MOLECULAR CHARACTERIZATION OF AMERICAN CUTANEOUS LEISHMANIASIS IN THE TRI‑BORDER AREA OF ASSIS BRASIL, ACRE STATE, BRAZIL

Preliminary observations of the urbanization and domiciliation of the American cutaneous leishmaniasis in Rio Branco, Acre, Western Amazon

BACKGROUND

The American cutaneous leishmaniasis (ACL) is expanding in peri-urban environments.

METHODS

An entomological survey was conducted in the area of the occurrence of an autochthonous urban case of ACL. Sandflies and a parasitological slide of the human case were submitted for molecular diagnosis.

RESULTS

Nyssomyia whitmani and Ny. antunesi were the most frequently collected species. Ny. whitmani and Bichromomyia flaviscutellata were positive for Leishmania guyanensis and L. lainsoni, respectively. The human case tested positive for L. lainsoni.

CONCLUSIONS

Sandflies and Leishmania parasites present in urban forest may occur frequently in nearby domiciliary environments; thus, these areas must be monitored.

Severe mucosal leishmaniasis with torpid and fatal evolution

Mucosal leishmaniasis is a clinical condition that is difficult to diagnose and treat and usually precedes a cutaneous leishmaniasis condition with a long latency period as observed in our study of a patient who experienced a torpid evolution in 9 months, caused by having had cutaneous leishmaniasis on the neck without therapeutic treatment, although with ulcer closure 18 years earlier, incomplete treatment with antimonials and amphotericin B, with the destruction of the eyeball, a large area of necrosis on the face and nasal bone exposure. Additionally, the patient had chronic anemia (9.4 g/dl), lymphopenia and neutrophilia (lymphocytes 13.1%, neutrophils 84.4%), and co-infections by fungi (yeasts and hyphae) and Gram-negative bacteria (multidrug-resistant Proteus mirabilis and Escherichia coli) leading to sepsis and subsequent death of the patient.

Genotypic and phylogenic analyses of cutaneous leishmaniasis in Al Ahsa, Eastern Saudi Arabia during the coronavirus disease 2019 pandemic: First cases of Leishmania tropica with the predominance of Leishmania major

During the coronavirus disease 2019 lockdown period, a surge in sandflies and cutaneous leishmaniasis (CL) cases was observed in Al-Ahsa, Saudi Arabia. Skin punch biopsies were obtained from 100 patients clinically diagnosed with CL in Al-Ahsa who had no travel history in the last 6 months. Impression smears were used following a three-step polymerase chain reaction (PCR) protocol using genus-specific primers targeting kDNA and ITS1. Leishmania speciation was determined by ITS1 PCR/nested PCR-restriction fragment length polymorphism and sequencing. A phylogenetic tree was constructed. The associated patient characteristics were analyzed. Using internal transcribed spacer one (ITS1)-PCR/nested PCR, 98 cases were considered true-positive CL. Leishmania major was the predominant species, and Leishmania tropica was identified in three cases. Microscopy had poor sensitivity and perfect specificity. Direct ITS1-PCR missed nine cases. Sex, residence, and treatment outcome were significantly associated with the occurrence of Leishmania; distribution of skin lesion(s) and treatment outcome were significantly associated with Leishmania genotype. This is the first time that L. tropica was identified as a cause of CL in human in Al-Ahsa, in addition to the predominant zoonotic species, L. major. We recommend using ITS1-nested PCR for negative cases by ITS1-PCR. Further exploration of Leishmania transmission dynamics in vectors and reservoir animals is essential for designing effective preventive measures.

Remarkable diversity, new records and Leishmania detection in the sand fly fauna of an area of high endemicity for cutaneous leishmaniasis in Acre state, Brazilian Amazonian Forest

