Objective: to investigate the first reported cases of strongyloidiasis in the Solomon Islands, and to establish whether this disease poses a risk to personnel of the Regional Assistance Mission to Solomon Islands (RAMSI).

Design, setting and participants: Retrospective review of the pathology database of the RAMSI Medical Facility in Honiara, Solomon Islands, for the period 1 July 2006 –

30 September 2007.



Main outcome measures: number and clinical features of confirmed cases of Strongyloides stercoralis infestation, as diagnosed by serological tests or faecal microscopy.



Results: fourteen confirmed cases of strongyloidiasis in previously healthy RAMSI participants were identified. Of 13 patients with notes available, symptoms documented

at presentation included epigastric pain (10 patients), diarrhoea (7) and urticaria (4). Clinical disease in all patients responded to oral antihelminthic therapy (albendazole or ivermectin).



Conclusions: Strongyloidiasis is endemic in the Solomon Islands and a risk for RAMSI personnel. Australian medical professionals should be aware of this potentially fatal and

lifelong infestation, particularly the importance of an occupation history, appropriate diagnostic tests, effective treatment and adequate follow-up to document cure. We recommend implementation of a postdeployment screening program for strongyloidiasis

Pattison, David A.

Speare, Richard

English

ResearchOnline at James Cook University

PUBLIC  HEALTHStrongyloidiasis in personnel of the Regional Assistance Mission to Solomon Islands (RAMSI)David A Pattison and Richard SpeareThe Medical Journal of Australia ISSN:0025-729X 18 August 2008 189 4 203-206©The Medical Journal of Australia 2008www.mja.com.auPublic Healthare given chemotherapy or other immuno-suppressant drugs (including corticoster-oids). In this syndrome, autoinfective larvaedisseminate in large n mbers from the gas-trointestinal tract, leading to superimposedbacterial meningitis and septicaemia; it hasa mortality rate of up to 87%.230 SeMainStronmicroResupartiat prMABSTRACTObjective:  To investigate the first reported cases of strongyloidiasis in the Solomon Islands, and to establish whether this disease poses a risk to personnel of the Regional Assistance Mission to Solomon Islands (RAMSI).Design, setting and participants:  Retrospective review of the pathology database of the RAMSI Medical Facility in Honiara, Solomon Islands, for the period 1 July 2006 – ptember 2007. outcome measures:  Number and clinical features of confirmed cases of gyloides stercoralis infestation, as diagnosed by serological tests or faecal scopy.lts:  Fourteen confirmed cases of strongyloidiasis in previously healthy RAMSI cipants were identified. Of 13 patients with notes available, symptoms documented esentation included epigastric pain (10 patients), diarrhoea (7) and urticaria (4). Clinical disease in all patients responded to oral antihelminthic therapy (albendazole or ivermectin).Conclusions:  Strongyloidiasis is endemic in the Solomon Islands and a risk for RAMSI personnel. Australian medical professionals should be aware of this potentially fatal and lifelong infestation, particularly the importance of an occupation history, appropriate diagnostic tests, effective treatment and adequate follow-up to document cure. We recommend implementation of a postdeployment screening program for MJA 2008; 189: 203–206strongyloidiasis.tromiatoS ngyloides stercoralis is a soil-trans-tted parasitic gastrointestinal nem-de that can persist for years in thehuman intestine through the production ofautoinfective larvae.1 Patients at risk ofstrongyloidiasis should be screened to pre-vent hyperinfection syndrome before theyAlthough strongyloidiasis occurs inPapua New Guinea,3 Fiji4 and Vanuatu,5 ithas not been reported in the SolomonIslands. This may be because faecal micro-scopy is not routinely performed at theNational Referral Hospital in Honiara, andserology testing is not available in theSolomon Islands (Dr Tenneth Dalipanda,Chief Executive Officer and Medical Super-intendent, National Referral Hospital, Hon-i a r a ,  S o lo m