Transactions of The Royal Society of Tropical Medicine and Hygiene最新文献

Background: Cutaneous leishmaniasis (CL) is a vector-borne protozoal infection that causes skin lesions. Military personnel make up around 45% of UK cases. This study reports an outbreak of 35 soldiers with suspected CL from an exercise in Belize.

Methods: A prospective clinical analysis was conducted to characterise case presentations. Diagnostic results, time to cure and adverse effects were recorded.

Results: Thirty cases had laboratory-confirmed CL and three had suspected/resolved CL. Fifty percent of lesions were on the ear or face and 45% were on sites normally covered by clothing. Combined laboratory testing of skin biopsies confirmed a diagnosis in all cases. Ninety-three percent of species identified were Leishmania mexicana. Initial treatment was with miltefosine in 27 of the 30 confirmed cases. Five patients required second-line treatment with liposomal amphotericin B and one patient required third-line treatment with meglumine antimoniate.

Conclusions: This study characterised the largest outbreak of CL from Belize in British Army personnel for at least 25 y. Aspects of this outbreak were atypical and more research is required to investigate these. A simultaneous testing strategy with histology, microscopy and polymerase chain reaction of biopsy samples was sensitive. Treatment with miltefosine was less effective than expected in L. mexicana infection.

Most previous research about the dangers of extreme weather events was applicable to populations in high-income countries. Data summarising harms related to extreme weather events in low-income settings are lacking. A systematic review thematically summarising evidence about weather event-linked harms and responses in low- and lower-middle-income countries was conducted. Peer-reviewed and grey literature was systematically searched and selected. Data were extracted about harms, responses and outcomes relevant to six WHO building blocks of healthcare systems. Framework analysis was used to identify predominant themes related to harms, responses and the WHO building blocks. In total, 183 reports were included. Flooding and high winds were the most common types of extreme weather events documented. The main community experience themes identified were the displacement of populations and disruption. The main themes identified for health service delivery were vulnerability, disruption and resilience. Documented examples of resilience or recovery were far fewer for all six WHO healthcare system building blocks than descriptions of vulnerability and disruption. Extreme weather events can be highly disruptive and harmful to healthcare systems and communities in LMIC settings that are often already highly vulnerable.

Background: Pediatric snakebites remain a neglected public health threat in rural Sri Lanka, where limited access to emergency care places children at heightened risk. Despite the high burden, there is a striking lack of research focused on strengthening preparedness in vulnerable communities.

Methods: A descriptive cross-sectional study was conducted in two high-incidence districts: Ampara and Polonnaruwa. Using cluster sampling, 518 parents of children aged <5 y completed structured, self-administered questionnaires assessing knowledge of snake identification and prehospital care interventions. Associations between sociodemographic variables and knowledge were analyzed using χ2 tests.

Results: Although 98.3% correctly identified the Indian cobra, only 34.6% recognized Russell's viper, and 82% misclassified the non-venomous rat snake as venomous. Prior first-aid training was significantly associated with improved knowledge on snake identification (p=0.02), symptoms and complications (p=0.00) and pre-hospital care (p=0.01). Misconceptions persisted: 29.3% believed antivenom should be given to all bite victims. Higher socioeconomic status was linked to better prehospital care knowledge (p=0.00), while lower parental education was associated with poorer knowledge (p=0.00). Personal or household snakebite experience showed no significant association (p>0.05).

Conclusions: Despite high exposure risk, caregiver preparedness is low. Community-based education targeting high-risk families is urgently needed to reduce preventable pediatric snakebite morbidity and mortality.

In 1925, Dr Hother McCormack Hanschell, then director of the venereal diseases clinic at the Seamen's Hospital in London, published a paper entitled 'On the influence of race in venereal disease' in Transactions of the Royal Society of Tropical Medicine and Hygiene. The aim of the study, in Hanschell's words, was to evaluate whether it was possible to 'detect any racial influence on the course of three venereal diseases (ulcus molle, gonorrhoea and syphilis) in the individual patient'. The paper presents a window into epidemiological research, discourses on colonial medicine, and biological theories based on racial essentialism prevalent in the early 20th century. The issues raised by this paper continue to have implications for practice and research in tropical medicine today.

Background: Amino acid (AA) substitutions in the hepatitis B virus (HBV) S gene are key drivers of diagnostic evasion, vaccine breakthrough infections and immune escape. Understanding regional mutation profiles is essential for public health intervention. This study aimed to characterize the prevalence and mutation patterns of the HBV S gene in eastern China.

Methods: In this cross-sectional study, serum samples from 244 patients with chronic HBV infection were collected. The S gene was amplified by nested polymerase chain reaction, followed by genotyping and AA substitution analysis using Geno2pheno HBV and the MEGA 11.0 platform. Concurrent laboratory assessments included serological (HBsAg, anti-HBs, HBeAg, anti-HBe), biochemical (ALT, AST) and virological (HBV DNA load).

