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Time course of inhibition of return in a spatial cueing paradigm with distractors

Eng V, Lim A, Janssen SMJ, Satel J

Acta Psychol (Amst), 2018 Feb;183:51-57.
PMID: 29328938 DOI: 10.1016/j.actpsy.2017.12.011

Studies of endogenous and exogenous attentional orienting in spatial cueing paradigms have been used to investigate inhibition of return, a behavioral phenomenon characterized by delayed reaction time in response to recently attended locations. When eye movements are suppressed, attention is covertly oriented to central or peripheral stimuli. Overt orienting, on the other hand, requires explicit eye movements to the stimuli. The present study examined the time course of slowed reaction times to previously attended locations when distractors are introduced into overt and covert orienting tasks. In a series of experiments, manual responses were required to targets following central and peripheral cues at three different cue-target intervals, with and without activated oculomotor systems. The results demonstrate that, when eye movements are suppressed, behavioral inhibition is reduced or delayed in magnitude by the presence of a distractor relative to conditions without distractors. However, the time course of behavioral inhibition when eye movements are required remains similar with or without distractors.
Fulltext Synthesis, Characterization, Adsorption Isotherm, and Kinetic Study of Oil Palm Trunk-Derived Activated Carbon for Tannin Removal from Aqueous Solution

Lim A, Chew JJ, Ngu LH, Ismadji S, Khaerudini DS, Sunarso J

ACS Omega, 2020 Nov 10;5(44):28673-28683.
PMID: 33195920 DOI: 10.1021/acsomega.0c03811

Oil palm trunk (OPT) represents one of the five main oil palm biomass wastes with high carbon content that can be economically converted to a large surface area, porous activated carbon (AC) adsorbent to treat palm oil mill effluent wastewater in Indonesia and Malaysia. In the first portion of this work, the design of the experiment was used to determine the optimum set of synthesis parameters required to maximize the iodine number of AC [i.e., Brunauer-Emmett-Teller (BET) specific surface area indicator] prepared from OPT via chemical activation route using H3PO4. The iodine numbers of AC and AC yield were probed as the impregnation ratio, the activation time, and the activation temperature were varied in the range of 0.28-3.47, 5.68-69.32 min, and 379-521 °C, respectively. An impregnation ratio of 2.29, an activation time of 6 min, and an activation temperature of 450 °C were identified as the optimum set of synthesis parameters. In the second portion of the work, the AC synthesized using the optimum parameters were then characterized and tested as an adsorbent for tannin. N2 sorption results revealed that the AC exhibits type IV isotherm, that is, contains micropores and mesopores and displays a relatively high BET specific surface area of 1657 m2 g-1. Adsorption equilibria isotherms for tannin adsorption onto the AC were collected at three different pH of 2, 4, and 6 and were nonlinearly fitted using Langmuir and Freundlich isotherm models, where the Langmuir isotherm gave better fitting than Freundlich. The higher adsorption capacity at lower pH can be explained in terms of the absence of electrostatic repulsion interaction between the AC surface and the tannic acid species as suggested by the point of zero charges (pHpzc) of 4.8 and an increasing ionization of tannic acid with pH rise between 4 and 7. Adsorption kinetics data were also obtained at four different pH of 2, 4, 6, and 8 where the nonlinear pseudo-first-order model best fitted the kinetic at pH of 2 and the nonlinear pseudo-second-order model represented the kinetic best at the remaining higher pH, which suggests that tannin adsorption onto AC occurred by physisorption at pH of 2 and by chemisorption at pH of 4, 6, and 8.
Stimulus-response incompatibility eliminates inhibitory cueing effects with saccadic but not manual responses

Eng V, Lim A, Kwon S, Gan SR, Jamaluddin SA, Janssen SMJ, et al.

