Human coronavirus (HCoV) NL63 is recognized as a common cause of upper respiratory infections and influenza-like illness. In screening children with acute undifferentiated febrile illness in a school cohort in rural Haiti, we identified HCoV-NL63 in blood samples from four children. Cases clustered over an 11-day period; children did not have respiratory symptoms, but two had gastrointestinal complaints. On phylogenetic analysis, the Haitian HCoV-NL63 strains cluster together in a highly supported monophyletic clade linked most closely with recently reported strains from Malaysia; two respiratory HCoV-NL63 strains identified in north Florida in the same general period form a separate clade, albeit again with close linkages with the Malaysian strains. Our data highlight the variety of presentations that may be seen with HCoV-NL63, and underscore the apparent ease with which CoV strains move among countries, with our data consistent with recurrent introduction of strains into the Caribbean (Haiti and Florida) from Asia.
Diarrheal diseases (DD) are leading causes of disease burden, death, and disability, especially in children in low-income settings. DD can also impact a child's potential livelihood through stunted physical growth, cognitive impairment, and other sequelae. As part of the Global Burden of Disease Study, we estimated DD burden, and the burden attributable to specific risk factors and particular etiologies, in the Eastern Mediterranean Region (EMR) between 1990 and 2013. For both sexes and all ages, we calculated disability-adjusted life years (DALYs), which are the sum of years of life lost and years lived with disability. We estimate that over 125,000 deaths (3.6% of total deaths) were due to DD in the EMR in 2013, with a greater burden of DD in low- and middle-income countries. Diarrhea deaths per 100,000 children under 5 years of age ranged from one (95% uncertainty interval [UI] = 0-1) in Bahrain and Oman to 471 (95% UI = 245-763) in Somalia. The pattern for diarrhea DALYs among those under 5 years of age closely followed that for diarrheal deaths. DALYs per 100,000 ranged from 739 (95% UI = 520-989) in Syria to 40,869 (95% UI = 21,540-65,823) in Somalia. Our results highlighted a highly inequitable burden of DD in EMR, mainly driven by the lack of access to proper resources such as water and sanitation. Our findings will guide preventive and treatment interventions which are based on evidence and which follow the ultimate goal of reducing the DD burden.
Leptospirosis is a zoonotic bacterial disease caused by pathogenic species of the genus Leptospira. Disease incidence is known to be attributed to environmental and social conditions which promote the spread of reservoir hosts, primarily rodents. A well-being program was conducted to determine the seroprevalence and risk factors associated with leptospirosis in urban poor communities occupying low-cost flat accommodation and squatter settlements in the vicinity of Wilayah Persekutuan, Kuala Lumpur. Blood samples from a total of 532 volunteers were screened for the detection of IgG and IgM antibodies against leptospirosis using ELISA. Demographic data were collected for each participant through a questionnaire survey before blood collection. The overall seroprevalence was low (12.6%, n = 67/532; 95% CI: 9.9-15.7%), with 8.1% (n = 43/532) being seropositive for anti-Leptospira IgG, indicating previous infection, and 4.9% (n = 26/532) for anti-Leptospira IgM, indicating current infection. Two significant factors such as host age (P ≤ 0.01) and knowledge of disease transmission (P = 0.017) significantly influenced the presence of anti-Leptospira IgM, whereas the detection of anti-IgG indicated the presence of clean drinking water sources (P = 0.043). Despite the low prevalence, the transmission of leptospirosis does occur among urban poor communities, suggesting the need for undertaking public awareness programs.
