630 RESEARCH IN PROGRESS

had more people who were not mobile compared with the villages without CRWs. However, during evalua- tion the villages with CRWs had more improved and independent participants than the other villages. They were also more socially integrated into their families and communities than the others. It is evident that the participants in CRW villages had better rehabilitation outcomes and it is thus concluded that the CRW approach is effective.

P l a s m a 25=Hydroxyvi tamin D3 does not vary over the course o f a malar ia l in fect ion

Katie Newens , S u z a n n e Fi l teau and A n d r e w T o m k i n s Centre for International Child Health, Institute of Child Health, University College, 30 Guilford Street, London WCIN 1EH, London

Both clinical vitamin D deficiency and low plasma 25-Hydroxyvitamin D3 (25OHD3) have been asso- ciated with an increased risk of respiratory infections. However, it is not clear whether low plasma 25OHD3 level is the cause or the result of infection. The aim of this study was to determine the effect of Plasmodium falciparum malaria infection on plasma 25OHD3 concentration in 25 patients admitted to the Hospital for Tropical Diseases, London, UK. Blood samples were taken daily during the course of their stay in hospital and at a follow-up session 2 - 6 weeks after discharge. Time course data showed no change in 25OHD3 level during the infection. Four- teen patients had both an admission and follow-up sample; median 25OHD3 level at admission was 25.6 n g / m L (interquartile range 23.0-40.2) which did not differ from that at the follow-up session, median 25.2 n g / m L (interquartile range 19.4-32.1, P = 0.084). To conclude, 25OHD3 level is not af- fected during the course of a severe malarial infec- tion. Since 25OHD3 is not an acute phase reactant, it can be used as a measure of vitamin D status even in subjects who are currently ill.

HIV vo luntary counse l l ing and testing: is it bene - f ic ial to the rural c o m m u n i t i e s o f Uganda?

Gilbert Ngat ia Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK

The aim of the study was to investigate to what extent rural communities in Uganda value HIV voluntary counselling and testing (VCT) as a prevention strategy. Qualitative data was obtained from a cross-section of respondents and different approaches to collecting in- formation were applied to different groups. A total of 10 focus group discussions were undertaken with men, women, youths, and teachers. Twenty-five semi-struc- tured interviews were conducted with health care provi- ders, opinion leaders, local government, and traditional healers. In-depth interviews with people living with HIV were also conducted. Misconceptions about HIV trans- mission exist in the rural areas. Most respondents ac- cepted VCT as an HIV/AIDS prevention strategy in principle. However, VCT was regarded as 'double fa- cete'. Access and high quality VCT services can attract more users of VCT while stigma and inadequate com- munity education can negatively influence the utiliza- tion of V C T services. Key stakeholders are critical in VCT expansion as integrated VCT services improve access and coverage and they are more sustainable. V C T is now part of a comprehensive approach to HIV, which links it with other critical services. In addition, community sensitization is an integral part of VCT services. Successful VCT services involve contribution and efforts of different partners, who can provide a range of different HIV/AIDS support.

The prevalence o f s p l e n o m e g a l y in different occu- pat ional groups in Kumas i , Ghana

Cordel le Ofori and Pooja Shorey Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK

Palpable enlargement of the spleen is a common finding in patients presenting to medical services in the tropics (Onuigbo, M. A. & Mbah, A. U., 1992: West African Journal of Medicine, 11, 72-78). Despite this there are no recent studies describing the prevalence of splenomegaly in West Africa. This study aimed to (i) describe the prevalence of splenomegaly in different occupational groups in Kumasi, Ghana and (ii) deter- mine whether it is related to demographic or socio- economic factors. A total of 518 subjects from different occupational groups was interviewed using a question- naire about their demographic and socio-economic characteristics and clinically examined for splenome- galy. Each individual was assigned a socio-economic score (Gwatkin, D. R. et al., 2000: <http://www.world bank.org/poverty/health/data/index.htm >). Splenome- galy was found in 2.7%. This is less prevalent than previously described in West Africa (Greenwood, B. M. et al., 1987: Annals of Tropical Medicine and Para- sitology, 81, 345-354). There was a significant associa- tion between splenomegaly and level of education (P < 0.05). There is an indication that there may also be an association with socio-economic status, however, this requires further analysis. There was no significant asso- ciation between splenomegaly and age, gender, occupa- tion, or ethnic group.

