Update in Infectious Diseases

Neurological infection seems to be an important group of infectious disease. This group of disorders has become an important focus in neurology and general medicine. In Thailand, there are many interesting emerging and endemic neurological infections. In this specific chapter, the author will present details of some interesting clinical reports on important emerging and endemic neurological infection in Thailand.

Opisthorchis viverrini is an important trematode infection in the Northeastern Region of Thailand.Following a number of epidemiology studies and trial projects, the national liver fluke control program has been developed and operated under different National Public Health Development Plans. Presently, the program is being operated and focused on the northeastern provinces of Thailand. A survey in Non Sam Ran village, Borabue District, Mahasarakam Province where the high prevalence of opisthorchiasis was mentioned, was performed during October 1999. The setting was a village under the control program with annual praziquantel distribution. A brief survey of self-prevention behaviors towards intestinal parasite infection of the villagers was performed. Purposive sampling of 56 villagers from each available house in the village was performed. According to the questionnaires, all villagers admitted wearing shoes, avoiding eating raw food and using toilet. However, some (44.6 %) still disclosed using hand without washing before eating. In interest, most (89.3 %) replied self-prescribing antihelminthic drug to get rid of their own intestinal parasites. Furthermore, we also performed stool examination in all 56 sampled villagers (16.2 %). In interest, there was no case of opisthorchiasis. However, 7 cases (12.5 %) of Ascaris lumbricoides infection and 7 cases (12.5 %) of Entamoeba spp infection were detected. Comparing to other nearby setting without previous control program, low prevalence of trematode infection in our studied community is detected. However, the high prevalence of nematode and protozoa infections in this setting was still observed. Nevertheless, some poor hygienic practice such as using hands without washing before eating, due to the traditional belief are still detected.

An important problem at present is the contamination of drinking water. In this paper, the author will focus on the parasitic contamination in water and further implication on human health. The important parasites that are usually mentioned as major contaminants will be briefly reviewed. In addition to water contamination, soil contamination is another important problem. Basically, soil contamination with pathogenic parasite is a big public health problem in tropical developing countries. Diseases transmitted by soil are common in many tropical areas, including Thailand. In this article, the author summarized the prevalence of soil contamination with pathogenic parasite in Thailand. According to analysis, overall prevalence of contamination is equal to 7.8 %. There is no significant correlation between setting and prevalence.

Enterobius vermicularis is an important helminthic infection among children in rural areas of developing countries. In our previous reports, a high prevalence of enterobiasis among the children in the far rural community, Mae Suk, Northern Thailand was noted. An active control program for enterobiasis in our community is set and distribution of antihelminthic drugs and a longitudinal follow-up to assess the effectiveness of our control program was performed. Here, the author reports a dramatic decrease of the prevalence of enterobiasis in this rural area.

Conjunctivitis is an infectious disease of the eye which is very common in Thailand. The disease can spread widely and especially during the rainy season in Thailand. The authors performed a literature review on the reports of Conjunctivitis outbreak in Thailand in order to summarize the outbreak information. A literature review of the papers concerning Conjunctivitis outbreak in Thailand was performed using the database of published works cited in the Index Medicus and Science Citation index. The literature review focused mainly on all conjunctivitis outbreaks that have been published. The reported location of the outbreak in the literature usually occurred in central Thailand mostly in the capital city, Bangkok. Some outbreaks can be found in other parts of Thailand such as the Northeastern Thailand. The time of outbreak is usually around August which is around the rainy season in Thailand. There is no significant difference of the infection between male and female. The calculated overall mean age of patients is 16 years which is the school age. Conjunctivitis is a common eye infection caused by many kinds of organisms which is highly contagious and is able to spread just by contact. The disease is not severe and can be treated by topical antibiotics. However it is much wise to keep the infection from spreading by keeping the patients away from social for about a week.

Background: Bird flu or avian flu, caused by H5N1 virus, is a new emerging infectious disease. It is noted that this H5N1 virus jumped the species barrier and caused severe disease with high mortality in humans in Vietnam and Thailand. Many were reported noted on nucleotide for HA of H5N1 in Thailand. However, there is no comparison on the structure of the protein encoded by the isolated HA in Thailand.

Method: Here, the author performed this study to compare the secondary and tertiary structures of the isolated HA from different sources in Thailand. The author used a bioinformatic technique to predict the secondary and tertiary structures of HA of H5N1 isolated in Thailand.

Result: Using NNPREDICT and CPHmodels 2.0 servers, the calculation for secondary and tertiary structures of H5N1 of HA isolated in Thailand was performed. The predicted structures of all 20 HA are same.

Conclusion: The structures of H5N1 derived from natural and non-natural hosts of virus are same. This implies that the mutation might not be the important factor leading to the cross species infection in Thailand but the individual defect of non-avian host might be the possible factor.

Legionella is important human pathogen.The surveillance for legionella in water reservoir is suggested. Contamination by legionella in natural hot springs may pose a significant health risk to people who use such water for recreation activities.The aim of this work is to summarize the pattern on legionella contamination in hot spring pools in Thailand. According to the search, there are 13 on radon in 83 hot spring pools in Thailand (December 2007). The number of hot springs with legionella contamination is equal to 48 (57.8 %). In addition to legionella, situation on free living amoeba in hot spring pools in Thailand is also presented in this article.

