Clinical and microbiological predictors of healing in Buruli ulcer disease.

Introduction: Wound measurements are relevant in monitoring the rate of healing (RoH) and may predict time to healing. Predicting the time to healing can help improve the management of Buruli ulcer. We examine three methods for the determination of RoH and their use as predictors of time to healing. Methods: Lesion measurements of Buruli ulcer patients treated from 2007 to 2022 were obtained with acetate sheet tracings (2D) or Aranz software (3D) fortnightly. RoH was determined using the absolute area, percentage area reduction and linear methods at 4 weeks post onset of antibiotic treatment. Predicted time to healing was compared to the actual healing time. Baseline characteristics were assessed for associations with healing. Results: All three methods for calculating the RoH significantly distinguished between fast and slow healers (p < 0.0001). The predicted healing time using the linear method was comparable to the actual healing time for fast healers (p = 0.34). The RoH was influenced by the form of lesion, with plaques [OR 2.19 5 %CI (1.2-3.6), p = 0.009], and oedemas [OR 8.5; 95 %CI (1.9--36.9), p = 0.004] being associated with delayed healing. The proportion of patients with paradoxical reactions 16 % vs 3 %, p < 0.0001), higher baseline bacterial load (75/104;72 % vs 21/47;45 %, p = 0.001) and delayed clearance of viable organisms (71/104;68 % vs 9/47;19 %, p < 0.0001) was higher in the slow healers than the fast healers. Conclusion: Predicted healing rates were comparatively lower for slow healers than fast healers. Baseline characteristics associated with healing can be explored for an improved disease management plan to reduce patient and caregiver anxiety.

Two cases of COVID-19 presenting with severe malaria: a clinical challenge (case report).

The novel coronavirus (COVID-19) pandemic has stretched the medical resources of both developed and developing countries. The global focus on COVID-19 may lead to the neglect of other infectious diseases such as malaria which is still endemic in many African countries. Some similarities in malaria and COVID-19 disease presentations may also lead to late diagnosis of either disease which could complicate the effects. Here, we present two cases of a 6-year-old child and a 17-year-old female who presented to a primary care facility in Ghana with a clinical and microscopy-confirmed diagnosis of severe malaria complicated by thrombocytopenia. As their symptoms worsened with associated respiratory complications, nasopharyngeal samples were taken for real-time polymerase chain reaction (RT-PCR) and tested positive for severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Clinicians, policymakers, and public health practitioners should be alert to the variety of presenting symptoms of COVID-19 and its similarity to malaria to mitigate the risk of mortality from either disease.

Prevalence of Plasmodium falciparum gametocytaemia in asymptomatic school children before and after treatment with dihydroartemisinin-piperaquine (DP).

Background: Asymptomatic Plasmodium carriers form the majority of malaria-infected individuals in most endemic areas. A proportion of these asymptomatically infected individuals carry gametocytes, the transmissible stages of malaria parasites, that sustain human to mosquito transmission. Few studies examine gametocytaemia in asymptomatic school children who may form an important reservoir for transmission. We assessed the prevalence of gametocytaemia before antimalarial treatment and monitored clearance of gametocytes after treatment in asymptomatic malaria children. Methods: A total of 274 primary school children were screened for P. falciparum parasitaemia by microscopy. One hundred and fifty-five (155) parasite positive children were treated under direct observation with dihydroartemisinin-piperaquine (DP). Gametocyte carriage was determined by microscopy seven days prior to treatment, day 0 before treatment, and on days 7, 14 and 21 post initiation of treatment. Results: The prevalence of microscopically-detectable gametocytes at screening (day -7) and enrolment (day 0) were 9% (25/274) and 13.6% (21/155) respectively. Following DP treatment, gametocyte carriage dropped to 4% (6/135), 3% (5/135) and 6% (10/151) on days 7, 14 and 21 respectively. Asexual parasites persisted in a minority of treated children, resulting in microscopically detectable parasites on days 7 (9%, 12/135), 14 (4%, 5/135) and 21 (7%, 10/151). Gametocyte carriage was inversely correlated with the age of the participants (p = 0.05) and asexual parasite density (p = 0.08). In a variate analysis, persistent gametocytaemia 7 or more days after treatment was significantly associated with post-treatment asexual parasitaemia at day 7 (P = 0.027) and presence of gametocytes on the day of treatment (P < 0.001). Conclusions: Though DP provides both excellent cure rates for clinical malaria and a long prophylactic half-life, our findings suggest that after treatment of asymptomatic infections, both asexual parasites and gametocytes may persist in a minority of individuals during the first 3 weeks after treatment. This indicates DP may be unsuitable for use in mass drug administration strategies towards malaria elimination in Africa.

Distribution of intestinal parasites of baboons (Papio anubis) and warthogs (Phacochoerus aethiopicus) at the Mole National Park, Ghana.

The identification of intestinal parasite of baboons (Papio anubis) and warthogs (Phacochoerus aethiopicus) was undertaken at the Mole National Park, Ghana. The main objective of the study was to determine the types and prevalence of intestinal parasites in baboons and warthogs in the Mole National Park. A total of nineteen (19) and twenty-three (23) samples were collected from the baboons and warthogs, respectively, and examined using the direct saline smear and formol-ether concentration technique for the identification of cysts, eggs and larvae of parasites. The survey showed that 94.74% of the baboon samples examined was infected with at least one parasite, whereas that of the warthogs showed 95.65% prevalence. A total of seven (7) and eight (8) different parasites were identified in baboon and warthog faecal samples, respectively. Strongyloides sp. had the highest prevalence in baboons (84.21%) and warthogs (78.26%). The second prevalent parasite identified was Ascaris sp. in the baboons (31.58%) and warthogs (30.43%). The results showed a high level of multiparasitism in these wild animals and an increased risk of zoonotic transmission which may result from interaction with inhabitants of the park community.

Rapid growth inhibitory activity of a YafQ-family endonuclease toxin of the Helicobacter pylori tfs4 integrative and conjugative element.

Prokaryotic and archaeal chromosomes encode a diversity of toxin-antitoxin (TA) systems that contribute to a variety of stress-induced cellular processes in addition to stability and maintenance of mobile elements. Here, we find DinJ-YafQ family TA systems to be broadly distributed amongst diverse phyla, consistent with other ParE/RelE superfamily TAs, but more unusually occurring as a multiplicity of species-specific subtypes. In the gastric pathogen Helicobacter pylori we identify six distinct subtypes, of which three are predominantly associated with the mobilome, including the disease-associated integrative and conjugative element (ICE), tfs4. Whereas, the ICE-encoded proteins have characteristic features of DinJ-YafQ family Type II TA systems in general, the toxin component is distinguished by a broad metal-ion-dependent endonuclease activity with specificity for both RNA and DNA. We show that the remarkably rapid growth inhibitory activity of the ICE toxin is a correlate of a C-terminal lysine doublet which likely augments catalytic activity by increasing the positive electrostatic potential in the vicinity of the conserved active site. Our collective results reveal a structural feature of an ICE TA toxin that influences substrate catalysis and toxin function which may be relevant to specific TA-mediated responses in diverse genera of bacteria.