BACKGROUND: The palm oil industry is the largest contributor to global production of oils and fats. Indonesia and Malaysia are the largest producers of palm oil. More than a million workers are employed in this industry, yet there is a lack of information on their occupational health and safety.
OBJECTIVE: To identify and summarize occupational hazards among oil palm plantation workers.
METHODS: A search was carried out in June 2018 in PubMed, Web of Science, Scopus, and Ovid. Relevant publications were identified by a systematic search of four databases and relevant journals. Publications were included if they examined occupational hazards in oil palm plantation workers.
RESULTS: 941 publications were identified; of these, 25 studies were found eligible to be included in the final review. Of the 25 studies examined, 19 were conducted in Malaysia, 2 in Costa Rica, and one each in Ghana, Indonesia, Myanmar, Papua New Guinea, and Cameroon. Oil palm plantation workers were found to be at risk of musculoskeletal conditions, injuries, psychosocial disorders, and infectious diseases such as malaria and leptospirosis. In addition, they have potential exposure to paraquat and other pesticides.
CONCLUSION: In light of the potential of palm oil for use as a biofuel, this is an industry with strong growth potential. The workers are exposed to various occupational hazards. Further research and interventions are necessary to improve the working conditions of this already vast and growing workforce.
Pulsed-field gel electrophoresis (PFGE) of XbaI-digested chromosomal DNA was performed on 133 strains of Salmonella enterica serovar Typhi obtained from Papua New Guinea, with the objective of assessing the temporal variation of these strains. Fifty-two strains that were isolated in 1992 and 1994 were of one phage type, D2, and only two predominant PFGE profiles, X1 and X2, were present. Another 81 strains isolated between 1997 and 1999 have shown divergence, with four new phage types, UVS I (n = 63), UVS (n = 5), VNS (n = 4), and D1 (n = 9), and more genetic variability as evidenced by the multiple and new PFGE XbaI profiles (21 profiles; Dice coefficient, F = 0.71 to 0.97). The two profiles X1 and X2 have remained the stable, dominant subtypes since 1992. Cluster analysis based on the unweighted pair group method using arithmetic averages algorithm identifies two main clusters (at 87% similarity), indicating that the divergence of the PFGE subtypes was probably derived from some genomic mutations of the X1 and X2 subtypes. The majority of isolates were from patients with mild and moderate typhoid fever and had various XbaI profiles. A single isolate from a patient with fatal typhoid fever had a unique X11 profile, while four of six isolates from patients with severe typhoid fever had the X1 pattern. In addition, 12 paired serovar Typhi isolates recovered from the blood and fecal swabs of individual patients exhibited similar PFGE patterns, while in another 11 individuals paired isolates exhibited different PFGE patterns. Three pairs of isolates recovered from three individuals had different phage types and PFGE patterns, indicating infection with multiple strains. The study reiterates the usefulness of PFGE in assessing the genetic diversity of S. enterica serovar Typhi for both long-term epidemiology and in vivo stability and instability within an individual patient.
Distal renal tubular acidosis (dRTA) caused by mutations of the SLC4A1 gene encoding the erythroid and kidney isoforms of anion exchanger 1 (AE1 or band 3) has a high prevalence in some tropical countries, particularly Thailand, Malaysia, the Philippines and Papua New Guinea (PNG). Here the disease is almost invariably recessive and can result from either homozygous or compound heterozygous SLC4A1 mutations.
Dengue virus (DENV) circulates in human and sylvatic cycles. Sylvatic strains are both ecologically and evolutionarily distinct from endemic viruses. Although sylvatic dengue cycles occur in West African countries and Malaysia, only a few cases of mild human disease caused by sylvatic strains and one single case of dengue hemorrhagic fever in Malaysia have been reported. Here we report a case of dengue hemorrhagic fever (DHF) with thrombocytopenia (13000/µl), a raised hematocrit (32% above baseline) and mucosal bleeding in a 27-year-old male returning to Spain in November 2009 after visiting his home country Guinea Bissau. Sylvatic DENV-2 West African lineage was isolated from blood and sera. This is the first case of DHF associated with sylvatic DENV-2 in Africa and the second case worldwide of DHF caused by a sylvatic strain.
