Properties and potential of agarwood hydrosol as a drink: a review

Agarwood is resinous valuable heartwood of Aquilaria tree resulting from self–defence mechanism towards injuries or damages exerted on the tree. Agarwood essential oil is usually extracted through a process of hydrodistillation or steam distillation which is beneficial for commercial purposes such as perfumeries and cosmetics. Hydrosol, a byproduct of the process produced in abundance and underutilized particularly in the agarwood industry. Hydrosol of agarwood is an aromatic compound that is believed to have chemical properties similar to essential oils that consist of positive antioxidant activity and positive biological activity for living cells. Several studies on properties of hydrosol of agarwood show that it contained zero nutrient but varied with minerals in the appropriate proportion that safe for human consumption. Thus, this review was aimed to discuss the agarwood hydrosol processing methods, characteristics, antioxidants properties and its comparisons to other plants hydrosol that have been commercially used as human consumption as in flavoured and non-flavoured beverages

Solvent used in extraction process of agarwood: a systematic review

The method of extraction of Agarwood is usually dependent on the purpose of the extract. This systematic review aims to look at the number of studies that use different types of solvents in the process of extraction. There are 3 types of solvents commonly used in the extraction of agarwood essential oils namely methanol, ethanol and water. Each solvent produces different extracts in terms of quantity and quality of the final product. However, there is controversy over the use of solvents as it may cause a cytotoxic effect on the user. Another common type of solvent is water. Although water is a cheap solvent and relatively safe, aqueous extracts have more impurities that make isolating the desired compound difficult. After the extraction process, the crude extract was fractionated into the desired compounds and this technique is widely applied, especially in the whole process of extraction of the agarwood. In conclusion, extraction solvents have certain advantages and disadvantages, and this is one of the reasons why this extraction method depends on the purpose of using the final product such as agarwood essential oil.

Corporate Social Responsibility in Islamic and Conventional View: A Theoretical Approach

.

Capacitated vehicle-routing problem model for scheduled solid waste collection and route optimization using PSO algorithm

Waste collection widely depends on the route optimization problem that involves a large amount of expenditure in terms of capital, labor, and variable operational costs. Thus, the more waste collection route is optimized, the more reduction in different costs and environmental effect will be. This study proposes a modified particle swarm optimization (PSO) algorithm in a capacitated vehicle-routing problem (CVRP) model to determine the best waste collection and route optimization solutions. In this study, threshold waste level (TWL) and scheduling concepts are applied in the PSO-based CVRP model under different datasets. The obtained results from different datasets show that the proposed algorithmic CVRP model provides the best waste collection and route optimization in terms of travel distance, total waste, waste collection efficiency, and tightness at 70-75% of TWL. The obtained results for 1 week scheduling show that 70% of TWL performs better than all node consideration in terms of collected waste, distance, tightness, efficiency, fuel consumption, and cost. The proposed optimized model can serve as a valuable tool for waste collection and route optimization toward reducing socioeconomic and environmental impacts.

Landfill area estimation based on integrated waste disposal options and solid waste forecasting using modified ANFIS model

Solid waste prediction is crucial for sustainable solid waste management. The collection of accurate waste data records is challenging in developing countries. Solid waste generation is usually correlated with economic, demographic and social factors. However, these factors are not constant due to population and economic growth. The objective of this research is to minimize the land requirements for solid waste disposal for implementation of the Malaysian vision of waste disposal options. This goal has been previously achieved by integrating the solid waste forecasting model, waste composition and the Malaysian vision. The modified adaptive neural fuzzy inference system (MANFIS) was employed to develop a solid waste prediction model and search for the optimum input factors. The performance of the model was evaluated using the root mean square error (RMSE) and the coefficient of determination (R(2)). The model validation results are as follows: RMSE for training=0.2678, RMSE for testing=3.9860 and R(2)=0.99. Implementation of the Malaysian vision for waste disposal options can minimize the land requirements for waste disposal by up to 43%.

Prediction of municipal solid waste generation using nonlinear autoregressive network

Most of the developing countries have solid waste management problems. Solid waste strategic planning requires accurate prediction of the quality and quantity of the generated waste. In developing countries, such as Malaysia, the solid waste generation rate is increasing rapidly, due to population growth and new consumption trends that characterize society. This paper proposes an artificial neural network (ANN) approach using feedforward nonlinear autoregressive network with exogenous inputs (NARX) to predict annual solid waste generation in relation to demographic and economic variables like population number, gross domestic product, electricity demand per capita and employment and unemployment numbers. In addition, variable selection procedures are also developed to select a significant explanatory variable. The model evaluation was performed using coefficient of determination (R(2)) and mean square error (MSE). The optimum model that produced the lowest testing MSE (2.46) and the highest R(2) (0.97) had three inputs (gross domestic product, population and employment), eight neurons and one lag in the hidden layer, and used Fletcher-Powell's conjugate gradient as the training algorithm.

