Cutaneous manifestations in HIV positive patients.

Cutaneous manifestations are common clinical findings among HIV positive patients. The causes may be bacteria, viruses, fungi and other non-infectious agents. This study was conducted at the Pramongkutklao Hospital skin clinic to determine the frequency distribution of cutaneous manifestations in HIV positive patients. A total of 147 patients with HIV seropositivity were recruited and divided into a retrospective group and a prospective study group. For the retrospective study, hospital records of 129 patients who attended from January 1995 to November 1998 were recruited. The prospective study was carried out from November 1998 to January 1999 and 18 patients were recruited. Cutaneous finding among patients in the two studies were evaluated. There were ten common cutaneous manifestations observed in the retrospective and prospective study including pruritic papular eruptions (PPE) (51.2%, 50%), oral candidiasis (16.7%, 21.7%), herpes zoster (10.9%, 5.6%), oral hairy leukoplakia (10%, 5.6%), unclassified eczema (9%, 11.1%), urticaria (5.6%, 3.1%), seborrheic dermatitis (4.7%, 16.7%), folliculitis (4.7%, 5.6%), prurigo simplex (4.7%, 5.6%), and Steven-Johnson syndrome (3.9%, 0%). However, the distribution of cutaneous manifestations in the two studies were not significantly different. These findings may be useful as baseline data for common cutaneous manifestations in HIV positive patients.

Prevalence of cytomegalovirus antibodies among various age groups of Thai population.

The prevalence of CMV antibody in various groups of Thai population was studied. Pregnant women and young children had been infected with CMV more than the other studied groups. Children of both sex had equal chance of getting CMV infection while the risk of CMV infection in adult between male and female was significantly difference (p < 0.001). Pregnant women had higher chance to get CMV infection than normal women. Prevalence of CMV antibody at present was similar to previous studies.

Simplified, rapid diagnosis of respiratory syncytial virus from clinical specimens.

DOT ELISA was compared with RT-PCR and tissue culture to detect RSV from nasopharyngeal aspirates. DOT ELISA had diagnostic sensitivity and specificity of 65.62% and 93.92%, respectively. The results indicate that DOT ELISA can be used for screening detection of RSV from clinical specimens and is suitable for small laboratories in the provincial areas of developing countries.

Monoclonal antibody-based dot-blot ELISA for the detection of Salmonella in foods.

Monoclonal antibody (MAb) produced to polysaccharides in the LPS molecule of salmonellae was used in a dot-blot ELISA for detecting Salmonella in 873 food samples, ie 100 fresh chicken, 261 frozen chicken, 78 pork, 84 beef, 100 hen eggs, 100 duck eggs, 50 sea-mussels, 50 shrimps and 50 squids in comparison with the conventional culture method. Salmonella culture from foods involved the following steps: pre-enrichment, enrichment in selective medium, isolation on selective and indicator media, followed by biochemical and serological identification of appropriate colonies, respectively. The whole culture procedure took 5 days. Food samples from the selective enrichment medium were also subjected to the MAb-based dot-blot ELISA. The whole procedure of dot-blot ELISA took less than 2 hours. Among 873 food samples, salmonellae could be recovered from 7.4% of the samples by the bacterial isolation method (16% of fresh chicken, 8.8% of frozen chicken, 24.4% of pork, 3.6% of beef and 2% each of hen eggs and duck eggs, respectively). Salmonella derby were predominant among pork samples while S.paratyphi B biovar java predominated in chicken. The MAb-based dot-blot ELISA were positive in 19.5% of the food samples, i.e. 30% of fresh chicken, 27.6% of frozen chicken, 34.6% of pork, 21.4% of beef, 20% of shrimp, 16% of sea-mussels, 2% of hen eggs and 4% of duck eggs. The sensitivity and specificity of the MAb-based dot-blot ELISA compared to the bacterial culture method were 81.5% and 85%, respectively. The discrepancy of the data between the culture method and the dot-blot ELISA might be due to the fact that the culture method could detect only living cells at numbers that gave at least one isolated colony on the selective/differential plate while the dot-blot ELISA detects any form of Salmonella antigen. The monoclonal antibody-based dot-blot ELISA offers several advantages over the conventional bacterial culture method when it is used for screening of Salmonella contamination in foods, especially export foods. These include rapidity, cost-effectiveness and simplicity (the dot-blot ELISA does not need highly trained personnel or equipment, in contrast to the culture method). The test can be performed in field conditions and the result can be read visually. It also offers multisample analysis at one time which renders more samples of food for screening possible, thus false negative results are fewer which, in turn, assures the quality of the export food in a cost-saving, short time frame.