The species richness of Amazonian phlebotomines is considered to be one of the highest in the world. In the present study, we investigated the richness and diversity of phlebotomine fauna in Xapuri city, Acre state, Western Brazilian Amazonia, which is an area that is highly endemic for cutaneous leishmaniasis. Sand fly collections were performed monthly from August 2013 to July 2015 (288 h total of sampling effort) in intradomiciliary, peridomiciliary, and forested environments of two localities. Collected females were dissected, microscopically examined for flagellates in their guts, and preserved in ethanol. A total of 21,197 specimens comprising 14 genera and 57 species were collected, and the majority of these were Nyssomyia, Psychodopygus, and Trichophoromyia genera. Three new records of phlebotomine species for Acre are presented here, including Brumptomyia brumpti, Psathyromyia pradobarrientosi, and for the first time in Brazil, Th. omagua. In Xapuri, the phlebotomine fauna of different ecotopes was varied in regard to abundance, diversity, and frequency, and they included proven and permissive vectors of Leishmania spp. The fauna discovered in the forested areas (57 species) was richer and more diverse than was that (33 species) identified in the peri‑ and intra-domiciles. The identification of Leishmania subgenera that were present in sand fly guts according to SSU rRNA sequences revealed ten and three species harboring Leishmania of subgenera Viannia and Leishmania (most likely Leishmania amazonensis), respectively. The presence of Leishmania (Leishmania) in sand flies are reported here for the first time in Acre. The presence of L. (Viannia) spp. in Brumptomyia sp. and Lutzomyia sherlocki. and the occurrence of mixed infections with Leishmania of both subgenera in Ps. lainsoni have been reported for the first time in Brazil. Taken together, data from previous studies and from the present study highlight the remarkable complexity of phlebotomine fauna that is possibly due to the well-preserved Xapuri forested areas sustaining vital economic activities of plant extraction and ecological tourism. Our findings also provide new insights into the ongoing adaptation of Trichophoromyia and Psychodopygus species to human habitats.

Overcoming the Negligence in Laboratory Diagnosis of Mucosal Leishmaniasis

The northern region of Brazil, which has the largest number of cases of tegumentary leishmaniasis (TL) in the country, is also the region that has the highest diversity of species of vectors and Leishmania parasites. In this region, cases of mucosal leishmaniasis (ML), a clinical form of TL, exceed the national average of cases, reaching up to 12% of the total annual TL notifications. ML is associated with multiple factors, such as the parasite species and the viral endosymbiont Leishmania RNA virus 1 (LRV1). Being a chronic parasitological disease, laboratory diagnosis of ML poses a challenge for health services. Here, we evaluated more than 700 clinical samples from patients with clinical suspicion of TL, including patients with cutaneous leishmaniasis (CL) and mucosal leishmaniasis, comparing the results of parasitological tests—direct parasitological examination by microscopy (DP) and conventional PCR (cPCR) targeting of both kDNA and hsp70. The DP was performed by collecting material from lesions through biopsies (mucosal lesions) or scarification (cutaneous lesions); for PCR, a cervical brush was used for sample collection. Blood samples were tested employing standardized real-time PCR (qPCR) protocol targeting the HSP70 gene. PCR tests showed higher sensitivity than DP for both CL and ML samples. Considering ML samples only (N = 89), DP showed a sensitivity of 49.4% (N = 44) against 98.8% (N = 88) for kDNA PCR. The qPCR hsp70 for blood samples from patients with ML (N = 14) resulted in superior sensitivity (50%; N = 7) compared to DP (21.4%; N = 3) for samples from the same patients. Our results reinforced the need to implement a molecular test for the diagnosis of ML, in addition to proposing methods less invasive for collecting material from TL patients. Sample collection using a cervical brush in lesions observed in CL and ML patients is easy to perform and less invasive, compared to scarification and biopsies. Blood samples could be a good source for qPCR diagnosis for ML patients. Thus, we propose here a standardized method for collection and for performing of molecular diagnosis of clinical samples from suspicious ML patients that can be applied in reference services for improving ML diagnosis.

Occurrence of Leishmania infection in the immediate geographic region of Ji-Paraná, Rondônia State, Brazil

INTRODUCTION

This study evaluated the epidemiology of American cutaneous leishmaniasis in the immediate region of Ji-Paraná, Rondônia State.

METHODS

Samples and epidemiological data were collected from 105 patients.

RESULTS

Leishmania infection was observed in 58 (55.2%) patients, and Leishmania braziliensis was present in 82.9% of the 41 sequenced samples. Infected patients were predominantly male (93.1%). Leishmania infection was twice as prevalent among rural inhabitants versus urban inhabitants. Lesions were more frequent in the upper limbs (arms/hands, 41.82%).

CONCLUSIONS

The present data corroborate the zoonotic profile of cutaneous leishmaniasis; this information could help to improve surveillance and control strategies.

