Protection from cholera by adding lime juice to food - results from community and laboratory studies in Guinea-Bissau, West Africa

Safeguarding drinking water: A brief insight on characteristics, treatments and risk assessment of contamination

Water pollution stands as a critical worldwide concern, bearing extensive repercussions that extend to human health and the natural ecosystem. The sources of water pollution can be diverse, arising from natural processes and human activities and the pollutants may range from chemical and biological agents to physical and radiological contaminants. The contamination of water disrupts the natural functioning of the system, leading to both immediate and prolonged health problems. Various technologies and procedures, ranging from conventional to advanced, have been developed to eliminate water impurities, with the choice depending on the type and level of contamination. Assessing risks is a crucial element in guaranteeing the safety of drinking water. Till now, research is continuing the removal of contaminates for the sake of supplying safe drinking water. The study examined physical, inorganic, organic, biological and radiological contaminants in drinking water. It looked at where these contaminants come from, their characteristics, the impact they have and successful methods used in real-world situations to clean the contaminated water. Risk assessment methodologies associated with the use of unsafe drinking water as future directives are also taken into consideration in the present study for the benefit of public concern. The manuscript introduces a comprehensive study on water pollution, focusing on assessing and mitigating risks associated with physical, inorganic, organic, biological and radiological contaminants in drinking water, with a novel emphasis on future directives and sustainable solutions for public safety.

Physical Activity and Natural Products and Minerals in the SARS-CoV-2 Pandemic: An Update

Coronavirus-disease 19 (COVID-19) has rapidly become a global public health issue, and there is a desperate need for strategies of prevention, reduction, and treatment to halt the epidemic. The coronavirus affects the immune system, and individuals with a compromised immune system, such as those with diabetes, hypertension, obesity, are more susceptible to this virus. Lifestyle-related variables such as physical activity and nutritional supplements can decrease inflammatory markers, increase anti-inflammatory and antioxidant status, and improve the immune system. Lifesty-lerelated variables play preventive roles against various infectious diseases including COVID-19. This review highlights the effects of physical activity and nutrients supplements on the immune system and their possible benefits in combating the harms caused by infection with the COVID-19 virus.

Prevention and control of cholera with household and community water, sanitation and hygiene (WASH) interventions: A scoping review of current international guidelines

Introduction

Cholera remains a frequent cause of outbreaks globally, particularly in areas with inadequate water, sanitation and hygiene (WASH) services. Cholera is spread through faecal-oral routes, and studies demonstrate that ingestion of Vibrio cholerae occurs from consuming contaminated food and water, contact with cholera cases and transmission from contaminated environmental point sources. WASH guidelines recommending interventions for the prevention and control of cholera are numerous and vary considerably in their recommendations. To date, there has been no review of practice guidelines used in cholera prevention and control programmes.

Methods

We systematically searched international agency websites to identify WASH intervention guidelines used in cholera programmes in endemic and epidemic settings. Recommendations listed in the guidelines were extracted, categorised and analysed. Analysis was based on consistency, concordance and recommendations were classified on the basis of whether the interventions targeted within-household or community-level transmission.

Results

Eight international guidelines were included in this review: three by non-governmental organisations (NGOs), one from a non-profit organisation (NPO), three from multilateral organisations and one from a research institution. There were 95 distinct recommendations identified, and concordance among guidelines was poor to fair. All categories of WASH interventions were featured in the guidelines. The majority of recommendations targeted community-level transmission (45%), 35% targeted within-household transmission and 20% both.

Conclusions

Recent evidence suggests that interventions for effective cholera control and response to epidemics should focus on case-centred approaches and within-household transmission. Guidelines did consistently propose interventions targeting transmission within households. However, the majority of recommendations listed in guidelines targeted community-level transmission and tended to be more focused on preventing contamination of the environment by cases or recurrent outbreaks, and the level of service required to interrupt community-level transmission was often not specified. The guidelines in current use were varied and interpretation may be difficult when conflicting recommendations are provided. Future editions of guidelines should reflect on the inclusion of evidence-based approaches, cholera transmission models and resource-efficient strategies.

