Strongyloidiasis: challenges in diagnosis and management in non-endemic Kuwait

Among immunocompromised individuals, hyper-infection with Strongyloides stercoralis may occur and lead to fatal strongyloidiasis. To clinicians and laboratory diagnosticians in non-endemic countries such as Kuwait, this severe infection poses a particular problem. The clinical histories and signs and symptoms of four Kuwaiti cases of S. stercoralis hyper-infection were reviewed. Each of the four was found not only to have lived in an area where S. stercoralis was endemic but also to have been treated with immunosuppressive steroids (for medical problems unrelated to the nematode infection). When they presented with undiagnosed hyper-infections their clinical features were confusing. Three of the cases, all with low eosinophil counts, died but the other, who was treated with thiabendazole, survived. In the light of these observations, healthy medical examinees who had recently moved from endemic zones were checked for asymptomatic S. stercoralis infection, both by stool examination and ELISA-based serology. Of 381 stool samples investigated over a 3-month period, 183 (48%) were found positive for helminths, 7% for S. stercoralis. Of 198 individuals from endemic zones who were screened after another medical examination, 71 (35.8%) were found positive for intestinal helminth parasites, including one (1.45%) infected with S. stercoralis. Although ELISA appear reliable in making a presumptive diagnosis of strongylodiasis, the results of such assays are not very specific and are best interpreted in conjunction with the patient's clinical status. The concurrent administration of anthelminthics to patients prescribed steroids who, because they live or have lived in an area where S. stercoralis is endemic, are at risk of infection with the nematode, should be considered.

Modified Giemsa staining for rapid diagnosis of malaria infection

OBJECTIVES

To develop and evaluate a rapid method for the diagnosis of malaria infection by microscopy of stained blood films.

SUBJECTS AND METHODS

Blood specimens were collected from randomly selected confirmed malaria cases (n = 75) and suspected malaria cases (n = 175). The microscopy was done on each set of blood films stained by modified and the standard Giemsa staining methods.

RESULTS

All the 75 previously diagnosed malaria cases were confirmed by the microscopy of blood films stained by both methods. Forty-nine (28%) of the 175 cases suspected for malaria infection showed malarial parasites on microscopy of blood films stained by both methods. However, due to homogeneous staining and clearer background of the blood films it was possible to determine the parasite species in 65% of the cases on microscopy of the thick films stained with the modified method compared to only 20% with the standard method. Further, the turnaround time for reporting the microscopy test result was 15-20 and 45-50 min with modified and standard staining methods, respectively.

CONCLUSION

Our data showed that performance of the modified staining method in detecting malarial parasites was comparable to that of the standard staining method. Moreover, the modified staining method was rapid, easy to use, and reliable.

Drug-resistant Plasmodium falciparum infection in immigrants and non-immune travellers

OBJECTIVE

To detect the incidence of drug-resistant Plasmodium falciparum malaria infection in immigrants and travellers in non-endemic Kuwait.

METHODS

Over a period of 3 years, July 1995 to September 1998, 1352 malaria patients were enrolled in the study. Of these, 1293 were immigrants from countries where malaria is endemic and 59 were non-immune travellers with a recent history of travel to these countries. The in vitro drug sensitivity was determined in 892 patients.

RESULTS

In all, 892 of 1352 (66.0%) P. falciparum isolates were successfully cultured in vitro for drug sensitivity and 419 (47.0%) isolates showed in vitro resistance to chloroquine or mefloquine. Fifty-six (13.4%) isolates were resistant to both drugs. Chloroquine resistance was observed in > 70% of the isolates from Africa and India followed by Pakistan (39.9%) and Bangladesh (35.9%). The resistance to mefloquine ranged from 26.2% in isolates from Sri Lanka to 47.5% in isolates from African countries.

CONCLUSION

The study highlights the important trend in drug resistance in P. falciparum malaria in immigrants from south-east Asian and African countries.

Diagnosis of abdominal hydatid cyst disease: the role of ultrasound and ultrasound-guided fine needle aspiration cytology

OBJECTIVE

To retrospectively analyze the role of ultrasound (US) imaging and US-guided fine needle aspiration cytology in the diagnosis and management of abdominal hydatid cyst disease (HCD).

SUBJECTS AND METHODS

The medical records of 55 diagnosed cases of HCD seen between January 1986 and December 2000 at Mubarak Al-Kabeer Hospital and Al-Amiri Hospital in Kuwait were reviewed for demographic and clinical data, including radiology and serology. The US findings of the patients were classified into four types as follows: type I: single or multiple well-defined cysts, with or without detached or collapsed wall and with or without echogenic contents; type II: single or multiple cysts with peripheral cysts, with or without echogenic contents; type III: solid or semisolid lesions, and type IV: cysts with calcified walls.

