Tropical high altitude and severe asthma in adults: house dust mite sensitization and phenotypic distribution.

BACKGROUND: There is a lack of information on house dust mite (HDM) sensitization and phenotype distribution in patients with severe asthma (SA) living permanently at high-altitude (HA) in tropical regions, which may be different. OBJECTIVE: The aim of this study was to characterize adults with SA in a tropical high altitude city (2,640 m): Bogotá, Colombia. MATERIAL AND METHODS: This observational cross-sectional study included severe asthmatic outpatients (n = 129) referred to the ASMAIRE program of the Fundación Neumológica Colombiana in Bogotá (2,640 m). Clinical history, spirometry, total IgE, blood eosinophils, and skin prick test (SPT), including HDM allergens, were performed. Phenotype definitions: Allergic/atopic (AA): IgE ≥100 IU/mL and/or at least one positive SPT; eosinophilic (EOS): blood eosinophils ≥300 cells/µL; type 2-high: AA and/or EOS phenotype; type 2-low: non-AA/non-EOS phenotype (IgE <100 IU/mL, negative SPT, and blood eosinophils <300 cells/µL). RESULTS: A total of 129 adults with SA were included, 79.8% female. Phenotype distribution: AA: 61.2%; EOS: 37.2%; type 2-high: 72.1%; type 2-low: 27.9%. Among AA patients, HDM sensitization was present in 87% and 34.9% were non-eosinophilic. There was a significant overlap between the phenotypes. CONCLUSIONS: In contrast to non-tropical high-altitude regions, we found a high frequency of HDM sensitization in patients with AA phenotype living in a tropical high-altitude city. We also found a discrete lower frequency of EOS phenotype with no other significant differences in the phenotypic distribution compared to that described at low altitudes. We propose that tropical location may modify the effect of high altitude on HDM concentrations and allergenicity.

Fractional exhaled nitric oxide (FeNO) and respiratory symptoms in junior high school students in Penang, Malaysia: the role of household exposure.

We studied associations between fractional exhaled nitric oxide (FeNO), health and household exposure among school children (N = 348) in Penang, Malaysia. Multiple logistic regression and linear mixed models were applied. Overall, 46.0% had elevated FeNO (>20 ppb) and 10.6% diagnosed asthma. Male gender (p = 0.002), parental asthma or allergy (p = 0.047), cat allergy (p = 0.009) and seafood allergy (p < 0.001), diagnosed asthma (p = 0.001), wheeze (p = 0.001), ocular symptoms (p = 0.001), rhinitis (p = 0.002) and respiratory infections (p = 0.004) were all associated with FeNO. Students exposed to ETS had lower FeNO (p = 0.05). Dampness and mould was associated with wheeze (p = 0.038), especially in wooden homes (interaction p = 0.042) and among students with elevated FeNO (interaction p = 0.024). Cat keeping increased rhinitis (p = 0.041) and respiratory infections (p = 0.008) and modified the dampness associations. In conclusion, FeNO can be associated with ocular and respiratory symptoms. Elevated FeNO, cat keeping and a wooden house can enhance the risk of wheeze when exposed to dampness and mould.

The Spread of the COVID-19 Outbreak in Brazil: An Overview by Kohonen Self-Organizing Map Networks.

Background and objective: In the current pandemic scenario, data mining tools are fundamental to evaluate the measures adopted to contain the spread of COVID-19. In this study, unsupervised neural networks of the Self-Organizing Maps (SOM) type were used to assess the spatial and temporal spread of COVID-19 in Brazil, according to the number of cases and deaths in regions, states, and cities. Materials and methods: The SOM applied in this context does not evaluate which measures applied have helped contain the spread of the disease, but these datasets represent the repercussions of the country's measures, which were implemented to contain the virus' spread. Results: This approach demonstrated that the spread of the disease in Brazil does not have a standard behavior, changing according to the region, state, or city. The analyses showed that cities and states in the north and northeast regions of the country were the most affected by the disease, with the highest number of cases and deaths registered per 100,000 inhabitants. Conclusions: The SOM clustering was able to spatially group cities, states, and regions according to their coronavirus cases, with similar behavior. Thus, it is possible to benefit from the use of similar strategies to deal with the virus' spread in these cities, states, and regions.

Blood cytokine, chemokine and growth factor profiling in a cohort of pregnant women from tropical countries.