Nipah virus is a recently emergent paramyxovirus that is capable of causing severe disease in both humans and animals. The first outbreak of Nipah virus occurred in Malaysia and Singapore in 1999 and, more recently, outbreaks were detected in Bangladesh. In humans, Nipah virus causes febrile encephalitis with respiratory syndrome that has a high mortality rate. The reservoir for Nipah virus is believed to be fruit bats, and humans are infected by contact with infected bats or by contact with an intermediate animal host such as pigs. Person to person spread of the virus has also been described. Nipah virus retains many of the genetic and biologic properties found in other paramyxoviruses, though it also has several unique characteristics. However, the virologic characteristics that allow the virus to cause severe disease over a broad host range, and the epidemiologic, environmental and virologic features that favor transmission to humans are unknown. This review summarizes what is known about the virology, epidemiology, pathology, diagnosis and control of this novel pathogen.
Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) mediates parasite sequestration to the cerebral microvasculature via binding of DBLβ domains to intercellular adhesion molecule 1 (ICAM1) and is associated with severe cerebral malaria. In a cohort of 187 young children from Papua New Guinea (PNG), we examined baseline levels of antibody to the ICAM1-binding PfEMP1 domain, DBLβ3PF11_0521, in comparison to four control antigens, including NTS-DBLα and CIDR1 domains from another group A variant and a group B/C variant. Antibody levels for the group A antigens were strongly associated with age and exposure. Antibody responses to DBLβ3PF11_0521 were associated with a 37% reduced risk of high-density clinical malaria in the follow-up period (adjusted incidence risk ratio [aIRR] = 0.63 [95% confidence interval {CI}, 0.45 to 0.88; P = 0.007]) and a 25% reduction in risk of low-density clinical malaria (aIRR = 0.75 [95% CI, 0.55 to 1.01; P = 0.06]), while there was no such association for other variants. Children who experienced severe malaria also had significantly lower levels of antibody to DBLβ3PF11_0521 and the other group A domains than those that experienced nonsevere malaria. Furthermore, a subset of PNG DBLβ sequences had ICAM1-binding motifs, formed a distinct phylogenetic cluster, and were similar to sequences from other areas of endemicity. PfEMP1 variants associated with these DBLβ domains were enriched for DC4 and DC13 head structures implicated in endothelial protein C receptor (EPCR) binding and severe malaria, suggesting conservation of dual binding specificities. These results provide further support for the development of specific classes of PfEMP1 as vaccine candidates and as biomarkers for protective immunity against clinical P. falciparum malaria.
Virulence of Shigella is attributed to the genes presence in chromosome or in the megaplasmid. The apy gene which is located in the megaplasmid of Shigella species encodes for apyrase enzyme, a pathogenesis-associated enzyme causing mitochondrial damage and host cell death. In this study we constructed an apy mutant of Shigella flexneri by insertional activation using a kanamycin resistant gene cassette. The wild type apy gene of S. flexneri 2a was PCR amplified, cloned and mutated with insertion of kanamycin resistant gene cassette (aphA). The mutated construct (apy: aphA) was subcloned into a conjugative suicidal vector (pWM91) at the unique Sma1 and Sac1 sites. The mutation of the wild apy gene in the construct was confirmed by DNA sequencing. The mutated construct was introduced into wild type S. flexneri 2a by conjugation with Escherichia coli. After undergoing homologous recombination, the wild apy gene was deleted from the construct using the sucrose selection method. Non-functional activity of the apyrase enzyme in the constructed strain by colorimetric test indicated the successful mutation of the apyrase enzyme. This strain with mutated apy gene was evaluated for its protective efficacy using the guinea pig keratoconjunctivitis model. The strain was Sereny negative and it elicited a significant protection following challenge with wild S. flexneri strain. This apy mutant strain will form a base for the development of a vaccine target for shigellosis.
