Cryptococcal meningitis in human immunodeficiency virus (HIV)-positive and HIV-negative patients.

This study compared clinical manifestations, blood biochemistry and cerebrospinal fluid (CSF) results of HIV-positive and HIV-negative patients with cryptococcal meningitis. We collected 57 cases of cryptococcal meningitis from cytological specimens submitted to the Department of Tropical Pathology, Faculty of Tropical Medicine. Pertinent clinical data were analyzed retrospectively in 47 cases for clinical manifestations, laboratory features and outcomes of 38 HIV-positive and 9 HIV-negative patients. Headache was the most common symptom seen in all cases, of which 70.2% occurred with fever. CSF examination of both groups revealed elevated opening pressure. Increased CSF protein and depressed CSF glucose levels were seen in HIV-negative cases, which differed from HIV-positive cases, where a slight change was noted. CSF pleocytosis in HIV-positive patients was variable. Forty-eight percent of HIV-positive patients had CSF leukocyte counts below 20 cells/ mm3. None was found in the HIV-negative patients. Specific treatments with amphotericin B and fluconazole were given. Five fatal cases of cryptococcal meningitis were noted, all of which were HIV-positive. There were statistically significant differences in blood neutrophils, blood eosinophils, CSF leukocyte counts, CSF neutrophils, CSF lymphocytes, CSF glucose, and CSF total protein, in HIV-positive and HIV-negative patients (p = 0.050, p = 0.022, p = 0.002, p = 0.016, p = 0.047, p = 0.031, p = 0.009, respectively).

Various morphologic features of Gnathostoma spinigerum in histologic sections: report of 3 cases with reference to topographic study of the reference worm.

Gnathostomiasis is common in Southeast Asian countries and can be found sporadically in other parts of the world mainly due to human migration. The definitive diagnosis can be given either by identification of the parasite isolated from the patient or through histologic section of the lesion. It is therefore important for pathologists to be familiar with the morphology of parasitic larvae which varies according to the levels of section-cutting so that the diagnosis will not be misled. We present three cases of gnathostomiasis with different features of parasitic morphology and compare these with the reference adult worm.

Can treatment of P. vivax lead to a unexpected appearance of falciparum malaria?

Of 994 patients admitted to the Bangkok Hospital for Tropical Diseases for P. vivax malaria, 104 (10.5%) experienced appearance of Plasmodiumfalciparum following drug treatment for P. vivax . In all patients, P. falciparum parasites were not found by microscopic examination upon admission. The mean time for P. falciparum appearance was 12.6 days after the commencement of chloroquine treatment. Patients experiencing appearance of P. falciparum had significantly lower hematocrit, and greater initial P. vivax parasite counts. We use a mathematical model to explore the consequences of chloroquine treatment of such mixed infections. Both clinical results and features of the model suggest that such "hidden infections" may be quite common, and that the appearance of P. falciparum may be stimulated by treatment of P. vivax.

Does HIV infection accelerate the development of hepatocellular carcinoma? A case report in a young man.

Hepatocellular carcinoma (HCC) is an important cancer. It occurs more often in men than women, and occurs mostly in people 50 to 60 years old. HCC has not been previously reported in a young HIV-seropositive patient in Thailand. We documented a very rare case of HCC in a 33 year old man. He was diagnosed and treated as Salmonella septicemia and tuberculosis. However, additional diagnosis based on pathological study disclosed a moderately differentiated HCC. Immunohistochemical study of the liver tissue was positive for hepatitis B surface antigen (HBsAg).

Mycobacterium szulgai lymphadenitis mimicking Kikuchi's disease in Thailand.

Mycobacterium szulgai is rarely found to be a cause of reported infection. Two thirds of cases were reported as pulmonary presentations, while the rest were infections of soft tissues or bone. In Thailand, few pulmonary infections due to M. szulgai have been reported. This is the first case of M. szulgai lymphadenitis confirmed by tissue culture. The patient presented with prolonged fever and tender enlarged cervical nodes. Histological findings showed large histiocytes with necrotic background compatible with Kikuchi's disease. However, the culture proved the case to be one of M. szulgai infection. That means this mycobacterium should be included in the differential diagnosis of fever with lymphadenitis.