Dengue infection is a major vector-borne disease. The classical sings and symptoms of this infection include high fever, violent headache, chill and rash. However, there are a number of atypical forms of dengue infection including those presented with severe liver dysfunction. Sporadic case reports of dengue hepatic encephalopathy are documented in Thailand. Here, the author presents a summative study on the clinical presentation and outcome among Thai patients with dengue encephalopathy in the previous studies. A literature review on the prospective studies concerning dengue hepatic encephalopathy in Thailand was performed. According to this study, 4 reports covering 19 cases (12 females and 7 males) of dengue encephalopathy among the Thai can be detected. The summative on clinical presentation of all patients are presented in Table 1. The average age (mean ± SD) of all subjects is 8.0 ± 3.0 (range = 2-13 years old). Classified by grade on dengue infection, there are 14 grade IV, 4 grade III and 1 grade II. Most of the hepatic encephalopathy occur in convalescent stage (14 cases, 73.7 %). Concerning the depth of hepatic encephalopathy, there are 8 level IV, 6 level III, 4 level II and 1 level I. Of 16 known cases, the duration of encephalopathy ranges from 0.8 to 26 days (average 8.2 ± 6.6 days). Of 15 known cases, the liver span ranges from 2 to 6 cm (average 3.7 ± 1.2 cm). Concerning the laboratory investigation, severe hepatitis (SGOT and SGPT > 200 U/L) can be seen in all cases. Hypoglycemia and hyponatremia can be detected in 6 and 5 cases, respectively. Most of the cases (15 cases, 78.9 %) received conventional treatment and most (12 cases, 63.2 %) recovered completely.

An important parasitic infection among HIV infected patients is the cryptosporidiosis. Cryptosporidium parvum is an intestinal parasitic protozoon that causes severe diarrhea and may lead to death in immunocompromised hosts. In HIV infected cases with cryptosporidiasis, four main clinical syndromes were identified: chronic diarrhea, choleralike disease, transient diarrhea, and relapsing illness. In this paper, the authors presented the prevalence of cryptosporidiosis among Thai HIV-infected patients with diarrhea in comparison to the previous noted prevalence in the past decade. The prevalence of among Thai HIV infected patients with diarrhea in the previous decade is equal to 7.14 %. The present prevalence of among Thai HIV infected patients with diarrhea is investigated with the same protocol. Overall 25 HIV infected cases could be detected giving the prevalence equal to 18.95 % (25/193). Of interest, although the HAART therapy is easily available in Thailand, at present the prevalence of cryptosporidiosis is still very high in the HIV seropositive patients with diarrhea. Therefore, the authors hereby propose that the wide distribution of HAART therapy did not affect the prevalence of cyrptosporidiosis among HIV seropositive patients with diarrhea.

CONTEXT: Capillaria phillipinensis infection is a round worm infection. Capillaria phillipinensis is considered a zoonotic disease of migratory fish-eating birds.

OBJECTIVE: Here, the author performed a literature review on the reports of C. philippinensis in Thailand in order to summarize the characteristics of this infection among the Thai patients.

DESIGN: This study was designed as a descriptive retrospective study. A literature review of the papers concerning C. philippinensis infections in Thailand was performed.

RESULTS: Due to this study, there have been at least 8 reports of C. philippinensis infection, of which 1 case was lethal (Table 1). There are at least 12 Thai cases with C. philippinensis infections. The age ranges from 13 to 58 years. Of seven well-documented cases, 5 were males and 2 were females. Most (10/12) cases were detected from stool examination: One was detected by Gastroduodenoscopy: The other case (1/12) was detected after the patient died.

CONCLUSION: In conclusion, C. philippinensis infection is sporadically noted in Thailand. The diagnosis is usually by stool examination. The survival rate of these infections is high if the diagnosis is correct and is quite low if the diagnosis is too late. The treatment of this infection is an antiparasitic drug such as mebendazole and albendazole.

Zygomycosis is a rare fungal infection. It is noted sporadically throughout the world. In Thailand, this illness has been noted since 1978. We hereby present a retrospective study concerning the previous literatures regarding Zygomycosis in Thailand. According to this study, 27 cases of Zygomycosis of 15 literatures were studied retrospectively. Of these 27 cases, 16 were females and 11 were males. The average age was 38.5 + 18.1 years. In this study, 23 patients (85.2%) were infected with Mucorales and 4 patients were infected with Entomophthorales. Of the 23 cases with Mucorales infections, 16 patients (59.2%) were rhinocerebral, 3 patients (11.1%) were pulmonary, 3 patients (11.1%) were cutaneous and 1 patient (3.7%) was gastrointestinal. Of these 23 patients, 52.2% had DM, 17.4% had CRF, 17.4% had the history of non-steroid immunosuppressive drug use, 4.3% had the history of steroid use and 4.3% had prolonged antibiotic drug use. Of 13 Mucorales-the cases infected with adequate data for further analysis, 9 (69.2%) died. Concerning the left 4 patients (14.8%) with Entomophthorales infecions all had subcutaneous zygomycosis. None of these 4 cases died. In conclusion, the zygomycosis in Thai patients is similar to the prior reports. Nevertheless, However, we find a trend of female adult premodinance of infection.

Hepatitis virus infection is an important infection in medicine. There are many hepatitis viruses. There are many new researches on molecular biology aspect of hepatitis viruses. The author hereby presents some new example on epitope preference in wild and mutated precore of hepatitis B virus, weak linkage in HGV 5' non-coding region and transmembrane topology of hepatitis B envelope proteins.