Albendazole stimulates outward migration of Gnathostoma spinigerum to the dermis in man.

Human gnathostomiasis is characterized by space-occupying inflammatory lesions and/or hemorrhage as a result of the migration of, very often, a single larva of Gnathostoma spinigerum. Intermittent cutaneous migratory swellings occurring over years is the most common manifestation and the rare cerebral invasion may be fatal. There are currently no effective anthelminthics for this infection. During a double-blind randomized placebo control trial evaluating the efficacy of albendazole in cutaneous gnathostomiasis at a dosage of 400 mg twice daily for two weeks, it was observed that gnathostome larvae tended to migrate outward as a result of the treatment so that they could be recovered by excisional biopsy or by picking with a needle. In the placebo-treated group (N = 40), no such migration was observed during the 8,470 patient-days of follow-up while in the albendazole-treated group (N = 41) there was one worm in an excisional biopsy done on day 16 and two worms were removed from the skin by the patients themselves on days 8 and 0. Assuming that the period of drug exposure of the gnathostomes was the 14 days of albendazole administration plus another washout period of 7 days (equivalent to 20 half-lives of the active detectable metabolite), the total patient-days of albendazole exposure was 830. The rate of outward migration of gnathostomes in the drug treated group (3 per 830 patient-days) was significantly (p < 0.0001) higher than in the placebo group (0 per 8,470 patient-days).(ABSTRACT TRUNCATED AT 250 WORDS)

Gnathostoma larva migrans among guests of a New Year party.

An outbreak of Gnathostoma larva migrans occurred among guests of a New Year's party in Chachoengsao, Thailand. Nine people who consumed a raw fish dish called 'Hu-sae' contracted the disease. Five of them developed gastro-intestinal symptoms consisting of nausea, vomiting, abdominal cramps and diarrhea as early as within the first 24 hours, while in the other four, symptoms started on the following day. After the initial symptoms pertaining to the gut, malaise, chest discomfort, cough, myalgia, weakness, itching and migratory swellings were experienced. Eosinophilia was demonstrated in every patient with a mean (+/- SE) count of 5,516 +/- 1,010 cells/cu mm. Detection of antibody against aqueous extracts of G. spinigerum adult antigen using an enzyme-linked immunosorbent assay showed a titer of 1:1,600 or greater in every patients except one who had a titer of 1:400 (positive greater than or equal to 1:400). This outbreak illustrates the high attack rate when heavily infected fish are consumed.

Immune responses following killed whole vibrio-B subunit oral cholera vaccine in human volunteers.

Immunogenicity of killed whole vibrio and B subunit oral cholera vaccines in American and Thai volunteers were analysed in terms of significant rise of antibody titre. Three doses of 2 x 10(11) killed vibrios and 5 mg of cholera toxin B subunit were given at two-week intervals. There were no differences in the percent of volunteers with significant rise of serum immunoglobulin G and secretory immunoglobulin A (sIgA) to cholera toxin. However, the percent with significant rises of serum antibody to whole cell V. cholerae Inaba measured by vibriocidal titre and serum immunoglobulin G, and secretory immunoglobulin A to lipopolysaccharide (LPS) measured by ELISA in American volunteers were significantly different from those in Thai volunteers (89% VS 45%, 68% VS 9% and 53% VS 0%, respectively) (p less than 0.05).

Adherence of human eosinophils to infective filariform larvae of Necator americanus in vitro.

Eosinophilia is common in hookworm infection but the interaction between eosinophils and the larval stage of the parasite is poorly understood. The present study was conducted to test the ability of the eosinophils to adhere to infective filariform larvae of Necator americanus in vitro. Adherence of eosinophils to the larvae was found to be serum dependent. Antibody facilitated eosinophil adherence but this was maximal in the presence of complement. The adherence was greatly diminished by EGTA treated normal human serum (NHS) and was completely abolished when NHS was treated with either EDTA or heat-inactivation, suggesting that the process can be facilitated through complement activation via the alternative pathway. As with other nematodes, the surface of hookworm larvae appeared to be both antigenic and complement-activating. Although it is not known whether eosinophil adherence has any larvicidal effect, the present study demonstrated for the first time a definite interaction between human eosinophils and hookworm filariform larvae.

