Research and Reports in Tropical Medicine最新文献

Purpose: Improving access to malaria treatment in rural remote areas remains a major challenge facing innovative strategies, such as Accredited Drug Dispensing Outlets (ADDOs) and Community Health Workers (CHWs) programs in Tanzania. This study tested the effectiveness of a financial benefit approach to motivate CHWs to improve prompt access to malaria treatment.

Patients and methods: We applied a quasi-experimental study design in rural-remote areas in Kilosa district, Tanzania. Febrile children in selected intervention areas were provided access to malaria diagnostic and treatment at a minimal fee to CHWs and compared with non-intervention areas. We measured impact using difference in differences (DID) analysis.

Results: At baseline, 870 children <5 years of age were recruited and 1,127 in post-intervention. The DID in prompt access to malaria diagnostics and treatment was 28.0% in favor of intervention. A net pre and post decrease (DID=24.1%) in seeking care from public facilities was observed, signifying decrease in workload. Incidentally, knowledge on malaria treatment increased in intervention area (DID 11%-21%).

Conclusion: Using the financial benefit approach, CHWs were able to significantly improve prompt access to malaria diagnostics and treatment in rural remote areas. Scaling up of the strategy might speed up the pace toward achieving national target of accurate diagnosis and appropriate treatment by 80% in 2020.

Malaria and HIV, two of the world's most deadly diseases, are widespread, but their distribution overlaps greatly in sub-Saharan Africa. Consequently, malaria and HIV coinfection (MHC) is common in the region. In this paper, pertinent publications on the prevalence, impact, and treatment strategies of MHC obtained by searching major electronic databases (PubMed, PubMed Central, Google Scholar, ScienceDirect, and Scopus) were reviewed, and it was found that the prevalence of MHC in SSA was 0.7%-47.5% overall. Prevalence was 0.7%-47.5% in nonpregnant adults, 1.2%-27.8% in children, and 0.94%-37% in pregnant women. MHC was associated with an increased frequency of clinical parasitemia and severe malaria, increased parasite and viral load, and impaired immunity to malaria in nonpregnant adults, children, and pregnant women, increased in placental malaria and related outcomes in pregnant women, and impaired antimalarial drug efficacy in nonpregnant adults and pregnant women. Although a few cases of adverse events have been reported in coinfected patients receiving antimalarial and antiretroviral drugs concurrently, available data are very limited and have not prompted major revision in treatment guidelines for both diseases. Artemisinin-based combination therapy and cotrimoxazole are currently the recommended drugs for treatment and prevention of malaria in HIV-infected children and adults. However, concurrent administration of cotrimoxazole and sulfadoxine-pyrimethamine in HIV-infected pregnant women is not recommended, because of high risk of sulfonamide toxicity. Further research is needed to enhance our understanding of the impact of malaria on HIV, drug-drug interactions in patients receiving antimalarials and antiretroviral drugs concomitantly, and the development of newer, safer, and more cost-effective drugs and vaccines to prevent malaria in HIV-infected pregnant women.

Purpose: This study was to investigate weaning practices used by mothers when transitioning infants from breast milk to complementary foods and to determine the role these foods have in the transmission of gastrointestinal parasites.

Participants and methods: On average, of the 175 mothers extensively interviewed, 93% said they had breast-fed their infants. Approximately 20.8% of mothers had added some other liquid to their infant's diet at 3 months, while most mothers had added other liquids at 6 months (39.0%) and >6 months (32.1%). Some mothers expanded food offerings to infants before 3 months. The percentage of mothers who had added other liquids to their infants' diet was reported by age of the infant: as early as 1 day (2.5%), <1 week (1.9%), first month (3.1%), 3 months (20.8%), 6 months (39.0%), and >6 months (32.1%). These foods included fruit, vegetables, meat, and grains. The maximum age a child was found to be still breastfeeding was 13 years.

Results: Forty percent of mothers involved in this survey reported that their children were diagnosed and/or treated for gastrointestinal parasitic infection. Routes of infection of protozoan and helminth parasites likely resulted from contaminated complementary foods and water given to infants while still breast-feeding or from contaminated foods after breast-feeding had been completed. Contaminated water is a likely source of protozoan parasites. Contaminated water was fed to infants, mixed with formula or complementary foods, or used to wash bottles for infant feeding. There was an absence of hand-washing by children and mothers before eating or while preparing foods.

Conclusion: The major source of soil-transmitted helminth infections was likely the result of unwashed or uncooked pureed fruit or vegetables used as complementary foods, unpasteurized animal milk, insanitary food storage, poor living conditions with exposed dirt floors, and exposure to roaming domestic animals.