Cerebrospinal fluid analysis in eosinophilic meningoencephalitis.

Eosinophilic meningoencephalitis (EME) remains an important neurological disease and is widely distributed in Thailand. We analyzed the cytological specimens of 56 EME cases. Pertinent clinical data were analyzed retrospectively and correlated with the cerebrospinal fluid (CSF)analysis. Headache was the commonest symptom seen in all EME cases. History of raw or partially cooked Pila snail ingestion was elicited from most patients. There was a marked seasonal occurrence between July to January. Patients received specific treatment as supportive therapy, which included spinal taps, analgesics and corticosteroids, was adequate. No fatal cases were seen. The CSF specimens were sorted into two categories: fresh CSF and hematoxylin and eosin (H&E) stained centrifuged CSF sediment. There was a statistically significant difference between the number of eosinophils and lymphocytes of fresh CSF and the H&E stained centrifuged CSF sediment (p = 0.001 and 0.001 respectively). The CSF glucose and the number of eosinophils in both methods were significantly correlated (p = 0.000, p = 0.008 for fresh CSF and the H&E stained centrifuged CSF sediment respectively). Moreover, the number of eosinophils was statistically significant with the protein in the CSF (p = 0.013), and intracranial pressure (ICP) (p = 0.025). Higher yields of eosinophils, especially in the early course of the disease, can readily be detected in the H&E stained centrifuged CSF sediment, whereas fresh specimens were negative. Further tests may increase the sensitivity and specificity of EME diagnostic results.

In vivo-in vitro model for the assessment of clinically relevant antimalarial cross-resistance.

Cross-resistance may be considered one of the most important factors leading to decreased drug susceptibility of Plasmodium falciparum. The study aimed to determine whether clinically relevant cross-sensitivity of P. falciparum existed between artemisinin and mefloquine. Seventy-six patients with falciparum malaria were admitted and treated with artemisinin derivatives. Treatment response parameters were assessed and in vitro drug sensitivity tests were performed with artemisinin, mefloquine, quinine, and chloroquine. Distinct in vitro cross-sensitivity between artemisinin and mefloquine was observed (p = 0.604; P < 0.001). To assess the relevance of this finding for clinical cross-resistance, we used an analytical model based on the relation of in vivo treatment response parameters (fever, parasite and symptom clearance) to a single reference drug with in vitro drug sensitivity data of several other drugs. Artemisinin (R = 0.554; P = 0.009) and mefloquine (R = 0.615; P = 0.002) in vitro drug sensitivities were equally well reflected in the in vivo treatment response to artemisinin, thereby suggesting the clinical relevance of in vitro cross-sensitivity.

Inducible nitric oxide synthase expression is increased in the brain in fatal cerebral malaria.

AIMS: Nitric oxide (NO) has been hypothesized to play a major role in the pathogenesis of cerebral malaria caused by P. falciparum infection. NO may act as a local neuroactive mediator contributing to the coma of cerebral malaria (CM). We hypothesized that increased expression of inducible nitric oxide synthase (iNOS) may cause increased release of NO, and examined the expression and distribution of iNOS in the brain during CM. MATERIAL AND RESULTS: Brain tissues from fatal cases of cerebral malaria in Thai adults were examined using immunohistochemical staining to detect iNOS. The distribution and strength of staining was compared between 14 patients with CM, three of whom were recovering from coma, and controls. iNOS expression was found in endothelial cells, neurones, astrocytes and microglial cells in CM cases. There was also strong staining in macrophages surrounding ring haemorrhages. iNOS staining was decreased in recovering malaria cases compared to acute CM, and was low in controls. Quantification showed a significant association between the intensity and number of iNOS positive vessels with the severity of malaria related histopathological changes, although the total number of cells staining was not increased compared to recovering CM cases. CONCLUSIONS: This study indicates that an acute induction of iNOS expression occurs in the brain during CM. This occurs in a number of different cells types, and is increased in the acute phase of CM compared to cases recovering from coma. As NO may activate a number of secondary neuropathological mechanisms in the brain, including modulators of synaptic function, induction of iNOS expression in cerebral malaria may contribute to coma, seizures and death.

