Successful extraction and PCR amplification of Giardia DNA from formalin-fixed stool samples.

Extracting genomic DNA of pathogenic agents from formalin-fixed specimens is inherently difficult. Storage of samples in formalin results in nucleic acid cross-linking and DNA fragmentation. In this study, DNA was extracted from 45 Giardia-positive stool samples stored in formalin and subjected to PCR amplification targeting the triose phosphate isomerase (tpi), beta gardin (bg) and glutamate dehydrogenase (gdh) genes. Samples were rehydrated by using a descending alcohol series before DNA extraction using a commercial kit. This was followed by EDTA-mediated inhibition of DNase activity and prolonged treatment with proteinase K to digest contaminating proteins. DNA was amplified at rates of 64.4% (29/45) at the tpi, 40% (18/45) at the bg and 20% (9/45) at the gdh loci as seen on nested PCR. DNA quality was subsequently tested in a genotyping experiment which produced high-quality sequences at the tpi (41.2%; 12/29) bg (50%; 9/18), and gdh (22.2%; 2/9) loci and enabled differentiation of Giardia strains at the subtype level. The modified extraction protocol was effective at removing inhibitors and reversing cross-linking of DNA. However, PCR amplification was limited to short fragments of DNA which resulted in highest success rate on amplification of the shortest (334 bp) gene fragment tested.

Dysregulated TGF-ß Production Underlies the Age-Related Vulnerability to Chikungunya Virus.

Chikungunya virus (CHIKV) is a re-emerging global pathogen with pandemic potential, which causes fever, rash and debilitating arthralgia. Older adults over 65 years are particularly susceptible to severe and chronic CHIKV disease (CHIKVD), accounting for >90% of all CHIKV-related deaths. There are currently no approved vaccines or antiviral treatments available to limit chronic CHIKVD. Here we show that in old mice excessive, dysregulated TGFß production during acute infection leads to a reduced immune response and subsequent chronic disease. Humans suffering from CHIKV infection also exhibited high TGFß levels and a pronounced age-related defect in neutralizing anti-CHIKV antibody production. In vivo reduction of TGFß levels minimized acute joint swelling, restored neutralizing antibody production and diminished chronic joint pathology in old mice. This study identifies increased and dysregulated TGFß secretion as one key mechanism contributing to the age-related loss of protective anti-CHIKV-immunity leading to chronic CHIKVD.

Multilocus sequence analysis of Giardia spp. isolated from patients with diarrhea in Austria.

Giardia duodenalis is a protozoan parasite causing intestinal infections in a wide range of mammals. Two distinct assemblages, A and B, infect humans predominantly; however, both are believed to be generally zoonotic. Giardia strains associated with infections in Austria have not been investigated at the molecular level. In this study, 65 human stool samples microscopically positive for Giardia spp. were subjected to DNA isolation and nested PCR targeting fragments of the glutamate dehydrogenase (gdh), triose phosphate isomerase (tpi), and beta-gardin (bg) genes. A total of 52 samples were successfully analyzed using PCR and DNA sequencing. Assemblage B was detected most frequently and accounted for 65.4% (34/52) of infections, while Assemblage A accounted for 34.6% (18/52). There was a high level of genetic diversity among the isolates with 46.2% designated as sub-assemblage BIV (24/52), 25% sub-assemblage AII (13/52), 19.2% sub-assemblage BIII (10/52), and 9.6% sub-assemblage AI (5/52). No mixed infections were detected. The results suggest that the majority of infections were imported and that endemic anthroponotic transmission plays a minor role in Austria.

Molecular epidemiology and multilocus sequence analysis of potentially zoonotic Giardia spp. from humans and dogs in Jamaica.

Giardia spp. are the causative agents of intestinal infections in a wide variety of mammals including humans and companion animals. Dogs may be reservoirs of zoonotic Giardia spp.; however, the potential for transmission between dogs and humans in Jamaica has not been studied. Conventional PCR was used to screen 285 human and 225 dog stool samples for Giardia targeting the SSU rDNA gene followed by multilocus sequencing of the triosephosphate isomerase (tpi), glutamate dehydrogenase (gdh), and ß-giardin (bg) genes. Prevalence of human infections based on PCR was 6.7 % (19/285) and canine infections 19.6 % (44/225). Nested PCR conducted on all 63 positive samples revealed the exclusive presence of assemblage A in both humans and dogs. Sub-assemblage A-II was responsible for 79.0 % (15/19) and 70.5 % (31/44) of the infections in humans and dogs, respectively, while sub-assemblage A-I was identified at a rate of 15.8 % (3/19) and 29.5 % (13/44) in humans and dogs, respectively. The predominance of a single circulating assemblage among both humans and dogs in Jamaica suggests possible zoonotic transmission of Giardia infections.