The small pseudoscorpion family Pseudochiridiidae Chamberlin, 1923 comprises two genera and 12 extant species recorded from Asia (Burma, Christmas Island, Indonesia, India, Nepal, Malaysia, New Guinea, Philippines, Nicobars and Sumba), eastern, central and southern Africa (Chad, D.R. Congo, Kenya, South Africa, Tanzania), Madagascar, Seychelles (Aldabra), North America (Florida) and the Caribbean Islands of Dominican Republic and Cuba (Harvey 2013, Barba & Barroso 2013); one unidentified species is mentioned for the fauna of Mexico (Ceballos 2004). A fossil species has been described from Dominican amber by Judson (2007), who predicted the presence of this family in South America.
The complete mitochondrial genome of a highland freshwater crayfish, Cherax monticola, was recovered by shotgun sequencing. The mitogenome consists of 15,917 base pairs containing 13 protein-coding genes, 2 ribosomal subunit genes, 22 transfer RNAs and a non-coding AT-rich region. The base composition of C. monticola is 33.46% for T, 21.48% for C, 33.71% for A and 11.35% for G, with an AT bias of 67.17%.
A 22-year-old Malay female presented with left eye floaters for 2 weeks, associated with temporal visual field defect and metamorphopsia for 3 days. She has a guinea pig and a hedgehog at home, but denied being bitten or scratched by them. Her visual acuity at presentation was 6/12 on the left eye and 6/6 on the right eye. Her left eye relative afferent pupillary defect was barely positive with mild anterior chamber reaction. Fundus examination of the left eye showed mild vitritis, swollen optic disc with macular star, crops of active choroidal lesions at superonasal retina with a linear arrangement in the form of migratory track nasally. However, there were no nematodes seen on fundus examination. Investigations showed normal full blood count with no eosinophilia and positive serology test for Bartonella henselae. She was diagnosed to have dual infection - diffuse unilateral subacute neuroretinitis (DUSN), based on the presence of crops of choroidal lesions with migratory track, and cat scratch disease (CSD) based on a positive serological test. She was treated with oral albendazole 400 mg 12 hourly for 6 weeks for DUSN and oral doxycycline 100 mg 12 hourly for 4 weeks for CSD. Focal laser had been applied to the area of migratory track in the left eye. Her left eye vision improved to 6/6 at 1 month after treatment, with resolution of neuroretinitis.
The Oriental, Australasian and Oceanian genus Caiusa Surcouf, 1920 is revised, species concepts being based on male and female genitalia. A key to males for all known species, and a key to females for all except one are given. All relevant types still in existence have been studied, complete synonymies given and the geographical distribution reconsidered. The eight species included in the genus are: Caiusa borneoensis sp. nov. (Malaysia, Thailand, Vietnam); Caiusa coomani Séguy, 1948 (China, Malaysia, Singapore, Thailand, Vietnam); Caiusa indica Surcouf, 1920 (Australia, Cambodia, India, Indonesia, Malaysia, Papua New Guinea, Philippines, Singapore, Solomon Islands, Sri Lanka, Thailand, Vietnam); Caiusa karrakerae sp. nov. (Malaysia, Thailand); Caiusa kurahashii sp. nov. (Indonesia, Japan, Philippines); Caiusa pooae sp. nov. (Thailand); Caiusa testacea Senior-White, 1923 (India, Nepal, Sri Lanka) and Caiusa violacea Séguy, 1925, stat. rev. (Cambodia, China, Laos, Malaysia, Taiwan, Thailand, Vietnam). A lectotype is designated for Caiusa indica to fix the interpretation of the name. Caiusa nigronitens Senior-White, 1923, syn. nov. and Caiusa surcoufi Bezzi, 1927, syn. nov. are established as junior synonyms of Caiusa indica. Caiusa violacea is correctly diagnosed and errors in the original description of the female holotype are pointed out. Caiusa dubiosa Villeneuve, 1927 is established as a junior synonym of C. violacea, syn. nov. Seven Caiusa species have been reared from the egg mass of various species of frogs. The