RESULTS

The overall accuracy of US in the diagnosis of HCD was 80% (44/55 cases). US examination was suggestive of HCD type I, 16/19 (84%), type II, 21/23 (91%), type III, 3/8 (38%), and type IV, 4/5 (80%). For the 11 remaining undiagnosed cases, US was useful for localizing the lesions for US-guided fine needle aspiration cytology. It established the diagnosis in all the 11 cases, without precipitating complications.

CONCLUSION

US alone was valuable for diagnosing and localizing HCD in the abdomen except for solid-type lesions. US-guided fine needle aspiration cytology was useful in localizing and establishing the diagnosis of HCD in the cases where US alone was ineffective.

An unusual case of biliary atresia

Intrahepatic biliary cysts are rarely seen in the patients with biliary atresia. We describe a ten-month-old child with biliary atresia in whom the abdominal imaging studies (ultrasonography, computed tomographic scan and magnetic resonance cholangiopancreatography) revealed multiple intrahepatic biliary cysts ('bile lakes'). The child also had intrapulmonary shunting of blood due to pulmonary arteriovenous fistulae, which were demonstrated on contrast-enhanced echocardiography. Both these findings, 'bile lakes' and pulmonary arteriovenous fistulae occur rarely in biliary atresia.

Invasive amebiasis: challenges in diagnosis in a non-endemic country (Kuwait)

Invasive zymodemes of the enteric protozoan Entamoeba histolytica infect the large intestine and cause extra-intestinal lesions such as amebic liver abscess (ALA). The clinical manifestations of ALA are protean, particularly in patients presenting in a non-endemic, desert country such as Kuwait, and diagnosis becomes problematic. In this study, we present cases of ALA to illustrate the clinical and diagnostic challenges. For serodiagnosis of ALA, we compared the sensitivity and specificity of the indirect hemagglutination assay (IHA) with the ImmunoTab assay and an enzyme-linked immunosorbent assay (ELISA) for this geographic region. We tested sera of 110 patients with ALA, 1,224 patients suspected of having invasive amebic infection, and 50 Europeans with no travel history to an amebic-endemic area. The IHA was simple, rapid, easy to perform, and reliable (sensitivity = 99%, specificity > 95%). The performance of the IHA in detecting ALA in suspected cases was significantly better than that of the ELISA and the ImmunoTab test. Compared with the IHA, both the ELISA and ImmunoTab assay detected relatively higher numbers of false-positive cases (4.7% and 3.6%, respectively). With the availability of ultrasound and computed tomography scans, the serology correlates excellently with the clinical presentation. In chronic cases where fibrosis may be present around the abscess, the IHA has limitations, as in the follow-up of treated patients. Pitfalls in diagnosis are highlighted by discussing the differential diagnosis of ALA from bacterial hepatic abscesses and infected hydatid cysts. Most importantly, the IHA in such cases was invariably at a titer that is considered not significant.

Pelvic abscess from enterobius vermicularis. Report of a case with cytologic detection of eggs and worms

BACKGROUND

Enterobius vermicularis is known to produce perianal and ischioanal abscesses and invade the peritoneal cavity via the female reproductive system, causing pelvic peritonitis. However, there are only rare case reports on the cytodiagnosis of these parasitic lesions.

CASE

A 28-year-old woman was admitted with a tender left iliac fossa mass and greenish vaginal discharge. Ultrasonogram and computed tomography scan confirmed the presence of a mass lesion suggestive of a tuboovarian abscess. Cytologic examination of the pus obtained during left salpingo-oophorectomy revealed the presence of ova of E vermicularis and fragments of the adult worm in an inflammatory exudate consisting predominantly of neutrophils, eosinophils and occasional epithelioid cell granulomas. Paraffin sections of the tuboovarian mass showed necrotizing epithelioid cell granulomas, but neither ova nor any worm section was identified. Although the possibility of tuberculosis was considered histologically, Ziehl-Neelsen (Z-N) stain for acid-fast bacilli was negative. Z-N staining of the smear and mycobacterial culture of the pus also did not yield positive results.

CONCLUSION

E vermicularis may cause tuboovarian abscess with necrotizing epithelioid granulomas mimicking tuberculosis. Cytologic examination of the pus is helpful in the diagnosis.

Cryptosporidiosis in Kuwaiti children: seasonality and endemicity

OBJECTIVE

To detect the incidence of cryptosporidial infection in children presenting with gastrointestinal symptoms at the local hospital in Kuwait.

METHODS

Over a period of 3 years, September 1995 to August 1997, a single fecal sample from 3549 children was analyzed by modified saframin-methylene blue (SM-B) staining and a direct immunofluorescence test for the presence of Cryptosporidium oocysts.