The performance of the SD BIOLINE Dengue DUO® rapid immunochromatographic test kit for the detection of NS1 antigen, IgM and IgG antibodies during a dengue type 1 epidemic in Jamaica.

BACKGROUND: Dengue is an important mosquito-borne viral infection that affects millions of persons worldwide. Early diagnosis is necessary to effect appropriate management and decrease mortality. Immunochromatographic tests are advantageous in producing dengue test results within 30 min but these results should be sensitive and specific. In this study we evaluated the diagnostic performance of the SD BIOLINE Dengue DUO® rapid immunochromatographic test kit. A panel of 309 dengue and 30 non-dengue single serum samples characterized by using reference enzyme-linked immunosorbent assays (ELISAs) was used. These samples were received in the virology laboratory for routine testing during a dengue type 1 outbreak between October to December, 2012. RESULTS: The overall diagnostic sensitivities of the SD BIOLINE Dengue DUO® rapid testfor IgM, IgG and NSI were 49.3% (95% CI: 41.3-57.4), 39.1% (95% CI: 33.3-45.2) and 90% (95% CI: 82.1-94.7), respectively. The IgM and IgG detection rates were significantly lower than that of the NSI (p < 0.001). However the combination of the IgM detection with NS1 detection or both NS1 and IgG resulted in a significant (p < 0.001) increase in sensitivity to 97.5% (95 % CI: 92.9-99.2) and 98.9% (95 % CI: 96.0-99.7), respectively. These higher sensitivities were achieved without any decrease in specificities. CONCLUSIONS: This study revealed that combining two or more parameters of the SD BIOLINE Dengue DUO® rapid kit significantly improved the sensitivity of diagnosis of dengue virus infection and supports its usefulness in the Jamaican setting.

Isolation and genotyping of acanthamoeba strains from soil sources from Jamaica, West Indies.

Acanthamoeba spp. are opportunistic pathogens that are ubiquitous in nature. Many species of this genus are responsible for a fatal encephalitis and keratitis in humans and other animals. Seventy-two soil samples were collected from the parishes across Jamaica and assessed for the presence of Acanthamoeba spp. Cultivation was carried out on non-nutrient agar plates seeded with heat killed Escherichia coli. PCR and sequencing of the DF3 region were carried out in order to genotype the isolated strains of Acanthamoeba. Thermotolerance and osmotolerance assays were utilized to investigate the pathogenic potential of the Acanthamoeba isolates. Acanthamoeba spp. was isolated from 63.9% of soil samples. Sequencing of the DF3 region of the 18S rDNA resulted in the identification of genotypes T4, T5, and T11. T4 genotype was most frequently isolated. Most isolates were thermotolerant or both thermotolerant and osmotolerant, indicating that they may present the potential to cause disease in humans and other animals.

Isolation and molecular characterization of Acanthamoeba genotypes in recreational and domestic water sources from Jamaica, West Indies.

Free living amoebae (FLA) are amphizoic protozoa that are ubiquitous in nature. Infection with FLA may result in neurological, ocular and skin infections. Exposure to Acanthamoeba occurs frequently through water contact and knowledge of the presence of the organisms in water sources is important in understanding transmission dynamics. The distribution of Acanthamoeba was studied in recreational and domestic water samples collected from across Jamaica. Morphological assessment and polymerase chain reaction revealed Acanthamoeba spp. isolates in 50.6% (42/83) and 17.3% (14/81) of recreational and domestic water, respectively. Sequencing of the DF3 region of the 18S rDNA resulted in the identification of genotypes T3, T4, T5, T10 and T11 corresponding to Acanthamoeba spp: A. griffini, A. triangularis, A. lenticulata, A. culbertsoni and A. hatchetti. Moreover, T4 was the most frequently isolated genotype in both recreational and domestic water. Thermotolerance and osmotolerance assays indicated that most isolates were potentially pathogenic. This is the first report of T3 and T10 genotypes in the Caribbean and the first report of these Acanthamoeba spp. in Jamaican waters. The study shows that there is potential risk of infection to contact wearers who practise poor lens care. Further, Acanthamoeba should be considered as a cause of neurological infections in Jamaica.

