American Journal of Tropical Medicine and Hygiene最新文献

Skin-related neglected tropical diseases (NTDs) represent an emerging public health and economic challenge in India. In the present prospective observational study, out-of-pocket expenditure and catastrophic health expenditure among patients diagnosed with mycetoma, subcutaneous mycoses, leishmaniasis, and cutaneous tuberculosis and nontuberculous mycobacterial (TB-NTM) infections were assessed. Using structured questionnaires, direct and indirect costs were recorded over a 6-month period. Of the 21 patients enrolled (median age 42 years), 42.9% were household heads and 61.9% lived below the international poverty line. The mean direct and indirect medical costs were $171 ± $113 and $315 ± $338, respectively, with treatment costs being the major driver of expenditure. Catastrophic health expenditure was observed in 95.2% of patients, and in nearly one-quarter of cases, health expenses exceeded the total family income. Notably, patients with TB-NTM incurred the highest individual expenses (mean $642 ± $323). The economic fallout was profound: 33.3% of patients lost employment because of disease-related disability. The study findings highlight the urgent need for enhanced public healthcare access, expanded insurance coverage-including outpatient services and essential medications-and targeted social support to reduce the crippling financial burden of skin-related NTDs in vulnerable populations. In addition, the development of standardized, country-specific diagnostic and treatment guidelines is critical for facilitating early diagnosis, timely intervention, and the prevention of disability and impoverishment in affected populations.

Anopheles mascarensis (An. mascarensis; De Meillon, 1947) is a mosquito species endemic to Madagascar and the Comoros Archipelago. In the past, it was confused with Anopheles marshalli (Theobald, 1929), a continental African species that does not exist in Madagascar. Malaria transmission is highly heterogeneous in Madagascar. Principal and secondary mosquito vectors, as well as malaria parasite species, may vary from one region to another. Anopheles mascarensis has been identified as the main vector of malaria in the east and southeast of Madagascar, while it plays the role of a secondary vector in other Malagasy regions. Differences in behavior between An. mascarensis populations from the east coast and those from the Central Highlands of Madagascar suggest that An. mascarensis may be composed of sibling species. In the present review, unpublished data on the geographical distribution of An. mascarensis were assembled to update the previous distribution map published in 1966. In addition, published data on the biology of this mosquito, its geographical variants, and records of its role in malaria transmission were analyzed. The published data highlight a significant difference between populations from the east coast and those from the Central Highlands, revealing a possible gradient along different climatic and biogeographic regions of Madagascar. This analysis supports the idea that An. mascarensis may consist of a complex of sibling species. With advances in molecular tools, testing this hypothesis is increasingly within reach.

Prompt diagnosis and effective treatment are key malaria interventions that rely on community knowledge and adherence to treatment. With the emergence of artemisinin resistance in Rwanda, ensuring optimal malaria treatment practices within communities is essential. This study examined malaria knowledge, attitudes, and practices among febrile patients at government clinics to identify factors influencing malaria treatment practices. A cross-sectional study was conducted in six health facilities in moderate- to high-malaria-transmission areas of Rwanda. Patients or caregivers of children with fevers were enrolled and interviewed using semistructured questionnaires. From December 2023 to February 2024, 406 participants were enrolled; 71% (n = 289/406) of participants owned insecticide-treated nets, and 51% (n = 205/406) received indoor residual spraying. Malaria knowledge was high among respondents, with 81% (n = 329/406) correctly identifying symptoms, 72% (n = 291/406) understanding transmission modes, and 74.6% (n = 303/406) aware of effective control measures. However, of the 44.3% (n = 180/406) who received malaria treatment in the last 6 months, only 46% (n = 83/180) completed the appropriate 3-day medication course; 37% (n = 66/180) stopped within 2 days, and 11% (n = 19/180) went over 3 days. Furthermore, 27% (n = 109/406) took antimalarials for fever; the majority (54%; n = 49/109) received medication from drug outlets/pharmacies. Although knowledge and attitudes toward malaria treatment were high, adherence was poor, thereby exacerbating the risk of developing resistance. Effective interventions are urgently needed to improve antimalarial adherence, particularly in sub-Saharan African countries with documented antimalarial resistance.