Solid waste forecasting using modified ANFIS modeling

Solid waste prediction is crucial for sustainable solid waste management. Usually, accurate waste generation record is challenge in developing countries which complicates the modelling process. Solid waste generation is related to demographic, economic, and social factors. However, these factors are highly varied due to population and economy growths. The objective of this research is to determine the most influencing demographic and economic factors that affect solid waste generation using systematic approach, and then develop a model to forecast solid waste generation using a modified Adaptive Neural Inference System (MANFIS). The model evaluation was performed using Root Mean Square Error (RMSE), Mean Absolute Error (MAE) and the coefficient of determination (R²). The results show that the best input variables are people age groups 0-14, 15-64, and people above 65 years, and the best model structure is 3 triangular fuzzy membership functions and 27 fuzzy rules. The model has been validated using testing data and the resulted training RMSE, MAE and R² were 0.2678, 0.045 and 0.99, respectively, while for testing phase RMSE =3.986, MAE = 0.673 and R² = 0.98.

IMPLICATIONS

To date, a few attempts have been made to predict the annual solid waste generation in developing countries. This paper presents modeling of annual solid waste generation using Modified ANFIS, it is a systematic approach to search for the most influencing factors and then modify the ANFIS structure to simplify the model. The proposed method can be used to forecast the waste generation in such developing countries where accurate reliable data is not always available. Moreover, annual solid waste prediction is essential for sustainable planning.

Feature extraction using Hough transform for solid waste bin level detection and classification

This paper deals with the solid waste image detection and classification to detect and classify the solid waste bin level. To do so, Hough transform techniques is used for feature extraction to identify the line detection based on image's gradient field. The feedforward neural network (FFNN) model is used to classify the level content of solid waste based on learning concept. Numbers of training have been performed using FFNN to learn and match the targets of the testing images to compute the sum squared error with the performance goal met. The images for each class are used as input samples for classification. Result from the neural network and the rules decision are used to build the receiver operating characteristic (ROC) graph. Decision graph shows the performance of the system waste system based on area under curve (AUC), WS-class reached 0.9875 for excellent result and WS-grade reached 0.8293 for good result. The system has been successfully designated with the motivation of solid waste bin monitoring system that can applied to a wide variety of local municipal authorities system.

Phytotoxicity of wastewater containing lead (Pb) effects Scirpus grossus

Phytoremediation is an environment-friendly and cost-effective method to clean the environment of heavy metal contamination. A prolonged phytotoxicity test was conducted in a single exposure. Scirpus grossus plants were grown in sand to which the diluted Pb (NO3)2 was added, with the variation of concentration were 0, 100, 200, 400, 600, and 800 mg/L. It was found that Scirpus grossus plants can tolerate Pb at concentrations of up to 400 mg/L. The withering was observed on day-7 for Pb concentrations of 400 mg/L and above. 100% of the plants withered with a Pb concentration of 600 mg/L on day 65. The Pb concentration in water medium decreased while in plant tissues increased. Adsorption of Pb solution ranged between 2 to 6% for concentrations of 100 to 800 mg/L. The Bioaccumulation Coefficient and Translocation Factor of Scirpus grossus were found greater than 1, indicating that this species is a hyperaccumulator plant.

Malaria in a cohort of Javanese migrants to Indonesian Papua

The epidemiology of infection by Plasmodium falciparum and P. vivax was investigated among Javanese migrants to an endemic region of Papua, Indonesia. A cohort of 243 migrants from Java was followed for malaria in a new settlement village in the endemic Armopa area of north-eastern Papua, beginning on the day each migrant arrived in the village. The subjects were monitored during home visits (three/week) and by the twice-monthly production of bloodsmears that were checked for malarial parasites. At the end of 33 months, 159 (65%) of the subjects remained under follow-up. The prevalence of parasitaemia in the village declined from 16% among those already living there when the study began in August 1996, to 5% when the study finished in June 1999. Over this period, 596 infections by P. falciparum and 723 by P. vivax occurred in the cohort, 22 and 27 of the subjects each experiencing at least six infections by P. falciparum and P. vivax, respectively. The incidence of malarial infection was higher during the first and second years post-migration (3.2 and 2.7 infections/person-year) than during the third (1.2 infections/person-year). Although the geometric mean parasite counts for P. falciparum increased over time (1209, 1478, and 1830 parasites/microl in the first, second and third years, respectively), the corresponding values for P. vivax (497, 535 and 490 parasites/microl) showed no such trend. Only one of the nine subjects who developed severe malaria (requiring intravenous quinine therapy) was a child, giving an odds ratio for a case of severe malaria being in an adult of 6.1 (P=0.08).

