A first report of Pseudosuccinea columella (Say, 1817), an alien intermediate host for liver fluke, in Malawi.

Starting in October 2021, quarterly malacological surveys have been undertaken in Malawi, with the sampling of 12 specified freshwater habitats throughout a calendar year. Each survey monitors the presence of aquatic intermediate snail hosts of medical and veterinary importance. In March 2023, the alien lymnaeid species Pseudosuccinea columella was encountered for the first time in the surveys, in Nsanje District. This species identity was later confirmed upon DNA analysis of mitochondrial ribosomal 16S sequences. In July 2023, P. columella was also noted at single sites within Mangochi and Chikwawa Districts, and again in Nsanje District, with an additional location observed. Of particular importance, our sampled location in Mangochi District was directly connected to Lake Malawi, which expands the species list of invasive molluscs in this lake. While P. columella is a well-known intermediate snail host for human and animal fascioliasis, screening collected snails for trematode cercariae, alongside molecular xenomonitoring, did not yield equivocal evidence of active fluke infection. However, the newly recognized presence of this alien intermediate snail host within Lake Malawi, and along the Shire River Valley, flags a new concern in altered local transmission potential for human and animal fascioliasis.

An alien intermediate snail host in Malawi - Orientogalba viridis (Quoy and Gaimard, 1832) - A new concern for schistosomiasis transmission in Africa?

The freshwater amphibious snail Orientogalba viridis commonly occurs in eastern Asia, on certain Pacific islands and more importantly has recently dispersed into Europe. Since this snail is now considered an invasive species, its distribution is of growing parasitological interest as an alien intermediate host for various trematodes, particularly liver flukes. As part of ongoing surveillance for snail-borne diseases in Malawi, a population of O. viridis was first observed in May 2023, alongside an alarming presence of a human schistosome cercaria. This snail population later underwent detailed morphological characterisation with both snail and parasite identities confirmed upon DNA barcoding. This seminal observation triggered more extensive local snail surveys, finding 3 further populations in separated rice paddies, with further field-caught snails (n = 465) screened for infection and a selection used for repeated experimental challenges with miracidia from Schistosoma haematobium and Schistosoma mattheei. Although no field-caught (and experimentally exposed) snail was seen to shed schistosome cercariae, molecular xenomonitoring for schistosomiasis provided tangible evidence of putative transmission potential. Our first report of O. viridis here in Malawi, and more broadly in Africa, flags a need for increased vigilance for this invasive species alongside local clarification(s) of its transmission potential for trematodiases of either medical and/or veterinary importance.

How can schistosome circulating antigen assays be best applied for diagnosing male genital schistosomiasis (MGS): an appraisal using exemplar MGS cases from a longitudinal cohort study among fishermen on the south shoreline of Lake Malawi.

We provide an update on diagnostic methods for the detection of urogenital schistosomiasis (UGS) in men and highlight that satisfactory urine-antigen diagnostics for UGS lag much behind that for intestinal schistosomiasis, where application of a urine-based point-of-care strip assay, the circulating cathodic antigen (CCA) test, is now advocated. Making specific reference to male genital schistosomiasis (MGS), we place greater emphasis on parasitological detection methods and clinical assessment of internal genitalia with ultrasonography. Unlike the advances made in defining a clinical standard protocol for female genital schistosomiasis, MGS remains inadequately defined. Whilst urine filtration with microscopic examination for ova of Schistosoma haematobium is a convenient but error-prone proxy of MGS, we describe a novel low-cost sampling and direct visualization method for the enumeration of ova in semen. Using exemplar clinical cases of MGS from our longitudinal cohort study among fishermen along the shoreline of Lake Malawi, the portfolio of diagnostic needs is appraised including: the use of symptomatology questionnaires, urine analysis (egg count and CCA measurement), semen analysis (egg count, circulating anodic antigen measurement and real-time polymerase chain reaction analysis) alongside clinical assessment with portable ultrasonography.