RESULTS

Cryptosporidium oocysts were detected in 51 (10%) children with diarrhea. Prevalence was highest (73%) in children > 2 years of age compared with children < 2 years of age. The maximum number of cases, 38 of 51 (75%), was seen during the months January to April, indicating a marked seasonal variation. Polyparasitism was common in children with diarrhea; however, 43 of the 51 (84%) children with cryptosporidiosis had cryptosporidium infection only. Blastocystis hominis and Endolimax nana were the most common parasites detected (38% and 15%, respectively). Forty-seven of the 51 (90%) children with cryptosporidiosis were Kuwaiti and gave no history of travel abroad, suggesting that the infection was acquired indigenously. Sociodemographic information on children with cryptosporidiosis suggests three possible modes of transmission of infection: drinking contaminated water stored in overhead water tanks, person to person, or contact with infected animals.

CONCLUSION

In this study, we observed water-borne transmission of cryptosporidium infection in children with diarrhea. The infection is seasonal and endemic.

Leishmaniasis diagnosed by liver biopsy: management of two atypical cases

Two patients presenting with pyrexia of unknown origin were diagnosed as having visceral leishmaniasis based on the presence of Leishmania donovani bodies in liver tissue. Of particular interest is that these two case reports suggest that in patients with pyrexia of unknown origin, a liver biopsy for L. donovani bodies should be considered even when several months have passed since leaving an endemic area, when splenomegaly is absent, when bone marrow examination and serology are not diagnostic, and even when abnormal coagulation necessitates a transjugular liver biopsy.

Diagnosis of imported malaria by Plasmodium lactate dehydrogenase (pLDH) and histidine-rich protein 2 (PfHRP-2)-based immunocapture assays

This study was conducted to evaluate the performance of two rapid non-microscopic assays: Plasmodium lactate dehydrogenase (pLDH) assay (OptiMAL) and Plasmodium falciparum histidine-rich protein 2 (PfHRP-2) assay (ICT Malaria). The assays were used to detect malaria infection in 515 immigrants living in Kuwait. The performance of both assays was compared to that of microscopy of Giemsa-stained thick blood films and to each other. Of the 515 patients tested, 163 were positive for malaria parasites by microscopy of thick blood film. Of these, 87 were infected with Plasmodium vivax parasites, 63 with P. falciparum, 1 with Plasmodium malariae, and 12 had mixed infections of P. falciparum and P. vivax. The PfHRP-2 assay detected 53 P. falciparum infections and, as expected, failed to detect all but one case of P. vivax. Three cases of mixed infections were also not detected by this assay. The pLDH assay detected 56 P. falciparum cases and 77 P. vivax infections but failed to detect 4 cases of mixed infections. Compared to microscopy, the performance of both the assays to diagnose P. falciparum infection was comparable. The sensitivity for the PfHRP-2 assay was 82% with a specificity of 99.0% and for the pLDH assay the sensitivity was 89% with a specificity of 99.5%. The PfHRP-2 assay detected 4 false positive cases, 2 of which were also detected by the pLDH assay. These patients reported treatment with chloroquine in the last 2-5 weeks. Though the immunocapture diagnostic assays may be helpful in certain situations, microscopy of thick blood film is still the method of choice in diagnosing imported malaria.

Comparison of the OptiMAL test with PCR for diagnosis of malaria in immigrants

The OptiMAL test (Flow Inc., Portland, Oreg.), which detects a malaria parasite lactate dehydrogenase (pLDH) antigen, has not been evaluated for its sensitivity in the diagnosis of malaria infection in various epidemiological settings. Using microscopy and a PCR as reference standards, we performed a comparison of these assays with the OptiMAL test for the detection of Plasmodium falciparum and Plasmodium vivax infection in 550 immigrants who had come from areas where malaria is endemic to reside in Kuwait, where malaria is not endemic. As determined by microscopy, 125 (23%) patients had malaria, and of these, 84 (67%) were infected with P. vivax and 36 were infected with P. falciparum; in 5 cases the parasite species could not be determined due to a paucity of the parasites. The PCR detected malaria infection in 145 (26%) patients; 102 (70%) of the patients had P. vivax infection and 43 had P. falciparum infection. Of the five cases undetermined by microscopy, the PCR detected P. falciparum infection in two cases, P. vivax infection in two cases, and mixed (P. falciparum plus P. vivax) infection in one case. Correspondingly, the OptiMAL test detected malaria infection in 95 patients (17%); of these, 70 (74%) had P. vivax infection and 25 were infected with P. falciparum. In this study, 61 (49%) of the 125 malaria cases, as confirmed by microscopy, had a degree of parasitemia of <100 parasites per microl, and 23 (18%) of the cases had a degree of <50 parasites per microl. Our results show that the sensitivity of the OptiMAL test is high (97%) at a high level of parasitemia (>100 parasites/microl) but drops to 59% when the level is <100 parasites/microl and to 39% when it is <50 parasites/microl. In addition, the OptiMAL test failed to identify four patients whose blood smears contained P. falciparum gametocytes only. We conclude that the sensitivity and specificity of the OptiMAL test are comparable to those of microscopy in detecting malaria infection at a parasitemia level of >100 parasites/microl; however, the test failed to identify more than half of the patients with a parasitemia level of <50 parasites/microl. Thus, the OptiMAL test should be used with great caution, and it should not replace conventional microscopy in the diagnosis of malaria infection.