Atten Percept Psychophys, 2017 May;79(4):1097-1106.
PMID: 28229429 DOI: 10.3758/s13414-017-1295-8

There are thought to be two forms of inhibition of return (IOR) depending on whether the oculomotor system is activated or suppressed. When saccades are allowed, output-based IOR is generated, whereas input-based IOR arises when saccades are prohibited. In a series of 4 experiments, we mixed or blocked compatible and incompatible trials with saccadic or manual responses to investigate whether cueing effects would follow the same pattern as those observed with more traditional peripheral onsets and central arrows. In all experiments, an uninformative cue was displayed, followed by a cue-back stimulus that was either red or green, indicating whether a compatible or incompatible response was required. The results showed that IOR was indeed observed for compatible responses in all tasks, whereas IOR was eliminated for incompatible trials-but only with saccadic responses. These findings indicate that the dissociation between input- and output-based forms of IOR depends on more than just oculomotor activation, providing further support for the existence of an inhibitory cueing effect that is distinct to the manual response modality.
Sound production in the tiger-tail seahorse Hippocampus comes: Insights into the sound producing mechanisms

Lim AC, Chong VC, Chew WX, Muniandy SV, Wong CS, Ong ZC

J Acoust Soc Am, 2015 Jul;138(1):404-12.
PMID: 26233039 DOI: 10.1121/1.4923153

Acoustic signals of the tiger-tail seahorse (Hippocampus comes) during feeding were studied using wavelet transform analysis. The seahorse "click" appears to be a compounded sound, comprising three acoustic components that likely come from two sound producing mechanisms. The click sound begins with a low-frequency precursor signal, followed by a sudden high-frequency spike that decays quickly, and a final, low-frequency sinusoidal component. The first two components can, respectively, be traced to the sliding movement and forceful knock between the supraorbital bone and coronet bone of the cranium, while the third one (purr) although appearing to be initiated here is produced elsewhere. The seahorse also produces a growling sound when under duress. Growling is accompanied by the highest recorded vibration at the cheek indicating another sound producing mechanism here. The purr has the same low frequency as the growl; both are likely produced by the same structural mechanism. However, growl and purr are triggered and produced under different conditions, suggesting that such "vocalization" may have significance in communication between seahorses.
Fulltext Sharing a microbe with man's best friend: A case of canine streptococcal infection in a diabetic patient

Cheong BM, Lim AY

Med J Malaysia, 2015 Oct;70(5):318-9.
PMID: 26556125

We report a case of a diabetic patient with an infected leg wound leading to septicemia and abscess formation in the contra-lateral leg due to Streptococcus canis. This organism belongs to the Lancefield group G and is more commonly found in dogs. It is often mistaken for Streptococcus dysgalactiae which is a human strain of streptococci. Infections in humans are not common and usually involve infected wounds or ulcers and the surrounding soft tissue. In most reported cases, patients had close contact with domestic dogs and a pre-existing wound as a portal of entry. Our patient recovered after surgical debridement and drainage of abscess together with antibiotics. This organism is sensitive to common antibiotics like penicillin, amoxycillin, cephalosporins and erythromycin. The incidence of infections due to Streptococcus canis may be under-reported as laboratories may just report an isolate as group G streptococcus. Susceptible patients with wounds or ulcers should be counselled on proper wound care and advised to avoid or minimise contact with the family dog.
Study site: Hospital Raja Permaisuri Bainun, Ipoh, Perak
Sensory adaptation and inhibition of return: dissociating multiple inhibitory cueing effects

Lim A, Eng V, Janssen SMJ, Satel J

Exp Brain Res, 2018 05;236(5):1369-1382.
PMID: 29520444 DOI: 10.1007/s00221-018-5225-3

Inhibition of return (IOR) refers to an increase in reaction times to targets that appeared at a previously cued location relative to an uncued location, often investigated using a spatial cueing paradigm. Despite numerous studies that have examined many aspects of IOR, the neurophysiological mechanisms underlying IOR are still in dispute. The objective of the current research is to investigate the plausible mechanisms by manipulating the cue and target types between central and peripheral stimuli in a traditional cue-target paradigm with saccadic responses to targets. In peripheral-cueing conditions, we observed inhibitory cueing effects across all cue-target onset asynchronies (CTOAs) with peripheral targets, but IOR was smaller and arose later with central targets. No inhibition was observed in central-cueing conditions at any CTOAs. Empirical data were simulated using a two-dimensional dynamic neural field model. Our results and simulations support previous work demonstrating that, at short CTOAs, behavioral inhibition is only observed with repeated stimulation-an effect of sensory adaptation. With longer CTOAs, IOR is observed regardless of target type when peripheral cueing is used. Our findings suggest that behaviorally exhibited inhibitory cueing effects can be attributed to multiple mechanisms, including both attenuation of visual stimulation and local inhibition in the superior colliculus.
Fulltext Response Priming with Horizontally and Vertically Moving Primes: A Comparison of German, Malaysian, and Japanese Subjects

