TRANSACTIONS OF THE ROYAL SOCIETY OF TROPICAL MEDICINE AND HYGIENE (1999) 93,21-22
lsoenzyme characterization of Leishmania tropica in the emerging epidemic focus of Taza (north Morocco)
M . Bichichi’l*, M. Riyad’ and N. Guessous- Idrissi’*
’ Laboratoire de Parasitologic-Mycologic, Uniti d’Etudes et de Recherche sur les Leishmanioses, Fact& de Midecine et Pharmacie et Centre Hospitalier Ibn Rochd, 19 rue Tarik Zbn Ziad, Casablanca, Morocco; ‘Laboratoire de Microbiologic et des Sciences de l’Environnement, Faculti des Sciences de Ben Msick Sidi Othman, Casablanca, MoroccoKeywords:
cutaneous leishmaniasis, Leishmania tropica, iso- enzymes, epidemiology, MoroccoCutaneous leishmaniasis (CL) is well known in the south of Morocco where zoonotic epidemic foci due to
Leishmania major,and endemic anthroponotic foci due to
L.tropica,have been reported during the 1980s
(ANONYMOUS,
1992). In 1995, an emerging epidemic focus of human CL caused by
L. tropica ina northern city of Morocco-Taza-was identified. Since then, an ac- tive survey has been carried out and this focus has been described by
GUESSOUS-IDRKSI et al.(1997). The purpose of this short report is to present and analyse new complementary data.
As reported before, the active
surveyconcerned the neighbourhoods where the index cases lived, and con- sisted of medical consultations with the systematic treatment with meglumine antimonate of all confirmed cases. The diagnosis was confirmed by examination of Giemsa-stained smears and/or culture in NNN med- ium. Parasite isolates were characterized by isoenzymes on cellulose acetate using 12 loci: nucleotidase 1 and 2, superoxide dismutase, phosphoglucomutase, glucose phosphate isomerase, phosphogluconate dehydrogen- ase, glucose 6-phosphate dehydrogenase (G6PD), as- partate aminotransferase, malate dehydrogenase, malic enzyme, isocitrate dehydrogenase, and malate phos- phate isomerase.
Thus, between October 1995 and June 1998, 179 CL cases were confirmed, of whom 142 were from the city of Taza, mostly from its margins in newly settled areas. The remaining 37 cases were from 9 rural surrounding communities within a radius of 1%
90 km. According to the date of appearance of lesions,
the disease incidence decreased significantly after 1997 and particularly in per&urban neighbourhoods (Table), suggesting an anthroponotic transmission of the para- site at least in Taza city. However, the regular emer- gence of cases from an increasing number of rural localities suggests: (i) the existence of previously un- known microfoci, identified owing to the awareness of the medical and paramedical staff and the local popu- lation; (ii) a zoonotic cycle particularly in the rural localities as described or suspected in other foci of
L.tropica (BEN IS~L & BEN RACHID, 1989; KAMHAWI et al.,
1995).
The analysis of the electrophoretic patterns of 28
L.tropica
stocks showed that 2 zymodemes are circulating:
25 stocks (20 urban and 5 rural) are indistinguishable from zymodeme MON-102, while the 3 remaining isolates (2 urban and 1 rural) called MON-X, differ from
L. tropicaMON-102 on just one locus, G6PD, but are different from the 6 other zymodemes characterized in the south of Morocco by
PRATLONG et al.(1991) (MON-107,MON-109,MON-112,MON-113,MON-
122, MON-123). Thus, in contrast to the well known genetic polymorphism of
L. tropicain Moroccan south- em foci, in Taza it seems that 2 zymodemes are circulat- ing, of which MON- 102 is predominant, as in the south.
This reinforces the hypothesis of an anthroponotic intro- duction from the south through human travel, and could be considered also as an argument for an epidemic situation in which one virulent strain is predominant.
However, the existence of the variant MON-X suggests that the isoenzyme diversity in Taza could be more important than so far observed.
Acknowledgements
This work was supported by the USA Agency for Interna- tional Development and the National Institutes of Health, through the MERC (Middle East Regional Cooperation) program (contract NOl-AO-45185). We are grateful to Pro- fessor J. P. Dedet and Dr F. Pratlong from the World Health Organization Reference Laboratory for Leishmaniasis in Mon- tpellier, France, who kindly provided the reference south Moroccan strains of Leishmania, and the local authorities of the province of Taza for their logistical support.
References
Anonymous (1992). Ministire de la Sante Publique du Maroc, Direction de 1’Epidimiologie et des Programmes Sanitaires.
SpCcial leishmanioses. Bulletin Epi&mioZogique, 7, l-20.
