The influx of low skilled workers from socioeconomically deprived neighbouring countries to Malaysia has raised concerns about the transmission of communicable gastrointestinal diseases such as giardiasis and cryptosporidiosis to the local population. Therefore, a cross sectional study was conducted to investigate the prevalence of both diseases and the genetic diversity of these pathogens in the migrant population. Microscopic examination of faecal samples from 388 migrant workers involved in five working sectors were screened and 10.8% (n = 42) were found to be positive with Giardia spp. and 3.1% (n = 12) with Cryptosporidium spp. infections. PCR amplicons at the triosephosphate isomerase (tpi) gene were successfully obtained for Giardia duodenalis from 30 (30/388; 7.73%) samples with assemblages AII and B in 13 (13/30; 43.3%) and 17 (17/30; 56.7%) positive samples, respectively. Nine samples (9/388; 2.3%) were identified as Cryptosporidium parvum using PCR-RFLP analysis. Country of origin, duration of residence in Malaysia and working sectors significantly influenced G. duodenalis assemblage AII infections amongst the targeted population. Meanwhile, C. parvum infection was significantly associated with those working in the food service sector. Despite the low presence of pathogenic G. duodenalis and C. parvum in the study population, the results highlight the risk of anthroponotic foodborne and waterborne transmission and therefore call for implementation of control strategies through improvements in personal hygiene and sanitation standards.
Access to clean and safe drinking water that is free from pathogenic protozoan parasites, especially Cryptosporidium parvum and Giardia lamblia that cause gastrointestinal illness in humans, is still an issue in Southeast Asia (SEA). This study is the first attempt to detect the aforementioned protozoan parasites in water samples from countries in SEA, using real-time polymerase chain reaction (qPCR) assays.
This cross-sectional study determined the prevalence of cryptosporidiosis in HIV-infected patients using polymerase chain reaction (PCR). Stool specimens were collected from HIV infected patients who were admitted to Hospital Raja Perempuan Zainab II, Kota Bharu, Malaysia, for various indications from December 2004 to December 2005. A modified acid-fast stain was performed on the direct stool smears, then the stool specimens were further tested using nested PCR targeting the 18S rRNA gene of Cryptosporidium parvum, with a built-in internal control (IC). Out of 59 samples, 11 were positives. Nested PCR identified a total of nine samples (16%) compared to microscopy, which identified only three samples. All PCR negative results showed IC amplicons, suggesting that these samples were true negatives and were not due to inhibition of PCR. This study highlights the importance of molecular diagnosis in determining the true prevalence and epidemiology of C. parvum.
Cryptosporidium species are protozoan parasites that infect humans and a wide variety of animals. This study was aimed at identifying Cryptosporidium species and genotypes isolated from avian hosts. A total of 90 samples from 37 different species of birds were collected throughout a 3-month period from April 2008 to June 2008 in the National Zoo of Kuala Lumpur, Malaysia. Prior to molecular characterization, all samples were screened for Cryptosporidium using a modified Ziehl-Neelsen staining technique. Subsequently samples were analysed with nested-PCR targeting the partial SSU rRNA gene. Amplicons were sequenced in both directions and used for phylogenetic analysis using Neighbour-Joining and Maximum Parsimony methods. Although 9 (10%) samples were positive for Cryptosporidium via microscopy, 8 (8.9%) produced amplicons using nested PCR. Phylogenetic trees identified all the isolates as Cryptosporidium parvum. Although C. parvum has not been reported to cause infection in birds, and the role of birds in this study was postulated mainly as mechanical transporters, these present findings highlight the significant public health risk posed by birds that harbour the zoonotic species of Cryptosporidium.
Cryptosporidium is a protozoan parasite of humans and animals and has a worldwide distribution. The parasite has a unique epidemiology in Middle Eastern countries where the IId subtype family of Cryptosporidium parvum dominates. However, there has been no information on Cryptosporidium species in Yemen. Thus, this study was conducted in Yemen to examine the distribution of Cryptosporidium species and subtype families. Fecal samples were collected from 335 patients who attended hospitals in Sana'a city. Cryptosporidium species were determined by PCR and sequence analysis of the 18 s rRNA gene. Cryptosporidium parvum and C. hominis subtypes were identified based on sequence analysis of the 60 kDa glycoprotein (gp60) gene. Out of 335 samples, 33 (9.9%) were positive for Cryptosporidium. Of them, 97% were identified as C. parvum whilst 1 case (3%) was caused by C. hominis. All 7 C. parvum isolates subtyped belonged to the IIaA15G2R1 subtype. The common occurrence of the zoonotic IIa subtype family of C. parvum highlights the potential occurrence of zoonotic transmission of cryptosporidiosis in Yemen. However, this postulation needs confirmation with future molecular epidemiological studies of cryptosporidiosis in both humans and animals in Yemen.