The Indonesian government has provided iron-folic acid (IFA) supplementation in response to maternal pregnancy iron-deficiency anemia. However, community-based cohorts on IFA's effects on maternal and infant anemia are limited. A mixed-method study design with a primary longitudinal cohort was used to observe the association between IFA and anemia in mothers and infants. Iron-folic acid supplementation was observed throughout pregnancy. Anemia status was based on a single hemoglobin assessment using HemoCue Hb 201 + in the second or third trimester of pregnancy for the mother and at birth for the infant. Qualitative data were collected via in-depth interviews (IDIs) and a forum group discussion (FGD). Iron-folic acid supplementation with > 180 tablets throughout pregnancy was associated with lower pregnancy anemia (adjusted relative risk [aRR] = 0.25, 95% CI: 0.092-0.664, P = 0.006) after adjusting for potential confounding variables. Supplementation with IFA was not associated with infant anemia (RR = 1.033, 95% CI: 0.70-1.54, P = 0.873 for 90-180 tablets and RR = 1.07, 95% CI 0.70-1.63, P = 0.774 for > 180 tablets). The IDIs and FGD suggested that IFA and multivitamin content knowledge, IFA consumption monitoring, and paternal involvement were important in IFA supplementation and effectiveness in reducing anemia. Iron-folic acid supplementation was associated with reduced maternal but not infant anemia. Because maternal anemia is associated with infant anemia, an anemia monitoring program for women in early pregnancy is vital in addressing infant health. Paternal involvement was also identified as a major factor in maternal and child health.
Leptospirosis is an important zoonotic disease with worldwide distribution and nonspecific clinical manifestation. We report a case of fatal leptospirosis in a previously healthy woman with a causative agent. A young adult Indian woman was brought in dead to the forensic department. Ten days before, she developed fever, dizziness with headache, myalgia, diarrhea, and vomiting. Routine inquest and autopsy were performed on the deceased, revealing hemorrhagic lungs with extensive intra-alveolar hemorrhages, pale liver with dissociation and separation of hepatocyte plates, and edematous brain with histiocyte and lymphocyte infiltration in the parenchyma and meninges. Heart tissue depicts myocarditis and pericarditis inflammatory changes. Cerebrospinal fluid (CSF) was turbid in appearance with mildly elevated leukocytes, predominantly lymphocytes. Real-time PCR targeting lipL32 gene of pathogenic Leptospira was detected in the blood, CSF, brain, kidney, heart, and liver. The genetic profile of the causative agent was ST149 (multi-locus sequence typing Scheme 3). This study illustrates the usefulness of Leptospira PCR assay in postmortem diagnosis and addresses the need for further surveillance to identify the epidemiological link of the disease.
Co-infection of melioidosis and leptospirosis is uncommon. We report here four such cases, confirmed by blood culture for melioidosis and blood polymerase-chain reaction for leptospirosis, which occurred among rescuers involved in a search and rescue operation for a young man who was suspected to have drowned in Lubuk Yu, a recreational forest in Pahang, Malaysia. Despite treatment, three of the patients died from the co-infection.
Toxoplasma gondii primary infection in pregnancy is associated with poor obstetric outcomes. This study aimed to determine the seroprevalence of Toxoplasma infection in pregnant migrant and refugee women from Myanmar attending antenatal care in Thailand. A random selection of 199 residual blood samples from first antenatal screen in 2014-2015 was tested for Toxoplasma IgG and IgM antibodies. Seroprevalence of Toxoplasma infection was 31.7% (95% confidence interval = 25.6-38.4). Avidity testing in the three positive IgM cases indicated all were past infections. Multiparity (≥ 3 children) was significantly associated with higher Toxoplasma seropositivity rates. Seroprevalence of T. gondii infection in this pregnant population is similar to the only other report from Myanmar, where multiparity was also identified as a significant association. Toxoplasma infection is important in pregnant women. Nevertheless, in this marginalized population, this infection may be given less priority, due to resource constraints in providing the most basic components of safe motherhood programs.
The simian parasite Plasmodium knowlesi is now the commonest cause of malaria in Malaysia and can rapidly cause severe and fatal malaria. However, microscopic misdiagnosis of Plasmodium species is common, rapid antigen detection tests remain insufficiently sensitive and confirmation of P. knowlesi requires polymerase chain reaction (PCR). Thus available point-of-care diagnostic tests are inadequate. This study reports the development of a simple, sensitive, colorimetric, high-throughput loop-mediated isothermal amplification assay (HtLAMP) diagnostic test using novel primers for the detection of P. knowlesi. This assay is able to detect 0.2 parasites/μL, and compared with PCR has a sensitivity of 96% for the detection of P. knowlesi, making it a potentially field-applicable point-of-care diagnostic tool.