Primary infection by Plasmodium falciparum or P. vivax in a cohort of Javanese migrants to Indonesian Papua

The clinical and parasitological characteristics of the first naturally acquired malarial infection have rarely been documented in humans. When 243 migrants from non-endemic Java were followed from the day of their arrival in Indonesian Papua, 217 (89%) were found to become infected with Plasmodium falciparum and/or P. vivax before they were lost to follow-up. The incidence of malarial infection in the children investigated (who were aged 6-10 years) was indistinguishable from that in the adults (aged >20 years), with 1.10 and 1.14 P. falciparum infections/person-year (relative risk=0.97; 95% confidence interval=0.72-1.29) and 1.47 and 1.49 P. vivax infections/person-year (relative risk=0.99; 95% confidence interval=0.72-1.29), respectively. During their first infections, the children had higher P. falciparum parasitaemias than the adults (with geometric means of 1318 and 759 parasites/microl, respectively; P=0.04) but similar P. vivax parasitaemias (with geometric means of 355 and 331 parasites/microl, respectively; P=0.76). At first infection, 56% of the subjects were febrile and 90% complained of symptoms. There were no differences between children and adults with respect to these two parameters, either for P. falciparum or P. vivax. These findings indicate that, with promptly diagnosed and treated uncomplicated malaria, migrant children and adults in north-eastern Indonesian Papua have an equal risk of malarial infection and of disease following their first infections with P. falciparum and P. vivax.

Adult Javanese migrants to Indonesian Papua at high risk of severe disease caused by malaria

Migrants from Java arrive in hyperendemic Papua, Indonesia lacking exposure to endemic malaria. We evaluated records of evacuation to hospital with a diagnosis of severe malaria from a transmigration village in northeastern Papua. During the first 30 months, 198 residents with severe disease were evacuated (7.5 evacuations/100 person-years). During this period the risk of evacuation for adults (> 15 years of age) was 2.8. (95% CI = 2.1-3.8; P < 0.0001) relative to children, despite apparently equal exposure to risk of infection. Relative risk (RR) for adults was greatest during the first 6 months (RR > 16; 95% CI > or = 2.0-129; P = 0.0009), and diminished during the second 6 months (RR = 9.4; 95% CI = 2.7-32.8; P < 0.0001) and the third 6 months (RR = 3.7; 95% CI = 1.7-7.9; P = 0.0004). During the next two 6-month intervals, the RR for adults was 1.6 and 1.5 (95 % CI range 0.8-2.6; P < 0.18). Adults lacking chronic exposure were far more likely to progress to severe disease compared to children during initial exposure, but not after chronic exposure to infection.

Land application technique for the treatment and disposal of sewage sludge

Some of the major concerns when applying sewage sludge to land include the potential effect on pH and cation exchange capacity; the mobility and the accumulation of heavy metals in sludge treated soil; the potential of applying too much nutrients and the problems associated with odors and insects. The main objective of this study is to identify the effects of sewage sludge application on the physical and chemical properties of sludge treated soil. Sewage sludge was applied to soil at various rates ranging from 0 L/m2 to 341 L/m2. In order to simulate the natural environment, the study was carried out at a pilot treatment site (5.2 m x 6.7 m) in an open area, covered with transparent roofing material to allow natural sunlight to pass through. Simulated rain was applied by means of a sprinkler system. Data obtained from sludge treated soil showed that the pH values decreased when the application rates were increased and the application period prolonged. The effect of sewage sludge on cation exchange capacity was not so clear; the values obtained for every application rate of sewage sludge did not indicate any consistent behaviour. The mobility of heavy metals in soils treated with sludge were described by observing the changes in the concentration of the heavy metals. The study showed that Cd has the highest mobility in sludge treated soil followed by Cu, Cr, Zn, Ni and Pb.

