Estimation of parasitaemia in imported falciparum malaria using the results of a combined rapid diagnostic test. No big help from haematological parameters.

BACKGROUND: Microscopy continues to be the mainstay for the evaluation of parasitaemia in malaria but requires laboratory support and microbiological experience. Other fast and simple methods are necessary. METHODS: A retrospective observational study of imported malaria treated from July-2007 to December-2020 was carried out to evaluate the association between the degree of parasitaemia and both rapid diagnostic tests (RDT) reactivity patterns and haematological parameters. Plasmodium falciparum monoinfections diagnosed by peripheral blood smear and/or polymerase chain reaction (PCR),which also had a positive RDT result in the same blood sample, were included in the study. RESULTS: A total of 273 patients were included. Most of them were male (n = 256; 93.8%) and visiting friends and relatives (VFR) travellers (n = 252; 92.3%). Patients with plasmodial lactate dehydrogenase (pLDH) or aldolase and histidine-rich protein 2 (HRP-2) co-reactivity (Pan/Pf pattern) had a parasitaemia range between 0 and 37% while those with just HRP-2 reactivity (P. falciparum pattern) had ranges between 0 and 1%. Not a single case of P. falciparum pattern was found for parasitaemia ranges greater than 1%, showing a negative predictive value of 100% for high parasitaemia. All the correlations between haematological parameters and parasitaemia resulted to be weak, with a maximum rho coefficient of -0.35 for lymphocytes and platelets, and of 0.40 for neutrophils-to-lymphocytes count ratio. Multivariate predictive models were constructed reflecting a poor predictive capacity. CONCLUSIONS: The reactivity pattern of RDT allows a rapid semi-quantitative assessment of P. falciparum parasitaemia in travellers with imported malaria, discriminating patients with lower parasite loads. Haematological parameters were not able to estimate parasitaemia with sufficient precision.

Accuracy of Three Serological Techniques for the Diagnosis of Imported Schistosomiasis in Real Clinical Practice: Not All in the Same Boat.

Schistosomiasis is a neglected tropical disease despite of being a major public health problem affecting nearly 240 million people in the world. Due to the migratory flow from endemic countries to Western countries, an increasing number of cases is being diagnosed in non-endemic areas, generally in migrants or people visiting these areas. Serology is the recommended method for screening and diagnosis of schistosomiasis in migrants from endemic regions. However, serological techniques have a highly variable sensitivity. The aim of this study was to evaluate retrospectively the sensitivity of three different serological tests used in real clinical practice for the screening and diagnosis of imported schistosomiasis in sub-Saharan migrant patients, using the detection of schistosome eggs in urine, faeces or tissues as the gold standard. We evaluated three different serological techniques in 405 sub-Saharan patients with confirmed schistosomiasis treated between 2004 and 2022: an enzyme-linked immunosorbent assay (ELISA), an indirect haemagglutination assay (IHA) and an immunochromatographic test (ICT). The overall sensitivity values obtained with the different techniques were: 44.4% for IHA, 71.2% for ELISA and 94.7% for ICT, respectively. According to species, ICT showed the highest sensitivity (S. haematobium: 94%, S. mansoni: 93.3%; and S. intercalatum/guineensis: 100%). In conclusion, our study shows that Schistosoma ICT has the best performance in real clinical practice, when compared to ELISA and IHA, in both S. mansoni and S. haematobium infections.

Misleading eosinophil counts in migration-associated malaria: do not miss hidden helminthic co-infections.