D e v e l o p m e n t o f a h ighly sensi t ive rea l - t ime poly- merase cha in react ion as a tool for quant i fy ing Leishmania in sandfl ies

S. Ranas inghe , R. Maingon , J. G. C. H a m i l t o n and R. D. W a r d Centre for Applied Entomology and Parasitology, School of Life Sciences, Keele University, Staffordshire ST5 5BG, UK

Lutzomyia longipalpis is the main vector of Leishmania infantum/L, chagasi, the protozoan that causes visceral leishmaniasis in Latin America. The sandfly appears to be more attracted to Leishmania-infected hamsters than to uninfected hamsters (O'Shea, B., 2001: Transactions, 96, 117-118).We are currently testing the hypothesis that the bloodfeeding behaviour of sandflies is also manipulated by Leishmania and that Leishmania- infected sandflies are more attracted to host odour. Should this be the case, it will be of interest to identify the Leishmania stages responsible for the manipulation and to establish if this requires a parasite load threshold value. We describe the development of a highly sensitive and robust real-time polymerase chain reaction (PCR) method to quantify Leishmania in sandflies. PCR pri- mers amplifying a 90 bp region for the single copy D N A polymerase gene from Leishmania infantum were se- lected (Stephane, B., 2001: Clinical and Diagnostic La- boratory Immunology, 8, 828-831) .The Lutzomyia longipalpis periodicity (per) gene was chosen as an inter- nal standard (an 80 bp PCR product). Initial endpoint PCR results are promising in that as little as 1 fg of Leishmania DNA in as much as 100 ng of sandfly DNA could be amplified with no cross-genomic amplification.

Gender differences in att i tudes and pract ices in heal th wi th in househo lds in the Congo

Pa luku Sabuni , Sal ly Theoba ld and S. Be r t e l Squire Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK

Access to modern health care is poor in the Congo.

RESEARCH IN PROGRESS 631

People are using other resources, such as household self-medication, which are frequently disregarded or criticized by health professionals, policy makers, and researchers. Qualitative research methods were carried out in Marabo and Mukulia in the Congo to explore women and men's perceptions of illness and preventive and curative practices. The data was analysed by apply- ing a gender lens to Kleinman's (1980) model of house- hold steps occurring when a household member is ill. Data revealed that women and men divided illnesses into 2 main groups: those treatable by modem medi- cine at home or hospital and those treatable only by indigenous medicine. Women have a deeper under- standing of common illnesses and household practices. Young people (girls and boys) were reluctant to use indigenous medicine as it was perceived as old fash- ioned and a painful intervention. Modes of treatment differed by gender. Women mostly used enemas, drink- able potions, home deliveries, and inhalation, while men used injections and circumcision. Both women and men used scarification, skin ointment, and ear or eye drops. Policy makers should integrate an awareness of household caring strategies into the national health services, promote sage practice, and improve commu- nication between health professionals and female and male household members.

I n v e s t i g a t i o n s i n t o t h e c h e m i c a l e c o l o g y o f the h o u s e d u s t m i t e , Dermatophagoides farinae

A. C. S k e l t o n 1'2, M. B i r k e t t 2, M. C a m e r o n 1 a n d J. P icke t t 2 ~London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK; 2Bio- logical Chemistry Division, Rothamsted Research, Harpen- den, HeroCordshire AL5 2JQ~ UK

House dust mites (HDM), Dermatophagoides farinae, are a significant health problem, their faeces are highly allergenic (Tovey, E. et al., 1981: Nature, 289, 592-593; Robinson, C. et al., 1997: Clinical and Experi- mental Allergy, 27, 10-21) and can cause atopic dis- eases such as asthma, rhinitis, and dermatitis (Platts- Mills, T. A. E. & de Weck, A. L., 1989: Journal of Allergy and Clinical Immunology, 83, 416-427). Chemi- cal acaricides are the most common method to control H D M , however re-colonization of H D M after applica- tion is typical. Despite the variety of methods to control H D M (Colloff, M. J., 1990: Pesticide Outlook, 1,2, 3-8) , novel approaches are needed to supplement exhausted measures. One approach is the use of semi- ochemicals (behaviour-modifying chemicals). The aim of this project is to investigate aspects of chemical ecology and mite behaviour, for the potential develop- ment of a control tool in the field. Dermatophagoides farinae mites were separated from the culture medium (Hart, B. J. & Fain A., 1987: Acarologia, 28, 251-254), and then soaked in hexane to extract potential semio- chemicals. Extracts were analysed, and mite-specific peaks tentatively identified, using gas chromatography and coupled gas chromatography-mass spectrometry. Known mite attractants were used to develop a robust bioassay, the y-tube olfactometer, which has been used to test the mite-derived hexane extracts. The D. farinae extract has been successfully fractionated using liquid chromatography (Millar, J. G. & Haynes, K. F. (editors), 1998: Methods in Chemical Ecology, Volume I: Chemical Methods) and behavioural activity has been demonstrated from one of these fractions.

