A CASE REPORT ON THE UNUSUAL FINDING OF SCHISTOMA MANSONI OVA

1. Sivaranjini Alagiri , Anupma Jyoti Kindo , Dhivyalakshmi
Sri Ramachandra Medical College & Research Institute
Chennai

2. INTRODUCTION
 Humans are hosts to nearly 300 parasitic species.
 Parasitic infections are cosmopolitan and contribute
considerably to the global burden of communicable diseases.
 It is one of the chief concerns of public health in under -
developed & developing countries.
 Contributing factors are malnutrition, population density,
economic conditions, poor sanitation and life style.
 Increased incidence in developed countries may be attributed to
- mass influx of immigrant population from endemic areas
- tourism
- immunosuppression
F.E.G.Cox.Clin Microbiol Rev.2002

3. GLOBAL BURDEN
 Global Burden of Disease Study 2013
- nearly 1million deaths are due to parasitic infections,
globally.
Plos Medicine Journals’ Blog,2015

4. HISTORY
• Eggs of intestinal helminths have been found in mummified
faeces dating thousands of years back.
• Earliest reports were documented by the Egyptians-Ebers
Papyrus of 1500BC.
• Helminthiases have changed the course of Cold War. Acute
schistosomiasis weakened the Chinese troops ,long enough for
American fleets to enter straits of Taiwan (blood-fluke that
saved Formosa)
• German scientist Dr.Theodore Bilharz – first described adult
schistosomes in portal vein of a cadaver(1851)
• Sir Patrick Manson(1902) discovered ova of S.mansoni.

5. SCHISTOSOMIASIS - EPIDEMIOLOGY
 Schistosomiasis is one of the oldest known parasitic infections.
 Prevalent in tropics & sub-tropics
 Annual incidence – 200 million globally
 Estimated annual deaths d/t schistosomiasis is around 200,000
 An estimated 600 million people at risk in 76 endemic
countries.
 Schistosomiasis control has been successfully implemented
over the past 40 years in several countries, including Brazil,
Cambodia, China, Egypt, Mauritius and Saudi Arabia
WHO Factsheets.2015
http://whqlibdoc.who.int/trs/WHO_TRS_912

6. GLOBAL DISTRIBUTION OF
SCHISTOSOMIASIS
Michael Walsh (2012).Schistosomiasis. Infection Landscapes.

7.  India is considered non-endemic for schistosomiasis –
attributed to absence of intermediate host for human
schistosomes.
 There has been reports of sporadic indigenous cases.
 Cercarial dermatitis in Tribal villages of Assam , Chhattisgarh,
Madhya Pradesh and Jabalpur.
 Several schistosome species causing zoonotic disease are
prevalent in India.
 Endemic foci for human schistosomiasis
- Gimvi village in Ratnagiri district, Maharashtra
- Thirupparankundram village, Chennai
- Lahager village, Madhya Pradesh
M. C. Agrawal and V. G. Rao.Journal of Parasitology Research.2011

8. IMPENDING THREAT TO INDIA
 Abundance of aquatic bodies and irrigation practices in India
provides ideal environment for the intermediate hosts.
 Population migration from endemic areas d/t globalisation and
tourism.
 Poor sanitation and lack of vector control measures pose a risk
for the spread.
 Under-reporting of schistosomiasis d/t
- lack of suspicion
- lack of public awareness to seek medical attention

9. EXPERIMENTS TO DETERMINE PREVALENCE
OF INTERMEDIATE HOST IN INDIA
FINDINGS
Soparkar(1919) Cercarial fauna of snails were analysed in the water bodies in
Bombay. All 17 species were animal schistosome cercariae
Annandale et al(1920) Tested 1532 common snails ,out of which 11 cercariae were
found.All were negative for human schistosome and all were
resistant to miracidia of S.haematobium
Gadgi et al(1956) Identified Ferrissia tenuis as the intermediate host of the
S.haematobium , which caused an outbreak in Gimvi
village,Maharashtra.
These experiments depict the absence of cercariae causing
human schistosomiasis due to lack of suitable intermediate
hosts and hence naturally controls the spread of schistosomiasis in
India. Arunava Kali.Journal of Clinical and Diagnostic Research. 2015