Urinary schistosomiasis associated with hepatitis C virus infection

We studied 26 adult patients referred for cystoscopy: 13 consecutive patients with schistosome ova on bladder biopsy and antibodies to Schistosoma species in serum were classified as having urinary schistosomiasis, while 13 consecutive patients without schistosome ova on bladder biopsy and who were negative for antibodies to Schistosoma species in serum served as controls. Nine of 13 patients (70%) and none of 13 controls (p < 0.0005) had antibodies to hepatitis C virus in serum (anti-hepatitis C virus). All controls and patients who were negative for anti-hepatitis C virus had normal serum alanine aminotransferase levels, while 2 of 9 (22%) positive for anti-hepatitis C virus had elevated levels. Our study shows that patients with urinary schistosomiasis are at high risk for anti-hepatitis C virus positivity and that some of them may have active liver disease. Therefore, it is imperative to screen patients with urinary schistosomiasis for associated hepatitis C virus infection and liver disease.

Dirofilariasis in Kuwait: first report of human infection due to Dirofilaria repens in the Arabian Gulf

Zoonotic dirofilariasis has been reported sporadically from many areas of the world but thus far, there are no such reports from the Arabian Peninsula. We present the first report of human dirofilariasis from this region in the Middle East and discuss the significance of the finding. A fixed, elongated mass in the abdominal wall of a 50-year-old Kuwaiti man was excised and a worm was identified in an abscess in tissue sections. The location of the nodule in subcutaneous tissue, the diameter of the worm in section, the multilayered cuticle with fine longitudinal ridges on the external layer, prominent internal cuticular ridges, and abundant somatic muscles suggested the diagnosis of the worm as Dirofilaria (Nochetiella) repens, a natural parasite of dogs and cats in Asia, Africa, and Europe.

Cystic hydatid disease: pitfalls in diagnosis in the Middle East endemic area

Ultrasound (US) and computerized tomography (CT) have made a significant contribution to accurately localizing focal lesions. Such imaging techniques have been found useful in assessing a hydatid aetiology of cystic lesions. However, we present 23 cases which demonstrate that these modalities in isolation are not adequate in diagnosing hydatid cysts, as claimed from this geographic area. Simple, congenital, choledochal and pancreatic pseudocysts were cystic lesions misinterpreted as hydatid cysts, as were infective disorders such as amoebiasis and tuberculosis. The appearance of a lipoma and an ovarian intra-abdominal cystadenoma and an intra-hepatic haematoma were among other conditions that were labelled as hydatid cysts on US/CT. However, in all the cyst/mass lesions that were misdiagnosed, counter-immunoelectrophoresis (CIEP), with an antigen that elicits an arc-5 in immunoelectrophoresis on cellulose acetate membranes as a substrate, did not detect any anti-Echinococcus antibodies in patients' sera. This was in contrast to the classic indirect haemagglutination test which was equivocal in some cases. The CIEP was specific and excluded hydatidosis though such a diagnosis was ventured on US and/or CT. We therefore conclude that a specific and sensitive serological test is mandatory for confirming a preoperative diagnosis of CHD. When surgery is not immediate, a negative serological test such as the CIEP would in addition indicate US or CT-guided aspiration of cyst fluid for cytological evaluation and/or enzyme immunoassay, thereby avoiding the cost and morbidity of laparotomy. Furthermore, chemotherapy is now a viable alternative provided the diagnosis is unequivocal. This may be a prudent protocol before a further decision on management is envisaged.

Anti-HCV-positive cirrhosis associated with schistosomiasis

Hepatosplenic schistosomiasis is occasionally associated with cirrhosis and progressive hepatic decompensation. The aim of the present study was to determine the prevalence of antibody to hepatitis C virus in patients with schistosomiasis and cirrhosis. The prevalence of anti-HCV was studied in 12 consecutive cases of schistosomiasis associated with biopsy proven cirrhosis. All patients had a past history of schistosomiasis and high titers of schistosomal antibodies in serum (1:32 to 1:4096). Five of the 12 patients had hepatic catheterization and were found to have sinusoidal involvement with corrected sinusoidal pressures ranging from 19 to 23 mm Hg. Four had ascites, six had pedal edema, and eight had peripheral signs of chronic liver disease in the form of palmar erythema, spider nevi, and/or gynecomastia. Ten of the 12 cases (83%) were repeatedly positive for anti-HCV/ELISA. These results suggest that when patients with schistosomiasis develop cirrhosis, associated hepatitis C virus infection should be suspected.