Cytoadherence characteristics of Plasmodium falciparum isolates in Thailand using an in vitro human lung endothelial cells model.

Using an in vitro model of human lung endothelial cells, we studied different characteristics of Plasmodium falciparum isolates as potential factors for malaria severity in 2 Thai patient groups: 27 with complicated malaria and 42 with uncomplicated malaria. In regard to binding properties, no association existed between cytoadherence and rosette phenotypes (P = 0.1) and hypothrombocytemia increased the cytoadherence level (P = 0.007). Cytoadherence was significantly associated with malaria severity (P = 0.05) in contrast to rosette formation (P = 0.9). Intercellular adhesion molecule-1 and chondroitin-4-sulfate were major receptors of cytoadherence in those with complicated malaria compared with those with uncomplicated malaria (P < 10(-4)). Chondroitin-4-sulfate could act as a putative receptor for malaria complications in non-pregnant women. CD36 was the main receptor in patients with uncomplicated malaria (P < 10(-3)). Vascular cell adhesion molecule-1 and E-selectin played a minor role in 2 groups (P = 0.6). Qinghaosu derivatives were more efficient than other antimalarial drugs, but a positive correlation was observed between the 50% inhibitory concentrations of halofantrine and quinine and the number of adhesive parasitized red blood cells, suggesting their influence on cytoadherence.

Opportunistic infections in the liver of HIV-infected patients in Thailand: a necropsy study.

Liver necropsy from patients infected with human immunodeficiency virus was analyzed in 117 cases. Wide ranges of opportunistic infections were recorded in 47%. Cryptococcosis (21.4%) was the most outstanding infection, followed by tuberculosis (16.2%), cytomegalovirus (5.1%) and penicillosis (3.4%). Non-specific alterations of the liver tissues included fatty steatosis (49.6%), fibrosis (55.6%), portal inflammation and reactive hepatitis. Cases of chronic active and chronic passive hepatitis and one case of hepatocellular carcinoma were reported. In the infected liver, predominant pathological changes included granuloma and spotty necrosis, which were attributed to tuberculous hepatitis. Infection with Cryptococcus usually showed no associated pathological change. The sensitivity for the clinical diagnosis of Cryptococcus was 88.8% and specificity was 91.7%. For tuberculosis, sensitivity was 20% and specificity was 67.9%.

Is there any artemisinin resistance in falciparum malaria?

We reported two cases of complicated falciparum malaria who had poor response to artesunate with delayed parasite clearance times. They were splenectomized patients who were treated with high doses of artemisinin derivatives. Our cases showed the importance of the spleen in the clearance of malaria parasites and had different clinical outcome, one fatal and one recovery. The host factors, the parasitemia count, the quality of antimalarial chemotherapy and blood level of the antimalarial drugs must be considered in relation to the causes of the delayed clearance of parasitemia.

Absence of knobs on parasitized red blood cells in a splenectomized patient in fatal falciparum malaria.

We present a case report of fatal falciparum malaria of a splenectomized adult Thai patient. The patient developed high peripheral parasitemia and showed signs of severe malaria with multiorgans involvement. Ultrastructure of Plasmodium falciparum-infected red blood cells in a fatal splenectomized patient and pathological features are reported for the first time with special emphasis on the role of the spleen as a modulating cytoadherence phenotype of parasitized red blood cells (PRBC). In this patient, adherence of the PRBC to the vascular endothelium of brain, kidney and lung including blood circulating cells, was noted, despite the absence of knob on the surface of the PRBC.

A study of anemia in pregnant women with Plasmodium falciparum at district hospitals in Vientiane, Lao PDR.