o n  I s l a n d s ,  pe r s o n a lcommunication).The only published survey of soil-trans-mitted helminths in the Solomon Islandswas conducted in a semi-urban environ-ment, and reported that 40.7%–45% ofchildren tested were infected with a soil-transmitted helminth — Ascaris lumbri-coides, hookworm or Trichuris trichiura.6Protracted ethnic tensions in the Solo-mon Islands (1998–2003) resulted in theestablishment of the Regional AssistanceMission to Solomon Islands (RAMSI).Member countries of the Pacific IslandsForum, under Australia’s leadership, estab-lished RAMSI in 2003 with the aim ofrestoring law and order and assisting theSolomon Islands’ economic recovery. Par-ticipating nations have sent several thou-sand military personnel, police officers andcivilian advisers to the Solomon Islands;most are from Australia and New Zealand.Until recently, before returning to theircountry of origin, RAMSI personnelreceived mebendazole, which is ineffectiveagainst S. stercoralis.7The RAMSI Medical Facility in Honiarais contracted by the Australian Govern-ment to provide comprehensive health carefor RAMSI personnel, who are estimated tonumber around 1000 at any given time.At the Medical Facility, we diagnosedstrongyloidiasis in several personnel. Thisled to concern for undiagnosed personnelwho return home to non-endemic regions,where the awareness of the implications ofprior exposure is limited. Prescription ofchemotherapy, corticosteroids or otherimmunosuppressive medications withoutappropriate screening and treatment in thiscohort would be of particular concern.Therefore, we undertook a retrospectivereview of the RAMSI Medical Facilitypathology database to determine the epi-demiology of strongyloidiasis in RAMSIpersonnel and the need for a postdeploy-ment screening program.METHODSCases of S. stercoralis infestation werediagnosed based on faecal microscopy orserology.Stool samples were examined via directmicroscopy of faeces concentrate (MiniParasep faecal parasite concentration kit;DiaSys, Wokingham, Berkshire, UK) by anonsite medical scientist. S. stercoralis can bedifferentiated from Strongyloides fuelleborni(which causes limited disease in humans)based on the presence of larvae and noteggs in the faeces.8Serological tests were performed at theQueensland Medical Laboratory, Brisbane,using enzyme-linked immunosorbent assay(ELISA). Optical density was categorised asnegative (< 0.9 optical density units[ODU]), equivocal (0.9–1.2 ODU), or posi-tive (> 1.2 ODU).We retrospectively reviewed the patho-logy database of the RAMSI Medical Facil-ity for the period 1 July 2006 – 30September 2007. We searched the databasefor the results of faecal examinations andStrongyloides serological tests. The medicalrecords of patients with positive resultswere reviewed, if available.RESULTSWe found 168 faecal examination resultsand 34 Strongyloides serological test results;some patients had received both tests. Weidentified 14 patients with S. stercoralisinfestation: 11 men and three women(average age, 36 years). Only one patientwas deployed from an area with highJA • Volume 189 Number 4 • 18 August 2008 203PUBLIC  HEALTHendemicity (Patient 9, from South-EastAsia) (Box 1). S. fuelleborni infestation wasnot observed.Thirteen of the 14 patients had casenotes available for review. Among these,epigastric pain exacerbated by eating wasthe most common symptom (10/13; 77%).Diarrhoea and urticaria or other skin mani-festations were reported in 54% (7/13) and31% (4/13) of individuals, respectively(Box 1).Importantly, we found that the symp-toms of strongyloidiasis were frequentlymisinterpreted. Epigastric pain was misdia-gnosed as gastro-oesophageal reflux, andwas thus treated unsuccessfully with pro-ton-pump inhibitors. Two patients withurticarial rash were diagnosed as havinginsect bites and were treated with cortico-steroids. Notably, Patient 1 received 40 mgmethylprednisolone intramuscularly, anddeveloped lower abdominal pain, backpain and dysentery 2 days later, whichnecessitated hospital admission. Faecalmicroscopy revealed S. stercoralis larvae,and prompt treatment with albendazole ledto resolution