Randomized, parallel placebo-controlled trial of primaquine for malaria prophylaxis in Papua, Indonesia

Malaria causes illness or death in unprotected travelers. Primaquine prevents malaria by attacking liver-stage parasites, a property distinguishing it from most chemoprophylactics and obviating 4-week postexposure dosing. A daily adult regimen of 30 mg primaquine prevented malaria caused by Plasmodium falciparum and P. vivax for 20 weeks in 95 of 97 glucose-6-phosphate dehydrogenase (G6PD)-normal Javanese transmigrants in Papua, Indonesia. In comparison, 37 of 149 subjects taking placebo in a parallel trial became parasitemic. The protective efficacy of primaquine against malaria was 93% (95% confidence interval [CI] 71%-98%); against P. falciparum it was 88% (95% CI 48%-97%), and >92% for P. vivax (95% CI >37%-99%). Primaquine was as well tolerated as placebo. Mild methemoglobinemia (mean of 3.4%) returned to normal within 2 weeks. Blood chemistry and hematological parameters revealed no evidence of toxicity. Good safety, tolerance, and efficacy, along with key advantages in dosing requirements, make primaquine an excellent drug for preventing malaria in nonpregnant, G6PD-normal travelers.

Chloroquine/doxycycline combination versus chloroquine alone, and doxycycline alone for the treatment of Plasmodium falciparum and Plasmodium vivax malaria in northeastern Irian Jaya, Indonesia

Combination therapy is one method of overcoming the global challenge of drug-resistant Plasmodium falciparum malaria. We conducted a hospital-based 28-day in vivo test comparing chloroquine/doxycycline to chloroquine or doxycycline alone for treating P. falciparum and Plasmodium vivax malaria in Irian Jaya, Indonesia. Eighty-nine patients with uncomplicated falciparum malaria were randomized to standard dose chloroquine (n = 30), doxycycline (100 mg every 12 hours [7 days], n = 20), or chloroquine with doxycycline (n = 39); corresponding numbers for vivax malaria (n = 63) were 23, 16, 24. Endpoints were parasite sensitivity (S) or resistance (RI/RII/RIII). Of the 105 evaluable patients, chloroquine/doxycycline cured (S) 20/22 (90.9% [95% CI 78.9-100%]) patients with P. falciparum malaria; 2/22 (9.1% [0-21%]) were RIII resistant. Doxycycline cured 11/17 (64.7% [42.0-87.4%]) patients, and chloroquine 4/20 (20% [2.5-37.5%]). Against P. vivax, chloroquine/doxycycline cured (S) 12/17 (70.6% [48.9-92.2%]) patients, doxycycline 4/12 (33.3% [6.6-59.9%]), and chloroquine 5/17 (29.4% [7.7-51.1%]). Chloroquine/doxycycline was effective against P. falciparum but only modestly effective against P. vivax. These findings support the use of chloroquine/doxycycline as an inexpensive alternative to mefloquine for treating chloroquine-resistant P. falciparum but not chloroquine-resistant P. vivax in this setting.

Malaria prophylaxis using azithromycin: a double-blind, placebo-controlled trial in Irian Jaya, Indonesia

New drugs are needed for preventing drug-resistant Plasmodium falciparum malaria. The prophylactic efficacy of azithromycin against P. falciparum in malaria-immune Kenyans was 83%. We conducted a double-blind, placebo-controlled trial to determine the prophylactic efficacy of azithromycin against multidrug-resistant P. falciparum malaria and chloroquine-resistant Plasmodium vivax malaria in Indonesian adults with limited immunity. After radical cure therapy, 300 randomized subjects received azithromycin (148 subjects, 750-mg loading dose followed by 250 mg/d), placebo (77), or doxycycline (75, 100 mg/d). The end point was slide-proven parasitemia. There were 58 P. falciparum and 29 P. vivax prophylaxis failures over 20 weeks. Using incidence rates, the protective efficacy of azithromycin relative to placebo was 71.6% (95% confidence interval [CI], 50.3-83.8) against P. falciparum malaria and 98.9% (95% CI, 93.1-99.9) against P. vivax malaria. Corresponding figures for doxycycline were 96.3% (95% CI, 85.4-99.6) and 98% (95% CI, 88.0-99.9), respectively. Daily azithromycin offered excellent protection against P. vivax malaria but modest protection against P. falciparum malaria.

Age-dependent susceptibility to severe disease with primary exposure to Plasmodium falciparum

This study investigated the incidence of severe disease following primary exposure to Plasmodium falciparum by nonimmune children and adults in Irian Jaya, Indonesia. Four months after arrival, the cross-sectional prevalence of P. falciparum was 72%, and the monthly cumulative incidence of clinical diagnoses of malaria was 81%. Delirium or unconsciousness prompted evacuation to the hospital. Records of emergency evacuation of persons with a clinical diagnosis of malaria revealed an incidence density among adults (>15 years) of 1.34 events/person-year in the third month, whereas the rate in children remained stable at approximately 0.25 events/person-year (relative risk = 4.51, 95% confidence interval [CI] = 1.94-11). Through the first 6 months of exposure, 23.2% of adults were evacuated to the hospital with a diagnosis of malaria compared with 8.6% of children (relative risk = 2.7, 95% CI = 1.9-3.8). In this population with relatively few infants or people of advanced age, the risk of severe disease following primary exposure to P. falciparum increased with age.

