A CASE REPORT ON THE UNUSUAL FINDING OF SCHISTOMA MANSONI OVA Sivaranjini Alagiri , Anupma Jyoti Kindo , Dhivyalakshmi Sri Ramachandra Medical College & Research Institute Chennai
A CASE REPORT ON THE UNUSUAL FINDING OF
SCHISTOMA MANSONI OVA
Sivaranjini Alagiri , Anupma Jyoti Kindo , DhivyalakshmiSri Ramachandra Medical College & Research Institute
Chennai
INTRODUCTIONHumans 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
GLOBAL BURDENGlobal Burden of Disease Study 2013 - nearly 1million deaths are due to parasitic infections,
globally.
Plos Medicine Journals’ Blog,2015
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.
SCHISTOSOMIASIS - EPIDEMIOLOGYSchistosomiasis is one of the oldest known parasitic infections.Prevalent in tropics & sub-tropicsAnnual incidence – 200 million globallyEstimated annual deaths d/t schistosomiasis is around 200,000An 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.2015http://whqlibdoc.who.int/trs/
WHO_TRS_912
GLOBAL DISTRIBUTION OF SCHISTOSOMIASIS
Michael Walsh (2012).Schistosomiasis. Infection Landscapes.
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
IMPENDING THREAT TO INDIAAbundance 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
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 causinghuman schistosomiasis due to lack of suitable intermediate hosts and hence naturally controls the spread of schistosomiasis inIndia. Arunava Kali.Journal of Clinical and Diagnostic Research. 2015
SCHISTOSOMIASIS
Water borne helminthic infection Definitive host -HumansIntermediate host - freshwater snailsInfective form - cercariaeHabitat – 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
ANTHROPOPHILIC SCHISTOSOMESSchistosoma
speciesIntermediate 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
Adapted from Melvin, Brook and Salum,1959
CASE REPORTIntestinal Schistosomiasis
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
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
STOOL EXAMINATIONSAMPLE - freshly passed stool collected in a sterile screw capped container GROSS EXAMINATION Colour – yellowish brown Consistency – watery Blood – present Mucous - presentMICROSCOPIC EXAMINATION Saline wet mount – plenty of oval shaped eggs measuring 120-175µm * 40-70µm - prominent sharp lateral spine - embryonated - non operculated
Ova of Schistosoma mansoni characterised by a sharp lateral spine
RESULTSBased 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.
TREATMENTPraziquantel – 40mg/kg Repeat stool sample was found to be negative for ova.Strict personal hygieneAbstinence from water activities to avoid infestation of water
bodies
REPORTS OF HUMAN SCHISTOSOMIASIS IN INDIA
REPORTED BY FINDINGSHatch (1878) First case of human schistosomiasis in India
Report of urinary schistosomiasis in 12 patientsPowell (1903) First indigenous case of human schistosomiasis in IndiaDe 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 IndianHooton (1914) Indigenous case from Rajkot, GujaratDe Mello(1936) Urinary schistosomiasis in a young boy from GoaGadgil et al(1955) Indigenous case of S.haematobium infection from Nasik district.
Arunava Kali.Journal of Clinical and Diagnostic Research. 2015
DISCUSSIONThis 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.