reproductive mode of the eighth species, i.e., C. indica, is unknown. Five species, i.e., C. borneoensis, C. coomani, C. karrakerae, C. kurahashii and C. violacea have been reared from one or more of the foam nesting frog species Chiromantis nongkhorensis (Cochran, 1927), Polypedates leucomystax (Gravenhorst, 1927), Polypedates megacephalus Hallowell, 1861, Rhacophorus annamensis Smith, 1924, Rhacophorus dulitensis Boulenger, 1892, Rhacophorus kio Ohler & Delorme, 2005 and Rhacophorus owstoni (Stejneger, 1907) all belonging in the family Rhacophoridae in Anura. These five Caiusa species all have a specialised ovipositor tip, with small spine-like setae on the ST8 and the hypoproct, probably enabling the flies to oviposit on a foam nest with a hardened outer surface. They form a monophyletic group on account of these features of the ovipositor, unique in the Oestroidea. The sixth species, C. testacea, has been reared from a frog egg mass, the frog species being unknown. Its ovipositor structure is also unknown. The seventh species, C. pooae, has been reared once from the jelly-like egg mass of Feihyla hansenae (Cochran, 1927), also in Rhacophoridae. Caiusa pooae females do not have spine-like setae on the ovipositor, a fact correlated with the soft outer surface of the jelly-like egg mass on which a C. pooae female had oviposited. The extreme rarity of C. pooae oviposition on Feihyla hansenae egg masses may indicate that this fly perhaps has another, unknown, regular oviposition substrate. Caiusa pooae and C. indica make up a second monophyletic group within Caiusa. Caiusa indica, the most common and most widespread species of the genus, has an ovipositor structure similar to C. pooae. Its breeding substrate is unknown and it occurs both within and outside the distributional area of Rhacophoridae. Possibly both C. indica and C. pooae share a regular oviposition substrate that has still to be discovered. The holotype female of Plinthomyia emimelania Rondani, 1875 from Sarawak is established as a member of the genus Bengalia Robineau-Desvoidy, 1830, thus Plinthomyia Rondani, 1875 becomes a junior synonym of Bengalia Robineau-Desvoidy, 1830, syn. nov. It is removed from the synonymy of Phumosia Robineau-Desvoidy, 1830.
Crinum asiaticum Linn plant is used in Malaysia as a rheumatic remedy and to relieve local pain. In the present study, we examined the anti-inflammatory effects of this plant extract on carrageenan-induced hind paw oedema in mice. C. asiaticum was serially extracted with petroleum ether, followed by chloroform and lastly, methanol. The chloroform and methanol extracts of the plant given orally (50 mg kg-1) caused significant (p < 0.05; n = 7) reduction in paw oedema but the petroleum ether extract did not induce significant effect (p > 0.05) on paw oedema. The methanol extract was then dissolved in water and extracted consecutively with chloroform, ethyl acetate and butanol. The chloroform fraction of methanol extract (CFME) treatment (50 mg kg(-1)) significantly reduced (p < 0.05; n = 7) the acute paw oedema. This may indicate that active anti-inflammatory compounds are present in the CFME. In an attempt to study the mechanism of action of its anti-inflammatory activity, the effects of CFME on BK- and histamine-induced contractions were investigated in isolated rat uterus and guinea-pig ileum preparations, respectively. It was found that CFME caused dose-dependent reduction (p < 0.05; n = 6) of the contractile response induced by BK and shifted the log dose-response curve of histamine to the right. The present findings suggest that C. asiaticum possessed an anti-inflammatory activity as suggested by its use in traditional medicine. The anti-inflammatory activity of this plant could not have been due to its anti-bradykinin activities as CFME non-specifically inhibited BK-induced contraction. It also suggest that CFME may contain compound(s) with anti-histaminic properties. The significance of these findings is discussed.