A descriptive cross-sectional study was carried out among pregnant women attending antenatal care at the district hospital, with suspected clinical manifestation of malaria in order to determine the prevalence of anemia and malaria among pregnant women and to determine any correlation between degree of anemia and degree of malaria parasitemia in pregnancy with malaria infection. This is a quantitative research method using face-to-face questionnaire. This study was undertaken at the district hospitals of Vientiane Prefecture and Vientiane Province. Sixty-eight pregnant women with suspected malarial clinical manifestations attending the antenatal care at these hospitals were recruited during June - October, 1998. The subjects were asked about their sociodemographic, socio-economic characteristics, gravida and parity, gestational age, last pregnancy and past history of hematology diseases. Blood samples (dry smear for thick and thin blood films) were examined at the same time for Plasmodium falciparum. The study showed that the prevalence of anemia (Hb < 11 g/dl) and severe anemia (Hb 4-6.9 g/dl) in the total sample population was 48.5% and 8.8% respectively. However, the prevalence of anemia among pregnant women with malaria was 68.75% compared to those without malaria infection (42.31%), but the difference was not statistically significant (p=0.117). A plausible explanation could be small sample size. The prevalence of severe anemia in pregnancy with malaria parasitemia was 18.8% compared to those without parasitemia (5.8%). The difference was not statistically significant (p=0.102). The difference of the mean hemoglobin level in falciparum positive cases and falciparum negative cases was clinically and statistically significant (RR = 1.63 and p=0.00679). There was some evidence of a negative correlation between the degree of anemia and parasitemia count (r= -0.19 and r2= -0.04). In conclusion this population had high prevalence of anemia in pregnant women and P. falciparum may be the main factor associated with anemia. There is a need to investigate other causes of anemia among pregnant women. Our results suggest that frequent and regular antenatal monitoring is necessary for the pregnant women. They should be encouraged to attend antenatal clinics through health education, increased health personnel awareness of proper management for the pregnant women with fevers from malarial endemic areas. There is a need for further research in this area in order to obtain adequate sample size.

Chloroquine sensitivity of Plasmodium vivax in Thailand.

Chloroquine has been the standard treatment for Plasmodium vivax malaria for more than 40 years in most regions of the world. Recently, however, chloroquine-resistant P. vivax has been reported from Oceania, several parts of Asia, and South America. In order to assess the situation in Thailand, 886 patients with vivax malaria who were admitted to the Bangkok Hospital for Tropical Diseases from 1992 to 1997 were followed prospectively. Most of the patients had been infected on the western border of Thailand and were experiencing their first malarial infection when admitted. All received oral chloroquine (approximately 25 mg base/kg body weight, administered over 3 days) and then were randomized to receive primaquine (15 mg daily for 14 days) or no further treatment. All the patients were initially responsive to chloroquine, clearing their parasitaemias within 7 days, and there were no significant differences in the clinical or parasitological responses between those treated with primaquine and those given no further treatment. Plasmodium vivax parasitaemias re-appeared within 28 days of chloroquine treatment in just four patients. In each of these four cases, re-treatment with the same regimen of chloroquine resulted in eradication of the parasitaemia, with no further appearance of parasitaemia during the next, 28-day, follow-up period. These data indicate that virtually all acute (i.e. blood-stage) P. vivax infections acquired in Thailand can still be successfully treated with chloroquine.

Randomized dose-ranging study of the safety and efficacy of WR 238605 (Tafenoquine) in the prevention of relapse of Plasmodium vivax malaria in Thailand.

WR 238605 is an 8-aminoquinoline developed for the radical cure of Plasmodium vivax. Forty-four P. vivax-infected patients were randomly assigned to 1 of 4 treatment regimens: 3 groups received a blood schizonticidal dose of chloroquine followed by WR 238605: group A (n=15) received 300 mg daily for 7 days; group B (n=11), 500 mg daily for 3 days, repeated 1 week after the initial dose; group C (n=9), 1 dose of 500 mg. A fourth group (D; n=9) received chloroquine only. Among patients who completed 2-6 months of follow-up (n=23), there was 1 relapse in group B (day 120) and 1 in group C (day 112). Among patients treated with chloroquine only, there were 4 relapses (days 40, 43, 49, and 84). WR 238605 was safe, well tolerated, and effective in preventing P. vivax relapse.