Hepatitis B problem in Thailand.

HBV infection is hyperendemic in Thailand. Approximately 5 million Thais are chronic HBV carriers. The prevalence of HBV markers in general population varies from 40-60%. Approximately 10-20% of children between the ages 1-5 years have serologic evidence of HBV infection and this prevalence increases with age reaching a plateau of 40-60% by age 20. High risk groups are household contacts of HBsAg carriers and babies born to HBsAg positive mothers. Approximately 75% of the babies born to HBsAg & HBeAg positive mothers become HBsAg positive at 3 months after birth. A few studies showed that the HBV prevalence of hospital personnel and other high risk groups is similar to that of the general population. The prevalence of chronic HBsAg carrier varies from 5-10% and is highest among age groups 10-30 years. Primary hepatocellular carcinoma (PHC) is the first and third most common cancer among Thai males and females, respectively. Approximately 35%-75% of PHC in adults are HBsAg positive. Histological studies showed that 47.3% of cryptogenic cirrhosis, 58%-66% of PHC and 35%-85% of cryptogenic cirrhosis with PHC were HBsAg positive. Studies on Hepatitis B immune globulin and Hepatitis B vaccine revealed a 70% and 56%, respectively, reduction in the HBsAg prevalence of infants born to HBsAg and HBeAg positive mothers. More epidemiologic, clinical and laboratory studies on HBV infection are being carried out by groups of scientists and investigators in the Ministry of Public Health and many medical schools. A national committee has been appointed to plan strategy for controlling HBV.

ELISA for immunodiagnosis of human gnathostomiasis.

An ELISA for immunodiagnosis of human gnathostomiasis using a crude water extract of third-stage larvae of G. spinigerum as antigen, and alkaline phosphatase labelled goat antihuman IgG in the indicator system was developed and evaluated. At the titre of 1:400 and above positive results were observed in 100% of 4 parasitological confirmed and 10 eosinophilic meningo-encephalitis (EME) typical of gnathostomiasis cases, 56% of 160 cutaneous migratory swelling cases, 33% of 24 cases with EME typical of A. cantonensis infections, 23% of 92 cases with other parasitic infections and 1.5% of blood donors. The overall sensitivity was 59% and specificity 84%. The predictive value was 77%. The results indicated that ELISA is potentially useful for immunodiagnosis of gnathostomiasis but improvement of sensitivity and specificity is needed.

Studies on the chemotherapy of human opisthorchiasis: II. Clinical trial of niclofolan.

A clinical trial of Niclofolan on human opisthorchiasis was carried out in 60 patients admitted to the Hospital for Tropical Diseases. Two dosage regimen, 2 mg and 3 mg per kg body weight repeated after a 72 hour interval was administered to 31 and 4 patients respectively. Comparative evaluation with the placebo group of 25 patients was made by the Stoll count on day 20, 40 and 60 after treatment. On day 60 percentage egg reduction of the treated and the placebo groups were similar. Mild and transient side effects such as nausea, anorexia, myalgia and arthralgia were recorded in all 3 groups but more severe in the higher dosage group. In this study, Niclofolan failed in reducing the egg production of Opisthorchis viverrini.

Clinical trial of flubendazole on hookworm, Trichuris trichiura and Ascaris lumbricoides infections.

Flubendazole, a parafluoro analoque of mebendazole, was given to 89 service men with hookworm, Trichuris trichiura and Ascaris lumbricoides infections. The drug was given either as two doses of 300 mg at 12 hour interval (regimen A) or as two doses of 300 mg at 24 hour interval (regimen B). At four weeks follow-up the mean percentage egg reduction for hookworm was 88% and 96% in regimen A and B respectively. There were too few cases of Trichuris and Ascaris infection to allow comparison of the two regimens, but flubendazole appeared to be as effective and the single day regimen more convenient than difetasone for trichuriasis and levamisole for ascariasis. Side effects were few, mild and transient.