of symptoms.We cannot report detailed follow-upinformation due to the limited duration ofdeployments and difficulty accessingpatients’ records upon return to their coun-tries of origin. However, Box 1 details thetreatments given after strongyloidiasis wasdiagnosed, and the initial clinical response.The standard treatments used were oralalbendazole 400 mg twice daily for 3 daysor a single dose of oral ivermectin 200 μg/kg.DISCUSSIONThis retrospective audit identifies the Solo-mon Islands as an S. stercoralis-endemicregion and RAMSI personnel as being atrisk of infestation.A strength of this study was the presenceof a facility in the Solomon Islands capableof performing microscopy and with accessto serological testing. Many of these caseswould not have been diagnosed withoutserological testing.The literature provides limited data onthe symptoms of acute strongyloidiasis.Our data on presenting symptoms are use-ful and serve to remind clinicians to con-sider strongyloidiasis as a differentialdiagnosis in all symptomatic returnedRAMSI personnel, particularly those pre-senting with epigastric pain, diarrhoea orurticaria. Larva currens — a rapidly pro-gressing rash caused by migration of thelarvae and pathognomonic of strongyloi-diasis — was not documented in this caseseries. This is consistent with previousreports that suggest it is rarely seen in acuteinfestations.9Given the nature of the study, and fluctu-ation in numbers and frequent rotation ofRAMSI personnel, we cannot estimate dis-ease incidence. However, it is likely thatour audit underestimated the number of1 Cases of strongyloidiasis in personnel of the Regional Assistance Mission to Solomon Islands: clinical and laboratory features, treatment and responsePatientAge (years), sex RoleEosinophils* ( 109/L)Strongyloides serology (ODU)†Faecal microscopy Clinical features Treatment (response)1 23, F NZDF 0.5 nd + Epigastric pain, skin rash, dysenteryAlbendazole (SR)2 36, M TDS 0.6 < 0.9 + Epigastric pain, urticaria Albendazole, ivermectin (SR)3 40, M NZPF nd nd + Diarrhoea, urticaria Albendazole (SR, faeces − )4 56, F NZPF nd nd + Epigastric pain, diarrhoea Albendazole, ivermectin (intermittent diarrhoea, faeces − , serology 1.0 ODU)5 52, M AFP nd nd + Diarrhoea Albendazole (SR)6 31, M AFP < 0.5 nd + Epigastric pain, diarrhoea Albendazole (diarrhoea, faeces − ); ivermectin (SR)7 33, M Civilian (SI)1.0 3.4 − Epigastric pain Albendazole, ivermectin (SR)8 43, M TPF 2.7 2.4 − Epigastric pain, diarrhoea Untreated (SR, serology 4.8); albendazole, ivermectin (SR)9 53, F Civilian (SE Asia)0.7 4.3 nd Skin rash Ivermectin (SR)10 46, M Civilian (Aust)3.5 3.5 + Epigastric pain, diarrhoea Ivermectin (SR)11 25, M NZDF 8.6 1.7 nd Epigastric pain Albendazole, ivermectin (SR, eosinophils 0.6  109/L)12 19, M NZDF 3.3 1.8 nd Epigastric pain Albendazole, ivermectin (SR)13 22, M NZDF 0.5 1.2 nd Epigastric pain Albendazole, ivermectin (SR, serology < 0.9)14 24, M ADF 6.7 1.5 nd na naAust = Australia. ADF = Australian Defence Force. AFP = Australian Federal Police. faeces − = negative result on faecal microscopy. na = history not available. nd = not done. − = negative. NZDF = New Zealand Defence Force. NZPF = New Zealand Police Force. ODU = optical density units. + = positive. SE = South-East. SI = Solomon Islands. SR = symptom resolution. TDS = Tonga Defence Services. TPF = Tonga Police Force.* Reference range, < 0.5  109/L. † Reference range, > 1.2 ODU. ◆204 MJA • Volume 189 Number 4 • 18 August 2008PUBLIC  HEALTHRAMSI personnel infected during the studyperiod because:• strongyloidiasis can be asymptomatic;10• symptomatic individuals might havefailed to seek medical attention or beentreated empirically with antihelminthictherapy;• some personnel might have developedsymptoms only after leaving the SolomonIslands; and• diagnostic tests have significant limitations.A recent study suggests the StrongyloidesELISA is significantly less sensitive inreturned travellers (patients with acuteinfestation, similar to our cohort) com-pared with immigrants with previousc h ro n i c  e x p o s u r e  ( 73 %  v  9 8% ;P < 0.001).11 Further, the time