Jpn. J. Infect. Dis., 54, 1081110, 2001

Short Communication

Loa loa and Mansonella persians Infections in Ijebu North,Westem Nigeria: a ParasitologlCal Study
Olufemi M. Agbolade* and Dora 0. Akinboye.
Department of Biological Sciences, Ogun State University,PM.B. 2002, Ago‑Iwoye andlDepartment of Zoology, University oflbadan, Ibadan, Nigeria(Received January 9, 2001. Accepted April 4, 2001)

SUMMARY: The prevalence and intensity OfLoa loa and Mansonellaperstans were studied in three villages ofthe ljebu north area in Ogun State, westem Nigeria. Blood samples were collected by finger‑pricking from 373(181 males, 192 females) subjects with an age range of4 to 55 years. The blood samples were examined micro‑

scopically for the presence ofmicrofilariae (mf). L. loa and M. persians were present in the blood samples in 39(10･5%) and 12 (3･2%) of the subjects, respectively･ Neither of the infections were found to be sex‑dependent･The geometric mean of the L･ loa intensity Was l･8 mfper 50 LEI ofblood, while that ofMperstans was l･5 mf
per 50 lil. The prevalence of mixed infections of both L･ loa and M･ persians was 1 ･0%･Desplte the continued defbrestation and indiscriminate

has been no previous record ofM. persians infection in thebush‑bumlng that threaten the lives of vectors ofLoa loa andljebu division ofwestem Nigeria. The present study was there‑

Mansonella persians, recent reports of the occurrence of thesefore initiated to determine the current prevalence and intensity

infections in tropical Africa, including Nigeria, have beenofL. loa and M. persians infections in some communities ofmade (1‑4).

the ljebu north area of westem Nigeria･In the ljebu division of westem Nigeria, L. loa infection

The study area consisted ofAbata, Awori‑Jeje, and Mamu

was reported by Ogunba in 1971 and 1972. There has been novillages in the ljebu North Local Govemment Area of Ogun

further investlgations in the area, although the current study
sights were not included in Ogunba's study areas. Also, there

are approxlmately 8, 1 0, and 20 km, respectively,斤om Ago‑State, westpm Nigeria (Fig･ 1 ). Abata, Awori‑Jeje and MamuFig. I. Map showing the studyarca.
Source.. FcderalSurveys, Lagos* Co汀eSpOnding author

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Table 1 ･ Prevalence ofL･ loo and M･ peystansmicrofilariae according to sex
No. positive fわr

No･ examined No. positive for L. loo (%)

M. persEans (%)

Vil lagc

Mates Females Total Males Females Total
Abata25

Awori‑Jeje

Mamu

I18

33

58

38

38

121

239

276

10(928.5)

373

(8.0)

4

9(23.7)10((12.1)

6

4(10,5)13(17.I)

8.3)

21(II･6)

Iwoye (the Ogun State University town). The study area islocated between latitues 7000'and 7005 'N, longitudes 3050'

Males Females Total

20(18(9.4)(10.3)

8.4)

l(4.0)

5(4.2)

39(10.5)20(6.I)
04(3.3)6(3.3)

6(3.I)

3(5.2)
09(3.8)12(3.2)

endemicity between血e present study area and the area studied

by Ogunba. The presence of ChtySOPS Silacea and C. dimidiataand 3055 'E, and is covered by a thick rain‑forest vegetation.