Intestinal parasite infections after extended use of chloroquine or primaquine for malaria prevention

Comparative results of baseline and endpoint screening for intestinal parasites are reported from Javanese men enrolled in a year-long, placebo-controlled malaria prophylaxis trial in Irian Jaya. The objective was to detect nontarget qualitative changes that may have resulted from prolonged chloroquine (300 mg base weekly) or primaquine (0.5 mg base/kg daily) prophylaxis. Fresh fecal specimens were examined (blinded trial) for parasites and ova using a modified Kato-Katz thick smear method. More than 88% (94/106) of the baseline population was infected by 1 or more parasite species of which hookworm and Blastocystis hominis were dominant. Paired comparison between baseline and endpoint revealed no significant changes within the primaquine or chloroquine groups with regard to the variety of species found, the mean number of species or ova/subject, the relative proportion of infections caused by these species, or the occurrence of parasite-free, single, and multiple infections. Relative to placebo, there was a significantly greater proportion of infections by Entamoeba histolytica/dispar and a lower mean hookworm egg count in the chloroquine group. The endpoint proportion of new or increased infections in the primaquine group was significantly lower than that of the chloroquine group but comparable to that of the placebo. Despite the dosage employed, the frequency and duration of use, and excretion primarily through the bowels as the active parent compound, primaquine appeared to have little or no significant effect against a variety of common intestinal parasites. These largely negative results lend support for the safety and acceptability of primaquine as a daily malaria prophylactic in a population frequently at risk of intestinal helminth infections.

Halofantrine and primaquine for radical cure of malaria in Irian Jaya, Indonesia

The combination of halofantrine and primaquine therapies was calculated as a regimen for achieving radical curve of falciparum or vivax malaria in Irian Jaya, Indonesia, and compared with combined chloroquine and primaquine therapies. The patients who volunteered for the study [adult, male, Indonesian immigrants with no previous exposure to endemic malaria, normal glucose-6-phosphate dehydrogenase (G6PD) activity, uncomplicated malaria illness, no prior use of antimalarials, and parasitaemias of 0.001%-1.1%] were randomized to receive either halofantrine (24 mg base/kg bodyweight, in three equal doses over 12 h) or chloroquine (25 mg base/kg bodyweight over 48 h, in doses of 10, 10 and 5 mg base/kg at 24-h intervals). Each patient also received concurrent daily primaquine (0.5 mg base/kg bodyweight) for 14 days followed by the same dose on alternate days to day 28. A recurrent parasitaemia during the 28 days of follow-up constituted drug failure. Of the 40 cases of falciparum malaria and 26 cases of vivax malaria treated with halofantrine-primaquine, none had a recurrent parasitaemia (100% efficacy). In contrast, 20 of 30 patients with falciparum malaria and three of 27 with vivax malaria had recurrent parasitaemias after chloroquine-primaquine, giving efficacies of 33% and 89%, respectively. Halofantrine-primaquine was significantly more effective than chloroquine-primaquine against falciparum malaria (P < 0.001) but was similarly efficacious against vivax malaria (P = 0.23). On average, fever associated with falciparum or vivax malaria cleared 17 h faster with halofantrine-primaquine (P < 0.01) although there were no significant differences (P > 0.4) in parasite-clearance times between the two regimens. The halofantrine-primaquine regimen was also associated with a more rapid and significant decline in malaria-related physical complaints.

Survey of resistance to chloroquine by Plasmodium vivax in Indonesia

In February 1995 we surveyed to chloroquine among patients with Plasmodium vivax malaria at Nias Island, in the Indian Ocean near north-western Sumatra, Indonesa. The subjects, 21 indigenous males and females (6-50 years old) infected with > 40 asexual blood stage parasites of P. vivax per microliter of blood, had mild symptoms or none at all. Seven of these patients had > 100 ng/mL whole blood chloroquine levels before the first supervised dose of chloroquine (3 doses of 10 mg/kg, 10 mg/kg, 5 mg/kg of base given at 24 h intervals). Whole blood chloroquine levels on the last day of dosing confirmed normal absorption (range 413-3248, mean 1141, SD 616 ng/mL). Blood films were examined on days 0, 2, 4, 7, 11, 14, 18, 21 and 28 after initiating therapy. Three patients had recurrent asexual P. vivax parasitaemias between days 14 and 18, despite effective levels of chloroquine in whole blood (> or = 100 ng/mL) at the time of recurrence. Resistance to standard chloroquine therapy by P. vivax appeared in 14% of infections among residents of Nias.