Vibriosis and Aeromonas infection in shrimp: Isolation, sequencing, and control

Background and Aim: Shrimp is one of the most commonly consumed types of seafood. It is a very nutritious healthy food. Shrimp is low in calories and rich in protein and healthy fats. It also contains a treasure trove of vitamins and minerals. On the negative side, it may be affected by many bacterial diseases which affect its health. Furthermore, it may be incriminated as a vector of foodborne illnesses that range from mild gastrointestinal upset to life-threatening diseases. This study was designed to assess the clinical picture and zoonotic importance of vibriosis and Aeromonas infection in live shrimp and to study the antibacterial effect of citric acid (lemon juice) and acetic acid (vinegar) on these pathogens. Materials and Methods: A total of 170 live shrimp (Metapenaeus monoceros) samples were collected from Suez City, Egypt. The samples were examined clinically, and then, they were enriched into alkaline peptone water and cultivated on thiosulfate-citrate-bile salts-sucrose agar and ampicillin MacConkey agar for the isolation of Vibrio and Aeromonas species, respectively. The recovered isolates were confirmed biochemically and genotypically using duplex polymerase chain reaction (PCR) and sequencing. The germicidal effects of vinegar and lemon on artificially contaminated shrimp samples with Aeromonas hydrophila and Vibrio parahaemolyticus at different times (0.25, 1, 1.5, and 24 h) and temperatures (5° and 30°C) were studied. Results: The results revealed that some of the infected shrimp were hypoxic, lethargic with abnormal swimming behavior. In most cases, body appendages, telsons, uropods, and gills took black coloration. In addition, the hepatopancreas appeared soft, swollen, and congested. The prevalence rates of vibriosis in each of the musculature and hepatopancreas were 4.7%, while the prevalence rates of Aeromonas infection in the musculature and hepatopancreas were 11.8% and 11.2%, respectively. Duplex PCR showed that Aeromonas isolates gave double bands: 237 bp specific for gcat and 500 bp specific for 16S rRNA, while Vibrio spp. and Plesiomonas shigelloides isolates gave single band at 500 bp. The effect of organic acid treatment showed that acetic acid (vinegar 5%) had increasing reduction rates that reached its maximum level after 24 h; where it caused (100% inhibition) for A. hydrophila at both temperatures and (33.63% and 60% inhibition) for V. parahaemolyticus at refrigerator and room temperatures, respectively. Moreover, acetic acid was more effective at room temperature than at refrigerator temperature. Concerning the effect of lemon juice (citric acid), it was more effective than acetic acid at short marination (0.25 and 1 h) at both temperatures for the two pathogens. Moreover, lemon was more effective at refrigerator temperature than at room temperature at the same aforementioned time. The difference between the reduction effects of the two acids on both pathogens was statistically significant (p<0.0001). Conclusion: Overall, the examined shrimp samples were found to be vectors for Vibrio and Aeromonas spp. Application of hygienic measures during handling and cooking of shrimp should be esteemed. The organic acid treatment trial showed that vinegar and lemon juice can be used as a safe and economic method to limit the microbial contamination in seafood.

Temporal trend and spatial clustering of cholera epidemic in Kumasi-Ghana

Knowledge of the temporal trends and spatial patterns will have significant implications for effective preparedness in future epidemics. Our objective was to investigate the temporal trends and the nature of the spatial interaction of cholera incidences, dwelling on an outbreak in the Kumasi Metropolis, Ghana. We developed generalized nonparametric and segmented regression models to describe the epidemic curve. We used the pair correlation function to describe the nature of spatial clustering parameters such as the maximum scale of interaction and the scale of maximal interaction. The epidemic rose suddenly to a peak with 40% daily increments of incidences. The decay, however, was slower with 5% daily reductions. Spatial interaction occurred within 1 km radius. Maximal interaction occurred within 0.3 km, suggesting a household level of interactions. Significant clustering during the first week suggests secondary transmissions sparked the outbreak. The nonparametric and segmented regression models, together with the pair correlation function, contribute to understanding the transmission dynamics. The issue of underreporting remains a challenge we seek to address in future. These findings, however, will have innovative implications for developing preventive measures during future epidemics.

Individual and Household Risk Factors for Symptomatic Cholera Infection: A Systematic Review and Meta-analysis

Background

Cholera has caused 7 global pandemics, including the current one which has been ongoing since 1961. A systematic review of risk factors for symptomatic cholera infection has not been previously published.