Liver transaminase elevations after treatment in malaria volunteer infection studies (VISs) have raised safety concerns. We investigated transaminase elevations from two human Plasmodium vivax VISs where subjects were treated with chloroquine (n = 24) or artefenomel (n = 8) and compared them with studies in Thailand (n = 41) and Malaysia (n = 76). In the VISs, alanine transaminase (ALT) increased to ≥ 2.5 × upper limit of normal (ULN) in 11/32 (34%) volunteers, peaking 5-8 days post-treatment. Transaminase elevations were asymptomatic, were not associated with elevated bilirubin, and resolved by day 42. The risk of an ALT ≥ 2.5 × ULN increased more than 4-fold (odds ratio [OR] 4.28; 95% CI: 1.26-14.59; P = 0.02) for every log10 increase in the parasite clearance burden (PCB), defined as the log-fold reduction in parasitemia 24 hours post-treatment. Although an elevated ALT ≥ 2.5 × ULN was more common after artefenomel than after chloroquine (5/8 [63%] versus 6/24 [25%]; OR 5.0; 95% CI: 0.91-27.47; P = 0.06), this risk disappeared when corrected for PCB. Peak ALT also correlated with peak C-reactive protein (R = 0.44; P = 0.012). Elevations in ALT (≥ 2.5 × ULN) were less common in malaria-endemic settings, occurring in 1/41 (2.5%) Thai patients treated with artefenomel, and in none of 76 Malaysians treated with chloroquine or artemisinin combination therapy. Post-treatment transaminase elevations are common in experimental P. vivax infection but do not appear to impact on participant safety. Although the mechanism of these changes remains uncertain, host inflammatory response to parasite clearance may be contributory.
We evaluated the diagnostic sensitivity and specificity of two dot-enzyme-linked immunoassays (Typhidot and Typhidot-M; Malaysian Biodiagnostic Research SDN BHD, Kuala Lumpur, Malaysia), assessing IgG and IgM antibodies against the outer membrane protein (OMP) of Salmonella typhi, and the Widal test in comparison with blood culture in a consecutive group of children with suspected typhoid fever. Of 97 children with suspected typhoid fever, the disease was confirmed bacteriologically in 46 (47%), whereas 25 (26%) were considered to have typhoid fever on clinical grounds. An alternative diagnosis was made in 26 (27%). The Typhidot and Typhidot-M were superior to the Widal test in their diagnostic sensitivity and specificity, although values (sensitivity = 85-94% and specificity = 77-89%) were significantly lower than in other regional reports. The lower specificity of the Typhidot in our series may represent regional differences in the genomic structure and plasticity of the OMP of S. typhi and merits further evaluation of these tests in diverse geographic locations.
Previously, we reported the presence of imported trichinellosis in a Thai worker returning from Malaysia, who presented with progressive generalized muscle hypertrophy and weakness after eating wild boar meat. This work analyzed a partial small subunit of a mitochondrial ribosomal RNA gene of Trichinella larvae isolated from the patient. The results showed complete identity with a mitochondrial RNA gene of Trichinella papuae (GenBank accession no. EF517130). This is the first report of imported trichinellosis in Thailand caused by T. papuae. It is possible that T. papuae is widely distributed in the wildlife of Southeast Asia.
The malaria parasite rates and densities were compared in 79 ovalocytic-normocytic pairs of Malayan Aborigines matched for age, sex, proximity of residence to each other, and use of bed nets when sleeping in their jungle settlement in central Peninsular Malaysia. Malaria infection was determined from thick and thin Giemsa-stained blood films collected monthly for a period of six months. Blood films from ovalocytic individuals were found to be positive for malaria less often than in persons with normal red blood cells (P less than 0.05). Malaria infections per 100 person-months at risk were 9.7 in the ovalocytic group compared with 15.19 in the normocytic group. Among individuals parasitemic at any time, heavy infections (greater than or equal to 10,000 parasites/mm3 of blood) with Plasmodium falciparum, P. vivax, and P. malariae were encountered only in normocytic subjects, which comprised approximately 12.5% of the malaria-positive individuals in this group. In an earlier survey of 629 settlers that identified subjects for the above study, the prevalence of ovalocytosis was found to increase significantly with age. The above field observations support the view that ovalocytic individuals might have a survival advantage in the face of malaria. Consideration of the ovalocytic factor is indicated in future evaluations of malaria control measures in areas where ovalocytosis is prevalent.
