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African Health Sciences
Makerere University Medical School
ISSN: 1680-6905 EISSN: 1729-0503
Vol. 8, Num. 4, 2008, pp. 239-243
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African Health Sciences, Vol. 8, No. 4, Dec, 2008, pp. 239-243
Epidemiology, of bilharzias (schistosomiasis) in Uganda from
1902 until 2005
Emmanuel, I. Odongo Aginya 1 and Ekkehard Doehring 2
1. Gulu university Department of Microbiology Faculty of Medicine P.O.BOX 166 Gulu
2. Institute of Medical Parasitology University of Bonn (Germany).Currently a visiting professor in Paediatrics Department.
Faculty of Medicine Gulu University.
Correspondence: Emmanuel, I. Odongo Aginya, Gulu university Department of Microbiology, Faculty of Medicine P.O.BOX 166 Gulu
Code Number: hs08050
Abstract
Background: Schistosoma mansoni was observed and reported in Kuluva hospital Arua District in north western Uganda as early
as 1902. S. mansoni is widely distributed in Uganda along permanent water bodies.
Objective: To review the litreture on scistosomiasis in Uganda, since 1902.
Method: The core literature for this short review was searched from reports and publications by the British colonial Ministry
of Health Districts Medical officers and Entomologists. Additional information was obtained from Makerere University Medical
School library archives, London School of Hygiene and Tropical Medicine library archives, University of Antrwap, and post
independence publications on schistosomiasis in Uganda in various journals.
Results: Since it was first detected in 1902 Schistosoma (S) mansoni is more widely distributed in
Uganda than S. haematobium. However Schistosoma mansoni and S.
haematobium are of public health importance in Uganda and the importance of migrants and fishermen
in disseminating infections into non-infested areas and intensifying infection in areas already infested have been reported.
Conclusion: S.
mansoni has been on the increase in Uganda whereas S. haematobium is localized in sporadic foci in the north of
Uganda. Treatment with praziquantel the drug of choice in Uganda used in schistosomiasis control programme has reduced development
of severe schistosomiasis.
Introduction
The ancient Egyptians recorded comprehensive
clinical accounts of bilharziasis as laid down in the
papyrus Pfister1. Ebers and Hearst Ruffer proved the
presence of Schistosoma ova in mummies and Canopic jar
of mummified viscera2. The first published record of
the causative agent was after the post-mortem discovery
of the worm in the mesenteric veins of a patient in Kasr
el Aini Hospital in Cairo by Theodor
Bilharz3. The first published account of the taxonomy of the genus
Bilharzia was by Meckel Von Hemsbach two years after
Weinland named the genus Schistosoma (Meckel Von
Hemsbach 1856, Weinland 1858)4, 5. Three species of Schistosoma are known to be parasitic
to man. Schistosoma (S.)
haematobium, (Bilharz 1852)3 while Brumpt
named Schistosoma (S.) mansoni in 1931 (Brumpt
1931)6. Cort in 1919 was the first to identify cercariae of the
Japanese blood flukes, Schistosoma japonicum in Katsurada (Cort 1919)7. Bhalerrao in 1934 observed the occurrence
of Schistosoma japonicum in Katsurada in India (Bhalerrao 1934)8. Schistosoma mansoni and S. haematobium occur in Uganda. Besides these two schistosomes, S. intercalatum has been reported in 10 countries mainly in central
and West Africa, but also in Northern
Uganda9.
This short review will cover some of
the foundamental work on schistosomiasis in Uganda
from 1902 and show steps taken after, by the Uganda
Ministry of Health to control the transmission and morbidity
of schistosomiasis in Uganda.
Schistosome infections in
Uganda.
Schistosoma mansoni was first observed and reported
in Kuluva hospital Arua District north western Uganda
by Aldo Castallani and G.C Low in 1902 in a
hospitalised patient with sleeping
sickness10. McConnely 1923, Rawson & Gopal 1924 noted a high incidence of S. mansoni in the West Nile11,
12.
Nelson was the first to make a
complete assessment of the prevalence, distribution
and importance of schistosomiasis as a health problem
in Uganda, especially in West Nile13. He found that
the prevalence and intensity of infection was
highest immediately along the banks of the River Nile
and decreased with altitude and distance from the
Nile. Schwetz also made a similar observation that
altitude and distance influence the distribution of Bilharzia
in Lake Bunyonyi in Kabale in Western
Uganda14.
