hoapitalier Pitié- Salpêtrière, 75651 Paris, France, and Department of Pharmacology,
INSERM Unit 13,
Groupe Hospitalier
Bichat-Claude Bernard,
Paris
F. GAY M. H. BINET M. D. G. BUSTOS B. ROUVEIX M. DANIS C. ROY M. GENTILINI
1. Cosgriff TM, Pamplin CL, Craig CJ, Willet GP. Mefloquine failure in a case of falciparum malaria induced with a multidrug resistant isolate m a non-immune subject Am JTrop Med Hyg 1985; 34: 692-93. 2 Bygbjerg IC, Schaptra A, Flachs H, Gomme G, Jepsen S. Mefloquine resistance of falciparum malaria from Tanzania enhanced by treatment. Lancet 1983; i: 774-75. 3 Schwartz DE, Eckert G, Hartmann D, et al. Single dose kinetics of mefloquine in man. Chemotherapy 1982; 28: 70-84. 4. White NJ Drug treatment and prevention of malaria Eur J Clin Pharmacol 1988; 34: 1-14.
Diagnosis of malaria during chloroquine/proguanil prophylaxis SIR,-With the emergence of chloroquine-resistant Plasmodium falciparum malaria in Africa’ recommendations on the most effective chemoprophylaxis for long-term travellers to such areas have changed and nowadays include weekly chloroquine plus daily proguanip,3 We have experienced diagnostic difficulty in ten patients presenting with symptoms highly suggestive of malaria (fever, chills, fatigue, headache, arthralgia, muscle pain) while on regular chloroquine/proguanil prophylaxis at the appropriate dosage (table). A thin blood film (May-Griinwald-Giemsa stain) was negative in all patients. Thick blood films (Giemsa) contained parasites but they were hardly recognisable, being severely altered and atypical in shape and structure, with very irregular nuclei and vacuoles. Parasite counts calculated by a standard technique on 100 microscope fields’ were very low for all patients, ranging from 4 to 150/u) (table). All patients completely recovered after the institution of antimalarial therapy, usually quinine and/or pyrimethamine plus sulphadoxine (’Fansidar’). Our laboratory technicians had great difficulty in recognising parasites in blood and with low parasite counts. This could result in dangerous delays in diagnosis and treatment in less experienced centres, where the clinical picture might be incorrectly ascribed to other frequent infections. We are unaware of previous reports of severely altered P falciparum morphology and very low parasite counts
in
cases
of failed
be instituted without
delay in patients whose clinical picture is
compatible with malaria but whose blood films are "negative". Laboratory Division OCEAC, BP 288, Yaounde, Cameroon
CLAUDE HENGY
c/o Israel Embassy, Yaounde
DAVID GOZAL
1. Lobel HO, Campbell CC. Malaria prophylaxis and distribution of drug resistance. Clin Trop Med Commun Dis 1986; 1: 225-42. 2. Cook GC. Prevention and treatment of malaria. Lancet 1988; i: 32-36. 3. Anon. Vaccination certificate requirements and health advice for international travel. Geneva: World Health Organisation, 1987: 45. 4. Payne D. Use and limitations of light microscopy for diagnosing malaria at the primary health care level. Bull WHO 1988; 66: 621-26.