The immune status of women changes during and after pregnancy, differs between blood compartments at delivery and is affected by environmental factors particularly in tropical areas endemic for multiple infections. We quantified the plasma concentration of a set of thirty-one TH1, TH2, TH17 and regulatory cytokines, pro-inflammatory and anti-inflammatory cytokines and chemokines, and growth factors (altogether biomarkers), in a cohort of 540 pregnant women from five malaria-endemic tropical countries. Samples were collected at recruitment (first antenatal visit), delivery (periphery, cord and placenta) and postpartum, allowing a longitudinal analysis. We found the lowest concentration of biomarkers at recruitment and the highest at postpartum, with few exceptions. Among them, IL-6, HGF and TGF-ß had the highest levels at delivery, and even higher concentrations in the placenta compared to peripheral blood. Placental concentrations were generally higher than peripheral, except for eotaxin that was lower. We also compared plasma biomarker concentrations between the tropical cohort and a control group from Spain at delivery, presenting overall higher biomarker levels the tropical cohort, particularly pro-inflammatory cytokines and growth factors. Only IL-6 presented lower levels in the tropical group. Moreover, a principal component analysis of biomarker concentrations at delivery showed that women from Spain grouped more homogenously, and that IL-6 and IL-8 clustered together in the tropical cohort but not in the Spanish one. Plasma cytokine concentrations correlated with Plasmodium antibody levels at postpartum but not during pregnancy. This basal profiling of immune mediators over gestation and in different compartments at delivery is important to subsequently understand response to infections and clinical outcomes in mothers and infants in tropical areas.

Changes in plasma concentrations of 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D during pregnancy: a Brazilian cohort.

PURPOSE: To characterize the physiological changes in 25-hydroxyvitamin D [25(OH)D] and 1,25-dihydroxyvitamin D [1,25(OH)2D] throughout pregnancy. METHODS: Prospective cohort of 229 apparently healthy pregnant women followed at 5th-13th, 20th-26th, and 30th-36th gestational weeks. 25(OH)D and 1,25(OH)2D concentrations were measured by LC-MS/MS. Statistical analyses included longitudinal linear mixed-effects models adjusted for parity, season, education, self-reported skin color, and pre-pregnancy BMI. Vitamin D status was defined based on 25(OH)D concentrations according to the Endocrine Society Practice Guideline and Institute of Medicine (IOM) for adults. RESULTS: The prevalence of 25(OH)D <75 nmol/L was 70.4, 41.0, and 33.9%; the prevalence of 25(OH)D <50 nmol/L was 16.1, 11.2, and 10.2%; and the prevalence of 25(OH)D <30 nmol/L was 2, 0, and 0.6%, at the first, second, and third trimesters, respectively. Unadjusted analysis showed an increase in 25(OH)D (ß = 0.869; 95% CI 0.723-1.014; P < 0.001) and 1,25(OH)2D (ß = 3.878; 95% CI 3.136-4.620; P < 0.001) throughout pregnancy. Multiple adjusted analyses showed that women who started the study in winter (P < 0.001), spring (P < 0.001), or autumn (P = 0.028) presented a longitudinal increase in 25(OH)D concentrations, while women that started during summer did not. Increase of 1,25(OH)2D concentrations over time in women with insufficient vitamin D (50-75 nmol/L) at baseline was higher compared to women with sufficient vitamin D (≥75 nmol/L) (P = 0.006). CONCLUSIONS: The prevalence of vitamin D inadequacy varied significantly according to the adopted criteria. There was a seasonal variation of 25(OH)D during pregnancy. The women with insufficient vitamin D status present greater longitudinal increases in the concentrations of 1,25(OH)2D in comparison to women with sufficiency.

Assessment of gastrointestinal nematode infection, anthelmintic usage and husbandry practices on two small-scale goat farms in Malaysia.

Haemonchosis is a common problem on goat farms in tropical countries such as Malaysia. Prevention of production losses generally depends on the use of anthelmintic drugs, but is threatened by the emergence of anthelmintic resistance. This study investigates anthelmintic efficacy on small-scale Malaysian goat farms and describes putative risk factors. Adult goats had moderate to high pre-treatment faecal trichostrongyle egg counts, despite being housed on slatted floors and fed on cut-and-carry forage, raising questions about the source of nematode infection. Our results show multiple resistance to benzimidazole and macrocyclic lactone anthelmintic drugs and allow us to discuss the genetic origins of resistance with reference to farm husbandry and management. We conclude that improvement in Malaysian goat production efficiency will require the development of sustainable helminth control strategies, underpinned by a better understanding of the origins and population genetics of anthelmintic resistance.