Nelson further observed that enlarged
spleens and anaemia were a common clinical feature
among children around ten years old with high intensity
of infection. In a broader perspective, Webbe and
Jordan advanced the knowledge of schistosomiasis in
East Africa, which included Uganda, Kenya and
Tanzania15. In the seventies, studies by Ongom documented
the epidemiology and consequence of S.
mansoni infection among Jonam in a fishing village of Panyagoro
and Panyimur in West Nile15, 16.
In Lango district, now Lira district,
Schwetz reported vesical Bilharzia in the community living
in Aloi, Ayer along River Okole and other tributaries
of River Acwa17. Heamaturia was common among
both adults and children in this community.
Rosanelli reported cases of S. haematobium in Pader
district, formerly (East Acholi district) along River Odek,
a tributary of River Acwa. These areas are all
neighbouring Lira district where S.
haematobium is present according to
Rosanelli17. Many studies in Northern Uganda
were in the former West Nile district where S.mansoni infection is hyperendemic 12,
18. Bradley investigated the role of fishermen in disseminating S. mansoni in Lolui Island in Lake Victoria as an important
epidemiological aspect19. Prentice studied the epidemiology of S. mansoni among Caucasian immigrants and indigenous
Ugandans living near the shore of Lake Victoria and Entebbe 20. In 1961, Barnley and Prentice showed a prevalence
of S. mansoni to be (14%) in immigrants living in
Kampala and Entebbe with definite history of swimming in
Lake Victoria 20, 21, 22.
The Public Health importance of
migrants from schistosomiasis endemic areas of Uganda
in disseminating infections into non-infested areas
and intensifying infection in areas already infested has
been reported 19, 23. In most parts of Uganda,
schistosomiasis was thought to be an occupational disease mainly of
the rural poor communities. Nevertheless, recent
studies indicate that urban schistosomiasis is emerging in
water bodies within vicinities of some townships in
Uganda 24, 25. The fishing village of Kigungu in Entebbe is one
of such water bodies. Many people have been
acquiring schistosomiasis without knowing the source of
their infections. These have resulted in unexpected
increase in the incidence of S. mansoni observed in Entebbe
and Kampala hospitals. However, it was established that
the sources of major transmission foci were along
the canoes landing sites in Entebbe and streams
within Kampala 23, 25, 26.
The snails vectors which transmit the
parasites were detected as early as 1950 by Prentice (a
Senior Entomologist - Ministry of Health Uganda based
in Wandegeya Vector Control Division) 20, 21,
22. The snails found were the Bulinus
spp which transmit urinary Bilharziasis (Schistosoma
heaemotobium and the Biomphalaria spp which transmit intestinal Bilhaziasis
(Schistosoma mansoni) 27. The susceptibility of these snails (Biomphalaria spp) to Schistosoma mansoni were tested by Prentice 1950 in Wandegeya and repeated by
Odongo-Aginya 1987 in Uganda Virus Research Institute Entebbe 25, 27. Schistosoma haemotobium does not occur
in Entebbe despite the fact that the snail
intermediate host for the parasite, the Bulinus
spp, do exist in most parts of the shore line in Entebbe 25, 26, 27.
The upsurge of Schistosoma
mansoni in Entebbe
Schistosoma mansoni is the only species of
Schistosome occurring in the fishing villages and recreational
sites in Entebbe 24,25,26,27. Berrie, using faecal direct
smear method in Entebbe Hospital found 6.5% of
Katabi villagers with Schistosoma mansoni infections and
1.4% infection in Nakiwogo28. In 1963, Bradley
showed 14% (12 out of 86) of Schistosoma
mansoniin immigrant population living in
Entebbe29. Those infected had a history of sailing and swimming at
the present Sailing Club. Billinghurst reviewed
hospital records at Mulago between 1955-1964 and
found that 55 non-African had Schistosoma
mansoni and over half of those admitted having swum in the Lake
at Entebbe30. In the same year, a survey conducted
in Primary Schools in Entebbe among African and
Asian pupils showed that 8% infected children acquired
the infection from Lake Victoria in Entebbe while
in Bugonga fishing village 28 out of 190 (15%)
were found infected with Schistosoma
mansoni. These infections were higher among fishermen 17%.
In 1969 a total of 66 people wore studied at Kigungu and
13 (20%) were infected of which the majority were children 10 out of 13(77%) 30.
