P. R. Hira

Persistent Histidine-Rich Protein 2, Parasite Lactate Dehydrogenase, and Panmalarial Antigen Reactivity after Clearance of Plasmodium falciparum Monoinfection

ABSTRACT We tested 240 patients with Plasmodium falciparum monoinfection for persistent parasite antigenemia after successful standardized antimalarial therapy by using the ICT Malaria Pf/Pv and OptiMAL-IT assays that detect the malaria antigens Plasmodium falciparum histidine-rich protein 2 (HRP2) and parasite lactate dehydrogenase (pLDH), respectively, as well as a panmalarial antigen (PMA). The patients were screened for antigenemia on days 0, 3, 7, and 14 of follow-up. On day 0, all 240 patients showed positive reactivity with both assays. Of the 229 cases with negative parasitemia on day 3, persistent antigenemia was observed in 207 (90.4%) of the cases: 188 (82.1%) for HRP2 antigen and 75 (32.8%) for PMA. There was a gradual decrease in antigenemia on follow-up to day 14; however, the drop in reactivity to PMA was less than that for HRP2 antigen. In contrast to HRP2 antigenemia, there was a significant decrease in pLDH antigenemia to 38.4% and to 14.8% (PMA) on day 3 (P < 0.03). The pLDH antigenemia level dropped further to 14.8% on day 7. There was no significant association of persistent antigenemia with gametocytemia. One case with gametocytemia was negative for both the antigens. In conclusion, the OptiMAL-IT assay is more sensitive than the ICT Malaria Pf/Pv test for monitoring therapeutic responses after antimalarial therapy since the LDH activity ceases when the malarial parasite dies.

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.

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

Abstract 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 patients 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.

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.

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.

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.

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.

Risk of Introduction of Drug-Resistant Malaria in a Non-Endemic Country, Kuwait: A Real Threat?

Objectives: This study investigates the prevalence of drug-resistant malaria infection in Kuwait in patients with malaria infection to the two most important and primary antimalarial drugs, chloroquine and mefloquine. Study Subjects and Methods: In vitro screening of malarial parasites to chloroquine and mefloquine was done during 1994–1996 in all those cases who presented with malaria-like symptoms and had a parasite density of ≥1,000 asexual pure Plasmodium falciparum parasites per microlitre of blood and had not taken any antimalarial drugs during the last 3 weeks. Results: During 1987–1997 the total number of malaria cases detected ranged between 650 and 1,350 each year. More than 75% of the cases had Plasmodium vivax infection. The majority of these cases (>98%) were detected in individuals coming from various malaria-endemic areas to reside or work in Kuwait. Of the 575 cases tested for drug resistance 42 isolates (7.3%) were resistant to chloroquine (MIC >8 pmol) and 6 isolates (1.04%) were resistant to mefloquine (MIC >64 pmol). The 50% inhibitory concentrations were 2.7 and 4.8 pmol for chloroquine and mefloquine, respectively. All the 6 isolates that were resistant to mefloquine were also resistant to chloroquine. Chloroquine resistance was seen in patients from various malaria-endemic countries. Conclusion: To date no indigenous case of malaria has been detected in Kuwait, however, recent environmental and demographic changes in and around the State of Kuwait may threaten the present status of zero endemicity. In this study we show that 7.3% of the malaria isolates tested were resistant to chloroquine and 1.04% isolates were resistant to mefloquine.

Pressure sores and myiasis: flesh flies (Diptera: Sarcophagidae) complicating a decubitus ulcer

Myiasis is the infestation by dipterous larvae of the tissues of humans, other mammals and some other vertebrates, most commonly affecting cutaneous tissues close to natural orifices or wounds. Such infestation may be deleterious, when the larvae attack the host’s healthy tissues, or it may be benign, when the larvae confine their activities to diseased and dead tissue. In clinical settings, carefully controlled myiasis can even be of benefit to the host, helping to clear areas of necrosis from wounds and ulcers, in an approach often known as ‘maggot therapy’ (Sherman et al., 2000). In Kuwait, a desert country where one might expect a fairly restricted insect fauna because of the hot and dry environment, several cases of human myiasis have been described, including ophthalmomyiasis caused by Oestrus ovis (in the family Oestridae), intestinal myiasis caused by Megaselia sp. (Phoridae) and O. ovis, and urinary myiasis caused by Psychoda sp. (Psychodidae) (Hira et al., 1997). Although all of these infestations were community-acquired, nosocomial infections by the larvae of Lucilia sericata (Calliphoridae) and M. scalaris have also been reported in Kuwait (Hira et al., 2004). An autochthonous case of human myiasis caused by a fly species from yet another family, the Sarcophagidae, which was complicating a decubitus ulcer, has also recently been observed in Kuwait (see below).

Specificity of counterimmunoelectrophoresis with an arc-5 antigen for the diagnosis of cystic hydatid disease

Abstract A rapid and simple counterimmunoelectrophoresis (CIEP) on a cellulose acetate membrane with antigen that elicits an arc-5 precipitin line in immunoelectrophoresis (IEP) is sensitive for the diagnosis of cystic hydatid disease (CHD). Specificity was proven by assaying the sera of patients with amoebiasis, schistosomiasis, filariasis, infections due to a variety of soil-transmitted nematodes and Taenia solium cysticercosis. Other sera analysed were from healthy controls, and patients with malignancies and conditions in which a space-occupying mass or lesion was presumed to be a hydatid cyst on ultrasound (US) and/or computerized tomography (CT). Compared to the indirect haemagglutination (IHA) test, the CIEP was almost 100% specific.