Randomised placebo-controlled trial of primaquine for prophylaxis of falciparum and vivax malaria

Drug resistance has made malaria prevention difficult and the new agents are too expensive for widespread use. Primaquine, an established drug for treatment, is potentially useful for prevention. Malaria prophylaxis with primaquine was evaluated in Irian Jaya during one year in Javanese men who were not deficient in glucose-6-phosphate dehydrogenase (G-6-PD). 126 volunteers were randomised to receive 0.5 mg/kg primaquine base or placebo daily (double-blinded), or 300 mg chloroquine base weekly (open). The protective efficacy of primaquine relative to placebo was 94.5% (95% confidence interval 57-99) for Plasmodium falciparum and 90.4% (95% CI 58-98) for P vivax. Attack rates for either parasite did not differ significantly between the chloroquine and placebo groups. Incidence density of physical complaints not associated with parasitaemia was low (17-18 complaints/person-year) and was about the same in all groups except for cough, which was increased in the primaquine group. Complete blood counts were normal and no evidence of hepatic or renal dysfunction was found with primaquine. However, at 50 weeks the primaquine group had a mean methaemoglobin of 5.8% (range 1.4-13%), which declined by half within 7 days of ending prophylaxis. When used daily for one year by men with normal G-6-PD activity, primaquine was well tolerated and effective for prevention of malaria.

Treatment of chloroquine-resistant Plasmodium vivax with chloroquine and primaquine or halofantrine

Optimal therapy for infection by chloroquine-resistant Plasmodium vivax has not been established. From 1992 to 1994 during three separate studies, 147 Javanese residents of Irian Jaya infected by P. vivax were treated with either chloroquine (25 mg of base/kg during 3 days or 10 mg of base/kg in one dose) plus primaquine (10 mg/kg during 28 days or 2.5 mg/kg during 3 days) (n = 78), chloroquine plus placebo (n = 50), or halofantrine (24 mg base/kg in 12 h; n = 19). There was no difference in tolerance to or side effects of any of the regimens. Within 14 days of starting therapy, therapeutic failure among these patients was 44% for chloroquine, 5% for chloroquine plus primaquine (P < .001), and 0 for halofantrine (P < .001). After 28 days, therapeutic failure was 78%, 15%, and 6%, respectively. Thus, chloroquine plus primaquine in combination and halofantrine alone are effective therapies for chloroquine-resistant P. vivax.

Primaquine for prophylaxis against malaria among nonimmune transmigrants in Irian Jaya, Indonesia

A comparison of primaquine versus chloroquine for prophylaxis among nonimmune transmigrants from Java and Bali in the hyperendemic Arso region of Irian Jaya, Indonesia was conducted. Forty-five subjects received 0.5 mg of primaquine base/kg of body weight every other day, and 54 people in the same village received weekly 5 mg of chloroquine base/kg for 16-19 weeks beginning in December 1992. Plasmodium falciparum accounted for 18 of 30 infections with chloroquine, and four of five infections among subjects receiving primaquine. Plasmodium vivax was found in 12 people taking chloroquine but in just one person taking primaquine. The risk of malaria among people taking chloroquine relative to that among subjects taking primaquine was 3.96 (P = 0.014) for P. falciparum and 10.56 (P = 0.012) for P. vivax. Primaquine was better tolerated than chloroquine. The minimal protective efficacy for primaquine prophylaxis was 74% against P. falciparum and 90% against P. vivax among nonimmune children and adults living in Irian Jaya. These findings require confirmation with randomized, double-blinded, and placebo-controlled trials.

Malaria vaccine study site in Irian Jaya, Indonesia: Plasmodium falciparum incidence measurements and epidemiologic considerations in sample size estimation