Ophthalmomyiasis in Kuwait: first report of infections due to the larvae of Oestrus ovis before and after the Gulf conflict

We report for the first time four cases of ophthalmomyiasis due to the larvae of Oestrus ovis in Kuwait, before and after Operations Desert Shield and Desert Storm. The larvae were easily removed under local anaesthetic. The symptom complex of acute foreign body sensation, irritation, redness, lacrimation and photophobia resolved rapidly. Ophthalmic antibiotic and corticosteroid drops were also instilled and recovery was uneventful. The ophthalmomyiasis may not always be associated with contact with sheep-rearing per se. Medical personnel should therefore be aware that in cases of what might appear initially as acute, non-specific catarrhal conjunctivitis, patients with the persistent symptom complex should be re-examined to exclude ophthalmomyiasis due to the larvae of O. ovis in endemic areas.

Analysis of the in vitro lymphoproliferative responses and antibody levels to the arc-5 antigen in patients with cystic hydatid disease

Using a commercially-available, purified, arc-5 antigen, we examined the in vitro proliferative responses of peripheral blood mononuclear cells from hydatid patients and from healthy controls. Antibody levels of different immunoglobulin classes were also measured against the same antigen, in sera of both groups. Our findings indicate that lymphocytes from healthy controls do not proliferate to the arc-5 antigen, whereas lymphocytes from the majority of patients do. The negative or weak responses observed among a few patients were not due either to increased release of prostaglandins in culture or to a lack of responsiveness to Interleukin-2. Antibodies of all three classes, G, M and A, measured by an ELISA, were elevated in sera of patients when compared with controls. However, only levels of specific IgG antibodies gave an excellent discrimination of the disease state and these were of diagnostic value. No direct or inverse correlations between lymphoproliferative responses and antibody levels were observed in either group, although a few patients with relatively low antibody titres demonstrated very high proliferative responses. The possible use of the proliferative assay as an adjunct to serology in the diagnosis of hydatid disease is indicated.

Analysis of host components in hydatid cyst fluid and immunoblot diagnosis of human Echinococcus granulosus infection

To improve serodiagnosis of cystic hydatidosis, immunoblotting studies were performed to look for a highly specific parasite antigen(s). First, commercially available hydatid cyst fluid antigen preparations were characterized by SDS-PAGE and by immunoblotting with sera specific for parasite and host animal proteins. One preparation, designed for use in complement fixation tests, did not appear to be suitable for immunoblotting because of the low concentrations of parasite antigens. Several host proteins, including serum albumin and IgG, were detected in the cyst fluid. Sera from patients with Echinococcus granulosus infections and other parasitic diseases were examined by immunoblotting for antibodies against specific cyst fluid parasite antigens. Several parasite antigens were variably recognized. Only one antigen, a 40 kDa protein, was recognized by all E. granulosus-infected patients. Reactivity against this antigen was also observed in all sera from E. multilocularis, cysticercosis, and schistosomiasis patients as well as in some filariasis cases. Two E. granulosus antigens, molecules of 12.5 and approximately 17 kDa, were only recognized by antibodies from some E. granulosus patients.

An enzyme-linked immunosorbent assay using an arc 5 antigen for the diagnosis of cystic hydatid disease

We report on an easily standardized enzyme-linked immunosorbent assay (ELISA) for the diagnosis of cystic hydatid disease. The antigen used is commercially available, and purified to elicit an arc 5 precipitation line by immunoelectrophoresis (IEP) with sera of patients harbouring hydatid cysts. The IgG-ELISA was highly sensitive and specific, and of diagnostic value compared to total Ig-ELISA, IgM-ELISA or IgA-ELISA. When compared to the indirect hemagglutination test and to counterimmunoelectrophoresis using an arc 5 antigen, minimal cross-reactions were observed in sera of patients with a presumptive diagnosis of hydatidosis but none were observed in those harbouring intestinal helminths, schistosomes or filarial parasites. The assay is of low cost, simple to perform, and highly reproducible. The IgG-ELISA provides an unequivocal laboratory diagnosis of hydatidosis. It is eminently suited for accurate and early identification of hydatid disease patients, for instance in mass surveys, who may benefit immediately from currently available anthelmintics, thereby obviating the need for surgery later.