Tegumentary leishmaniasis by Leishmania braziliensis complex in Cochabamba, Bolivia including the presence of L. braziliensis outlier: Tegumentary leishmaniasis in Cochabamba, Bolivia

Leishmaniasis is caused by protozoans of the Leishmania genus, which includes more than 20 species capable of infecting humans worldwide. In the Americas, the most widespread specie is L. braziliensis, present in 18 countries including Bolivia. The taxonomic position of the L. braziliensis complex has been a subject of controversy, complicated further by the recent identification of a particular subpopulation named L. braziliensis atypical or outlier. The aim of this study was to carry out a systematic analysis of the L. braziliensis complex in Bolivia and to describe the associated clinical characteristics. Forty-one strains were analyzed by sequencing an amplified 1245 bp fragment of the hsp70 gene, which allowed its identification as: 24 (59%) L. braziliensis, 16 (39%) L. braziliensis outlier, and one (2%) L. peruviana. In a dendrogram constructed, L. braziliensis and L. peruviana are grouped in the same cluster, whilst L. braziliensis outlier appears in a separate branch. Sequence alignment allowed the identification of five non-polymorphic nucleotide positions (288, 297, 642, 993, and 1213) that discriminate L. braziliensis and L. peruviana from L. braziliensis outlier. Moreover, nucleotide positions 51 and 561 enable L. peruviana to be discriminated from the other two taxa. A greater diversity was observed in L. braziliensis outlier than in L. braziliensis-L. peruviana. The 41 strains came from 32 patients with tegumentary leishmaniasis, among which 22 patients (69%) presented cutaneous lesions (11 caused by L. braziliensis and 11 by L. braziliensis outlier) and 10 patients (31%) mucocutaneous lesions (eight caused by L. braziliensis, one by L. braziliensis outlier, and one by L. peruviana). Nine patients (28%) simultaneously provided two isolates, each from a separate lesion, and in each case the same genotype was identified in both. Treatment failure was observed in six patients infected with L. braziliensis and one patient with L. peruviana.

Clinical and epidemiological profiles of patients with American cutaneous leishmaniasis from the states of Pernambuco and Amazonas, Brazil

INTRODUCTION:

Brazil has a high number of cases of American cutaneous leishmaniasis (ACL) in the north and northeast regions. Therefore, continuous surveillance of environmental and socioeconomic factors in endemic areas is needed to develop strategic control measures. This study aimed to describe the clinical and epidemiological profiles of patients with ACL.

METHODS:

All patients were from the states of Amazonas and Pernambuco, and examinations were carried out between 2015 and 2018. All patients had a clinical and epidemiological history compatible with ACL after positive diagnostic tests. Information obtained from medical records included gender, employment activity, level of education, age, and number and sites of lesions.

RESULTS:

A total of 213 patients were included, of whom 30.98% were female and 69.02% were male. The main employment activity was agriculture (27.56%). The most common level of education was elementary (62.42%). The average age was approximately 39 years. The majority of the patients presented only with one lesion (54.87%), and legs/feet were the most commonly affected area (48.25%), followed by the arms/hands (44.75%).

CONCLUSIONS:

These data demonstrated that irrespective of the patients’ places of origin, interventions need to be focused on men of economically productive age, in view of the high risk of exposure to the vector in this group. Education activities need to be directed to farmers about the importance of protection against ACL vectors during work. Such information must also be directed to employers as a way of implementing and maintaining appropriate working conditions and stepping up vector control.

An overview of the sandfly fauna (Diptera: Psychodidae) followed by the detection of Leishmania DNA and blood meal identification in the state of Acre, Amazonian Brazil

BACKGROUND

In Acre state, Brazil, the dissemination of cutaneous leishmaniasis has increased in recent years, with limited knowledge of the potential Leishmania spp. vectors involved.

OBJECTIVES

Here, data concerning the sandfly fauna of Brasiléia municipality, Leishmania DNA-detection rates and the identification of blood meal sources of insects captured in 2013-2015 are presented.

METHODS

Parasite detection in female sandflies was performed individually by multiplex polymerase chain reaction (PCR) (Leishmania kDNA/sandfly cacophony-gene), with the identification of Leishmania spp. by hsp70-PCR and sequencing. The identification of blood gut-content from fed females was performed by cyt b-PCR and sequencing.

FINDINGS

A total of 4,473 sandflies were captured. A subgroup of 864 non-blood-fed females evaluated for the presence of Leishmania DNA showed 2.9% positivity for Leishmania (Viannia) braziliensis and L. (V.) guyanensis. The identification of blood meal sources was performed in 96 blood-fed females, allowing the identification of 13 vertebrate species. In nine/96 fed females, DNA from L. (V.) shawi, L. (V.) guyanensis, L. (V.) braziliensis and Endotrypanum sp. was detected.