(the vectors ofL. loa) in some parts of the ljebu division has

Abata, Awori‑Jeje, and Mamu currently have estimatedpreviously been documented (5). Similarities in the prevalences

human populations of approximately 250, 350 and 2,000,ofL･ loa among villages in the present study indicate similar

respectively･ The inhabitants of the villages are prlmarily

rates of transmission in the villages. In addition, similar

subsistence farmers, with a few traders at Mamu. Prior tocommencement of the study, pemission and ethical consent

prevalences among males and females show that both sexes
have been equally exposed to the infection, which is similar

were obtained from health persormel and heads of the corrmu‑to the finding of Mommers et al･ (7)･ Efforts are c.urrently
in progress to collect Chpysops spp. and to determlne theirnities as well as from particIPatlng individuals.
Three hundred and seventy‑three volunteers, with an age

vectorial capacities in the present study area.

range of4 to 55 years, including 181 males and 192 females,

Animportantfinding of the present study was the occurrence

participated in the study, which took place between October
1997 and July 1998. Blood samples were collected kom theofM. persians infection in the study area. M. persians has
previously been reported in other parts of Nigeria ( 1‑3), butvolunteers by the finger‑pricking method between I 1 :00 a.m.

this is the first time that it has been is reported in the Ijebu

and 2:00 p.m. Thick blood smears were made and stained

division of westem Nigeria. A preliminary 61mOnth study has

with buffered Giemsa solution (pH 7.2) for micro丘lariae (mf)revealed the presence of Culicoides spp. with afi1arial infec‑

detection, identification,and countlng. h each infected subject,tion rate of 8.6% in the study area (unpublished data). Similar

the mf intensityofeach infection was evaluated by the number

prevalence ofM. persians infection among males and females

ofmfper 50 lil ofblood. The chi‑square test (X2) wasused

have indicated equal exposure of both sexes. In this study,

to determine slgnificant differences and was tested at a 0.05

both L. loaand M. persians infections were pnmarily restrictedlevel of signi丘cance.

to subjects 20 years of age or younger, the reasons for which

The prevalence ofL. loa and M. persians mf according tosex in the study area are summarized in Table 1. Ofthe 373

may be investlgated fdher in a future study.
The recorded microfilarial intensityofL. loa in the study

subjects examined, 39 (10.5%) and 12 (3.2%) had L. loa

area was low, as has previously been reported by Ufbmadu etand M･ persians, respectively, in their blood samples. Theall ( I ) regarding central Nigeria. Also the microfilarial intensity

prevalences ofL･ loa infection among the three villages visitedofM. persians in the study area was low, which agrees withfindings of Mommers et al. (7) in southem Cameroon.
The detection of mixed infection ofL. loa and M. persians

were not slgnificantly different. Similarly, the prevalences of

M･ perstans in Abata and Mamu were not slgnificantly
different･ The total prevalences ofL. loa and M. persiansin the study area was another important finding, and is similar

among males and females were not significantly different.

to previous findings from other areas such as central Nigeria

Thiれy‑eight (97.4%) and 1 1 (91.7%) of the subjects with L.

(1 ) and southem Cameroon (7).

loa mfand M. persians mf, respectively, were 20 years old or
yO unger･ACKNOWLEDGMENTS

The microfilarial intensityofL. loa in the study area ranged

from 1‑20 mfper 50 Ill of blood, while that ofM. persians

The authors sincerely appreciate the cooperation of thewas from 1‑2 mfper 50 上上l ofblood. The geometric mean

health personnel, heads, and inhabitants of the communities

intensityofL. loa in each of the categories (males, females,visited.

and total lmales + females]) was I.8 mfper 50 lil of blood.

The geometoric mean intensity OfM. persians among males

REFERENCES(1 ･4 mf/50 LEI blood) was not significantly different froP

1. Ufomadu, G. 0., Nwoke, B. E. B., Akoh, J. I., Sato, Y.,
Ekejindu, G. 0. C., Uchida, A., Shiwaku, K., Tunbau,

that aヮOng females (1 ･7 mg50 LEI blood)･ The total geometnc

mean lntenSityofM.persians was 1.5 mfper 50 lil ofblood.
Three (1.0%) cases of mixed infection ofL. loa and M.

M･ and Ugo甲0, K･ K･ (1991)‥ The ワccurrence fo loiasis,mansonellosIS and wuchereriasis ln the Jarawa Riverpersians were recorded in the study area. Two of the mixed
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4. Gbakima, A. A. and Sahr, F. (1996): Filariasis in the

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