Vitamin D deficiency and depression among women from an urban community in a tropical country.

OBJECTIVE: To determine the association of vitamin D status with depression and health-related quality of life among women. DESIGN: This was a cross-sectional study conducted among women in Kuala Lumpur, Malaysia. Sociodemographic characteristics, physical activity status, perceived depression and health-related quality of life were assessed via a self-administered questionnaire. Fasting blood samples were taken for the analysis of 25-hydroxyvitamin D, parathyroid hormone, fasting blood glucose and full lipid profile. Complex samples multiple logistic regression analysis was performed. SETTING: Public secondary schools in Kuala Lumpur, Malaysia. SUBJECTS: Seven hundred and seventy female teachers were included. RESULTS: The mean age of participants was 41·15 (95 % CI 40·51, 41·78) years and the majority were ethnic Malays. Over 70 % of them had vitamin D deficiency (<20 ng/ml or <50 nmol/l) and two-thirds were at risk for depression. In the multivariate analysis, ethnic Malays (adjusted OR (aOR)=14·72; 95 % CI 2·12, 102·21) and Indians (aOR=14·02; 95 % CI 2·27, 86·59), those at risk for depression (aOR=1·88, 95 % CI 1·27, 2·79) and those with higher parathyroid hormone level (aOR=1·13; 95 % CI 1·01, 1·26) were associated with vitamin D deficiency, while vitamin D deficiency was negatively associated with mental health-related quality of life (Mental Component Summary) scores (aOR=0·98; 95 % CI 0·97, 0·99). CONCLUSIONS: Vitamin D deficiency is significantly associated with depression and mental health-related quality of life among women in Kuala Lumpur, Malaysia.

A review of dairy cattle heat stress mitigation in Indonesia.

Indonesia is a tropical country with a hot climate. In tropical nations such as Indonesia, heat stress is a key reason for the reduced productivity of dairy cattle. Heat stress is a combination of internal and external stimuli that affects an animal, raises its body temperature, and causes it to react physiologically. Most Indonesian dairy cattle are Friesian Holstein (FH), imported from European nations with a temperate environment with low temperatures in the range of 5°C-25°C. Indonesia has a tropical climate with a high ambient temperature that can reach 34°C during the day and the local relative humidity varies between 70% and 90%. Temperature and humidity are two microenvironment factors that may impact the production and heat release in FH cattle. More than 98% of the entire dairy cattle population in Indonesia is found on Java Island. On Java Island, there are between 534.22 and 543.55 thousand heads of cattle, while the dairy cattle population outside Java Island is just 6.59 thousand heads of cattle. The milk output climbs by an average of 3.34% per year, or approximately 909.64 thousand tons and the average annual growth in whole milk consumption was 0.19 L/capita. Indonesian cow milk output has been unable to keep pace with the country's increasing demand. This study aimed to review the strategies to mitigate heat stress in FH dairy cattle in Indonesia.

Assessing Alternatives to Locomotion Scoring for Detecting Lameness in Dairy Cattle in Tanzania: Infrared Thermography.

Lameness detection is a significant challenge. Locomotion scoring (LS), the most widely used system for detecting lameness, has several limitations, including its subjective nature and the existence of multiple systems, each with its own advantages and disadvantages. Therefore, this study aimed to evaluate whether the foot skin temperature (FST) of hind limbs, as measured using infrared thermography (IRT), could potentially be used as an alternative on Tanzanian dairy farms. Each of the three study farms were visited twice during the afternoon milking on consecutive days, with a total of 170 cows assessed. DairyNZ LS (4-point scale (0-3)) was undertaken on the first day as the cows exited the milking parlour after being milked, while on the following day, the plantar aspect of the hind limbs of the cows was thermally imaged while they were standing in the milking parlour, using a handheld T650sc forward-looking infrared camera. Mean FST was higher for cows with a locomotion score of 1 than those with a score of 0; higher for cows with a locomotion score of 2 than those with a score of 1; and higher for cows with a locomotion score of 3 than those with a score of 2, with each one-unit locomotion score increase being associated with a 0.57 °C increase in mean temperature across all zones. The optimal cut-off point of 38.0 °C for mean temperature across all zones was identified using a receiver operator characteristic curve. This cut-off point had a sensitivity of 73.2% and a specificity of 86.0% for distinguishing cows with a locomotion score ≥ 2 (clinical lameness). The prevalence of clinical lameness across all three farms was 33%, which meant that only 72% of cows with a mean FST across all zones ≥ 38.0 °C had been identified as clinically lame using LS. This study confirmed that IRT has the potential to be used to detect lameness on Tanzanian dairy farms. However, before it can be widely used, improvements in accuracy, especially specificity, are needed, as are reductions in equipment (IR camera) costs.

