BackgroundRecently, a real-time PCR assay known as photo-induced electron transfer (PET)-PCR which relies on self-quenching primers for the detection of Plasmodium spp. and Plasmodium falciparum was described. PET-PCR assay was found to be robust, and easier to use when compared to currently available real-time PCR methods. The potential of PET-PCR for molecular detection of malaria parasites in a nationwide malaria community survey in Haiti was investigated.MethodsDNA from the dried blood spots was extracted using QIAGEN methodology. All 2,989 samples were screened using the PET-PCR assay in duplicate. Samples with a cycle threshold (CT) of 40 or less were scored as positive. A subset of the total samples (534) was retested using a nested PCR assay for confirmation. In addition, these same samples were also tested using a TaqMan-based real-time PCR assay.ResultsA total of 12 out of the 2,989 samples screened (0.4%) were found to be positive by PET-PCR (mean CT value of 35.7). These same samples were also found to be positive by the nested and TaqMan-based methods. The nested PCR detected an additional positive sample in a subset of 534 samples that was not detected by either PET-PCR or TaqMan-based PCR method.ConclusionWhile the nested PCR was found to be slightly more sensitive than the PET-PCR, it is not ideal for high throughput screening of samples. Given the ease of use and lower cost than the nested PCR, the PET-PCR provides an alternative assay for the rapid screening of a large number of samples in laboratory settings.

BackgroundAs a nation reduces the burden of falciparum malaria, identifying areas of transmission becomes increasingly difficult. Over the past decade, the field of utilizing malaria serological assays to measure exposure has grown rapidly, and a variety of serological methods for data acquisition and analysis of human IgG against falciparum antigens are available. Here, different immunoassays and statistical methods are utilized to analyse samples from a low transmission setting and directly compare the estimates generated.MethodsA subset of samples (n = 580) from a 2012 Haitian nationwide malaria survey was employed as sample population of low falciparum endemicity. In addition to the Haitian samples, samples from 247 US residents were used as a reference population of ‘true seronegatives’. Data acquisition was performed through standard ELISA and bead-based multiplex assays assaying for IgG antibodies to the Plasmodium falciparum antigens MSP-1p19, MSP-1p42(D), MSP-1p42(F), and AMA-1. Appropriate parametric distributions and seropositivity cutoff values were determined by statistical measures.ResultsData from both assays showed a strong positive skew, and the lognormal distribution was found to be an appropriate statistical fit to the Haitian and American populations. The American samples served as a good serological true negative population for the multiplex assay, but not for ELISA-based data. Mixture model approaches to determine seronegative and seropositive populations from the Haitian data showed a high degree of distribution overlap—likely due to the historical low falciparum transmission in this nation. Different fittings to the reversible catalytic model resulted depending upon the immunoassay utilized and seropositivity cutoff method employed. Data were also analysed through fitting to penalized B-splines, presenting another possible analytical tool for the analysis of malaria serological data.ConclusionsStandardization of serological techniques and analyses may prove difficult as some tools can prove to be more useful depending on the area and parasite in question, making clear interpretation a vital pursuit. The presented analysis in the low-endemic nation of Haiti found malaria-naive US residents to be an appropriate seronegative reference population for the multiplex assay, and this assay providing consistent estimates between MSP-1 and AMA-1 antigens of percent seropositives for this low-endemic population.Electronic supplementary materialThe online version of this article (doi:10.1186/s12936-015-0955-1) contains supplementary material, which is available to authorized users.

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ObjectivesOver the last 15 years, the prevalence of HIV in Haiti has stabilised to around 2.0%. However, key populations remain at higher risk of contracting HIV and other sexually transmitted infections (STIs). The prevalence of HIV is 12.9% among men having sex with men (MSM). There is limited information about the prevalence of other STI in the Haitian population in general and even less among key populations. We assessed the burden ofChlamydia trachomatis(CT) andNeisseria gonorrhoeae(NG) and risk factors for infections among MSM in Haiti.MethodsA cross-sectional study was conducted. MSM were recruited from seven health facilities in Port-au-Prince. All samples were tested by nucleic acid amplification test, using GeneXpert. A survey was administered to the participants to collect socio-demographic, clinical and risk behaviour data.ResultsA total of 216 MSM were recruited in the study. The prevalence rates of CT and NG were 11.1% and 16.2%, respectively. CT NG co-infections were found in 10/216 (4.6%) of the participants. There were 39 MSM with rectal STI compared with 17 with genital infections. Participants between 18–24 and 30–34 years old were significantly more likely to be infected with NG than those aged 35 years or older (OR: 22.96, 95% CI: 2.79 to 188.5; OR: 15.1, 95% CI: 1.68 to 135.4, respectively). Participants who never attended school or had some primary education were significantly more likely to be infected with NG than those with secondary education or higher (OR: 3.38, 95% CI: 1.26 to 9.07). People tested negative for HIV were significantly more likely to be infected with CT than people living with HIV/AIDS (OR: 3.91, 95% CI: 1.37 to 11.2).ConclusionsPeriodic risk assessment and testing for STI should be offered in Haiti as part of a comprehensive strategy to improve the sexual health of key populations.

Background Haiti’s first COVID-19 cases were confirmed on March 18, 2020, and subsequently spread throughout the country. The objective of this study was to describe clinical manifestations of COVID-19 in Haitian outpatients and to identify risk factors for severity of clinical manifestations. Methods We conducted a retrospective study of COVID-19 outpatients diagnosed from March 18-August 4, 2020, using demographic, epidemiological, and clinical data reported to the Ministry of Health (MoH). We used univariate and multivariate analysis, including multivariable logistic regression, to explore the risk factors and specific symptoms related to persons with symptomatic COVID-19 and the severity of symptomatic COVID-19 disease. Results Of 5,389 cases reported to MOH during the study period, 1,754 (32.5%) were asymptomatic. Amongst symptomatic persons 2,747 (75.6%) had mild COVID-19 and 888 (24.4%) had moderate-to-severe disease; the most common symptoms were fever (69.6%), cough (51.9%), and myalgia (45.8%). The odds of having moderate-to-severe disease were highest among persons with hypertension (aOR = 1.72, 95% Confidence Interval [CI] (1.34, 2.20), chronic pulmonary disease (aOR = 3.93, 95% CI (1.93, 8.17)) and tuberculosis (aOR = 3.44, 95% CI (1.35, 9.14)) compared to persons without those conditions. The odds of having moderate-to-severe disease increased with age but was also seen among children aged 0–4 years (OR: 1.73, 95% CI (0.93, 3.08)), when using 30–39 years old as the reference group. All of the older age groups, 50–64 years, 65–74 years, 75–84 years, and 85+ years, had significantly higher odds of having moderate-to-severe COVID-19 compared with ages 30–39 years. Diabetes was associated with elevated odds of moderate-to-severe disease in bivariate analysis (OR = 2.17, 95% CI (1.58,2.98) but, this association did not hold in multivariable analyses (aOR = 1.22,95%CI (0.86,1.72)). Conclusion These findings from a resource-constrained country highlight the importance of surveillance systems to track emerging infections and their risk factors. In addition to co-morbidities described elsewhere, tuberculosis was a risk factor for moderate-to-severe COVID-19 disease.