Bermeitinger C, Kalbfleisch L, Schäfer K, Lim A, Goymann H, Reuter L, et al.

Adv Cogn Psychol, 2020;16(2):131-149.
PMID: 32665804 DOI: 10.5709/acp-0291-y

Response priming refers to the finding that a prime preceding a target influences the response to the target. With German subjects, horizontally moving dots as primes, and static arrows as targets, there are typically faster responses to compatible (i.e., prime and target are associated with the same response) as compared to incompatible targets (i.e., positive compatibility effect, PCE) with short stimulus onset asynchronies (SOAs). In contrast, with longer SOAs, subjects respond faster to incompatible as compared to compatible targets (i.e., negative compatibility effect, NCE). In the present study, we extended the evidence by adding vertically oriented materials. Furthermore, we tested subjects from Malaysia and Japan, where the vertical orientation is more present in daily life, and compared them to German subjects to investigate whether the amount of experience with one orientation influences the compatibility effects on this orientation. Overall, we found pronounced PCEs in the short SOA (i.e., 150 ms) but only reduced PCEs in the longer SOAs (i.e., 350, 550, and 750 ms) across all countries and orientations. There were no differences between the German and Malaysian samples, but the Japanese sample showed larger PCEs in the longer SOAs compared to both other samples. Furthermore, we found larger PCEs for horizontal than vertical materials in the short SOA and larger PCEs for vertical than horizontal materials in the longer SOAs. We discuss our findings in light of theories and findings on compatibility effects as well as attentional mechanisms.
Replicating remembering "remembering"

Janssen SMJ, Anthony K, Chang CYM, Choong EL, Neoh JY, Lim A

Memory, 2020 Dec 31.
PMID: 33382346 DOI: 10.1080/09658211.2020.1868525

When examining spontaneously recovered memories of childhood sexual abuse, victims report that there had been periods in which they had forgotten the abuse. However, there are sometimes people with whom the victim had spoken about the abuse during the period in which the victim had supposedly forgotten the abuse, suggesting the victim had not forgotten the abuse but the prior recall of the abuse. The underestimation of previous knowledge is termed the forgot-it-all-along effect. The goal of the present study was replicating the results of a laboratory study that had provided a theoretical understanding for the forgot-it-all-along effect by showing that people have difficulties remembering "remembering" when the memory had previously been recalled in a different context. The effect was replicated by using the same neutral context sentences, suggesting the finding was robust. We also extended the experimental design by using positive and negative context sentences, but it did not become smaller when the positive sentences provided the different context or larger when the negative sentences provided the different context. Although the sample sizes were sufficiently large to provide statistical power for the forgot-it-all-along effect, they may not have been sufficiently large to observe the moderation effects of emotional context.
Fulltext Rationale and protocol paper for the Asia Pacific Network for inherited eye diseases

Wong WM, Tham YC, Simunovic MP, Chen FK, Luu CD, Chen H, et al.