Hepatitis D virus (HDV) infection in individuals with chronic hepatitis B virus (HBV) is associated with accelerated liver disease and hepatocellular carcinoma (HCC). In this retrospective cohort of 1,337 HBsAg-positive patients at an urban safety-net hospital in Minneapolis, Minnesota, 41.6% were tested for anti-HDV antibodies, of whom 8.8% were positive. Among those testing positive, 28% had polymerase chain reaction-confirmed HDV infection. HDV Ab-positive patients were predominantly of African descent (88%), with 71% being Liberian. In comparison with HDV Ab-negative patients, those with HDV had a higher prevalence of cirrhosis (34.7% versus 12.2%), HCC (6.1% versus 2.8%), HIV (14.3% versus 8.3%), Hepatitis C virus (HCV) (10.2% versus 1.0%), and alcohol use (36.7% versus 27.8%). HDV Ab-positivity was associated with higher rates of advanced fibrosis in comparison with HDV Ab-negative individuals (36.7% versus 15%). Despite the high prevalence among Liberian patients, only 50% of this group was screened for HDV. Black race (OR: 3.75; 95% CI: 1.46-9.61), cirrhosis (OR: 3.56; 95% CI: 1.47-8.60), aspartate aminotransferase ≥80 U/L (OR: 3.05; 95% CI: 1.05-8.89), and HBV DNA <2,000 IU/mL (OR: 3.36; 95% CI: 1.61-6.98) as independent predictors of HDV Ab positivity. These findings underscore significant missed opportunities with risk-based screening and support universal HDV screening for HBsAg-positive individuals to improve detection and outcome.

Indoor residual insecticide spraying and the distribution of insecticide-treated nets have undoubtedly led to a significant reduction in the global malaria burden. However, insecticide resistance poses a threat to the effectiveness of these recommended control methods. In the present study, the aim was to determine the efficacy of SumiShield® 50WG (Sumitomo Chemical Co. Ltd., Tokyo, Japan), an insecticide containing clothianidin, a neonicotinoid, in controlling malaria vectors in Madagascar. The study was conducted over 9 months after the initial spraying in experimental huts made with walls coated using different substrates, and both wild anopheline mosquitoes and an Anopheles arabiensis (An. arabiensis) insecticide-susceptible laboratory strain were used. Mortality in wild mosquitoes remained above the WHO threshold of 80.0% for up to 8 months post-spray, when assessed up to 96 hours after capture, depending on the type of wall surface. SumiShield 50WG did not induce exophily or inhibit blood-feeding in wild mosquitoes because no significant differences were observed between treated and control huts regarding the rates of exophily and blood-fed mosquitoes. In An. arabiensis, the WHO mortality threshold was also met for up to 8 months post-spray when assessed up to 96 hours after exposure. However, during the ninth month, this threshold was not achieved, even when mortality was assessed up to 120 hours after exposure. The residual efficacy of the formulation, which lasts up to 8 months, is sufficient to cover the malaria transmission season in most endemic areas of Madagascar.

In 2018, insecticide-treated nets (ITNs) were mass distributed across Madagascar. The bio-efficacy of DawaPlus® 2.0 and PermaNet® 2.0 ITNs was assessed upon arrival and at 12, 24, and 36 months after distribution. Chemical analyses of insecticide residue on ITNs were also conducted. On arrival, mosquito mortality rates observed when exposed to DawaPlus 2.0 (86.4%) and PermaNet 2.0 nets (83.6%) exceeded the WHO's threshold of 80.0%. At 12, 24, and 36 months after distribution, mosquito mortality rates were <56% for all districts. Moreover, the knockdown effect was below the WHO threshold of 95.0% for all districts and at all time points, even for new ITNs. With the exception of the new DawaPlus 2.0, the deltamethrin residue on ITNs was also lower than the expected ranges of 80 mg/m2 ± 25% for DawaPlus 2.0 and 55 mg/m2 ± 25% for PermaNet 2.0; regardless of ITN age, the concentration of deltamethrin was <66 mg/m2 for DawaPlus 2.0 and <36 mg/m2 for PermaNet 2.0 ITNs. According to the manufacturers, ITNs are effective for 36 months; therefore, mass distribution campaigns are organized every 3 years. However, the DawaPlus 2.0 and PermaNet 2.0 ITNs exhibited a loss of bio-efficacy within 1 year of distribution. This bio-efficacy loss could be due to a manufacturing problem, poor storage and transportation conditions, or poor use and net care practices in Madagascar. Understanding and correcting the root causes of this issue is critical for guiding corrective actions, such as improving manufacturing processes, replacing ITNs more frequently, and increasing education on ITN care.