Cystic hydatid disease: aspects of the incidence in man in Kuwait, Arabian Gulf

Cystic hydatid disease (CHD) is endemic in Kuwait, but the exact extent of the disease in man has yet to be determined. The incidence was calculated by serological testing of sera from patients with a presumptive clinical diagnosis of hydatidosis and follow-up until the final diagnosis was determined. During a one-year period, 123 sera were received from two District General Hospitals serving a population of approximately 500,000. Eighteen patients had confirmed CHD, 17 were serologically positive in two tests, indirect haemagglutination (IHA) and counterimmunoelectrophoresis (CIEP), while another positive patient was identified through surgery and histopathology. These cases represent an estimated incidence rate of 3.6 per 100,000. Various factors, however, indicate that this is an underestimation of the true incidence. The infection rate of camels with hydatid cysts and dogs harbouring the adult worm, a possible measure of the true incidence in man, is considered high. Because of the nature of the population structure, the majority of patients were, in fact, non-Kuwaitis. Kuwaitis, who form 40% of the population, constituted about 30% of the CHD patients. Females were in the majority, the 21 to 50 yr. age-group being the most symptomatic. Hydatid cysts were most commonly present in the liver. Finally, compared to other countries at the time when a control programme was instituted, the incidence rate in Kuwait is moderate to high. However, the number of individuals with CHD does not appear alarming as the available capacity of the medical services is adequate.

Human cryptosporidiosis in the Arabian Gulf: first report of infections in children in Kuwait

During a 3-month pilot study, we identified ten children with cryptosporidiosis; they all presented with diarrhoea, most also with fever, vomiting and dehydration. For diagnosis, the formalin-acetate concentrate of the stool, and direct smears were stained for oocysts in safranin-methylene blue (S-MB). The negative staining of oocysts in trichrome-stained specimens was indicative and was confirmed by destaining and restaining in S-MB. Constraints contributing to the absence of reports from the Arabian Gulf were the lack of awareness of Cryptosporidium sp. as a cause of diarrhoea in children, inappropriate laboratory diagnostic techniques and, possibly, the initial referral of patients to polyclinics where mild cases may go undetected. Contaminated drinking water and close contact with domestic animals are possible modes of transmission of Cryptosporidium sp. but further studies are recommended to confirm this.

Human gnathostomiasis: infection with an immature male Gnathostoma spinigerum

Gnathostomiasis, usually caused by larvae of Gnathostoma spinigerum, is a significant cause of morbidity in the Far East. We report a case of gnathostomiasis involving a male Thai residing in Kuwait who presented with acute pain in the right iliac fossa. A resection of the terminal ileum and cecum was performed. Microscopic examination showed a parasite in an eosinophilic abscess. The nematode was identified as an immature male G. spinigerum based on size, morphology, and distribution of cuticular spines.

A modified indirect fluorescent antibody test for the diagnosis of brucellosis

We adapted the conventional indirect fluorescent antibody (IFA) test to assay IgM and IgG Brucella-specific antibodies to differentiate acute from chronic infections rather than measure total antihuman globulin specific antibodies. The results were compared with the slide agglutination test (SAT) used for screening and the quantitative microagglutination test (MAT). Of a total of 118 randomly selected samples sent for anti-Brucella antibodies received at a general hospital laboratory, 58 (47.9%) were found to be positive for IFA-IgG test but not necessarily by other tests. Eleven of these cases were positive for Brucella melitensis by culture. Sixty serum samples found negative for Brucella antibodies by IFA and other tests were of patients with medical conditions other than brucellosis. Fifty serum samples from healthy blood donors were negative for Brucella spp. antibodies by all the three tests. The IFA test was found to be a more sensitive test than MAT and distinguished an acute infection from chronic disease.

Diagnosis of cystic hydatid disease: role of aspiration cytology

Fine needle aspiration of mass lesions is reported in eleven patients in whom cystic hydatid disease (CHD) was not a differential diagnosis or whose serological results were negative. Aspiration was continued until no more fluid could be obtained. In five patients aspiration was done under ultrasound guidance. No sequelae were observed that could be attributed to aspiration per se. Aspirated fluid was stained with haematoxylin and eosin and giemsa or was passed through 5 micron polycarbonate filters which were then stained in the same way. The aspirated material and polycarbonate filters were also stained with trichrome which proved the best stain to demonstrate the acid-fast hooklets. Such filtration of the total volume of the aspirated material or that evacuated at operation is simple, quick, and accurate.