Asia Pac J Ophthalmol (Phila), 2024;13(1):100030.
PMID: 38233300 DOI: 10.1016/j.apjo.2023.100030

PURPOSE: There are major gaps in our knowledge of hereditary ocular conditions in the Asia-Pacific population, which comprises approximately 60% of the world's population. Therefore, a concerted regional effort is urgently needed to close this critical knowledge gap and apply precision medicine technology to improve the quality of lives of these patients in the Asia-Pacific region.
DESIGN: Multi-national, multi-center collaborative network.
METHODS: The Research Standing Committee of the Asia-Pacific Academy of Ophthalmology and the Asia-Pacific Society of Eye Genetics fostered this research collaboration, which brings together renowned institutions and experts for inherited eye diseases in the Asia-Pacific region. The immediate priority of the network will be inherited retinal diseases (IRDs), where there is a lack of detailed characterization of these conditions and in the number of established registries.
RESULTS: The network comprises 55 members from 35 centers, spanning 12 countries and regions, including Australia, China, India, Indonesia, Japan, South Korea, Malaysia, Nepal, Philippines, Singapore, Taiwan, and Thailand. The steering committee comprises ophthalmologists with experience in consortia for eye diseases in the Asia-Pacific region, leading ophthalmologists and vision scientists in the field of IRDs internationally, and ophthalmic geneticists.
CONCLUSIONS: The Asia Pacific Inherited Eye Disease (APIED) network aims to (1) improve genotyping capabilities and expertise to increase early and accurate genetic diagnosis of IRDs, (2) harmonise deep phenotyping practices and utilization of ontological terms, and (3) establish high-quality, multi-user, federated disease registries that will facilitate patient care, genetic counseling, and research of IRDs regionally and internationally.
Fulltext Proximal third femoral shaft fractures in children: prevention of angular deformities using bilateral Thomas splints

Kamal MH, Razak M, Ibrahim S, Lim A

Med J Malaysia, 2000 Sep;55 Suppl C:68-73.
PMID: 11200047

This is a prospective study to look at the outcome of unilateral proximal third femoral shaft fractures in children treated with a bilateral Thomas splint in the Department of Orthopaedic Surgery Universiti Kebangsaan Malaysia between the period of January 1996 and June 1998. Eighteen children aged between 2 years and 12 years old with unilateral proximal third fractures of the femoral shaft were treated using a bilateral Thomas splint. Angular deformities were measured using a goniometer metric scale before and after Thomas splints. The percentage of varus tilt corrected ranged from 17% to 72% with an average correction of 29% from the initial deformity and the difference was statistically significant (p < 0.05). The percentage of posterior tilt corrected ranged from 19% to 60% with the average correction of 20% from the initial deformity. The difference was statistically significant (p < 0.05). From this study, we conclude that bilateral Thomas splints can give a better correction of angular deformity for proximal third femoral shaft fractures in children below twelve years of age.
Proportions of circulating T cells with a regulatory cell phenotype increase with HIV-associated immune activation and remain high on antiretroviral therapy

Lim A, Tan D, Price P, Kamarulzaman A, Tan HY, James I, et al.

AIDS, 2007 Jul 31;21(12):1525-34.
PMID: 17630546

To examine the relationships between blood CD4 natural regulatory T (Treg) cells, plasma HIV RNA level, CD4 T-cell count and immune activation in untreated HIV-infected patients and immunodeficient patients beginning antiretroviral therapy (ART), using a novel phenotype to define Treg cells (CD25CD127CD4). Data were compared with established Treg cell markers (FoxP3, CTLA-4 and GITR).
Fulltext Post-treatment impact and needs of prostate cancer survivors in Malaysia; a qualitative study

Lee PY, Ng CJ, Ong TA, Lee YK, Khatijah Lim A, Cheong AT, et al.

Malays Fam Physician, 2017;12(3):18-24.
PMID: 29527275 MyJurnal

Introduction: There are limited studies conducted on the needs of cancer survivors in developing countries like Malaysia. This qualitative study aimed at exploring the post-treatment impact and needs of prostate cancer survivors.

Methods: A qualitative study design was used. One in-depth interview and four focus group discussions were conducted with 24 prostate cancer survivors (age range: 58-79 years) from government and private hospitals in Malaysia in 2013. Trained researchers used a topic guide to guide the interviews, which were audio-recorded, transcribed verbatim, checked and managed with Nvivo 10 software. A thematic approach was used to analyse the data.