Natural history and clinical course of patients with dermographism in a tropical country: a questionnaire-based survey.

Background: Dermographism is the most common form of chronic inducible urticaria. However, the natural history and clinical course of patients with dermographism in tropical countries has not fully been described. Objective: To examine clinical features, natural history and clinical course of dermographism in Thai patients according to their experiences. Methods: A cross-sectional, internet-based survey was conducted in 2021. All study respondents completed a 45-item questionnaire that was circulated on social media regarding dermographism. Results: Among the 2,456 respondents who reported dermographism, 1,900 had symptomatic dermographism (SD), while 556 had simple dermographism (SimD). Of the respondents who reported SD and SimD, the female to male ratio was 2.2:1 and 2.4:1, respectively. The median age of the first episode of SD and SimD was 16 and 15 years, respectively. Older age, greater body weight, cardiovascular diseases, allergic conjunctivitis, atopic dermatitis, changes in temperature, and family history of dermographism were all factors linked to an increased probability of SD. Half of the respondents with SD reported moderate itch severity. Moreover, about half of SD and almost all of SimD respondents let the wheal resolve on its own. Second generation H1-antihistamines were most commonly prescribed while over-the-counter medicines were taken by both SD and SimD respondents. Conclusion: This survey highlights several aspects of dermographism in Thai patients which can be useful for healthcare providers. SD is troublesome and affects the quality of life of many patients, leading some to seek medication themselves.

Bacterial Growth in Expressed Mother's Milk Stored and Transported Under Different Simulated Conditions in a Tropical Country.

Background: Research on how storage and transport of expressed human milk in a tropical country affect the milk bacterial count is limited. Materials and Methods: A cross-sectional descriptive study of 50 mothers of infants in a Sri Lankan tertiary neonatal unit was performed. Expressed mother's milk was divided into three bottles and kept under varied environmental conditions to simulate different storage and transport methods. Initial bacterial culture of milk was performed <30 minutes after expression, with further cultures at predetermined times. Bottles A and B were stored at room temperature and in a cool bag for the first 6 hours, respectively, and then refrigerated; and bottle C was refrigerated for 24 hours, transported in a cool bag for 6 hours, and rerefrigerated until 72 hours. Total colony counts >105 colony-forming units (CFU)/mL of viable microorganisms or >104 CFU/mL of either Enterobacteriaceae or Staphylococcus aureus were considered positive. Results: Initial culture was positive in 30% (15/50) of samples; majority, 87% (13/15), of these were S. aureus. For bottle A, 26% (13/50), 36% (18/50), 34% (17/50), and 26% (13/50) of samples were positive at 4, 6, 24, and 72 hours, respectively. For bottle B, positive cultures were found in 26% (13/50) and 17% (8/47) of samples at 24 and 72 hours, respectively. For bottle C, results were similar to bottle B. Conclusions: Transportation of expressed mother's milk for 4 hours in a tropical climate using a low-cost cool bag, with refrigeration at other times, maintained acceptable bacterial counts for up to 72 hours after expression. Hygienic practices at collection are extremely important as most samples with significant bacterial growth were positive on initial culture.

Vitamin D non-sufficiency is prevalent in children with chronic liver disease in a tropical country.

BACKGROUND: To determine vitamin D status in children with chronic liver disease (CLD) in a tropical country. METHODS: Cross-sectional study in Malaysian children with CLD. Factors affecting serum vitamin D level (definition: deficient < 30 nmol/L; insufficient 30-50 nmol/L; sufficient ≥ 50 nmol/L) was analyzed. RESULTS: Of the 59 children studied (males 32, 54%; median age 6.8 ± 5.3 years), the three most common causes were biliary atresia (n = 25), autoimmune hepatitis (n = 16) and sclerosing cholangitis (n = 6). The overall mean daily vitamin D intake was 715 ± 562 units/day. Thirteen (22%) patients had at least one clinical signs of rickets. Seventeen (29%) had serum bilirubin level ≥ 34 µmol/L. Eight (14%) children were deficient in vitamin D, eight (14%) were vitamin D-insufficient and 43 (73%) were sufficient. As compared with children with serum bilirubin <34 µmol/L, those with serum bilirubin ≥34 µmol/L were more likely to have rickets (24% vs. 65%; P < 0.002) and a lower serum vitamin D level (86.0 ± 54.9 nmol/L vs. 65.4 ± 48.2 nmol/L; P = 0.05) despite being given a significantly higher vitamin D dose (608 ± 571 vs. 970 ± 543 units/day; P = 0.008). The proportion of children with either deficient or insufficient vitamin D status was significantly higher in children with bilirubin level ≥34 µmol/L than in children <34 µmol/L (47% vs. 19%; P = 0.028). CONCLUSION: Vitamin D deficiency and insufficiency is common in children with CLD in a tropical country. Regular monitoring of vitamin D status and screening for metabolic bone disease in all children with CLD is recommended. Higher dose of oral supplement or parenteral route should be considered, especially in those with bilirubin ≥34 µmol/L.