Recent studies of Bilharziasis in Entebbe
and Kigungu indicated an up surge of the disease in
all fishing villages around Entebbe 20, 22, 23,
25.In 1982 Kinoti of Nairobi University Department
of Parasitology at the request of United Nation Development Programme (UNDP) and
Uganda Ministry of Health made assessment of schistosorniasis in the entire Uganda 22. In Entebbe, at Kigungu, Kinoti studied 64 people and out of
these 26 (40.6%) were infected. The study by Kinoti
was one of the first after the colonial rule in Uganda and
it revealed that bilharziasis is a much greater health problem in Entebbe fishing villages than it was previously believed 22. Bukenya studied 336 people in
Kigungu village. In this study 42 people out of 335(12.5%)
were found to be infected. The majority of the
people studied were between 30 and 40 years old 23.
In 1987 Odongo-Aginya and Mugish
studied 358 migrants from Schistosorniasis mansoni
endemic areas of Uganda living in Entebbe. High infection
of 144 out of 358 (56.2%) were found among people from schisiosomiasis endemic areas of West
Nile region living in various places along the fishing
villages in Entebbe. This is one of the best ways
of disseminating infections of bilharziasis to other
area. A survey was conducted for the snail
intermediate hosts and their susceptibility to the local strain of S. Mansoni, were tested 25.
In 1990 Lakwo and
Odongo-Aginya compared the prevalence of S.mansoni among 520 people that is 260 people from each village
of Nakiwogo and Kigungu in Entebbe. They found
that in both villages infections were high, with
Nakiwogo having 95(36.5%) while at Kigungu 40
(15.4%) people were infected. The lower figure of infection
in Kigungu was due to difference in the age group studied, older fisher men were studied in
Kigungu20. This might also explain why Bukenya
and Abongomera (1985) recorded a lower infection rate
at Kigungu. Their study was based on older people between 30-40 years old 23
Distribution of Schistosoma
mansoni in Uganda
It is clear that schistosomiasis
mansoni has
been building up in Entebbe and it is already a
health problem in this area20, 22, 23,
25. It is apparent that a similar upsurge of Bilharziasis is going on in
other part of Uganda 31. Recently described foci
of schistosomiasis in Uganda are characterised by
increasing prevalence and intensity of infection. New foci have
been described in the northern part of Uganda along the
non-seasonal large bodies of water with suitable
ecological habitats for the gastropod hosts of schistosomes 24, 31.
More recently Kabatereine showed that S. mansoni was prevalent in 38 districts of Uganda and S. haematobium occurred in just two districts of the 38 districts.
Presently, it is estimated that about four million Ugandans
have bilharziasis and 17 million are at risk of getting
the disease31.
Human water contact patterns in Uganda
Human water contact activities in Uganda have
been described mainly as recreational, domestic
and economic 11, 14, 20. In the dry season the level of many water bodies are reduced and the fast flow of the meandering rivers and streams slacken
occasionally forming small pools. This contributes
significantly towards disease transmission 14,
24. The human water contact during the dry seasons is especially high.
The transmission situation is aggravated by
refugee movement in Northern Uganda. However
recent epidemiological figures from the Northern part of
the country are lacking because of the insurgency which
has impeded field survey for over two decades.
Preparation for bilharzia control
A detailed plan of action was developed by health
and education officers from the original 18
selected districts. Advocacy at lower levels was achieved
through workshops for district civic and political
leaders, where programme objectives, implementation
strategy and the required support were
comprehensively discussed 31.
Management of schistosomiasis in Uganda
Uganda National Bilharzia Control
Programme (UNBCP) was instituted to reduce the worm load in
the school age children and the community at risk
of infection with bilharzia by annual mass
praziquantel (PZQ) chemotherapy31. Target groups are identified
by stool examination and PZQ administered to them according to the WHO guide
line. In schools treatment is carried out by teachers and in communities by
Community Drug Distributors, who are selected by the
concerned communities and trained by the district
trainers31. The training curriculum includes treatment
procedures, record keeping, action in case of unforeseen side
effects, and drug accountability. Their participation is
voluntary and unpaid.
Health education in Uganda
Public health education on schistosomiasis is of
paramount importance. This holds especially true for the village
level. Health committees and public talks, group focus
discussions and other methods of health education have been
practised in Uganda and their results have been published 7, 11,14,25,31. As of late public radio calls have supplemented the panel
of methods. The people were made aware of the disease
and its transmission by water contact activities. Special
emphasis was put on the health education of the primary
school children whose school is situated near water bodies.
In addition they were advised to avoid bathing at the lake 25, 31.