Public concern about the adverse environmental and human health impacts of organochlorine contaminants led to strict regulations on their use in developed nations two decades ago. Nevertheless, DDT and several other organochlorine insecticides are still being used for agriculture and public health programs in developing countries in Asia and the South Pacific. As a consequence, humans in this region are exposed to greater dietary levels of organochlorines. In this review, published information on organochlorine concentrations in foodstuffs from South and Southeast Asia and Oceanic countries has been compiled. Foodstuffs that contribute to human exposures and dietary intakes of organochlorines were examined, and the data compared with those reported from more developed nations. Among various developing countries in Asia, considerable information on organochlorines in foodstuffs has been available from India since the late 1960s. DDT and HCH were the major insecticides in Indian foodstuffs. Concentrations of these insecticides have declined more than two orders of magnitude in farm products, such as food grains and vegetables, in two decades. Milk and milk products are the major sources of dietary exposure to DDT and HCH in India. The residues of these insecticides in dairy products were close to or above the MRLs of the FAO/WHO. Dietary intake of DDT and HCH by Indians was > 100 fold that in more developed nations. Sporadic incidences of greater concentrations (> 1 microgram/g) of aldrin, dieldrin, and heptachlor have been measured in Indian vegetables. Untreated surface waters could be a potential source of DDT and HCH exposure. In most Southeast Asian countries DDT was the common contaminant in animal origin foodstuffs. The higher percentage of p,p'-DDT in meat and fish from Southeast Asian countries, except Japan and Korea, indicated the recent use of DDt in vector control operations. Dietary intakes of DDt and HCH in Southeast Asia were an order of magnitude less than those of Indians but 5- to 10 fold greater than in more developed nations. In addition to DDT, aldrin and dieldrin were prominent in meat collected from Thailand and Malaysia. Aquatic food products from more industrialized countries, such as Japan, South Korea, Hong Kong, and Taiwan, contained significant levels of PCBs. In South Pacific countries, particularly in Australia and New Zealand, chlordanes and PCBs were the most prevalent organochlorines in foodstuffs. Food contamination by DDT, HCH, aldrin, and dieldrin was less than in developing countries in Asia but greater than in the U.S. and Japan. Intake of PCBs in Australia was greater than in the U.S. Meat and fish were the major sources of organochlorine exposure by Australians. Human dietary intake of organochlorines has been declining more slowly in developing countries in Asia. Current intakes were at least 5- to 100 fold greater than those in more developed nations, suggesting a greater risk from organochlorine exposure. Factors such as malnutrition, common among rural poor in developing nations, can increase these risks. Of greatest concern is the magnitude of exposure to organochlorines to which infants and children are subjected through human and dairy milk. The estimated intake of DDT by infants was at least 100 fold greater than the ADI of the FAO/WHO. In addition to DDT, excessive exposures to HCH and dieldrin may cause potential health effects in infants because they are more vulnerable to toxic effects. The design and implementation of appropriate epidemiological studies and their integration with monitoring of human, food, and environmental samples would be a major step in assessing the risks of organochlorine residues in foods and controlling or eliminating them. With the continued globalization of trade in food products, and the concomitant risk that food contaminated through point-source pollution may be widely distributed, identification of sources and their control should be matters of
Persistent organochlorines in air, river water and sediment samples were analysed from eastern and southern Asia (India, Thailand, Vietnam, Malaysia, Indonesia) and Oceania (Papua New Guinea and Solomon Islands) to elucidate their geographical distribution in tropical environment. The concentrations of organochlorines in these abiotic samples collected from Taiwan, Japan and Australia were also monitored for comparison. Atmospheric and hydrospheric concentrations of HCHs (hexachlorocyclohexanes) and DDTs (DDT and its metabolites) in the tropical developing countries were apparently higher than those observed in the developed nations, suggesting extensive usage of these chemicals in the lower latitudes. CHLs (chlordane compounds) and PCBs (polychlorinated biphenyls) were also occasionally observed at higher levels in the tropics, implying that their usage area is also expanding southward. Distribution patterns of organochlorines in sediments showed smaller spatial variations on global terms, indicating that the chemicals released in the tropical environment are dispersed rapidly through air and water and retained less in sediments. The ratios of organochlorine concentrations in sediment and water phases were positively correlated with the latitude of sampling, suggesting that persistent and semivolatile compounds discharged in the tropics tend to be redistributed on a global scale.