Treatment of malarial acute renal failure by hemodialysis.

We studied 112 patients with malarial acute renal failure (ARF) during the period 1991-1997 at Bangkok Hospital for Tropical Diseases (Mahidol University, Bangkok, Thailand). Hemodialysis was performed in 101 (90.2%) of these patients. The mean number of times the patients were hemodialyzed was 6.5 (range = 1-27). Ninety-three (83.0%) patients were oliguric and the remainder were nonoliguric. Patients who had oliguric renal failure required more hemodialyses and had more complications than the nonoliguric patients. The oliguric patients had an eight-fold higher risk of requiring six or more hemodialyses (95% confidence interval = 1.2-53.9, P = 0.0008). The overall mortality rate was 10.7% (12 of 112). Eleven of the patients who died were jaundiced and eight of them had cerebral malaria with a Glasgow Coma Score < or = 8. We conclude that hemodialysis is a useful treatment for oliguric and nonoliguric ARF from severe malaria, particularly when initiated early in the course of the illness.

Cytokines associated with pathology in the brain tissue of fatal malaria.

Cytoadherence of Plasmodium falciparum-infected erythrocytes to the brain microvascular endothelial cells is believed to be an important cause of circulatory blockage in cerebral malaria. Cytokines released during acute infection may activate brain endothelial cells leading to increased binding of infected erythrocytes in the brain and reduced cerebral blood flow. This effect may be direct and more potent with the tissue-localized cytokines in the brain. In order to establish this relationship, brain tissues of cerebral and noncerebral malaria were compared. The most prominent histopathologic changes in the brain included edema, neuronal degeneration, ring hemorrhage, and percentage of parasitized erythrocytes sequestration were observed in cerebral malaria. Immunohistochemical staining of the brain sections demonstrated that tissue-localized TNF-alpha, IFN-gamma, IL-I1B, and IL-10 were associated with the histopathology. However, IL-4 was the only cytokine presented at moderate level in the brain tissue of noncerebral malaria which histopathology was the least. No tissue-localized cytokine was observed in the brain of P. vivax infection or of the car accident control cases.

Cytomegalovirus and Cryptosporidium infections in AIDS: a necropsy study.

A case of coinfection of cytomegalovirus (CMV) and Cryptosporidium in an AIDS patient is reported. Chronic diarrhea was the presenting symptom. Etiologic agents were diagnosed only at postmortem evaluation. CMV intranuclear inclusions were seen in the terminal ileum, colon and vermiform appendix. Cryptosporidium oocysts were also present in the intestinal brush border of the colon. Improvement of diagnostic procedures such as colonic biopsy and the use of appropriate staining procedure for AIDS patients with diarrhea can help identify the cause of illness.

Intracerebral hemorrhage due to nosocomial aspergillosis following neurosurgery.

A unique case of nosocomial aspergillosis following neurosurgery in a 10 year old girl was documented. She presented with intracerebral hemorrhage after three weeks of operation for evacuation of craniopharyngioma. To our knowledge, this is the first reported case of intracerebral hemorrhage due to nosocomial aspergillosis following neurosurgery.

Opportunistic protozoa in stool samples from HIV-infected patients.

A retrospective study of stool samples of HIV-infected patients from January 1994 to December 1995 submitted to the Department of Tropical Pathology was analyzed. There were twenty-two cases, all of which presented with chronic diarrhea. Result showed that 50% were infected with protozoa. These include Microsporidium (27.27%), Cryptosporidium (9.09%), Isospora belli (4.54%) and Giardia intestinalis cysts (9.09%). Other infections were Candida sp, Strongyloides stercoralis larva and Opisthorchis viverrini ova. The data stress the importance of opportunistic protozoa in the HIV-infected patients. Awareness of their existence of the diseases is important areas with increasing number of HIV-infected patients for early detection and proper treatment.