Sanitation. The establishment of pit latrines in all of
the homes of the country is encouraged and is under way 25.
Environmental control. Papyrus clearing of water
sites in swamps and bush clearing by mobilized inhabitants is
a cost effective way of reducing the risk of disease
transmission. The bush clearing along the lake has two positive
effects. Firstly, the snail population is distinctly reduced. A
lower number of snails mean a lower number of cercariae
and therefore a diminished risk of infection. Secondly, it
caused a change in the people's behaviour and reduced the
faecal contamination of the shore 25.
The (UNBCP) is implemented by
Vector Control Department in Wandegeya and assisted in
the districts, by Director of Medical Services, the
district vector control officers and district health educators
in the Ministry of Health 31.
Monitoring and evaluation
Monitoring and evaluation procedures were
designed to assess different aspects of the programme, such as
impact on health, coverage of the treatment campaign
and success and challenges in implementation. The
monitoring and evaluation began in 2003 with the
collection of baseline data from a cohort of 4351 children
and 1088 adults from 37 schools and nine communities 32, 33. Stool samples, and questionnaires were
used to measure reductions in prevalence, intensity and
morbidity resulting from disease and were collected on an
annual basis. Anthropometric measurements of the
school-aged children, (e.g. height and weight) were
also collected, as were finger-prick blood samples to assess
their anaemia status through the measurement of haemoglobin levels 31.
Process monitoring and evaluation
was carried out to assess awareness, perceptions
and adherence to the implementation guidelines of
the programme. Questionnaires were administered through independent external
evaluators to all stakeholders involved in the activities of the
programme. Programme costs, both in the district and
overall in the country, have been monitored. The results
indicated that aspects of the programme are cost effective
and will therefore be used to progress to a more
financial sustainable programme.
Discussion and recommendations
The control programmes in Uganda have been
supported by funding from the Bill and Melinda Gates
Foundation34. This has helped the country to sustain the
excellent start in eliminating the morbidity resulting
from schistosomiasis31. Potential sources of funding
that could be expected to assist the active the
programmes include those from the Ministry of Health. In
addition other international agencies like the European Union, and international organisations such as WHO, the
World Bank, the African Development Bank, the World
Food Programme and UNICEF have contributed funding towards the control of bilharziasis 31.
Intensive health education is vital, but
large-scale health education campaigns will serve no
purpose if alternatives to current water contact practices
are not available. Thus, efforts must continue to
persuade donors, as well as national agencies, to increase
the quantity of safe water supplies in areas endemic
for schistosomiasis. Additionally, improved sanitation
is required before elimination of these infections
can be considered a possibility.
Acknowledgements
We are grateful to Dr.Narcis Kabatereine and the
support staff of Vector Control Department Wandegeya for
the useful informations on the Schistosomiasis
Control Programme.
References
- Pfister E. Schistosomiasis (Bilharziasis) Archive Gesch.Medicine 1912; 6:12-20.
- Ruffer SMA. The presence of ova in mummies and
Canopic jar of mummified viscera. British Medical
Journal 1910; 1: 16-25.
- Bilharz T. Bir Beity Zur Helminthology
Humana. Zsch.f.wiss.Zoo 1852; 4: 53- 72.
- Meckel von Hemsbach JH. Biology of schistosome complexes Mikrogeologie, Berlin, 1856; 27-31.
- Weiland DF. Schistosome of the lower mammal. Human cestoides, Cambridge 1858; 12: 23-24.
- World Health Organisation Report of the
Informal Consultation on schistosomiasis Control.
1998WHO/CDS/CPC/SIP/99, December 1998; 2 Geneva 2-4.
- Odongo Aginya EI., Mueller A., Lakwo TL, Ndugwa
CM., Southgate VR., Schweigmann, U., Seitz, HM.,
Doehring Schwerdtfeger E. Evidence for the occurrence of Schistosoma intercalatum at Albert Nile in northern Uganda. America Journal of Tropical Medicine and Hygiene 1994; 50:723-726.
- Castallani DA. Oservazioni sopra alcuni casi di
Bilharziasis in Uganda. Annal Di Medicine Navale Anno.1X Vol 11, FASC
1-11 Luglio-Agosto 1903; 354-360.
- McConnely RE. Appendix, annual Report for Uganda
Medical Department 1922
- Rawson PH and Gopal B. Appendix, annual Report Uganda Medical Department for 1923.