Characterization of Musty Odor-Producing Actinomycetes from Tropics and Effects of Temperature on the Production of Musty Odor Compounds.

Geosmin and 2-methylisoborneol (MIB) outbreaks in tropical water bodies, such as Southeast Asia, by actinomycetes have not yet been elucidated in detail. Six Streptomyces isolates from lowland environments in Malaysia were selected and evaluated for their odor production under different temperatures. The gene responsible for the production of geosmin, geoA, was detected in all isolates, while only two isolates harbored tpc, which is responsible for 2-MIB production. This result suggested that geosmin and 2-MIB synthesis pathway genes already existed in the environment in the Tropics of Southeast Asia. Furthermore, our isolates produced musty odor compounds at 30°C, and differences were observed in musty odor production between various temperatures. This result indicated the potential for odor episodes in water bodies of the tropical countries of Southeast Asia throughout the year due to the mean annual ambient temperature of 27°C in the lowlands.

Vitamin D deficiency and length of pediatric intensive care unit stay: a prospective observational study.

BACKGROUND: Due to the limited data available in the pediatric population and lack of interventional studies to show that administration of vitamin D indeed improves clinical outcomes, opinion is still divided as to whether it is just an innocent bystander or a marker of severe disease. Our objective was therefore to estimate the prevalence of vitamin D deficiency in children admitted to intensive care unit (ICU) and to examine its association with duration of ICU stay and other key clinical outcomes. METHODS: We prospectively enrolled children aged 1 month-17 years admitted to the ICU over a period of 8 months (n = 101). The primary objectives were to estimate the prevalence of vitamin D deficiency (serum 25 (OH) <20 ng/mL) at 'admission' and to examine its association with length of ICU stay. RESULTS: The prevalence of vitamin D deficiency was 74 % (95 % CI: 65-88). The median (IQR) duration of ICU stay was significantly longer in 'vitamin D deficient' children (7 days; 2-12) than in those with 'no vitamin D deficiency' (3 days; 2-5; p = 0.006). On multivariable analysis, the association between length of ICU stay and vitamin D deficiency remained significant, even after adjusting for key baseline variables, diagnosis, illness severity (PIM-2), PELOD, and need for fluid boluses, ventilation, inotropes and mortality [adjusted mean difference (95 % CI): 3.5 days (0.50-6.53); p = 0.024]. CONCLUSIONS: We observed a high prevalence of vitamin D deficiency in critically ill children in our study population. Vitamin D deficient children had a longer duration of ICU stay as compared to others.

Ecuador publications in the Science Citation Index Expanded: institutions, subjects, citation and collaboration patterns / Publicaciones de Ecuador en el Índice de Citación de Ciencia: instituciones, categorías, citaciones y patrones de colaboración

Introduction: Ecuador, a country of 17 million inhabitants with a medium human development index of 0.75, has a small scientific productivity in relation to its size and population. Objective: To analyze Ecuador publications in the Science Citation Index Expanded, focusing on productivity, subjects, institutions, citations, and trends. Methods: We analyzed scientific publications by authors from Ecuador from 1900 to 2017 in the Science Citation Index Expanded and compared it with other tropical countries. Results: We found 16 document types (7 806 articles). The three most productive institutions were Universidad San Francisco de Quito, Pontificia Universidad Católica del Ecuador, and Escuela Politécnica Nacional. USA and Spain were the most frequent collaborating countries. Most articles were in English and ecology, botany, and zoology were common, but no field produced over 8 % of articles. However, ecology represents 11.3 % of the total citations. The most cited papers in the database were from large international biology and physics projects with minimal participation of Ecuadorean scientists. Article citations occurs mostly after the SCI stops counting. Conclusion: Science in Ecuador is growing but needs to greatly increase collaboration among Ecuadorean institutions to reduce its dependence on foreing projects. However, this study did not include articles published by the hundreds of Ecuadorean journals not covered by the SCI Expanded.