Results: Three main themes emerged from the analysis: (a) impact of prostate cancer on the survivors, (b) support needed for coping and (c) information needs. Prostate cancer has an important impact on the survivors' lifestyle after treatment. Some of them have to live with the post-treatment side effects. They were anxious about the possibility of relapse. In addition to family and peer support, there were participants who felt that spiritual support was important in helping them cope with the possibility of relapse. The survivors felt that they did not receive enough information about post-treatment care, dietary measures and supplements for relapse prevention, treatment and prognosis.

Conclusion: Prostate cancer has a significant impact on the survivor's lifestyle, emotional and physical health. They need information and emotional support from the healthcare professionals, family and peers. Therefore, it is important for healthcare providers to explore the needs of prostate cancer survivors and provide the necessary support.
Post-traumatic arachnoiditis: an unusual cause of Brown-Sequard syndrome

Ramli N, Merican AM, Lim A, Kumar G

Eur Radiol, 2001;11(10):2011-4.
PMID: 11702136

Brown-Sequard syndrome (BSS) is a unilateral cord injury characterised by an ipsilateral motor deficit with contralateral pain and temperature hypoaesthesia. Although there are a variety of causes, the majority of cases are generally of neoplastic origin or are traumatic in origin. We describe a rare cause of Brown-Sequard syndrome as a result of post-traumatic arachnoiditis. Magnetic resonance imaging with the use of thin-slice high-resolution constructive interference in steady state (CISS) and T2-weighted spin-echo sequence were used to demonstrate the cause and appearance of the lesion in the spinal canal and was useful in the assessment and management of the patient. This case illustrates the usefulness of the CISS sequence in MRI for elucidating arachnoiditis.
Fulltext Pilot study of formestane in postmenopausal women with breast cancer

Joseph JK, Lim AKH

Med J Malaysia, 1998 Mar;53(1):37-41.
PMID: 10968135

A pilot study of Formestane or 4-Hydroxyandrostenedione (Lentaron), a new endocrine agent, was conducted on 18 postmenopausal patients with locally advanced and metastatic breast cancer. 16 patients were evaluable for response and objective responses were seen in 4 patients (25%). Stabilisation of disease was seen in 5 patients (32%). Out of 17 patients evaluable for toxicity, 3 (18%) reported adverse effects including hot flushes, lethargy and myalgia. Adverse effects were mild, transient and no patient required discontinuation of drug. Our study confirms that Formestane is a well tolerated endocrine agent with low toxicity and reasonable efficacy in postmenopausal patients with locally advanced and metastatic breast cancer.
Fulltext Physicochemical Properties of Honey from Contract Beekeepers, Street Vendors and Branded Honey in Sabah, Malaysia

Robin Lim AH, Sam LM, Gobilik J, Ador K, Choon JLN, Majampan J, et al.

Trop Life Sci Res, 2022 Sep;33(3):61-83.
PMID: 36545058 DOI: 10.21315/tlsr2022.33.3.5

The chemical properties of honey depend on the source of collection to packaging, but little is known about honey in Sabah. The aim of this study was to distinguish between the physicochemical properties and mineral content of 76 honey samples from local sources and supermarkets in Sabah, which were from contract beekeepers, unknown sources and branded honey. Raw honey was collected from contract beekeepers, while honey from unknown source was obtained from street vendors and wet markets, while branded honey was purchased from local supermarkets. The chemical parameters of the honey were assessed using established methods, while the mineral content of the honey was determined using inductively coupled plasma optical emission spectroscopy (ICP-OES). Significant differences were found in several parameters measured in honey from different sources, with principal component analysis (PCA) showing clear separation between the measured parameters, yielding five factors that accounted for up to 72.25% of the total explained variance. Honey from contract beekeepers showed significant differences and higher mineral content (Ca, Cu, Fe, K, Mg, Na and Zn) compared to honey from unknown source and branded honey. Potassium was the most important element in the study with an average of 2.65 g/kg and 629.4 mg/kg for sources from contract beekeepers and branded honey, respectively. The honey from the contract beekeepers was of better quality due to its high mineral content. The results suggest that honey from contract beekeepers could be a good choice when it comes to high mineral content.
Orthography-phonology consistency in English: Theory- and data-driven measures and their impact on auditory vs. visual word recognition