Isolation and characterization of Acanthamoeba strains from soil samples in Gran Canaria, Canary Islands, Spain.

Free-living Amoebae of Acanthamoeba genus include non-pathogenic and pathogenic strains that are currently classified in 18 different genotypes, T1-T18. In this study, a survey was carried out to evaluate the presence of Acanthamoeba strains in soil samples collected between 2012 and 2013 in Gran Canaria Island, Canary Islands, Spain. Samples were inoculated onto non-nutrient agar (NNA) plates and were checked for the presence of Acanthamoeba. Identification of Acanthamoeba strains was based on the morphology of the cyst and trophozoite forms. Subsequently, positive samples were cloned for their molecular characterization at the genotype level by sequencing the DF3 region located in the 18S rDNA gene of Acanthamoeba as previously described. Sequencing results revealed the presence of T2, T5 and T4 genotypes within the studied samples. To the best of our knowledge, this is the first report demonstrating the presence of Acanthamoeba in Gran Canaria Island and the first study at the genotype level in the Canary Islands.

Building Research Capacity in Low- and Middle-Income Countries and Pandemic Preparedness: Lessons Learned and Future Directions.

Research capacity is a critical component of pandemic preparedness, as highlighted by the challenges faced during the Ebola outbreak in West Africa. Recent global initiatives, such as the Research & Development Task Force of the Global Health Security Agenda and the World Health Assembly's resolution on strengthening clinical trials, emphasize the need for robust research capabilities. This Perspective discusses the experiences of leaders in infectious disease research and capacity building in low- and middle-income countries, focusing on Colombia, Jamaica, and Pakistan. These case studies underscore the importance of collaborative efforts, interdisciplinary training, and global partnerships in pandemic response. The experiences highlight the necessity for rapid pathogen identification, capacity for genomic sequencing, and proactive engagement with policymakers. Challenges faced, including the shortage of trained staff and reliance on imported reagents, emphasize the ongoing need for building research capacity.

Seroprevalence and Genotype Diversity of Hepatitis C Virus in the Caribbean-A Review.

Hepatitis C (HCV) continues to present a global public health challenge, with no vaccine available for prevention. Despite the availability of direct-acting antivirals (DAAs) to cure HCV, it remains prevalent in many regions including the Caribbean. As efforts are made to eliminate HCV from the region, existing barriers, such as the high cost of DAAs and lack of an established database of HCV cases within the Caribbean, must be addressed. This review seeks to assess epidemiologic trends (seroprevalence and genotypic diversity) of HCV in the Caribbean and identify gaps in surveillance of the disease. The literature for the period 1 January 2005 to October 2022 was reviewed to gather country-specific data on HCV across the Caribbean. References were identified through indexed journals accessed through established databases using the following keywords: Caribbean, genotype distribution, and general epidemiologic characteristics. The usage pattern of HCV drugs was determined from information obtained from pharmacists across the Caribbean including Jamaica. The prevalence of HCV in the Caribbean was 1.5%; the region should therefore be considered an area of moderate HCV prevalence. The prevalence of HCV among intravenous drug users (21.9-58.8%), persons living with HIV/AIDS (0.8 to 58.5%), prisoners (32.8-64%), and men who have sex with men (MSM) (0.8-6.9%) was generally higher than in the general population (0.8-2.3%). Genotype 1 (83%) was most prevalent followed by genotypes 2 (7.2%) and 3 (2.1%), respectively. Less than 50% of countries in the Caribbean have reliable or well-curated surveillance data on HCV. Drugs currently being used for treatment of HCV infections across the Caribbean include Epclusa (sofosbuvir/velpatasvir) and Harvoni (ledipasvir/sofosbuvir). Some of these drugs are only available in the private sector and are sourced externally whenever needed. While trends point to a potentially higher prevalence of HCV, it will require well-designed random surveys to obtain better estimates of the infection seroprevalence, supported by strong public health laboratory systems. DAAs that are pan-genotypic should translate into treatments that are affordable, accessible, and available to improve cure rates and reduce the HCV burden in the population.