BACKGROUND: Lower eosinophil counts observed during acute malaria episodes could hide helminth-related eosinophilia. METHOD: Retrospective observational study with sub-Saharan migrants with imported malaria from May-2007 to May-2020. Absolute eosinophil count was determined upon diagnosis at hospital admission and at least once after clearance of parasitemia. Helminthic co-infections were investigated by searching for stool and urine parasites, serology for Strongyloides spp. and Schistosoma spp., and Knott and/or saponin tests for blood microfilariae. RESULTS: A total of 259 patients were included. Most of them were male (n = 237; 91.5%) and VFR travelers (n = 241; 93.1%). 131 patients (50.6%) were diagnosed with probable schistosomiasis, 15 (5.8%) with confirmed schistosomiasis, 16 (6.2%) with strongyloidiasis, 4 (1.6%) with soil-transmitted helminthiasis, and 4 (1.6%) with filariasis (Mansonella perstans). Prevalence of eosinophilia increased from 2.7% on admission to 32.5% during outpatient follow-up. Eosinophilia did not appear until several weeks after hospital discharge in up to 24% of the confirmed helminthic co-infections and in 61.1% of patients with probable schistosomiasis. Eosinophilia was associated with confirmed schistosomiasis and mansonellosis while 56.2% and 75% of cases with strongyloidiasis and soil-transmitted worms did not present eosinophilia at any time, respectively. CONCLUSIONS: Regardless of the absence of eosinophilia, patients hospitalized because of acute imported malaria might benefit from the screening of the main parasitic diseases, allowing for earlier diagnosis and treatment.

A large case series of travel-related Mansonella perstans (vector-borne filarial nematode): a TropNet study in Europe.

BACKGROUND: Infection with Mansonella perstans is a neglected filariasis, widely distributed in sub-Saharan Africa, characterized by an elusive clinical picture; treatment for mansonellosis is not standardized. This retrospective study aimed to describe the clinical features, treatment schemes and evolution, of a large cohort of imported cases of M. perstans infection seen in four European centres for tropical diseases. METHODS: Mansonella perstans infections, diagnosed by identification of blood microfilariae in migrants, expatriates and travellers, collected between 1994 and 2018, were retrospectively analysed. Data concerning demographics, clinical history and laboratory examinations at diagnosis and at follow-up time points were retrieved. RESULTS: A total of 392 patients were included in the study. Of the 281 patients for whom information on symptoms could be retrieved, 150 (53.4%) reported symptoms, abdominal pain and itching being the most frequent. Positive serology and eosinophilia were present in 84.4% and 66.1%, respectively, of those patients for whom these data were available. Concomitant parasitic infections were reported in 23.5% of patients. Treatment, administered to 325 patients (82.9%), was extremely heterogeneous between and within centres; the most commonly used regimen was mebendazole 100 mg twice a day for 1 month. A total of 256 (65.3%) patients attended a first follow-up, median 3 months (interquartile range 2-12) after the first visit; 83.1% of patients having received treatment based on mebendazole and/or doxycycline, targeting Wolbachia, became amicrofilaremic, 41.1-78.4% of whom within 12 months from single treatment. CONCLUSIONS: Lack of specific symptoms, together with the inconstant positivity of parasitological and antibody-based assays in the infected population, makes the clinical suspicion and screening for mansonellosis particularly difficult. Prospective studies evaluating prevalence of infection in migrants from endemic areas, infection-specific morbidity, presence of Wolbachia endosymbionts in M. perstans populations from different geographical areas and efficacy of treatment regimens are absolutely needed to optimize the clinical management of infection.

Migration-associated malaria from Africa in southern Spain.

BACKGROUND: The western area of the province of Almeria, sited in southern Spain, has one of the highest immigrant population rates in Spain, mainly dedicated to agricultural work. In recent years, there has been a significant increase in the number of cases of imported malaria associated with migrants from countries belonging to sub-Saharan Africa. The objective of our study is to describe the epidemiological, clinical and analytical characteristics of malaria patients treated in a specialized tropical unit, paying special attention to the differences between VFR and non-VFR migrants and also to the peculiarities of microscopic malaria cases compared to submicroscopic ones. METHODS: Retrospective observational study of migrants over 14 years of age with imported malaria treated from October 2004 to May 2019. Characteristics of VFR and non-VFR migrants were compared. Malaria cases were divided into microscopic malaria (MM) and submicroscopic malaria (SMM). SMM was defined as the presence of a positive malaria PCR test together with a negative direct microscopic examination and a negative rapid diagnostic test (RDT). Microscopic malaria was defined as the presence of a positive RDT and/or a positive smear examination. RESULTS: Three hundred thirty-six cases of malaria were diagnosed, 329 in sub-Saharan immigrants. Of these, 78.1% were VFR migrants, in whom MM predominated (85.2% of cases). In non-VFR migrants, SMM represented 72.2% of the cases. Overall, 239 (72.6%) patients presented MM and 90 (27.4%) SMM. Fever was the most frequent clinical manifestation (64.4%), mainly in the MM group (MM: 81.1% vs SMM: 20.0%; p < 0.01). The most frequent species was P. falciparum. Patients with SMM presented fewer cytopenias and a greater number of coinfections due to soil-transmitted helminths, filarial and intestinal protozoa compared to patients with MM. CONCLUSIONS: Imported malaria in our area is closely related to sub-Saharan migration. VFR migrants are the main risk group, highlighting the need for actions aimed at improving disease prevention measures. On the other hand, almost a third of the cases are due to SMM. This fact could justify its systematic screening, at least for those travelers at greater risk.