necessaryfor  se rocon vers i on in  h umans  i sunknown.12 Thus, false-negative resultsmay be obtained in patients tested beforeseroconversion. Faecal microscopy haslow sensitivity in chronic uncomplicatedstrongyloidiasis,10 and its sensitivity inacute strongyloidiasis is not clearlydefined. However, diagnostic accuracy canbe improved by examining multiple stoolsamples or using Strongyloides agar-plateculture.13It is vital to identify and treat individualswith strongyloidiasis before immunosup-pression in order to minimise the risk ofhyperinfection syndrome. Our study high-lights this, as systemic corticosteroids wereused to treat urticarial skin rash in two ofour 14 patients, with adverse con-sequences; corticosteroid treatment was alsothe precipitant of fatal disseminated strongy-loidiasis in a case reported in 2001.14The diagnosis of strongyloidiasis beforeimmunosuppression requires a high indexof suspicion. As Australian-led interven-tions in the Asia–Pacific region are likely toincrease, an increasing number of Austral-ians will be exposed to S. stercoralis. Thus,it is evident that all patients being consid-ered for immunosuppressive therapy musthave an occupational history taken. If thisreveals a geographic risk factor for strongy-loidiasis, appropriate testing and treatment(if positive) must be instituted beforeimmunosuppression.Accordingly, we propose a postdeploy-ment screening program comprising a fullblood count (to detect eosinophilia),Strongyloides serology and microscopy, andagar-plate culture of a stool specimen. Theabsence of a “gold-standard” test mandatesthe use of a combined diagnostic approach.These tests could be performed 3 monthsafter departure from the Solomon Islands,coinciding with screening for exposure tobloodborne viruses and tuberculosis tomaximise compliance with follow-up.Our incomplete follow-up data preventassessment of treatment efficacy. However,ivermectin is currently considered first-linetreatment for uncomplicated S. stercoralisinfestations due to its high efficacy (83%microscopic clearance after 3 months).15,16Although albendazole (400 mg twice dailyfor 3 days) is less efficacious (75% micro-scopic clearance after 6 months),17 itsbroader antihelminthic activity (especiallyagainst hookworm) makes it more suitablefor empirical treatment.18,19 It has recentlyreplaced mebendazole as the postdeploy-ment antihelminthic eradication therapyused by RAMSI.Follow-up serological testing to docu-ment eradication is a necessary part of ascreening program, as strongyloidiasis isconsidered a lifelong infestation untilproven eradicated. The case of a Laotianimmigrant to Australia who died fromStrongyloides hyperinfection caused byinadvertent immunosuppression a yearafter treatment with albendazole14 supportsthis component of the proposed screeningprogram (Box 2).Staff inductions have been changed toinclude information about the lifelongnature of strongyloidiasis infestation andits potentially fatal complications. RAMSIpersonnel are advised to avoid skin expo-sure to soil that may have been contami-nated by human faeces, principally bywearing appropriate footwear. Australianmedical professionals should be aware thatstrongyloidiasis is endemic in the SolomonIslands and that RAMSI personnel are atrisk of infestation. A postdeploymentscreening program is recommended for allRAMSI personnel.ACKNOWLEDGEMENTSWe thank Dr Orla Morrissey for reviewing themanuscript, Dr Ross Fountain and Lance CorporalJustine O’Dwyer from the New Zealand DefenceForce for patient follow-up, and Mr Robert Dwyer(medical scientist, RAMSI Medical Facility, Honiara)for input on parasitology.COMPETING INTERESTSNone identified.AUTHOR DETAILSDavid A Pattison, MB BS, Medical Officer1Richard Speare, MB BS, PhD, FAFPHM, Director21 RAMSI Medical Facility, Aspen Medical, Honiara, Solomon Islands.2 Anton Breinl Centre for Public Health and Tropical Medicine, James Cook University, Townsville, QLD.Correspondence: david.pattison@jcu.edu.auREFERENCES1 Grove DI. Human strongyloidiasis. Adv Parasi-tol 1996; 38: 251-309.2 Link K, Orenstein R. Bacterial complications ofstrongyloidiasis: Streptococcus