Workshop on research priorities for management and treatment of angiostrongyliasis(1).

In a concluding session of the workshop, the participants developed a list of 115 research and outreach needs, outlining the top 5-7 needs in each of 8 areas (Table). For complete information, including presenter details and abstracts, visit the workshop website at www.hawaii.edu/cowielab/Angio%20website%20home.htm.

Prevalence of SARS-CoV-2 antibodies after the Omicron surge, Kingston, Jamaica, 2022.

A cross-sectional SARS-CoV-2 serosurvey was conducted after the Omicron surge in Jamaica using 1,540 samples collected during March - May 2022 from persons attending antenatal, STI and non-communicable diseases clinics in Kingston, Jamaica. SARS-CoV-2 spike receptor binding domain (RBD) and/or nucleocapsid IgG antibodies were detected for 88.4% of the study population, with 77.0% showing evidence of previous SARS-CoV-2 infection. Of persons previously infected with SARS-CoV-2 and/or with COVID-19 vaccination, 9.6% were negative for spike RBD IgG, most of which were unvaccinated previously infected persons. Amongst unvaccinated previously infected people, age was associated with testing spike RBD IgG negative. When considering all samples, median spike RBD IgG levels were 131.6 BAU/mL for unvaccinated persons with serological evidence of past infection, 90.3 BAU/mL for vaccinated persons without serological evidence of past infection, and 896.1 BAU/mL for vaccinated persons with serological evidence of past infection. Our study of the first reported SARS-CoV-2 serosurvey in Jamaica shows extensive SARS-CoV-2 population immunity, identifies a substantial portion of the population lacking spike RBD IgG, and provides additional evidence for increasing COVID-19 vaccine coverage in Jamaica.

Prevalence of SARS-CoV-2 Antibodies after the Omicron Surge, Kingston, Jamaica, 2022.

A cross-sectional SARS-CoV-2 serosurvey was conducted after the Omicron surge in Jamaica using 1,540 samples collected during March â€" May 2022 from persons attending antenatal, STI and non-communicable diseases clinics in Kingston, Jamaica. SARS-CoV-2 spike receptor binding domain (RBD) and/or nucleocapsid IgG antibodies were detected for 88.4% of the study population, with 77.0% showing evidence of previous SARS-CoV-2 infection. Of persons previously infected with SARS-CoV-2 and/or with COVID-19 vaccination, 9.6% were negative for spike RBD IgG, most of which were unvaccinated previously infected persons. Amongst unvaccinated previously infected people, age was associated with testing spike RBD IgG negative. When considering all samples, median spike RBD IgG levels were 131.6 BAU/mL for unvaccinated persons with serological evidence of past infection, 90.3 BAU/mL for vaccinated persons without serological evidence of past infection, and 896.1 BAU/mL for vaccinated persons with serological evidence of past infection. Our study of the first reported SARS-CoV-2 serosurvey in Jamaica shows extensive SARS-CoV-2 population immunity, identifies a substantial portion of the population lacking spike RBD IgG, and provides additional evidence for increasing COVID-19 vaccine coverage in Jamaica.

Unique Cryptosporidium population in HIV-infected persons, Jamaica.

A cryptosporidiosis survey showed the presence of Cryptosporidium hominis, C. parvum, C. canis, and C. felis in 25, 7, 1, and 1 HIV-positive persons from Jamaica, respectively; 1 person had both C. hominis and C. felis. Multilocus sequence typing indicated the presence of a homogeneous but geographically distinct C. hominis population in Jamaica.

Population distribution and zoonotic potential of gastrointestinal helminths of wild rats Rattus rattus and R. norvegicus from Jamaica.