MAIN CONCLUSIONS

In Brumptomyia sp. and Evandromyia termitophila, the first report of Leishmania DNA-detection is provided in Acre; Nyssomyia shawi is implicated as potential vector of L. (V.) braziliensis and L. (V.) guyanensis for the first time in Brazil.

Comparison of BG-Lure and BG-Sweetscents attractants for field sampling of phlebotomine sand flies

Phlebotomines are important vectors of bacteria, viruses and protozoan parasites. Protozoans of the genus Leishmania which cause visceral and cutaneous leishmaniases, are among the most important etiologic agents transmitted by sand flies. Different blends of human and animal volatiles have been evaluated for use in surveillance and/or control of hematophagous insects. With regard to phlebotomine sand flies there are few records of attraction under laboratory and field conditions. This study was carried out at two collecting sites located in a Brazilian town with a high prevalence of cutaneous leishmaniasis. The aim of the present study was to evaluate the effect of adding two kinds of commercial bait which mimic human odors to light traps to attract sand flies and compare the results with those of light traps without any additional bait. The commercial baits, BG-Lure® and BG-Sweetscent®, were developed to catch anthropophilic mosquitoes. Three treatments were evaluated: 1 - HP light trap with BG-Lure® added; 2 - HP light trap with BG-Sweetscent® added and 3- HP light trap without any attractant. A total of 3,682 sand flies were collected during the study. Constrained correspondence analysis was applied to perform ordination of the captured community of sand fly species that could be explained by attractant, sampling site and sex. The most abundant species: Pintomyia nevesi, Nyssomyia whitmani and Nyssomyia antunesi were further investigated by fitting generalized linear mixed models. Only Ny. whitmani showed a slight indication of an increase in catches with BG-Lure®.

Drug-containing hydrophobic dressings as a topical experimental therapy for cutaneous leishmaniasis

Cutaneous leishmaniasis (CL), a clinical condition caused mainly by Leishmania amazonensis in Brazil, is characterized by topical, painless ulcers. The current treatment, based on intravenous administration of pentavalent antimonials, presents low adherence by patients and may cause serious adverse effects, leading to the need for searching new therapeutic options. Thus, this study aimed at evaluating a topical administration of "intelligent dressings" as an alternative treatment for CL. BALB/c mice were infected with L. amazonensis promastigotes. Afterward, lesions were treated with hydrophobic dressings incorporated with clinically used drugs. After lesion development, the following analyses were carried out: measurement of lesion diameters, biochemical analyses of serum, evaluation of the recovery of amastigote forms and histological analyses. No significant clinical changes in serum parameters were observed. The group that was treated with dressings impregnated with Glucantime^® displayed the lowest number of amastigotes recovered from tissues (parasite load). Conventional treatment with Glucantime^® (i.p.) was also able to reduce parasite load. After 6 weeks from the measurement of the lesions mice treated with dressings impregnated with Pentamidine displayed the smallest values. Representative histological aspects of the lesions showed the absence or few amastigotes inside the macrophages when mice were treated with dressings impregnated with Glucantime^® and Pentamidine, respectively. The findings presented here indicate that the topical treatments may constitute an alternative treatment option for CL.

Leishmania (Viannia) braziliensis type 2 as probable etiological agent of canine cutaneous leishmaniasis in Brazilian Amazon

Canine cutaneous leishmaniasis (CCL) is a zoonosis of public health interest, and in the Americas, Leishmania (Viannia) braziliensis has been identified as the main etiological agent. The present study sought to investigate Leishmania spp. infection in domestic dogs from a rural area of the Xapuri municipality, Acre state, Brazilian Amazonia. For this purpose, visits were carried out to domiciles where the human cases of American cutaneous leishmaniasis (ACL) occurred, followed by the clinical evaluation of the animals in search of clinical signs suggestive of CCL. Blood samples were collected from 40 dogs, 13 of which had lesions suggestive of CCL, and biopsies of these lesions were performed. The methods used were Neal, Novy, and Nicolle’s (NNN) medium cultures and direct parasitological examination. Further, to detect and characterize Leishmania DNA some molecular techniques were performed such as conventional polymerase chain reaction (PCR) and sequencing targeting SSU rDNA and ITS1, restriction fragment length polymorphism (RFLP) and high resolution melting (HRM) analysis targeting hsp70. The investigation revealed that the results obtained from the parasitological methods were negative. In PCR by ITS1 and network topology sequences, six strains from dogs, isolated from the Peruvian Andes, appeared identical to Leishmania (Viannia) braziliensis type 2 (99–100%). By other molecular methods these samples turned out to be positive to Leishmania (Viannia) sp.. The diagnosis of Leishmania in domestic dogs from Acre state showed a high proportion of infected animals, and the occurrence of L. braziliensis type 2 in Brazil for the first time. This new report suggests that L. braziliensis type 2 is both trans- and cis-Andean. However, more studies are needed regarding the clinical and diagnostic aspects of this species of Leishmania.