bovis menin-gitis. South Med J 1999; 92: 728-731.3 Shann F, Biddulph J, Vince J. Paediatrics fordoctors in Papua New Guinea: a guide fordoctors providing health services for children.2nd ed. Madang: Papua New Guinea Depart-ment of Health, 2003: 356.4 Thomas M, Woodfield G, Moses C, et al. Soil-transmitted helminth infection, skin infection,anaemia, and growth retardation in schoolchil-dren of Taveuni Island, Fiji. N Z Med J 2005;118: U1492.5 Einsiedel L, Spelman D. Strongyloides stercora-lis: risks posed to immigrant patients in anAustralian tertiary referral centre. Intern Med J2006; 36: 632-637.6 Hughes RG, Sharp DS, Hughes MC, et al.Environmental influences on helminthiasis andnutritional status among Pacific schoolchildren.Int J Environ Health Res 2004; 14: 163-177.7 Keystone JS, Murdoch JK. Mebendazole. AnnIntern Med 1979; 91: 582-586.8 Speare R. Identification of species of Strongy-loides. In: Grove DI, editor. Strongyloidiasis: an2 Recommendations for management of strongyloidiasisGeneral principles• Assume lifelong infestation unless eradication is proven• Screen high-risk groups before immunosuppression (especially with corticosteroids) to prevent hyperinfection syndromeHigh-risk groups• Indigenous Australians• Immigrants*• Returned travellers*• Expatriates: military, police and civilians (including Regional Assistance Mission to Solomon Islands personnel)*Diagnosis• Full blood count (to detect eosinophilia)• Serological tests• Faecal microscopy (± special techniques to increase sensitivity)Treatment• A single dose of ivermectin 200 μg/kg• Three-monthly follow-up (eosinophilia/serology)• Re-treatment if positive* From or who worked in endemic tropical regions. ◆MJA • Volume 189 Number 4 • 18 August 2008 205PUBLIC  HEALTHimportant roundworm infection of man. Lon-don: Taylor Francis, 1989: 11-82.9 Gill GV, Welch E, Bailey JW, et al. ChronicStrongyloides stercoralis infection in formerBritish Far East prisoners of war. QJM 2004; 97:789-795.10 Siddiqui AA, Berk SL. Diagnosis of Strongy-loides stercoralis infection. Clin Infect Dis 2001;33: 1040-1047.11 Sudarshi S, Stumpfle R, Armstrong M, et al.Clinical presentation and diagnostic sensitivityof laboratory tests for Strongyloides stercoralisin travellers compared with immigrants in anon-endemic country. Trop Med Int Health2003; 8: 728-732.12 Speare R, Durrheim DN. Strongyloides serol-ogy — useful for diagnosis and management ofstrongyloidiasis in rural Indigenous popula-tions, but important gaps in knowledge remain.Rural Remote Health 2004; 4: 264.13 Koga K, Kasuya S, Khamboonruang C, et al. Amodified agar plate method for detection ofStrongyloides stercoralis. Am J Trop Med Hyg1991; 45: 518-521.14 Lim L, Biggs BA. Fatal disseminated strongyloi-diasis in a previously treated patient. Med JAust 2001; 174: 355-356.15 Datry A, Hilmarsdottir I, Mayorga-Sagastume R,et al. Treatment of Strongyloides stercoralisinfection with ivermectin compared with alben-dazole: results of an open study of 60 cases.Trans R Soc Trop Med Hyg 1994; 88: 344-355.16 Marti H, Haji HJ, Savioli L, et al. A comparativetrial of single dose ivermectin versus three daysof albendazole for treatment of Strongyloidesstercoralis and other soil-transmitted helminthinfections in children. Am J Trop Med Hyg1996; 55: 477-481.17 Archibald LK, Beeching NJ, Gill GV, et al.Albendazole is effective treatment for chronicstrongyloidiasis. Q J Med 1993; 86: 191-195.18 Bailey MS, Thomas R, Green AD, et al.Helminth infections in British troops followingan operation in Sierra Leone. Trans R Soc TropMed Hyg 2006; 100: 842-846.19 Muennig P, Pallin D, Sell RL, et al. The costeffectiveness of strategies for the treatment ofintestinal parasites in immigrants. N Engl JMed 1999; 340: 773-779.(Received 12 Nov 2007, accepted 2 Mar 2008) ❏206 MJA • Volume 189 Number 4 • 18 August 2008

Strongyloidiasis in personnel of the Regional Assistance Mission to Solomon Islands (RAMSI)

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Strongyloidiasis in personnel of the Regional Assistance Mission to Solomon Islands (RAMSI)

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