Lim A, O'Brien B, Onnis L

Behav Res Methods, 2024 Mar;56(3):1283-1313.
PMID: 37553536 DOI: 10.3758/s13428-023-02094-5

Research on orthographic consistency in English words has selectively identified different sub-syllabic units in isolation (grapheme, onset, vowel, coda, rime), yet there is no comprehensive assessment of how these measures affect word identification when taken together. To study which aspects of consistency are more psychologically relevant, we investigated their independent and composite effects on human reading behavior using large-scale databases. Study 1 found effects on adults' naming responses of both feedforward consistency (orthography to phonology) and feedback consistency (phonology to orthography). Study 2 found feedback but no feedforward consistency effects on visual and auditory lexical decision tasks, with the best predictor being a composite measure of consistency across grapheme, rime, OVC, and word-initial letter-phoneme. In Study 3, we explicitly modeled the reading process with forward and backward flow in a bidirectionally connected neural network. The model captured latent dimensions of quasi-regular mapping that explain additional variance in human reading and spelling behavior, compared to the established measures. Together, the results suggest interactive activation between phonological and orthographic word representations. They also validate the role of computational analyses of language to better understand how print maps to sound, and what properties of natural language affect reading complexity.
Fulltext Ondansetron against metoclopramide/dexamethasone--a comparative study

Lim AKH, Haron MR, Yap TM

Med J Malaysia, 1994 Sep;49(3):231-8.
PMID: 7845271

This trial was carried out in Hospital Kuala Lumpur. Fifty-two patients who were scheduled to receive their first or subsequent courses of cancer chemotherapy with single dose cisplatinum containing chemotherapy regimens were evaluated. Thirty-four patients were given ondansetron in one group while 18 in the other group received metoclopramide with dexamethasone. The response to treatment was categorised as complete (0 emetic episode), major (1 or 2 emetic episodes), minor (3 to 5 emetic episodes) or failure (> 5 emetic episodes or rescue medication). Among the 52 patients, a complete or major control (0 to 2 emetic episodes) was achieved in 23/34 patients (68%) from the ondansetron group and in 3/18 patients (17%) from the metoclopramide with dexamethasone group (p < 0.002) on day 1. Similarly, the control of nausea was greater in the ondansetron group compared with the metoclopramide with dexamethasone group (p < 0.0009) on day 1. Two patients were excluded (dropped out) after day one from each of the two study groups due to excessive vomiting subsequent to cisplatinum therapy. From days 2 to 6, there was a trend in favour of ondansetron. Both treatments were well tolerated. The results of this trial show that in the prophylaxis of nausea and vomiting induced by cisplatinum containing chemotherapy, the efficacy of ondansetron is superior to that of a standard anti-emetic combination, metoclopramide with dexamethasone.
Novel life-history data for threatened seahorses provide insight into fishery effects

Lawson JM, Foster SJ, Lim AC, Chong VC, Vincent AC

J Fish Biol, 2015 Jan;86(1):1-15.
PMID: 25307290 DOI: 10.1111/jfb.12527

Life-history variables for three incidentally captured species of seahorse (Kellogg's seahorse Hippocampus kelloggi, the hedgehog seahorse Hippocampus spinosissimus and the three-spot seahorse Hippocampus trimaculatus) were established using specimens obtained from 33 fisheries landing sites in Peninsular Malaysia. When samples were pooled by species across the peninsula, sex ratios were not significantly different from unity, and height and mass relationships were significant for all species. For two of these species, height at physical maturity (HM ) was smaller than the height at which reproductive activity (HR ) commenced: H. spinosissimus (HM = 99·6 mm, HR = 123·2 mm) and H. trimaculatus (HM = 90·5 mm, HR = 121·8 mm). For H. kelloggi, HM could not be estimated as all individuals were physically mature, while HR = 167·4 mm. It appears that all three Hippocampus spp. were, on average, caught before reproducing; height at 50% capture (HC ) was ≥HM but ≤HR . The results from this study probe the effectiveness of assessment techniques for data-poor fisheries that rely heavily on estimates of length at maturity, especially if maturity is poorly defined. Findings also question the sustainability of H. trimaculatus catches in the south-west region of Peninsular Malaysia, where landed specimens had a notably smaller mean height (86·2 mm) and markedly skewed sex ratio (6% males) compared with samples from the south-east and north-west of the peninsula.
Fulltext Molecular epidemiology of Cryptosporidium in HIV/AIDS patients in Malaysia