Leishmania species in biopsies of patients with different clinical manifestations identified by high resolution melting and nested PCR in an Endemic district in Peru

Background

The parasite of the genus Leishmania causes a neglected disease known as leishmaniasis, which has different clinical aspects depending on the species that infects the person and the immune response of the patient. The objective was to determine, using molecular biology, the current circulating species of Leishmania in biopsies of different types of cutaneous leishmaniasis (CL) from the endemic district in the region of “Madre de Dios”, Peru.

Methods

The study's 19 samples were obtained in the Huepethue district in the “Madre de Dios” region from patients who were diagnosed for suspected leishmaniasis infection with three clinical manifestations. These were analyzed using kDNA-PCR, Nested-PCR and HRM-PCR to identify the genus of an infecting parasite as well as its species.

Results

kDNA-PCR detected all tests for the genus of Leishmania to be positive, while the Nested-PCR could not detect 20.9% of species (one L. (V.) braziliensis and three L. (V.) amazonensis), and the HRM-PCR detected all species presented in the samples. The most prevalent species was L. (V.) braziliensis (73.7%), and the clinical manifestations were ulcers (63.2%), superficial scabs (5.3%) and diffuse form (5.3%), followed by L. (V.) amazonensis (15.8%), manifesting ulcers (15.6%), and L. (V.) lainsoni (10.5%), manifesting superficial scabs (5.3%) and ulcers (5.3%). L. (V.) braziliensis, L. (V.) amazonensis and L. (V.) lainsoni were detected effectively using HRM-PCR in the samples with different clinical manifestations.

Conclusions

Highlighting the findings of a high diversity of Leishmania species using High Resolution Melting PCR in biopsies with different clinical manifestations of cutaneous leishmaniasis.

Phlebotomine sandfly (Diptera: Psychodidae) diversity and their Leishmania DNA in a hot spot of American Cutaneous Leishmaniasis human cases along the Brazilian border with Peru and Bolivia

In this study, we identified the phlebotomine sandfly vectors involved in the transmission of American Cutaneous Leishmaniasis (ACL) in Assis Brasil, Acre, Brazil, which is located on the Brazil-Peru-Bolivia frontier. The genotyping of Leishmania in phlebotomines was performed using polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism. A total of 6,850 sandflies comprising 67 species were captured by using CDC light traps in rural areas of the municipality. Three sandfly species were found in the state of Acre for the first time: Lutzomyia georgii, Lu. complexa and Lu. evangelistai. The predominant species was Lu. auraensis/Lu. ruifreitasi and Lu. davisi (total 59.27%). 32 of 368 pools were positive for the presence of Leishmania DNA (16 pools corresponding to Lu. davisi, and 16 corresponding to Lu. auraensis/Lu. ruifreitasi), with a minimal infection prevalence of 1.85% in Lu. davisi and 2.05% in Lu. auraensis/Lu. ruifreitasi. The Leishmania species found showed maximum identity with L. (Viannia) guyanensis and L. (V.) braziliensis in both phlebotomine species. Based on these results and similar scenarios previously described along the Brazil/Peru/Bolivia tri-border, the studied area must take into consideration the possibility of Lu. davisi and Lu. auraensis/Lu. ruifreitasi as probable vectors of ACL in this municipality.

Trichophoromyia auraensis is a putative vector

The sandfly Trichophoromyia auraensis has recently evolved as a proven vector of Leishmania (Viannia) endemic to state of Acre in the north of Brazil. This note is intended to propose a correction in the report of the first occurrence of natural infection of Leishmania (Viannia) in this species. We and the other scientific groups reinforced that Tr. auraensis is a possible vector involved in the transmission of American cutaneous leishmaniasis in Acre, Brazil.