The population distribution and zoonotic potential of gastrointestinal helminths in a naturally infected population of wild rats (Rattus rattus and Rattus norvegicus) in Jamaica are described. One hundred and thirty (29.7%) of 437 rats captured in the study were infected: 104 (35%) of 297 R. rattus compared with 26 (18.6%) of 140 R. norvegicus. Nine species of gastrointestinal helminths were recovered: Raillietina sp. (0.2%), Trichuris sp. (0.2%), Rictularia sp. (0.7%), Syphacia obvelata (1.1%), Strongyloides ratti (1.4%), Hymenolepis diminuta (3.8%), Protospirura muricola (4.3%), Moniliformis moniliformis (11.2%), and Nippostrongylus brasiliensis (14.2%). In a logistic model, the single risk factor identified for both M. moniliformis and P. muricola was R. rattus, compared with R. norvegicus (OR = 8.369 and 9.714, respectively). In comparison, the risk factor predicted for infection with N. brasiliensis was the northeastern section of Jamaica (OR = 11.000) compared with western Jamaica. Rictularia sp. represents a new geographic distribution record for the Caribbean region. Hymenolepis diminuta, M. moniliformis, Raillietina sp., and Rictularia sp. are potentially zoonotic, but only human infection with H. diminuta has been previously reported in the Caribbean.

Acanthamoeba infection as a cause of severe keratitis in a soft contact lens wearer in Jamaica.

We report the case of a 29-year-old Jamaican patient who presented with severe pain, redness, and swelling of both eyes. She was a regular soft contact lens wearer who did not maintain standard lens care. She was treated for a possible microbial/viral keratitis using topical ciprofloxacin drops, topical acyclovir ointment, and topical atropine drops. The response was inadequate, and scrapings from her cornea, contact lens cases, and both lenses revealed Acanthamoeba on microscopy, which was shown to be Acanthamoeba polyphaga using polymerase chain reaction. She was treated using chlorhexidine 0.02% hourly, ciprofloxacin every 4 hours, and atropine 1% every 12 hours, along with oral ketoconazole 200 mg twice daily with a dramatic response. However, she subsequently suffered slow corneal epithelial regrowth with severe scarring, vascularization, and cortical lens opacification and was referred for penetrating keratoplasty and cataract surgery. This is the first case of severe keratitis caused by Acanthamoeba to be reported from Jamaica and demonstrates that this emerging pathogen can be a cause of severe keratitis in the tropics.

Vannellid Species Isolated from Freshwater Source in a Park in Jamaica, West Indies.

Free-living amoebae (FLA) occupy a wide range of freshwater, marine, and soil habitats, and are opportunistic pathogens in human beings. While Acanthamoeba spp., Naegleria fowleri, and Balamuthia mandrillaris are well-known opportunistic organisms, Vannella epipetala is nonpathogenic. Sediments were collected from a freshwater source from a park in Jamaica to investigate the presence of FLA. Acanthamoeba and Naegleria spp. were not recovered; however, a Vannellid species identified by microscopy and PCR analysis as V. epipetala was isolated. These nonpathogens pose a threat to human beings as they may act as Trojan horses for microsporidian parasites and other pathogens, thereby facilitating their transmission to human beings.

Severe eosinophilic meningitis owing to Angiostrongylus cantonensis in young Jamaican children: case report and literature review.

Eosinophilic meningitis caused by Angiostrongylus cantonensis is an endemic and emerging disease that affects adults and children in Jamaica. Most cases resolve without sequelae, but young children are at high risk of neurological damage and death. Treatment with corticosteroids and albendazole is considered safe for adults and children, but protocols for its use in children have not been established. A 19-month-old infant with permanent neurological sequlae caused by Angiostrongylus cantonensis meningitis is reported, and five other Jamaican cases are summarized. A review of the literature of children with permanent neurological sequlae and death is presented. Children <5 years (especially <2) were at increased risk of incomplete recovery and death if they presented with bulbar signs, flaccid paresis and coma. None of the severe or fatal cases received early intervention with anthelminthics, and disease progression was not altered with corticosteroids. In view of the pathophysiology, necropsy reports and animal studies, it seems that the early use of larvicidals may change the course of severe presentations.

Trichosporon asahii among intensive care unit patients at a medical center in Jamaica.

We investigated an increase in Trichosporon asahii isolates among inpatients. We identified 63 cases; 4 involved disseminated disease. Trichosporon species was recovered from equipment cleaning rooms, washbasins, and fomites, which suggests transmission through washbasins. Patient washbasins should be single-patient use only; adherence to appropriate hospital disinfection guidelines was recommended.