Asma I, Sim BL, Brent RD, Johari S, Yvonne Lim AL

Trop Biomed, 2015 Jun;32(2):310-22.
PMID: 26691260 MyJurnal

Cryptosporidiosis is a particular concern in immunocompromised individuals where symptoms may be severe. The aim of this study was to examine the epidemiological and molecular characteristics of Cryptosporidium infections in HIV/AIDS patients in Malaysia in order to identify risk factors and facilitate control measures. A modified Ziehl-Neelsen acid fast staining method was used to test for the presence of Cryptosporidium oocysts in the stools of 346 HIV/AIDS patients in Malaysia. Standard coproscopical methods were used to identify infections with other protozoan or helminths parasites. To identify the species of Cryptosporidium, DNA was extracted and nested-PCR was used to amplify a portion of the SSU rRNA gene. A total of 43 (12.4%) HIV-infected patients were found to be infected with Cryptosporidium spp. Of the 43 Cryptosporidium-positive HIV patients, 10 (23.3%) also harboured other protozoa, and 15 (34.9%) had both protozoa and helminths. The highest rates of cryptosporidiosis were found in adult males of Malay background, intravenous drug users, and those with low CD4 T cell counts (i.e., < 200 cells/mm3). Most were asymptomatic and had concurrent opportunistic infections mainly with Mycobacterium tuberculosis. DNA sequence analysis of 32 Cryptosporidium isolates identified C. parvum (84.3%), C. hominis (6.3%), C. meleagridis (6.3%), and C. felis (3.1%). The results of the present study revealed a high prevalence of Cryptosporidium infection in hospitalized HIV/AIDS patients. The results also confirmed the potential significance of zoonotic transmission of C. parvum in HIV infected patients, as it was the predominant species found in this study. However, these patients were found to be susceptible to a wide range of Cryptosporidium species. Epidemiological and molecular characterization of Cryptosporidium isolates provides clinicians and researchers with further information regarding the origin of the infection, and may enhance treatment and control strategies.
Fulltext Modelling malaria in southernmost provinces of Thailand: a two-step process for analysis of highly right-skewed data with a large proportion of zeros

Ammatawiyanon L, Tongkumchum P, Lim A, McNeil D

Malar J, 2022 Nov 15;21(1):334.
PMID: 36380322 DOI: 10.1186/s12936-022-04363-8

BACKGROUND: Malaria remains a serious health problem in the southern border provinces of Thailand. The issue areas can be identified using an appropriate statistical model. This study aimed to investigate malaria for its spatial occurrence and incidence rate in the southernmost provinces of Thailand.
METHODS: The Thai Office of Disease Prevention and Control, Ministry of Public Health, provided total hospital admissions of malaria cases from 2008 to 2020, which were classified by age, gender, and sub-district of residence. Sixty-two sub-districts were excluded since they had no malaria cases. A logistic model was used to identify spatial occurrence patterns of malaria, and a log-linear regression model was employed to model the incidence rate after eliminating records with zero cases.
RESULTS: The overall occurrence rate was 9.8% and the overall median incidence rate was 4.3 cases per 1,000 population. Malaria occurence peaked at young adults aged 20-29, and subsequently fell with age for both sexes, whereas incidence rate increased with age for both sexes. Malaria occurrence and incidence rates fluctuated; they appeared to be on the decline. The area with the highest malaria occurrence and incidence rate was remarkably similar to the area with the highest number of malaria cases, which were mostly in Yala province's sub-districts bordering Malaysia.
CONCLUSIONS: Malaria is a serious problem in forest-covered border areas. The correct policies and strategies should be concentrated in these areas, in order to address this condition.

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