- Nelson GS. Schistosoma
mansoni infection in the West Nile District of Uganda. Part 1.The incidence of S.mansoni infection. East African Medical
Journal 1958a; 35:312-319,
- Schwert J. On vesical Bilharzia in the Lango, district
(Uganda). Communication. Transaction of the Royal Society of Tropical
Medicine and Hygiene. 1951a; 44: 501-514.
- Webbe G., Jordan P. Recent advances in knowledge
of schistosomiasis in East Africa Transaction of the Royal Society
of Tropical Medicine and Hygiene 1966; 6: 279-305.
- Ongom VL. and Bradley DJ. The epidemiology
and consequences of Schistosoma mansoni infection in west
Nile, Uganda, field studies of a community at Panyagoro. Transaction of the Royal Society of Tropical Medicine and
Hygiene 1972; 66: 835-851.
- Ongom VL. The earliest age of infection with S.mansoni in west Nile District of Uganda. East African Medical Journal 1973; 50:581-585.
- Schwert J. Schistosomiasis at Lake Bunyonyi, Kigezi
district Uganda. Transaction of the Royal Society of Tropical Medicine
and Hygiene 1951b; 44:515-520.
- Rosanelli JD. Some observations on vesical
schistosomiasis in Acholi district, Uganda. East African Medical Journal 1960; l37: 113- 116.
- Ongom VL. and Bradley DJ. The epidemiology
and consequences of Schistosoma mansoni infection in
West Nile Province, Uganda I. Field studies in a community
at Panyagoro. Transaction of the Royal Society of Tropical Medicine
and Hygiene 1986; 89: 243-246,
- Bradley DJ. The epidemiology of fishermen as
migrants. Observations on Small Island. East African Medical Journal 1968; 45: 254-262.
- Lakwo TL. and Odongo-Aginya EI. Schistosomiasis in
Entebbe Peninsula. East African Medical Journal 1990; 68: 43.
- Prentice MA. Distribution, Prevalence and transmission
of schistosomiasis in Uganda. Uganda Medical Journal 1972; 1:136-301.
- Kinoti GK. A report on schistosomiasis in Uganda.
Pamphlet (unpublished). Uganda Government Printing Department,
Entebbe. Ápr. 1978;17:19- 52 pp..
- Bukenya GB. and Abongomera AL. The prevalence
and intensity of S. mansoni and Ascaris
lumbricoides in a fishing village of Kigungu Entebbe. East African Medical Journal 1985; 62: 589.
- Prentice MA, Panesar TS, and Coles GC. Transmission
of Schistosoma mansoni in a large body of water. Annals of Tropical Medicine Parasitology. 1970; 64:339-348.
- Odongo-Aginya E.I and Mugisha C. The prevalence
of Schistosoma mansoni in migrants from endemic areas living in
the peninsula of Entebbe. East African Medical Journal 1987; 64: 571-57.
- Odongo-Aginya, E.I. A Preliminary study on
Intermediate snail hosts of schistosome in River Enyau Arua District,
Uganda. East African Medical Journal 1992; 69: 316-318.
- Prentice MA, Distribution, Prevalence and Transmission
of Schistosomiasis in Uganda. Uganda Medical Journal 1972; 1: 136.
- Berrie AD, and Goodman JD. The occurrence of
Schistosoma rodhaini Brumpt in Uganda. Annal Tropical Medicine
and parasitology 1962; 56: 207.
- Billinghurst JR, The clinical feature of infection
with Schistosoma mansoni in Uganda.The East African
Medical Journal. 1965;4:621-628.
- Kabatereine, NB. Schistosoma mansoni in Packwach,Nebbi District, Uganda, 40 years after Nelson. Tropical Medicine and Parasitolology. 1992; 43, 162-166
- Kabatereine, N.B. Progress towards countrywide
control of schistosomiasis and soil-transmitted helminthiasis
in Uganda. Transaction of the Royal Society of the
Tropical Medicine and. Hygiene. 2006; 100: 208-215
- Zhou, X.N. lThe public health significance and
control of schistosomiasis in China - then and
now. Acta Tropica. 2005; 96: 97-105
- Webbe, G. and el Hak,S. Progress in the control
of schistosomiasis in Egypt 1985-1988. Transaction of
the Royal Society Tropical Medicine and
Hygiene. 1990; 84: 394-400
- Montresor, A. et al. (2005) The WHO dose pole for the administration of praziquantel is also accurate in
non-African populations. Trans. R. Soc. Trap. Med. Hyg. 99, 78-81
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