Epidemiological aspects of American cutaneous leishmaniasis (ACL) in an endemic area of forest extractivist culture in western Brazilian Amazonia

The study sought to analyze clinical and epidemiological aspects of cutaneous leishmaniasis (CL) in Xapuri, Acre, Brazil. Data from 2008 to 2014 registered in the notification records of the disease of the Information System of the Complaints of Notification (SINAN), and the data of the Information Department of the Unified Health System (DATASUS) available from 2007 to 2013 were used and analyzed in the light of the statistics of the temporal series by the Prais-Winsten method and chi-squared test. A total of 906 cases were registered with 60.2% occurring in men and 39.7% in women. The groups from 0 to 4 years of age (48.0%) and from 5 to 19 years of age (23.3%) were the most affected. Regarding the clinical forms, 77.7% presented CL and 22.3% mucocutaneous leishmaniasis (MCL). Among the 896 cases with information on the diagnostic methods used, Montenegro's skin test predominated (66.4%), with a positive result of 95.8% for CL and 99.3% for MCL. Treatment with N-methylglucamine antimony was performed in 99.4% of the cases, but discontinuously used in the majority of patients. This study presents information which may be used as a tool for the epidemiological surveillance and control of the disease in Xapuri, a region which depends essentially on forest resources and ecological tourism.

Field Validation of SYBR Green- and TaqMan-Based Real-Time PCR Using Biopsy and Swab Samples To Diagnose American Tegumentary Leishmaniasis in an Area Where Leishmania (Viannia) braziliensis Is Endemic

The precise diagnosis of American tegumentary leishmaniasis (ATL) is an essential task due to the disease's associated morbidity. A noninvasive, extremely sensitive, and highly specific exam is critical, particularly for mucosal leishmaniasis (ML), in which a low parasite quantity is expected. We aimed to compare the diagnostic accuracy of swab and biopsy sample analysis using SYBR Green- and TaqMan-based real-time PCR (qPCR) assays with that of a composite reference standard consisting of the Montenegro skin test, serology, histopathology, smears, culture, and conventional PCR. In total, 55 patients with ATL (ML, 18 patients; cutaneous leishmaniasis [CL], 37 patients) and 36 patients without ATL were studied. qPCR analysis of swabs was more accurate when using SYBR Green (87.88%; 95% confidence interval [CI], 77.86 to 93.73 patients) than when using TaqMan (78.79%; 95% CI, 67.49 to 86.92%) (P = 0.031). SYBR Green (84.72%; 95% CI, 74.68 to 91.25%) was also more accurate than TaqMan (73.61%; 95% CI, 62.42 to 82.41%) for biopsy samples (P = 0.008). All qPCR methods were 100% specific. Swabs and biopsy specimens had similar sensitivity when using the same chemistry (P = 0.125 for SYBR Green and P = 0.625 for TaqMan). Moreover, qPCR achieved better performance than most existing techniques used for the diagnosis of ATL and also detected the Leishmania parasite in a greater proportion of patients than the associated histopathology, smear, culture, and conventional PCR techniques did. Swabs therefore represent a useful diagnostic tool because they not only are noninvasive but also can achieve an accuracy similar to that of biopsy samples. The high accuracy of SYBR Green-based qPCR may also reduce the requirement for associated parasitological tests for ATL diagnosis.

Pre-examination factors affecting molecular diagnostic test results and interpretation: A case-based approach

BACKGROUND

Multiple organizations produce guidance documents that provide opportunities to harmonize quality practices for diagnostic testing. The International Organization for Standardization ISO 15189 standard addresses requirements for quality in management and technical aspects of the clinical laboratory. One technical aspect addresses the complexities of the pre-examination phase prior to diagnostic testing.

METHODS

The Committee for Molecular Diagnostics of the International Federation for Clinical Chemistry and Laboratory Medicine (also known as, IFCC C-MD) conducted a survey of international molecular laboratories and determined ISO 15189 to be the most referenced guidance document. In this review, the IFCC C-MD provides case-based examples illustrating the value of select pre-examination processes as these processes relate to molecular diagnostic testing. Case-based examples in infectious disease, oncology, inherited disease and pharmacogenomics address the utility of: 1) providing information to patients and users, 2) designing requisition forms, 3) obtaining informed consent and 4) maintaining sample integrity prior to testing.

CONCLUSIONS

The pre-examination phase requires extensive and consistent communication between the laboratory, the healthcare provider and the end user. The clinical vignettes presented in this paper illustrate the value of applying select ISO 15189 recommendations for general laboratory to the more specialized area of Molecular Diagnostics.