Evaluation of eosinophilia in immigrants in Southern Spain using tailored screening and treatment protocols: A prospective study.

OBJECTIVE: To determine the etiology of eosinophilia in immigrant patients in Southern Spain. METHODS: Prospective study of immigrant patients with eosinophilia (> 500 Eo/µL) attended in a reference Tropical Medicine Unit and evaluated through the implementation of a specific protocol structured in different levels meant to be accomplished depending on the findings of each previous level. RESULTS: Out of the 549 patients included in the study (89.6% from sub-Saharan countries), a diagnosis of helminthiasis was reached in 417 (75.9%), mainly by Strongyloides stercoralis (n = 190), Schistosoma (n = 33) and Hookworms (n = 126). 30 patients (5.5%) had a non-parasitic disorder (asthma, allergic rhinoconjunctivitis, skin conditions and drug-related eosinophilia). Multiple helminthic infections were very common: in 107 patients (19.5%) 2 helminth species were identified, three in 21 patients (3.8%), and four or more in 6 patients (1.1%). Eosinophilia was resolved in 31 of the 33 patients (93.9%) who received empirical treatment with ivermectin, albendazole and praziquantel as an etiological diagnosis was not reached after applying the whole protocol. CONCLUSIONS: Diagnosis of helminthic infections in immigrant patients with eosinophilia can be improved by using tailored protocols based on geographical exposure. The implementation of these protocols may also save costs by systematizing diagnostic explorations. Empirical treatment with ivermectin, albendazol and praziquantel in sub-Saharan population when an etiologic diagnosis of eosinophilia has not been attained is an effective measure.

Streptococcus pneumoniae bacteremia: clinical and microbiological epidemiology in a health area of Southern Spain.

Streptococcus pneumoniae remains an important cause of bacteremia worldwide. Last years, a decrease of S. pneumoniae penicillin-resistant isolates has been observed. The objective of this study was to describe the episodes of bacteremia due to S. pneumoniae during a period of 11 years. Epidemiological and clinical data, serotypes causing bacteremia, antibiotic susceptibility and prognosis factors were studied. Over a period of 11 years, all the episodes of S. pneumoniae bacteremia were analysed. Their clinical and microbiological features were recorded. Statistical analysis was carried out to determine risk factors for pneumococcal bacteremia and predictors of fatal outcome. Finally, 67 S. pneumoniae bacteremia episodes were included in this study. The majority of cases were produced in white men in the middle age of their life. The main predisposing factors observed were smoking, antimicrobial and/or corticosteroids administration, chronic pulmonary obstructive disease and HIV infection, and the most common source of bacteremia was the low respiratory tract. The main serotypes found were 19A, 1, 14 and 7F. Seventy-seven percent of these isolates were penicillin-susceptible, and the mortality in this serie was really low. Statistical significance was observed between age, sex and race factors and the presence of bacteremia, and there was relationship between the patient's condition and the outcome. In our study, S. pneumoniae bacteremia is mainly from community-acquired origin mainly caused in men in the median age of the life. 40% of bacteremias were caused by serotypes 19A, 1, 7F and 14. During the period of study the incidence of bacteremia was stable and the mortality rate was very low.