T h e u s e o f D N A f i n g e r p r i n t i n g to c o r r e c t e s t i - m a t e s o f the p e r s o n a l p r o t e c t i o n by i n s e c t i c i d e - t r e a t e d b e d n e t s in T a n z a n i a

S e y i S o r e m e k u n 1,2, C a r o l i n e M a x w e l l 1,3, M a r t i n Z u w a k u u 3, C y n t h i a C h e n 2, E d w i n M i c h a e l 2 a n d C h r i s t o p h e r C u r t i s 1 1London School of Hygiene and

Tropical Medicine, Keppel Street, London WC1E 7HT, UK; 2Department of Infectious Disease Epidemiology, Imperial College London, Norfolk Place, London W2 IPG, UK; 3 Ubwari Field Station of Tanzanian National Institute

for Medical Research, Box 81, Muheza, Tanga, Tanzania

Estimates of the relative importance of the personal protection afforded by insecticide-treated nets, in com- parison with the 'mass effect' on the local vector popu- lation due to community-wide use, are normally based on the assumption that all the bloodfed mosquitoes collected inside a house have fed on the occupants of that house. This may not be the case and could result in the underestimation of the personal protection effect of a net. To increase the accuracy of these estimates, we used a multi-locus microsatellite system to make DNA 'fingerprints' from the blood of occupants of selected houses in Tanzanian villages with and without nets, and compared these with fingerprints obtained from blood- meals of the mosquitoes collected in those houses. Over 90% of the bloodmeals were successfully typed, and the proportions of bloodfed malaria vectors found to have fed on the occupants of the houses in which they were caught were not quite significantly different in villages with and without nets (88%, n = 109, and 95%, n = 118, respectively). Our data indicate that only a small correction needs to be made to existing estimates of personal protection to allow for bloodfed mosquitoes resting in netted rooms after feeding elsewhere.

[This oral presentation was awarded second prize at the meeting. ]

D o i n s e c t i c i d e - t r e a t e d ne t s p r o t e c t a g a i n s t v i s c - eral l e i s h m a n i a s i s v e c t o r s i n V e n e z u e l a ?

J e n n i f e r C. S t e v e n s o n 1 a n d M. D o r a F e l i c i a n g e l i 2 Z London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK; 2BioMed, University of Carabobo, Maracay, Venezuela

A crossover trial was carried out in Guarico State, Venezuela to assess the effectiveness of insecticide- treated nets (ITN) against visceral leishmaniasis vec- tors. Measures of abundance, mortality, and human landing of Lutzomyia evansi were obtained, within and outside untreated bednets and nets treated with a deltamethrin K-O tab. Sandfiies passed through both impregnated and untreated nets and fed successfully, indicating (i) standard mosquito nets of 25 holes/cm 2 did not provide a barrier against this sandfiy and (ii) impregnation of the net with a K-O tab (which was 5 years old) did not improve protection. Biting rates were reduced in rooms with ITNs but this was due to lower biting rates outside, not within, the net. No effect was seen on abundance of flies and mortality was low in rooms with treated nets. Subsequent bioassays with Venezuelan L. longipalpis s.l. and susceptible Anopheles stephensi (Beech) mosquitoes in the U K demonstrated a poor insecticidal action of the deltamethrin used de- spite chemical analysis indicating adequate dosage on the net. A sublethal repellent effect of the insecticide may have driven flies to rest on the walls and reduced outside biting rates. Further investigations are under- way to study shelf life and breakdown of K-O tabs.

B a c k - c a l c u l a t i o n o f the n u m b e r o f i n o c u l a t e d Plasmodium falciparum p a r a s i t e s in a d o c u m e n - t e d c a s e o f n e e d l e s t i c k m a l a r i a in a F r e n c h n u r s e

A. T a r a n t o l a 1, D . C. W a r h u r s t 2 a n d A. R a c h l i n e t i Groupe d'Etude des Risques d'Exposition des Soignams aux Agents Infectieux, Paris, France; 2London School of Hygiene and Tropical Medicine, Keppel Street, London ~VCIE 7HT, UK

A needlestick injury (NSI) caused occupational Plas-