10. SCHISTOSOMIASIS
 Water borne helminthic infection
 Definitive host -Humans
 Intermediate host - freshwater snails
 Infective form - cercariae
 Habitat – mesenteric ,vesical & pelvic venous plexus.
 There are about 23 species of Schistosoma identified so far.
 Only 7 are anthropophilic.
© Dr Peter Darben, Queensland University of Technology

11. ANTHROPOPHILIC SCHISTOSOMES
Schistosoma
species
Intermediate Host Schistosomiasis Endemic Region
S. haematobium Bulinus species Urogenital Africa , Middle East
S. japonicum Oncomelania
species
Gastrointestinal China, East Asia,
Philippines
S. mansoni Biomphalaria
species
Gastrointestinal Africa , South
America,
Caribbean, Middle
East
S. intercalatum Bulinus species Gastrointestinal Africa
S. mekongi Neotricula aperta Gastrointestinal South East Asia
S. guineensis Bulinus forskalii Gastrointestinal West Africa
S. malayensis Robertsiella species Gastrointestinal South East Asia

12. Adapted from Melvin, Brook and Salum,1959

13. CASE REPORT
Intestinal Schistosomiasis

14. PATIENT HISTORY
• 26 year old male
• College student from Chennai
• Native of Nigeria
• Recent travel to native place
• Trekking and swimming
PRESENTING COMPLAINTS
• Episodes of loose stools on & off for 2 weeks , with recent
episode lasting 4 days
• Not associated with fever/ abdominal discomfort / nausea /
vomiting

15. INVESTIGATIONS
• Haemoglobin - 15.3gm/dl
• RBC count - 5.5 million/mm3
• Total leucocyte count - 5800 cells/mm3
• P49.7L43.2E1.9M5B0.2
• Platelet count - 2.49 lakhs/mm3
• PCV - 44.6%
• MCV - 80.3fl
• MCH - 27.5pg
• MCHC - 34.3
• The patient was found to be retro-negative

16. STOOL EXAMINATION
 SAMPLE
- freshly passed stool collected in a sterile screw capped
container
 GROSS EXAMINATION
Colour – yellowish brown
Consistency – watery
Blood – present
Mucous - present
 MICROSCOPIC EXAMINATION
Saline wet mount – plenty of oval shaped eggs
measuring 120-175µm * 40-70µm
- prominent sharp lateral spine
- embryonated
- non operculated

17. Ova of Schistosoma mansoni characterised by a sharp lateral spine

18. RESULTS
 Based on the morphology, eggs were identified to be S.mansoni
ova.
 Diagnosis was supported by his history of swimming in an
area, endemic for schistosomiasis.
TREATMENT
 Praziquantel – 40mg/kg
 Repeat stool sample was found to be negative for ova.
 Strict personal hygiene
 Abstinence from water activities to avoid infestation of water
bodies

19. REPORTS OF HUMAN SCHISTOSOMIASIS IN
INDIA
REPORTED BY FINDINGS
Hatch (1878) First case of human schistosomiasis in India
Report of urinary schistosomiasis in 12 patients
Powell (1903) First indigenous case of human schistosomiasis in India
De Sa et al(1949) First case of urinary schistosomiasis in Indian from Gimvi
village,Ratnagiri,Maharashtra.
Index case leading to discovery of endemic focus
Santhanakrishnan et al Identified endemic focus in Thiruparankundram village,Chennai
Srivastava et al (1969) Identified lahager village, Madhya Pradesh as an endemic focus.
Christopher et al(1905) Polymorphism of eggs. Presence of ova of both S.haematobium
and S.spindle in urine of South Indian
Hooton (1914) Indigenous case from Rajkot, Gujarat
De Mello(1936) Urinary schistosomiasis in a young boy from Goa
Gadgil et al(1955) Indigenous case of S.haematobium infection from Nasik district.
Arunava Kali.Journal of Clinical and Diagnostic Research. 2015

20. DISCUSSION
 This case report is evidence enough to indicate that population
migration from endemic areas poses a significant threat of
schistosomiasis in India.
 Reports of sporadic cases indicate the possibility of indigenous
snails to serve as intermediate host for the parasite.
 Though cases of human schistosomiasis are very rare in India,
occurrence of new hybrid strains due to co-existence of
different species may serve as a potential risk for human
infections.
 Physicians are required to have a high level of suspicion for
this disease while evaluating parasitic infestations .
 It heralds importance of a surveillance strategy even in non-
endemic areas like India, to enable early identification of cases
and initiate prompt treatment ,thereby checking the spread of
this neglected tropical disease.