Introducción: Ecuador es un país con 17 millones de habitantes y un indice de desarrollo humano medio de 0.75, pero tiene una baja producción científica en relación con su tamaño y población. Objectivo: Analizar las publicaciones de Ecuador en el Índice de Citación de Ciencia enfocándose en la productividad, categorías, instituciones, citaciones y tendencias. Métodos: En la base de datos Science Citation Index analizamos las publicaciones científicas de autores con dirección ecuatoriana desde 1900 hasta 2017 y comparamos los resultados con otros países tropicales. Resultados: Encontramos 16 tipos de documentos (7 806 artículos). Las tres instituciones más productivas fueron Universidad San Francisco de Quito, Pontificia Universidad Católica del Ecuador, y Escuela Politécnica Nacional. Estados Unidos y España fueron los países con colaboración más frecuente. La mayoría de los artículos fueron escritos en inglés con Ecología, Botánica y Zoología como las categorías más comunes, pero ninguna supera una producción del 8 % del total de las publicaciones. Sin embargo, Ecología representa el 11.3 % del total de citaciones. Los artículos más citados en esa base de datos fueron de grandes equipos internacionales en Biología y en Física, con poca participación de científicos ecuatorianos. La mayoría de las citas se dan después de que el SCI detiene el conteo. Conclusión: La ciencia en Ecuador está creciendo, pero se necesita aumentar la colaboración entre las instituciones ecuatorianas para reducir la dependencia de proyectos extranjeros. Se debe considerar que este estudio no incluyó los artículos publicados por centenares de revistas ecuatorianas que no son cubiertas por el Science Citation Index.

Brunei Publications in the Science Citation Index Expanded (1973-2016): Bibliometrics and comparison with other tropical countries / Publicaciones de Brunei en el Science Citation Index Expanded (1973-2016): Bibliometría y comparación con otros países tropicales

Abstract Brunei is a small tropical country -located in Southeast Asia- for which there are no previous bibliometric studies. Here we analyze papers published by Brunei scientists from 1973 to 2016 in the Science Citation Index Expanded and compare results with other tropical countries. We identified 1 547 publications and 11 document types. The most productive categories were ecology, multidisciplinary geosciences, inorganic and nuclear chemistry, and environmental sciences. Singapore Medical Journal published most of these papers, and the three most productive institutions were Universiti Brunei Darussalam, RIPAS Hospital, and Universiti Teknologi Brunei. UK and Malaysia were the most frequent collaborating countries. M.A. Ali from the Universiti Brunei Darussalam was the most prolific author and a Brunei independent article written by C.K. Morley from the Universiti Brunei Darussalam in 2002 had the highest number of citations of the whole period and the highest number in 2016. The tropical countries of Central America and Asia have a few similarities but also important differences, and both are highly heterogeneous in scientific organization and productivity. Rev. Biol. Trop. 66(3): 1090-1100. Epub 2018 September 01.

Resumen Brunei es un pequeño país tropical del sudeste asiático, sobre el cual no hay estudios bibliométricos. Aquí analizamos los artículos publicados por científicos de Brunei de 1973 a 2016 y comparamos los resultados con otros países tropicales. Examinamos los documentos del Science Citation Index Expanded en la colección principal del Web of Science. Hallamos 1 547 publicaciones de Brunei con 11 tipos de documentos, donde las categorías más productivas fueron ecología, geociencias multidisciplinarias, química inorgánica y nuclear, y ciencias ambientales. Singapore Medical Journal publicó la mayoría, y las tres instituciones más productivas fueron: Universiti Brunei Darussalam, RIPAS Hospital y Universiti Teknologi Brunei. Reino Unido y Malasia fueron los países que más colaboraron con Brunei. M.A. Ali de la Universidad Brunei Darussalam fue el autor más prolífico. El mayor número total de citas, y el mayor número de citas en 2016, correspondieron a un artículo exclusivamente de Brunei, escrito por C. K. Morley de la Universiti Brunei Darussalam en 2002. Los países tropicales de América Central y Asia tienen algunas similitudes pero también diferencias importantes, siendo heterogéneos en su organización científica y productividad.