Oilseed rape
as a
potent antigen
SIR,-Oilseed rape pollen has been blamed for hayfever, asthma, and allergic dermatitis, but we can find no scientific evidence for this apart from a patient with contact dermatitis provoked by mustard seed (Brassica nigra) antigens who reacted on patch testing to oilseed rape (B napus) also.’ The availability of European Community subsidies has led to an increase in the amount of oilseed rape that is grown in the UK. In Scotland the amount of land under this crop increased from 1600 hectares in 1982 to about 42 000 hectares in 1988. On Tayside the increase has been from nil to 6000 hectares or so, and in the countryside it is difficult to avoid contact with the plant. Our serological investigation of sensitisation to oilseed rape shows that the pollen of this crop is one of the most potent antigens described to date. The sera tested had been sent to the allergy testing laboratories serving predominantly urban Glasgow and more rural Tayside for routine IgE antibody testing by radioallergosorbent test (RAST) to common allergens. No requests specifically mentioned oilseed rape allergy. Sera were stored at - 20°C. The "routine" antigens were mixed grasses, Dermatophagoides pteronyssinus, cat and dog dander, and mixed foods; tests for oilseed rape and mixed moulds (Penicillium notatum, Cladosporium herbarum, Aspergillus fumigatus, and Alternaria alternata) were done in Dundee on both sets of sera. We tested for mixed moulds, because rape, after flowering, is cut and left in the fields for several weeks before harvesting, during which time it often becomes mouldy. We used Thadebas’ RAST kits (Pharmacia) and recorded the results as 0 for no sensitisation and 1-4 for mild, moderate, high, or very high sensitisation. Total IgE levels were assayed by ’Phadezym’ kits (Pharmacia). In Dundee, 175 sera submitted between May and September, 1988, were tested and compared with 141 sera from Glasgow which had been collected during February, June, and July, 1988. (February and September both lie outside the flowering season of oilseed rape.) A further 82 Dundee sera from November and December, 1988, were also studied. ’
combined
chloroquine/proguanil
chemoprophylaxis. We suggest that empirical antimalarial therapy CLINICAL PICTURE AND PARASITE COUNT -
-
Seroprevalence of sensitisation to oilseed moulds in Tayside and Glasgow.
rape and mixed
Mixed mould results for Tayside in June and September, 1988, 96% and 129%, respectively
were
chloroquine and where mefloquine has not yet been used. Selection by drug pressure in the host may have happened during the prolonged prophylaxis (more than 3 months) and during treatment. However, even if selection of a resistant strain did take place by drug pressure under subtherapeutic doses, we cannot overlook another factor that could compound drug pressure-namely, selection by "therapeutic escape". This case raised questions about prolonged prophylaxis, or treatment with the same drug afterwards, especially in areas where mefloquine has been little used. Department of Parasitology, Tropical Medicine, and Public Health, INSERM Unit 313; and Paediatrics Service,
Groupe Hoapitalier Pitié- Salpêtrière, 75651 Paris, France, and Department of Pharmacology,
INSERM Unit 13,
Groupe Hospitalier
Bichat-Claude Bernard,
Paris
F. GAY M. H. BINET M. D. G. BUSTOS B. ROUVEIX M. DANIS C. ROY M. GENTILINI
1. Cosgriff TM, Pamplin CL, Craig CJ, Willet GP. Mefloquine failure in a case of falciparum malaria induced with a multidrug resistant isolate m a non-immune subject Am JTrop Med Hyg 1985; 34: 692-93. 2 Bygbjerg IC, Schaptra A, Flachs H, Gomme G, Jepsen S. Mefloquine resistance of falciparum malaria from Tanzania enhanced by treatment. Lancet 1983; i: 774-75. 3 Schwartz DE, Eckert G, Hartmann D, et al. Single dose kinetics of mefloquine in man. Chemotherapy 1982; 28: 70-84. 4. White NJ Drug treatment and prevention of malaria Eur J Clin Pharmacol 1988; 34: 1-14.