In this paper, we present a historical review of rickettsiosis in Central America and also the most recent findings of Rickettsia in ectoparasites. All countries of Central America have records of rickettsiosis. Regarding the typhus group rickettsioses, there is clinical or serological evidence of Rickettsia prowazekii in Guatemala, Rickettsia typhi in Panama, Guatemala, and Costa Rica and unidentified species of the typhus group in El Salvador. Concerning spotted fever group rickettsiosis, there is serological evidence of infection by Rickettsia akari in Costa Rica and confirmed cases involving Rickettsia rickettsii in Panama and Costa Rica. There are also reports of spotted fever group rickettsiosis in acute patients from Guatemala, Honduras, and Nicaragua. Serological studies in Central America show reactivity of Rickettsia ambyommatis, Rickettsia bellii, Rickettsia felis, Rickettsia rhipicephali, and R. rickettsii in domestic and wild mammals. Eight species of Rickettsia have been detected in ectoparasites from Central America: R. africae (or very similar), R. amblyommatis, R. asembonensis, R. bellii, R. felis, R. parkeri, R. rhipicephali, and R. rickettsii, in addition to undescribed strains such as Atlantic Rainforest, Colombianensi, IbR/CRC, Barva, Aragaoi, and Candidatus "Rickettsia nicoyana;" the latter being the only one associated with Argasidae (Ornithodoros knoxjonesi). R. amblyommatis is the most common species in Central America, seeing as it has been reported in 10 species of ticks and one of fleas in five of the seven countries of the region. In this study, we demonstrate that the genus Rickettsia is widely distributed in Central America and that rickettsiosis could be an underestimated problem in the absence of greater diagnostic efforts in undetermined febrile cases.

Background: Malaria is a febrile illness caused by protozoan parasites of the genus Plasmodium. It is prevalent in tropical and subtropical countries and becomes a challenge to a highly endemic area of Africa including Ethiopia. The West Armachiho district is a malaria-endemic lowland area where communities are experiencing hyperendemic malaria transmission.

Objective: The aim of this study was to determine the prevalence of malaria and the associated risk factors among asymptomatic migrant laborers in the West Armachiho district, Northwest Ethiopia.

Materials and methods: Community-based cross-sectional study was conducted from September to December 2016 on 385 migrant laborers selected by proportionate two-stage sampling method in Agricultural camps of the West Armachiho district. A standardized questionnaire was used to collect sociodemographic data and risk factors. Capillary blood was collected for Giemsa-stained blood film examination to detect and identify Plasmodium parasites. Data were coded, entered, checked for completeness, and analyzed using SPSS version-20 statistical software. Multivariate logistic regression was used to asses significantly associated risk factors. A P-value <0.05 was considered as statistically significant.

Results: The prevalence of malaria was found to be 18.4% (n=71). Education level, home area or origin of migrant laborers, number of visits, outdoor sleeping, and bed net utilization were associated with the risk of malaria (P<0.05).

Conclusion: Malaria was high in this study area and associated with outdoor sleeping, number of visits, home area, and bed net utilization.

Nodding syndrome is an enigmatic neuropsychiatric and epileptiform disorder associated with psychomotor, mental, and physical growth retardation. The disorder affects otherwise previously normal children aged 3-18 years, with a slight preponderance for the male child. Nodding syndrome has been described in rural regions of some low-income countries in sub-Saharan Africa including northern Uganda, South Sudan, and a mountainous region of southern Tanzania. The cause of the disorder has hitherto eluded scientists. Neuroimaging studies show involvement of the nervous system with associated severe cortical atrophy in the affected children. The affected communities have generated a number of perceived causes including some conspiracy theories related to intentional poisoning of water sources and foods, and causes related to fumes and chemicals from ammunitions used during civil wars in the affected regions. From biomedical perspectives, the treatment of the affected children is geared towards symptoms control and rehabilitation. There is evidence that seizures and behavioral problems including wandering and episodes of aggressions are controllable with anticonvulsants, especially sodium valproate and antipsychotics. No treatments have proven effective in reversing the course of the disorder, and cure remains a distant goal. Community members have used indigenous medicines, cleansing rituals, and prayer interventions, but have not perceived any reasonable improvements. A randomized controlled clinical trial is ongoing in northern Uganda to test the efficacy and effectiveness of doxycycline in the treatment of nodding syndrome. The hypothesis underlying the doxycycline trial underscores the role of antigenic mimicry: that antibodies generated against an antigen of a microorganism that resides inside the black fly-transmitted parasite, Onchocerca volvulus becomes directed against nervous tissue in the brain. This paper reviews some of the recent advances in researches on the etiologies, pathophysiology, and treatment of nodding syndrome.