Results: Mutation frequencies were 38.9% (95/244) in the major hydrophilic region and 22.1% (54/244) in the α determinant. Hotspot mutations included Q101R/K, I/T126S/T/V/A/I, Q129H/R, M133L/T, G145R/T/A and F/Y161Y/F. Notably, AA substitutions including L104F/W, T113S, T123P, I126V and G145T differed from previously reported variants. Additional novel mutation sites P105L, S117R/T and W156L were identified. The I92T, Y100C/S and I126S/T/V mutations showed specific associations with genotype C, whereas Y161F was exclusively detected in genotype B.

Conclusions: This study documents a high frequency of S gene mutations within critical immune regions among chronic HBV-infected patients in eastern China, alongside novel mutation sites and distinct genotype-dependent patterns. HBV genotype and age were independently associated with S gene mutation. These findings provide a molecular basis for optimizing regional diagnostic strategies and future vaccine design.

We report a case of hypereosinophilia syndrome (HES) due to Wuchereria bancrofti infection presenting with a deep venous thrombosis in a previously healthy adult male. The patient presented with a 3-mo history of low-grade intermittent fever and an acute onset of swelling of the left lower limb. Laboratory investigations revealed marked eosinophilia with a peak absolute eosinophil count of 8194 cells/µl and ultrasound evidence of extensive left iliofemoro-popliteal thrombosis. Our workup for secondary causes confirmed W. bancrofti antigen positivity, following which antiparasitic therapy was promptly initiated and a reduction in eosinophil count was noted. Our case highlights the importance of recognition of filariasis as a cause of reactive HES in an endemic region and recognising the thromboembolic complications that may arise from it.

Background: Hump-nosed pit vipers (genus Hypnale) are the most common cause of venomous snakebites in Sri Lanka, accounting for more than one-third of all snakebites, as they are widely distributed throughout the country. It is a highly medically important snake in Sri Lanka. Even though several life-threatening complications, including venom-induced consumption coagulopathy, acute kidney injury, venom-induced thrombotic microangiopathy and cardiac effects, are reported following their bites, no antivenom is currently available for Hypnale - envenomed patients either in Sri Lanka or India. Apart from the acute manifestations of snakebites, chronic health effects have rarely been described in the literature.

Methods: A case series of 11 patients who developed long-term health effects following hump-nosed pit viper bites was prospectively studied at the Teaching Hospital, Ratnapura, Sri Lanka, from June 2015 to May 2021. Data on clinical presentation, examination findings, investigations, management and two-year follow-up were collected.

Results: This case series describes some of the chronic health manifestations following hump-nosed pit viper bites in 11 patients, including chronic kidney disease, fasciotomy-related injuries, musculoskeletal disabilities and pulmonary effects.

Conclusion: Hump-nosed pit viper bites can cause severe long-term sequelae that require follow-up. Physicians should be aware of these manifestations when managing patients and this case series highlights the need for an effective antivenom for Hypnale bites.

Background: Transgender women (TGW) and men who have sex with men (MSM) are disproportionately affected by human immunodeficiency virus (HIV) and mental health challenges. Mental well-being influences uptake and adherence to HIV prevention and treatment. However, gaps in mental health service delivery present challenges for scalability in public health systems. Artificial intelligence (AI)-driven chatbots may offer a novel, scalable solution to expand access to mental health support.

Methods: This qualitative study was conducted at the Aurum POP INN clinic in Pietermaritzburg, KwaZulu-Natal. A multi-agent AI chatbot, designed to simulate supportive counselling based on the Inuka model, was piloted with TGW and MSM. Ten participants engaged in in-depth interviews after interacting with the chatbot. An additional 34 participants experienced both chatbot and in-person counselling through a randomised crossover design and then participated in four focus group discussions. The Unified Theory of Acceptance and Use of Technology and the Acceptability of Healthcare Interventions Framework guided the analysis.

Results: The chatbot was generally acceptable, with participants valuing its privacy, convenience and human-like interaction. Acceptability was enhanced by associations with modernity and anonymity. Trust, usability and accessibility improved engagement. Key barriers included slow response times, limited rapport and repetitive messaging.

Conclusions: AI chatbots offer a promising, scalable approach to supporting mental health among key populations in HIV care.

The fight against leprosy has entered the crucial final phase in India, with the government's announcement of a national plan for zero transmission by 2027. Presently, leprosy has pockets of high prevalence in India and unknown transmission chains. At this juncture, we focus on essential aspects of this disease to help everyone understand the basics of the causative agent, disease prognosis, epidemiology, disease-associated societal implications and prevention strategies. Our endeavour aims to inspire novel concepts among early career researchers for combating leprosy.

Background: Chemical control remains a widely used strategy to reduce morbidity from vector-borne diseases such as dengue. However, the potential health risks to exposed populations necessitates ongoing monitoring, particularly due to the toxicity and volume of insecticides employed.

Methods: This study assessed butyrylcholinesterase activity in residents of a city in southern Mexico during distinct periods of exposure to carbamate and organophosphate insecticides.

Results: A statistically significant inhibition of enzymatic activity was observed during the rainy season, which coincided with an increase in insecticide application.

Conclusions: These findings highlight the need for public health authorities to implement preventative measures aimed at minimizing poisoning risks associated with vector control activities.