Diagnosis of malaria during chloroquine/proguanil prophylaxis SIR,-With the emergence of chloroquine-resistant Plasmodium falciparum malaria in Africa’ recommendations on the most effective chemoprophylaxis for long-term travellers to such areas have changed and nowadays include weekly chloroquine plus daily proguanip,3 We have experienced diagnostic difficulty in ten patients presenting with symptoms highly suggestive of malaria (fever, chills, fatigue, headache, arthralgia, muscle pain) while on regular chloroquine/proguanil prophylaxis at the appropriate dosage (table). A thin blood film (May-Griinwald-Giemsa stain) was negative in all patients. Thick blood films (Giemsa) contained parasites but they were hardly recognisable, being severely altered and atypical in shape and structure, with very irregular nuclei and vacuoles. Parasite counts calculated by a standard technique on 100 microscope fields’ were very low for all patients, ranging from 4 to 150/u) (table). All patients completely recovered after the institution of antimalarial therapy, usually quinine and/or pyrimethamine plus sulphadoxine (’Fansidar’). Our laboratory technicians had great difficulty in recognising parasites in blood and with low parasite counts. This could result in dangerous delays in diagnosis and treatment in less experienced centres, where the clinical picture might be incorrectly ascribed to other frequent infections. We are unaware of previous reports of severely altered P falciparum morphology and very low parasite counts
in
cases
of failed
be instituted without
delay in patients whose clinical picture is
compatible with malaria but whose blood films are "negative". Laboratory Division OCEAC, BP 288, Yaounde, Cameroon
CLAUDE HENGY
c/o Israel Embassy, Yaounde
DAVID GOZAL
1. Lobel HO, Campbell CC. Malaria prophylaxis and distribution of drug resistance. Clin Trop Med Commun Dis 1986; 1: 225-42. 2. Cook GC. Prevention and treatment of malaria. Lancet 1988; i: 32-36. 3. Anon. Vaccination certificate requirements and health advice for international travel. Geneva: World Health Organisation, 1987: 45. 4. Payne D. Use and limitations of light microscopy for diagnosing malaria at the primary health care level. Bull WHO 1988; 66: 621-26.
Oilseed rape
as a
potent antigen
SIR,-Oilseed rape pollen has been blamed for hayfever, asthma, and allergic dermatitis, but we can find no scientific evidence for this apart from a patient with contact dermatitis provoked by mustard seed (Brassica nigra) antigens who reacted on patch testing to oilseed rape (B napus) also.’ The availability of European Community subsidies has led to an increase in the amount of oilseed rape that is grown in the UK. In Scotland the amount of land under this crop increased from 1600 hectares in 1982 to about 42 000 hectares in 1988. On Tayside the increase has been from nil to 6000 hectares or so, and in the countryside it is difficult to avoid contact with the plant. Our serological investigation of sensitisation to oilseed rape shows that the pollen of this crop is one of the most potent antigens described to date. The sera tested had been sent to the allergy testing laboratories serving predominantly urban Glasgow and more rural Tayside for routine IgE antibody testing by radioallergosorbent test (RAST) to common allergens. No requests specifically mentioned oilseed rape allergy. Sera were stored at - 20°C. The "routine" antigens were mixed grasses, Dermatophagoides pteronyssinus, cat and dog dander, and mixed foods; tests for oilseed rape and mixed moulds (Penicillium notatum, Cladosporium herbarum, Aspergillus fumigatus, and Alternaria alternata) were done in Dundee on both sets of sera. We tested for mixed moulds, because rape, after flowering, is cut and left in the fields for several weeks before harvesting, during which time it often becomes mouldy. We used Thadebas’ RAST kits (Pharmacia) and recorded the results as 0 for no sensitisation and 1-4 for mild, moderate, high, or very high sensitisation. Total IgE levels were assayed by ’Phadezym’ kits (Pharmacia). In Dundee, 175 sera submitted between May and September, 1988, were tested and compared with 141 sera from Glasgow which had been collected during February, June, and July, 1988. (February and September both lie outside the flowering season of oilseed rape.) A further 82 Dundee sera from November and December, 1988, were also studied. ’
combined
chloroquine/proguanil
chemoprophylaxis. We suggest that empirical antimalarial therapy CLINICAL PICTURE AND PARASITE COUNT -
-
Seroprevalence of sensitisation to oilseed moulds in Tayside and Glasgow.
rape and mixed
Mixed mould results for Tayside in June and September, 1988, 96% and 129%, respectively
were