Hydatid liver disease: problems in diagnosis in the Middle East endemic area

Imaging techniques such as ultrasound (US), liver scan and computerized tomography (CT) localize mass lesions in the liver and abdomen, and are valuable tools in the differential diagnosis of hydatid disease. However, we present two cases from Kuwait in the Middle East which demonstrate that these techniques alone are not as accurate as claimed in this geographical area. A sensitive and specific serological test is essential for a pre-operative diagnosis of hydatid disease. Discrepancies between radiological imaging and serological diagnosis are best resolved by cytology of the drained fluid and/or histopathological examination of the excised cyst. Negative serology would indicate ultrasound-guided aspiration of cyst fluid for cytological verification or enzyme immunoassay.

Aspects of imported malaria at a district general hospital in non-endemic Kuwait, Arabian Gulf

There is no indigenous mosquito-borne transmission of malaria in Kuwait. However, in a five year period at a district general hospital, the number of laboratory-diagnosed cases of malaria increased annually from 25 to 84, a rise of 336%. Except for two induced infections, all were imported, mainly from the Indian subcontinent. Plasmodium vivax was responsible for 87.29% of the cases; P.falciparum (12.05%), a mixed infection of P.vivax and P.falciparum (0.33%) and a case of P.ovale (0.33%) were also identified. Rapid preparation of acetone-fixed, Giemsa-stained thick blood films, a heightened awareness of the infection, examination of multiple samples of blood from patients and the general resurgence of malaria in endemic areas were some of the factors responsible for the high number of cases diagnosed. Most patients were young males and presented with clinical malaria due to P.vivax between May and October each year, an apparent seasonal peak. However, many were already resident in the country for a variable period. Patients with P.falciparum though, presented clinically within two weeks of arrival in the country. Parasite densities were calculated to monitor the progress of treatment and identify quickly any possible chloroquine-resistant P.falciparum strains. A policy of active prophylaxis is suggested to stem the tide of imported malaria.

Cytologic diagnosis of bancroftian filariasis in a nonendemic area

Parasitic infections are common in the developing countries, but the cytologic diagnosis of such infections is infrequent or rare. This paper presents four cases of filariasis caused by Wuchereria bancrofti diagnosed by cytologic examination and discusses some unusual observations. The finding of microfilariae in pleural fluid in the absence of the classic symptoms and signs of tropical pulmonary eosinophilia is highlighted. In two patients, nocturnal microfilaremia could not be demonstrated despite Nuclepore filtration, thus suggesting the possible merits of cytology in the primary diagnosis of a filarial infection. Even the diethylcarbamazine provocative test failed to elicit a peripheral microfilaremia in one patient, further emphasizing the importance of cytology as a diagnostic method in amicrofilaremic infections. Attention is drawn to the need for a high index of suspicion on the part of the cytologist in the identification of parasitic organisms in material from high-risk groups to achieve an early diagnosis of such infections and the prompt institution of appropriate chemotherapy. This may obviate the more serious pathologic changes of advanced disease, especially the disfigurement of chronic and late filariasis.

Counterimmunoelectrophoresis using an arc 5 antigen for the rapid diagnosis of hydatidosis and comparison with the indirect hemagglutination test

A modified counterimmunoelectrophoresis and a conventional indirect hemagglutination test were compared for routine diagnosis of human hydatid disease in an endemic area in the Middle East. Counterimmunoelectrophoresis was performed on a cellulose acetate membrane with dilutions of a commercially available antigen which interacts with sera of patients with confirmed hydatid disease to produce the arc 5 precipitin line. The test was performed with unconcentrated human sera and the lines stained in an aqueous solution of Ponceau red. Sensitivity (95.5% vs. 93.2%) and specificity (99.2% vs. 89.9%) were higher with counterimmunoelectrophoresis than with indirect hemagglutination. Cross-reactivity with sera of patients with other parasitic infections was noted with indirect hemagglutination but not with counterimmunoelectrophoresis. There was no cross-reactivity with sera of patients with autoimmune disorders by either test.

Induced malaria and antibody titres in acute infections and in blood donors in Kuwait

Concurrent with the increase in the number of imported cases of malaria into non-endemic Kuwait during the past 5 years, induced infections have been identified for the first time. We report 10 such cases over a 4-year-period. Of 8 transfusion-induced infections, 4 were due to Plasmodium falciparum and 4 to P. vivax. The mean incubation period for P. falciparum patients was 13 d and for P. vivax, 17 d. An accidental syringe-needle transmission and a congenital infection were due to P. falciparum and P. vivax respectively. Malarial antibody levels were assayed on commercially-available cultured P. falciparum schizonts by the indirect fluorescent antibody (IFA) test. To establish a base line, the sera of patients with blood film-confirmed P. falciparum and P. vivax were assayed. 96% of the P. falciparum sera were positive, the geometric mean titre (GMT) being 10,280. However, all sera from P. vivax patients were reactive but the GMT was lower at 505. 28% of sera from Kuwaitis and 45% of sera of a consecutive group of blood donors were also reactive, the respective GMTs being 38 and 51. The risk of transfusion malaria was calculated as 79 per million units drawn, an unacceptably high figure for a non-endemic country. We suggest a revised blood donor policy.