[Predictive factors of all-cause mortality in patients attending the medical emergency unit of Kinshasa University Hospital]. / Facteurs prédictifs de la mortalité des patients admis aux urgences médicales des cliniques universitaires de Kinshasa.

BACKGROUND: The management of medical emergencies is poorly organized in the Democratic Republic of Congo. In addition, the mortality of patients attending the medical emergency unit of Kinshasa University Hospital is relatively high, with death of patients occurring rather early. To date, factors associated with this mortality have been poorly elucidated. This study aimed to identify predictive factors of all-cause mortality in patients admitted to the medical emergency unit of the Kinshasa University Hospital. METHODS: Analytical prospective study of all patients admitted from 15th January to 15th February 2011 in the emergency unit of the internal medicine department of Kinshasa University Hospital (427 patients). Among these patients, 13 were dead at arrival and were excluded from this study. The 414 patients included were followed until discharge from the hospital. Demographic, clinical, biological, diagnostic, therapeutical and evolutive data were collected. Four multivariate logistic regression models were used to identify risk factors associated with mortality. RESULTS: Patients' median age was 40 years (interquartile range, 28-58 years), 54.5% were male, and 15.9% had a life-threatening pathological condition on admission. The overall mortality was 12.3%. According to multivariate analyses, transfer from other health care structures (OR: 3.5; 95% CI: 1.7-7.1), Glasgow Coma Scale score less than 14 on admission (OR: 11.1; 95% CI: 4.7-26.3), high creatinine level (OR: 4.2; 95% CI: 1.8-9.7), presence of cardiovascular (OR: 2.9; 95% CI: 1.5-5.7), renal (OR: 7.4; 95% CI: 3.2-17.3), hematologic and/or respiratory (OR: 6.1; 95% CI: 1.7-21.4) diseases, presence of sepsis and/or meningitis and encephalitis (OR: 5.2; 95% CI: 1.6-17.0) were significantly associated with a high risk of death. However, the Glasgow Coma Scale score less than 14 on admission and renal disease were the only predictive factors of mortality remaining after including demographic, clinical, diagnostic and therapeutical variables in the logistic regression model. CONCLUSION: Our study showed that transfer from another health care structure, low Glasgow Coma Scale score on admission, high creatinine level, cardiovascular, renal, hematologic and/or respiratory diseases, sepsis and/or meningitis and encephalitis were associated with an increased risk of death in Kinshasa University Hospital patients admitted in the medical emergency unit.

Lymphatic filariasis in Lower Shire, southern Malawi.

Surveys for lymphatic filariasis were carried out for the first time in Lower Shire (Nsanje and Chikawawa Districts) of southern Malawi, in April-June 2000. There were 3 phases. In phase I, questionnaire surveys in 48 randomly selected villages indicated that chronic manifestations of lymphatic filariasis ('swollen scrotum' and 'swollen legs') were common and widespread in the area. In phase II, volunteers from 10 of the villages reporting frequent manifestations of filariasis in phase I were examined with the ICT whole-blood test for Wuchereria bancrofti-specific circulating filarial antigen (CFA). The observed prevalence of CFA positivity was very high (range, 38.8-79.1% for the villages). In phase III, a more detailed parasitological, CFA and clinical investigation was carried out in 2 of the high CFA prevalence villages identified in phase II (1 in each district). Overall, 18.1% and 22.2% were positive for microfilariae, and 62.3% and 64.6% were positive for CFA in the 2 villages. Among those aged > or = 15 years, 3.7% and 1.3% had leg elephantiasis, and 17.9% and 13.0% (of males only) had hydrocoele. In both phase II and III, CFA prevalences were unexpectedly high, especially in children. This was probably related to a recent increase in transmission of filariasis as a result of extensive flooding in the area prior to the study. The study indicated that lymphatic filariasis is highly endemic in the Lower Shire area of Malawi, and calls for action towards its control.