Ben Isma& R. & Ben Rachid, M. S. (1989). Epidemiologic des leishmanioses en Tunisie. In: Maladies Tropic&s Transmis-
~~~~o~UPELF-UREF. Paris: John Libbey Eurotext, pp.
Guessous-Idrissi, N., Chiheb, S., Hamdani, A., Riyad, M., Bichichi, M., Hamdani, S. & Krimech, A. (1997). Cutaneous leishmaniasis: an emerging epidemic focus of
Leishmania Table. Distribution of cutaneous leishmaniasis cases in and around Taza by
date of appearance of lesions
YeaP 1992
19931994 1995 1996 1997 1998c
No. of urban cases
2 2 10 61 55 6 0
No. of rural cases
1
0 : 9 12 4
No. of localitiesb
g;
(1) gj gj
Total 3 2 ::
64 18 4
Total 136 33
“The date of appearance of lesions is not known for 10 cases.
bThe number of localities each year for rural cases is given in parentheses.
‘Until 12 June 1998.
169
*Author for correspondence: fax +212 2 475560, e-mail nguessous@casanet.net.ma
22 USA THISYAKORN ET/IL.
tropica in north
Morocco.
Transactions of the Royal Socie y of Tropical Medicine and Hygiene, 91,660-663.Kamhawi, S., Abdel-Hafez, S. K. & Arbagi, A. (1995). A new focus of cutaneous leishmaniasis caused by Leishmania tropica in northern Jordan. Transactions of the Royal Society of Tropical Medicine and Hygiene, 89,255-257.
Pratlong, F., Rioux, J. A., Dereure, J., Mahjour, J., Gallego, M.,
Guilvard, E., Ianotte, G., Perieres, J., Martini, A. & Saddild,A. (1991). Letihmania tropica au Maroc. IV. Diversite iso- zymique intrafocale. Annales de l’arasiwlogiie Humaine et Comparhe,66,96-99.
Received 21 September 1998; revised 30 November 1998;
accepted for publication 1 December 1998
TRANSACTIONS OFTHE ROYAL SOCIETY OFTROPICAL MEDICINE AND HYGIENE (1999) 93,22-23
Rainfall pattern, El Nifio and malaria in Uganda
A. H. D. KilianlJ, l? Langit, A. Talisunaz and G.
Kabagambes IGTZ German Technical Cooperation, Uganda; 2Malaria Control Unit, Ministy of Health, Uganda; -‘District Health Services, Kabarole Distriit, Uganda
Keywords: malaria, incidence, climate, rainfall, El Nitio, epi- demic, Uganda
During the months of January and February 1998 an increase in malaria cases has been reported in Uganda.
In the south-west of the country, an area at elevated al- titudes with normally only moderate-to-low malaria transmission and hence epidemic prone, the situation reached epidemic proportions putting considerable stress
onthe health service providers. This increase of
Plasmodium falciparuminfections has been attributed to increased and prolonged rains during October-Decem- ber 1997 caused by El Nifio Southern Oscillation (EN-
350 F 300 E 250 - z 200 E
‘ii 150 g 100 2 s 50 0
1995 1996
sociation between increased malaria incidence and El Niiio has previously been described for other parts of the tropics (BOUMA
et al.,1994; BOUMA
& VAN DER KAAY,1996). If such a linkage also exists in the Ugan- dan setting, analysis of rainfall patterns should be able to predict a malaria epidemic and enable the National Malaria Control Programme to have adequate meas- ures in place in time. We, therefore, analysed the inci- dence of reported clinical malaria cases and its correlation with rainfall between 1995 and 1998 in Kabarole District, western Uganda.
Malaria incidence measurement was based on the routine reports of clinical cases (generally without para- sitological confirmation) among children aged O-4 years obtained from 42 government health facilities in the dis- trict. To account for the facts that the number of cases seen at each unit varies with its size, and not all units submitted reports every month, a relative incidence was compiled as follows: for each unit the average number of cases per month was calculated for the period 1995-97 and the monthly malaria cases were expressed as a percentage departure from this mean. These rela- tive monthly incidences were then averaged over all re- porting health units for each month to give the district- wide mean relative incidences. Rain data were collected at 2 sites in the district, representing the maximum and minimum rain intensity and monthly rainfall calculated as the mean of the 2 measurements.
250 n
!E 200 f
150 E 2 1. 9, 100 ;- -.
e 50 3 - 0 5 Time ( months )
Figure. Correlation between rainfall (dashed line) and malaria incidence in children aged under 5 years (solid line) in Kabarole Dis- trict. For explanation of the relative incidence see text.