A malaria outbreak occurred in Farafangana District, Madagascar, in 2018, shortly after the implementation of insecticide-treated bed net distribution and indoor residual spraying campaigns. Entomological and epidemiological investigations were conducted to characterize disease transmission in six villages in three communes. Mosquitoes were collected using human landing catches, light traps, and pyrethrum spray catches. Vector biting behavior was described, and sporozoite indices were determined. To describe demographic and risk data, questionnaires were administered to individuals from randomly selected households, and rapid diagnostic tests (RDTs) were performed on consenting household members. Anopheles coustani (An. coustani), Anopheles gambiae s.s. (An. gambiae s.s.), Anopheles funestus (An. funestus), and Anopheles mascarensis (An. mascarensis) were the most frequently captured malaria vector species. Outdoor biting was common for all predominant Anopheles species collected (exophagy rates varied from 59.8% for An. gambiae s.s. to 100.0% for An. coustani), except for An. funestus, which exhibited an exophagy rate of less than 47.0%. Of 1,488 Anopheles mosquitoes collected, 25 (1.7%) had Plasmodium falciparum sporozoites, only one of which was collected indoors. The remaining 24 were collected outdoors, 13 (54.2%) of which were An. coustani. The other 12 specimens were An. funestus, Anopheles squamosus, An. gambiae s.s., and An. mascarensis. Of 226 individuals tested using RDTs, 71 (31.4%) had positive results. A total of 61 (85.9%) of these individuals were asymptomatic, most of whom were children. Highly infected secondary malaria vectors, in addition to primary vectors, combined with a predominance of exophagy, contributed to parasite transmission in the Farafangana District, where indoor-targeted vector control measures had been implemented. A high proportion of asymptomatic infections likely sustained transmission. Control strategies for outdoor biting should be explored.

The global burden of diabetes is influenced by population size, age structure, disease prevalence, and disease severity. However, systematic analyses of diabetes severity remain limited. This study estimated global trends and disparities in diabetes severity across sociodemographic index (SDI) levels using Global Burden of Disease 2021 data. Age-standardized mortality-to-prevalence ratio (MPR) and disability-adjusted life years-to-prevalence ratio (DPR) were used as proxies for severity. A higher MPR indicates greater case fatality, whereas a higher DPR reflects heavier per-case burden of disability and premature death. The slope index of inequality and relative index of inequality were used to measure disparities across SDI levels, and average annual percentage changes (AAPCs) were computed to quantify temporal trends. Globally, the age-standardized MPR decreased from 0.57% in 1990 to 0.32% in 2021 (AAPC = -1.81%, P <0.001), and DPR decreased from 20.62 to 14.86% (AAPC = -1.03%, P <0.001). Eastern Sub-Saharan Africa (e.g., Malawi) had the highest diabetes severity, whereas Eastern Europe (e.g., Russian Federation) exhibited increasing trends. SDI exhibited a near-linear negative correlation with diabetes severity. Although absolute disparities in diabetes severity between high- and low-SDI countries declined from 1990 to 2021, relative disparities increased. Type 1 diabetes was more severe than type 2 in individuals younger than 60 years, particularly in children under 5 years. This pattern reversed in older adults, with higher type 2 severity. Overall, although global diabetes severity declined from 1990 to 2021, disparities persist across regions, countries, age groups, and diabetes types.

Intralesional injection of pentavalent antimonials is a recommended treatment of cutaneous leishmaniasis (CL). We describe an allergic response to meglumine antimoniate after intralesional treatment of a CL lesion. A 61-year-old male resident of the United Kingdom developed an enlarging, nontender nodule on the right earlobe. Histological analysis and polymerase chain reaction testing confirmed a diagnosis of CL. Intralesional therapy with meglumine antimoniate was initiated, and two infiltrations were completed. After each administration, localized swelling and erythema were noted, and after the second infiltration, an urticarial rash also appeared on the patient's hands. An immunological hypersensitivity reaction, with mixed Type I and Type IV features, was suspected, and treatment was discontinued. The patient declined further treatment, and the lesion gradually resolved, with full recovery 36 months after the first treatment. Recent travel history suggested Spain as the most likely country of acquisition. This report also reviews the literature on allergy to antimonial drugs. The prevalence of pentavalent antimonial hypersensitivity varies considerably between studies, likely due to differences in reporting of adverse events. Clinicians treating leishmaniasis should be aware of this adverse effect of antimonials, which may require use of alternative therapies.