Rhinosporidiosis in Kuwait

Three cases of rhinosporidiosis are reported for the first time from Kuwait, a state in the Arabian Gulf. All patients were male expatriate workers from the Indian subcontinent. Relevant epidemiological, clinical and pathological aspects of the disease are discussed.

Malaria in non-endemic Kuwait: resident status of patients with imported infections and the need for prophylaxis

Kuwait is non-endemic for malaria but, with a large expatriate population, the number of imported infections has escalated from 87 in 1980 to 534 in 1984, an increase of over 613%. During a period of 1 year at the Infectious Diseases Hospital, where most of the cases were diagnosed each year, 16.7% of blood samples sent for microscopy were positive for malaria; 95.47% of these patients were hospitalized for an average of 4 days. In a 2-year period, only three (0.52%) Kuwaiti nationals imported the infection out of a total of 577 patients with malaria. About equal numbers of expatriate 'residents' and 'new arrivals' were responsible for the remainder, but over 80% of patients with Plasmodium falciparum were 'residents'. The proportion of residents among the patients is increasing and will be more pronounced with the downturn in the economy. To curtail the tide of imported malaria, the current data suggests the viability of an active campaign to offer chemoprophylaxis to travellers at risk who are essentially 'semi-immune visitors of a non-malarious area visiting a malarious area'. The benefits of simple prophylactic measures need to be emphasized. The disinfection of aircraft arriving from endemic zones should be mandatory.

Imported malaria in Kuwait

The number of imported malaria cases in Kuwait rose from 87 in 1980 to 504 in 1983, an increase of 579%. The continued resurgence of malaria in endemic zones, improved diagnostic techniques and a heightened awareness of imported malaria have contributed to the increase in the number of microscopically proved cases. Thick blood films fixed in acetone and stained in Giemsa proved a rapid method of diagnosis; species identification on the basis of a thin film on the same slide was performed with ease. Malaria was acquired in 38 countries. Most patients were young male adults. Most of the cases were due to Plasmodium vivax originating from India, although an increasing number of P. falciparum cases are also now being diagnosed from there. P. falciparum infections were evenly distributed throughout the year and most cases presented within 14 days of their arrival in the country. The highest number of P. vivax cases were diagnosed between May and October, when heat stress might have been a factor in precipitating a clinical attack of an infection previously acquired in the endemic zone. Attention is drawn to the importance of delayed attacks of P. vivax and, in semi-immunes, of P. falciparum. The time interval involved in establishing a history of "recent" travel in clinically suspected cases of malaria needs to be more clearly defined in each geographical area. Cases of induced malaria due to transfusion, accidental and congenital infections were identified. The fatality rate due to P. falciparum infections was low. In terms of the risk of renewed transmission, Kuwait may be considered a vulnerable area.

Hookworms and the species infecting man in Zambia

The rate of hookworm infections, determined by stool examination over a 7-month period, was 16.56% in medical examinees and 19.91% in in-patients in an urban hospital population in Zambia. The egg-load though was low. Culture of ova to the filariform larval stage, examination of adult worms expelled after anthelminthic treatment and collected at autopsy confirmed that the dominant species was Necator americanus. However, we report, perhaps for the first time, the presence of Ancylostoma duodenale in man in Zambia. Such information is important in assessing the clinical significance of hookworm infection in the country and for formulating a rational chemotherapeutic policy. No cases of infection with the 'false' hookworm Ternidens deminutus were identified.

Some helminthozoonotic infections in Zambia

Parasitic infections constitute an important group of zoonoses. Stool examination of inpatients, medical examinees and out-patients in a sub-tropical environment established that Inermicapsifer madagascariensis and Schistosoma mattheei are occasionally anthropozoonotic in Zambia. Strongyloides fülleborni, a species normally parasitic in primates is not uncommon in man; whether it is anthropozoonotic or a parasite well adapted to man in this part of Africa needs further investigation. The finding of unidentified spiruroid ova was considered to be due to a spurious infection. The need for the differentiation of such organisms from those commonly infecting man is emphasized especially since the literature on such a subject is so sparse in the country and on the continent.

Strongyloides fülleborni infections in man in Zambia

Rhabditiform larvae, and in two cases eggs, of Strongyloides spp. identified in the stools of Zambian patients were cultured to the free-living adult stage. Free-living adults of S. fülleborni, a parasite common in primates in Africa and Asia, were present in cultures from 13 (9.9%) of 131 cases of strongyloidiasis. In three of these cases, both S. fülleborni and S. stercoralis free-living adults were found.