Background: Banknotes are objects of great turnover and diffusion among the population, and can be efficient mechanisms in the dissemination of several intestinal parasites. This study investigated the presence of biological forms of intestinal parasites present in circulating cash banknotes in the city of Diamantina, Minas Gerais, Brazil, aiming to propose interventions aimed at improving local public health.

Materials and methods: Between February and April 2017, samples of banknotes collected in five commercial establishments of the city were analyzed, namely: 1) gas station, 2) supermarket, 3) butchery, 4) pharmacy and 5) free fair. Ten circulating banknotes of each value (R$2.00, R$5.00, R$10.00, R$20.00, R$50.00 and R$100.00) were exchanged for new banknotes, washed with Tween 80 and, after spontaneous sedimentation, analyzed under an optical microscope with a magnification of 10× and 40×.

Results: Cysts of Entamoeba coli (74.60%), cysts of Endolimax nana (16.94%), Giardia lam-blia cysts (4.44%), unidentified nematode larvae (2.02%), Hymenolepis sp. (0.81%), Taenia sp. (0.81%) and Ancylostomidae larvae (0.40%) were found.

Conclusions: The results revealed the need for improvements in basic sanitation, health and education activities that emphasized the importance of proper hand hygiene.

Background: The search for new antimalarial drugs has become progressively urgent due to plasmodial resistance to most of the commercially available antimalarial drugs. As part of this effort, the study evaluated the antimalarial activity of Cucumis metuliferus and Lippia kituiensis, which are traditionally used in Tanzania for the treatment of malaria.

Materials and methods: In vivo antimalarial activity was assessed using the 4-day suppressive antimalarial assay. Mice were infected by injecting via tail vein 1×10⁷ erythrocytes infected by Plasmodium berghei ANKA. Extracts were administered orally; chloroquine (10 mg/kg/day) and dimethyl sulfoxide (5 mL/kg/day) were used as positive and negative controls, respectively. The level of parasitemia, survival time, packed cell volume (PCV) and variation in body weight of mice were used to determine the antimalarial activity of the extract.

Results: The ethyl acetate, methanolic and chloroform extracts of C. metuliferus and L. kituiensis significantly (p<0.05) inhibited parasitemia in a dose-dependent manner and prevented loss of body weight at the dose levels of 600 mg/kg and 1500 mg/kg, respectively. In addition, the extracts prolonged the mean survival time of P. berghei-infected mice compared to the non-treated control. The plant extracts did not show reduction of PCV except at the low dose of 300 mg/kg. The highest suppression was recorded at the dose level of 1,500 mg/kg. At this dose, C. metuliferus in chloroform, methanolic and ethyl acetate extracts had percentage suppression of 98.55%, 88.89% and 84.39%, respectively, whereas L. kituiensis in ethyl acetate, chloroform and methanolic extracts exhibited suppression of the pathogens of 95.19%, 93.88% and 74.83%, respectively.

Conclusion: It is worth reporting that the two plants induced suppression which is equivalent to that induced by chloroquine (C. metuliferus chloroform and L. Kituiensis ethyl acetate). The two plants have been demonstrated to be potential sources of antimalarial templates.

Background: Multiple factors have been associated with the severity of infection by influenza A(H1N1)pdm09. These include H1N1 cases with proven coinfections showing clinical association with bacterial contagions.

Purpose: The objective was to identify H1N1 and copathogens in the Oaxaca (Mexico) population. A cross-sectional survey was conducted from 2009 to 2012. A total of 88 study patients with confirmed H1N1 by quantitative RT-PCR were recruited.

Methods: Total nucleic acid from clinical samples of study patients was analyzed using a TessArray RPM-Flu microarray assay to identify other respiratory pathogens.

Results: High prevalence of copathogens (77.3%; 68 patients harbored one to three pathogens), predominantly from Streptococcus, Haemophilus, Neisseria, and Pseudomonas, were detected. Three patients (3.4%) had four or five respiratory copathogens, whereas others (19.3%) had no copathogens. Copathogenic occurrence with Staphylococcus aureus was 5.7%, Coxsackie virus 2.3%, Moraxella catarrhalis 1.1%, Klebsiella pneumoniae 1.1%, and parainfluenza virus 3 1.1%. The number of patients with copathogens was four times higher to those with H1N1 alone (80.68% and 19.32%, respectively). Four individuals (4.5%; two males, one female, and one infant) who died due to H1N1 were observed to have harbored such copathogens as Streptococcus, Staphylococcus, Haemophilus, and Neisseria.

Conclusion: In summary, copathogens were found in a significant number (>50%) of cases of influenza in Oaxaca. Timely detection of coinfections producing increased acuity or severity of disease and treatment of affected patients is urgently needed.