We have investigated the effect of indomethacin on histamine- and acetylcholine (ACh)-induced responses in the intact and denuded epithelium of guinea pig isolated tracheal smooth muscle. Epithelium removal resulted in increased responsiveness to ACh and histamine. Indomethacin (2.8 microM) enhanced the sensitivity of both intact and denuded preparations to histamine and ACh. These findings suggest that the tracheal epithelium of guinea pig plays a protective role against bronchoconstrictors, such as ACh and histamine. Furthermore, indomethacin-mediated hyperresponsiveness caused by these agonists in epithelium denuded preparations might be a reflection of removal of prostaglandin (PG) biosynthesis. A similar process of interaction in indomethacin-treated asthmatic patients (with damaged airway epithelium) might take place. The significance of these findings is discussed.
We studied the effect of indomethacin, a cyclooxygenase inhibitor, on bradykinin-induced responses in the intact and denuded epithelium of the isolated tracheal smooth muscle in guinea pigs. Epithelium removal alone did not alter the responsiveness to bradykinin. Indomethacin (2.8 microM) enhanced the sensitivity to bradykinin of both intact and denuded preparations. This finding suggests that the tracheal epithelial may have no protective effect on the contractile responses induced by bradykinin. This may be due to the presence of high amounts of bradykinin-inactivating enzymes in the tracheal smooth muscle. Indomethacin-medicated potentiation caused by bradykinin in epithelium intact and denuded preparations may be an indication of removal of the bronchodilator prostaglandin biosynthesis. The significance of these findings is discussed.
Chloroquine-resistant Plasmodium vivax was originally reported in Papua, New Guinea by Reickman in 1989.1 In the same year, in Colombia, South America, Arias and Corredor2 reported relapses of 11 patients suffering from vivax malaria, following a chloroquine-primaquine regimen. Garavelli and Corti3 suggested chloroquine-resistant Plasmodium vivax may be present in Brazil following these therapeutic relapses. Further therapeutic failures in returned travelers from South America were reported by Moore et al (1994).4 We report vivax malaria in a group of expeditioners visiting Guyana who, whereas compliant with antimalarial chemoprophylaxis, developed clinical malaria, adding evidence to the presence of chloroquine-resistant Plasmodium vivax in South America. Raleigh International is a youth development charity that undertakes environmental and community projects around the world. These are usually in remote locations. Nine expeditions in countries such as Chile, Belize, Zimbabwe, Uganda, and Malaysia are organized annually. A project manager and a medical officer are placed at each site, along with approximately 10 venturers (age 17-25.) Participants are of all nationalities, but, at present, they are predominantly British.
Ovalocytosis, an hereditary condition in which most erythrocytes are oval in shape, is a polymorphism that occurs in up to 20% or more of the population in Papua New Guinea and Malaysia. Due to the geographical correlation of the trait with endemic malaria, the possibility of a selective advantage in resistance to malaria has been raised. In a study of 202 individuals with greater than or equal to 50% oval red cells matched by age, sex and village of residence with controls having less than or equal to 30% oval cells, ovalocytic subjects had blood films negative for Plasmodium vivax (P = 0.009), for P. falciparum (P = 0.044), and for all species of malaria parasites (P = 0.013), more often than controls. Among individuals parasitaemic at any time there were no clear differences in density of parasitaemia. However, in children 2 to 4 years old, parasite densities of both species were lower in ovalocytic subjects than in controls (0.01 less than P less than 0.025). The differential susceptibility to malaria infection suggested by this study has implications for the evaluation of interventions, including possible future vaccine field trials, in populations where high-frequency ovalocytosis is present.