Malaria epidemiologic and entomologic studies were performed during both the high transmission and low transmission seasons to characterize the Plasmodium falciparum malaria transmission at a proposed malaria vaccine trial site in Irian Jaya, Indonesia. The study population consisted of two subsets: native Irianese men with lifelong exposure to malaria and transmigrants who arrived from a nonmalarious area 2.5 years before the start of the study. All subjects received a radical cure for malaria and were then monitored weekly by blood film. Both P. falciparum malaria attack rates and incidence densities were calculated; transmigrants had a significantly higher rate (P = 0.003) than the Irianese during the low transmission season study (20-weeks long) but not during the high transmission season study (12-weeks long). Lack of exposure-induced immunity left the transmigrants at a minimum 17-25% greater relative risk of becoming parasitemic compared with the Irianese during the low transmission season study. During the high transmission season study, 50% of the transmigrants were P. falciparum positive by week 6 and 50% of the Irianese by week 9. During the low transmission season, 50% of the transmigrants were positive by week 10 and 43% of the Irianese were positive by week 17. Entomologic studies showed that Anopheles koliensis was the predominant vector (> 98% of anopheline catch). Entomologic inoculation rates for P. falciparum were 0.018 and 0.39 infective bites/person/night for the low and high transmission seasons, respectively. New P. vivax cases represented between 16% and 42% of all initial malaria cases.(ABSTRACT TRUNCATED AT 250 WORDS)

Age-specific prevalence of Plasmodium falciparum among six populations with limited histories of exposure to endemic malaria

The age-specific prevalence of Plasmodium falciparum parasitemia among residents of six villages in northeastern Irian Jaya, Indonesia, has been measured for a period of five years. All study subjects were transmigrants from Java living in Irian Jaya for three weeks to 72 months, depending upon the village and point of measurement. Fifteen separate estimates of prevalence were obtained from 4,554 Giemsa-stained thick blood films from 91 to 701 people (mean sample size = 304) among the six villages. The prevalence of parasitemia among people who had lived in Irian Jaya for less than one year did not decrease as a function of age, except in one village at eight months. In contrast, after 16 months to two years or more of residence, the prevalence of parasitemia decreased markedly with increasing age beyond 6-10 or 11-15 years. Social, behavioral, or entomologic characteristics of these populations did not explain the decreasing prevalence of parasitemia with age. An age-dependent naturally acquired protective immunity appeared to develop in all of these villages after 1-2 years of exposure to hyperendemic malaria.

Vivax malaria resistant to treatment and prophylaxis with chloroquine

Chloroquine has been the treatment of choice for vivax malaria for more than 40 years. Lately, several case-reports have suggested the emergence of resistance to chloroquine in Plasmodium vivax in Papua New Guinea and Indonesia. We undertook prospective treatment and prophylaxis trials of chloroquine in children and adults with vivax malaria living in Irian Jaya (Indonesia New Guinea). 46 villagers with P vivax parasitaemia were treated with chloroquine by mouth (25 mg base/kg body weight divided over 3 days) and followed up for 14 days. Parasitaemia cleared initially but recurred within 14 days in 10 (22%) subjects. All recurrences were in children younger than 11 years, 7 of whom were younger than 4 years; the failure rate among children under 4 was 70%. 7 of the patients with recurrences were given a second course of chloroquine. In all, the infections initially cleared but recurrent parasitaemia developed in 5 (71%) within 14 days. Whole-blood chloroquine concentrations were consistently above those previously shown to cure P vivax blood infections (90 micrograms/L whole blood). Subjects whose initial infections cleared and who had no parasitaemia on day 14 received weekly prophylaxis with chloroquine. Despite the presence of expected blood chloroquine concentrations, P vivax parasitaemia developed in 9 of 17 subjects receiving prophylaxis during 8 weeks of follow-up (median time to parasitaemia 5.3 weeks). Chloroquine can no longer be relied upon for effective treatment or chemoprophylaxis of P vivax blood infections acquired in this part of New Guinea.

Heightened transmission of stable malaria in an isolated population in the highlands of Irian Jaya, Indonesia

Malaria at an elevation of 1,500 meters is uncommon and is usually unstable when it occurs. To confirm reports of a recent increase in transmission of stable malaria in the Oksibil Valley, which is at an elevation of 1,250-1,500 meters in the Jayawijaya Mountains of Irian Jaya, Indonesia, five malariometric surveys were conducted in four villages between May 1990 and July 1991. A total of 3,380 blood smears, representative of 1,949 persons, was examined. Prevalence rates over the survey period were consistent in each of the four villages, averaging 10% for infants, 50% for children 1-4 years of age, 35% for those 5-9 years old, 28% for those 10-14 years old, and 16% for adults (greater than 15 years old). The spleen rate for the those less than five years old was 96%, with an average enlarged spleen score of 2.32. Plasmodium falciparum accounted for 55% of the infections in the valley, but P. vivax was the predominant species in those less than 10 years old. In the village of Kutdol at an elevation of 1,500 meters, P. malariae was identified in 43% of the positive smears. Four cases were diagnosed as P. ovale. Infection with P. falciparum without obvious clinical symptoms was common in both adults and children. Entomologic and epidemiologic data suggested that the recent upsurge in transmission coincided with the replacement of traditional village huts with the more modern social housing. This replacement required the extensive construction of drainage ditches, which inadvertently also served as additional vector breeding sites. We suspect that this manipulation of the environment, in an effort to improve the quality of life, created conditions conductive for heightened transmission of stable malaria.