Human anisakiasis is a zoonosis acquired by eating raw or undercooked infected seafood. Herein, we report a case of acute dysentery caused by anisakiasis in a 64-year-old man in Malaysia. A colonoscopy was performed and a nematode larva was found penetrating the mucosa of the ascending colon. Bleeding was observed at the site of penetration. Y-shaped lateral epidermal cords were seen from the cross section of the worm, which is a prominent feature of Anisakis larva. Molecular analysis using polymerase chain reaction of cytochrome oxidase 2 (cox2) gene confirmed the specimen to be larva of Anisakis simplex.
The lack of rapid, affordable, and accurate diagnostic tests represents the primary hurdle affecting malaria surveillance in resource- and expertise-limited areas. Loop-mediated isothermal amplification (LAMP) is a sensitive, rapid, and cheap diagnostic method. Five species-specific LAMP assays were developed based on 18S rRNA gene. Sensitivity and specificity of LAMP results were calculated as compared with microscopic examination and nested polymerase chain reaction. LAMP reactions were highly sensitive with the detection limit of one copy for Plasmodium vivax, Plasmodium falciparum, and Plasmodium malariae and 10 copies for Plasmodium knowlesi and Plasmodium ovale. LAMP positively detected all human malaria species in all positive samples (N = 134; sensitivity = 100%) within 35 minutes. All negative samples were not amplified by LAMP (N = 67; specificity = 100%). LAMP successfully detected two samples with very low parasitemia. LAMP may offer a rapid, simple, and reliable test for the diagnosis of malaria in areas where malaria is prevalent.
In this study, three molecular assays (real-time multiplex polymerase chain reaction [PCR], merozoite surface antigen gene [MSP]-multiplex PCR, and the PlasmoNex Multiplex PCR Kit) have been developed for diagnosis of Plasmodium species. In total, 52 microscopy-positive and 20 malaria-negative samples were used in this study. We found that real-time multiplex PCR was the most sensitive for detecting P. falciparum and P. knowlesi. The MSP-multiplex PCR assay and the PlasmoNex Multiplex PCR Kit were equally sensitive for diagnosing P. knowlesi infection, whereas the PlasmoNex Multiplex PCR Kit and real-time multiplex PCR showed similar sensitivity for detecting P. vivax. The three molecular assays displayed 100% specificity for detecting malaria samples. We observed no significant differences between MSP-multiplex PCR and the PlasmoNex multiplex PCR kit (McNemar's test: P = 0.1489). However, significant differences were observed comparing real-time multiplex PCR with the PlasmoNex Multiplex PCR Kit (McNemar's test: P = 0.0044) or real-time multiplex PCR with MSP-multiplex PCR (McNemar's test: P = 0.0012).
We report a case of Ancylostoma ceylanicum infection detected by endoscopy. It was diagnosed and confirmed using polymerase chain reaction (PCR) and DNA sequencing. The patient is a 58-year-old Malaysian woman who lives in a rural area, where uncontrolled populations of stray and semidomesticated dogs live in close proximity with humans.
Plasmodium knowlesi is now known as the fifth Plasmodium species that can cause human malaria. The Plasmodium merozoite surface protein (MSP) has been reported to be potential target for vaccination and diagnosis of malaria. MSP-1(33) has been shown to be immunogenic and its T cell epitopes could mediate cellular immune protection. However, limited studies have focused on P. knowlesi MSP-133. In this study, an approximately 28-kDa recombinant P. knowlesi MSP-1(33) (pkMSP-1(33)) was expressed by using an Escherichia coli system. The purified pkMSP-1(33) reacted with serum samples of patients infected with P. knowlesi (31 of 31, 100%) and non-P. knowlesi malaria (27 of 28, 96.43%) by Western blotting. The pkMSP-1(33) also reacted with P. knowlesi (25 of 31, 80.65%) and non-P. knowlesi malaria sera (20 of 28, 71.43%) in an enzyme-linked immunosorbent assay (ELISA). Most of the non-malarial infection (49 of 52 in by Western blotting and 46 of 52 in the ELISA) and healthy donor serum samples (65 of 65 by Western blotting and ELISA) did not react with recombinant pkMSP-1(33).