Age-dependent acquired protection against Plasmodium falciparum in people having two years exposure to hyperendemic malaria

An epidemiologic study of susceptibility to frequent and high-grade parasitemia by Plasmodium falciparum revealed that age-dependent acquired protection developed within a two-year period of exposure to hyperendemic infection pressure. The study was conducted in a single village in northeastern Irian Jaya, Indonesia, where half the residents were native to the province and the other half were transmigrants from areas of Java, where there is little or no malaria transmission. Five separate measures of susceptibility to the asexual parasitemia of falciparum malaria were derived from results of four months of biweekly surveillance of 240 volunteers. Increasing protection as a function of age among the Javanese was a consistent pattern among the five estimates of susceptibility. These age-dependent functions of protection were quantitatively parallel to those among life-long residents of Irian Jaya. When humoral immune responsiveness to ring-infected erythrocyte surface antigen (RESA) was measured by ELISA, a similar pattern emerged; the relative level of antibody to RESA increased as parallel functions of age among the two subpopulations. Acquired protective immunity against P. falciparum was not the cumulative product of many years of heavy exposure to antigen. Instead, the full benefit of protection appeared to develop quickly. The degree of protection was governed by recent exposure and age, independent of history of chronic heavy exposure.

Resistance to antimalarials by Plasmodium falciparum in Arso PIR, Irian Jaya, Indonesia

Between 1987 and 1990, susceptibility of Plasmodium falciparum to chloroquine and to Fansidar was measured in vivo in 151 volunteers using the standard 7-day test. All volunteers lived in Arso PIR, Irian Jaya. A 25 mg/kg dose of chloroquine base was administered over a three-day period to 92 volunteers positive for P. falciparum rings (greater than 10 rings/200 white blood cells). Fifty volunteers (54%) showed results consistent with resistance. Twenty-nine were classified RII, and 21 RIII. In November 1989, a single curative dose of Fansidar was administered to 59 volunteers divided among three groups with 18 months, four years, and life-long exposure to endemic malaria. The proportion of volunteers in each group still positive for P. falciparum on day 7 of followup was 54%, 0%, and 14%, respectively. Thus, immune status profoundly effected clinically response to Fansidar. Standard in vitro microtests were also performed on parasites from 11 volunteers against chloroquine, amodiaquine, quinine, pyrimethamine/sulfadoxine, and and mefloquine. Nine of ten isolates showed in vitro growth consistent with resistance to chloroquine. Tests with other drugs showed few isolates with results considered indicative of susceptibility. Arso PIR has a severe drug resistance problem.

Resistance to chloroquine by Plasmodium vivax in Irian Jaya, Indonesia

Evidence of emerging resistance to chloroquine by Plasmodium vivax is described from Irian Jaya (Indonesian New Guinea). Sixteen of 24 residents in the village of Arso PIR II taking supervised weekly chloroquine prophylaxis (5 mg base/kg) had asexual parasitemia with P. vivax at least once during eight weeks of surveillance. An American working in the same village developed symptomatic P. vivax parasitemia despite chloroquine prophylaxis. Five days after therapy with 600 mg chloroquine base, the asexual parasitemia in the American increased 40-fold, but cleared after treatment with 1,500 mg chloroquine base. Serum samples were not available from many of the cases, but six local residents and the American had serum levels of chloroquine in excess of the ordinarily suppressive 15 ng/ml at the time of their asexual parasitemias (16-70 ng/ml). The weekly 300 mg base tablet of chloroquine, which has been the standard for prophylaxis against malaria for more than 40 years, was not effective against P. vivax in Arso PIR, Irian Jaya.

Prevalence of malaria in native and transmigrant populations. Effects of age and history of exposure

A malaria prevalence study was performed in a village in Irian Jaya, Indonesia, that contains a population of people who have been exposed lifelong to hyperendemic malaria and another population of people who had arrived 18 months previously from areas of very low endemicity. Mean spleen sizes correlated positively with prevalence of malaria, not resistance to it. Prevalence of sexual and asexual blood stage parasites was higher in transmigrants than in the natives. The data also show that clinical resistance to malaria in this part of the world includes resistance to Plasmodium falciparum gametocytemia and that this is not the passive byproduct of a reduction in asexual parasites. This indicates that the introduction of native people into a populated malarious area will increase the percent of gametocyte carriers and may, thereby, increase the entomologic inoculation rate.