Methods

In accordance with PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, we performed a systematic review and meta-analysis of individual and household risk factors for symptomatic cholera infection.

Results

We identified 110 studies eligible for inclusion in qualitative synthesis. Factors associated with symptomatic cholera that were eligible for meta-analysis included education less than secondary level (summary odds ratio [SOR], 2.64; 95% confidence interval [CI], 1.41-4.92; I2 = 8%), unimproved water source (SOR, 3.48; 95% CI, 2.18-5.54; I2 = 77%), open container water storage (SOR, 2.03; 95% CI, 1.09-3.76; I2 = 62%), consumption of food outside the home (SOR, 2.76; 95% CI, 1.62-4.69; I2 = 64%), household contact with cholera (SOR, 2.91; 95% CI, 1.62-5.25; I2 = 89%), water treatment (SOR, 0.37; 95% CI, .21-.63; I2 = 74%), and handwashing (SOR, 0.29; 95% CI, .20-.43; I2 = 37%). Other notable associations with symptomatic infection included income/wealth, blood group, gastric acidity, infant breastfeeding status, and human immunodeficiency virus infection.

Conclusions

We identified potential risk factors for symptomatic cholera infection including environmental characteristics, socioeconomic factors, and intrinsic patient factors. Ultimately, a combination of interventional approaches targeting various groups with risk-adapted intensities may prove to be the optimal strategy for cholera control.

A Systematic Review and Meta-Analysis of the Association between Water, Sanitation, and Hygiene Exposures and Cholera in Case-Control Studies

Case-control studies are conducted to identify cholera transmission routes. Water, sanitation, and hygiene (WASH) exposures can facilitate cholera transmission (risk factors) or interrupt transmission (protective factors). To our knowledge, the association between WASH exposures and cholera from case-control studies has not been systematically analyzed. A systematic review was completed to close this gap, including describing the theory of risk and protection, developing inclusion criteria, searching and selecting studies, assessing quality of evidence, and summarizing associations between cholera and seven predicted WASH protective factors and eight predicted WASH risk factors using meta-analysis and sensitivity analysis. Overall, 47 articles describing 51 individual studies from 30 countries met the inclusion criteria. All eight predicted risk factors were associated with higher odds of cholera (odds ratio [OR] = 1.9-5.6), with heterogeneity (I²) of 0-92%. Of the predicted protective factors, five of seven were associated with lower odds of cholera (OR = 0.35-1.4), with heterogeneity of 57-91%; exceptions were insignificant associations for improved water source (OR = 1.1, heterogeneity 91%) and improved sanitation (OR = 1.4, heterogeneity 68%). Results were robust; 3/70 (5%) associations changed directionality or significance in sensitivity analysis. Meta-analysis results highlight that predicted risk factors are associated with cholera; however, predicted protective factors are not as consistently protective. This variable protection is attributed to 1) cholera transmission via multiple routes and 2) WASH intervention implementation quality variation. Water, sanitation, and hygiene interventions should address multiple transmission routes and be well implemented, according to international guidance, to ensure that field effectiveness matches theoretical efficacy. In addition, future case-control studies should detail WASH characteristics to contextualize results.

Cultural influences behind cholera transmission in the Far North Region, Republic of Cameroon: a field experience and implications for operational level planning of interventions

Introduction

In recent years, the Far North Region of Cameroon has experienced serious and recurrent cholera outbreaks. Yet, understanding of cultural influences on outbreaks and spread remain poorly understood. This qualitative study explored cultural influences on cholera exposure in this region.

Methods

Interviews and group discussions were conducted in two phases. Phase I involved key informants and phase II included focus group and household discussions. Thematic techniques including word repetition, key-indigenous-terms, and key-words-in-context were used for qualitative data analysis.

Results

Key informants attributed cholera etiology to dirt and spread through water (caneri) and food (group eating or faire-un-rond) while group discussions attributed it to a reprimand from god and transmission through the air. Participants suggested that funerals, weddings, open defecation, and mountaintop burial might influence cholera exposure and facilitate its spread. Hospital avoidance and non-adherence with cholera treatment regimens were linked to favorable beliefs about traditional medicine (rural-urban mentality confrontation). Furthermore, a multiplicity of ethnic languages, mistrust of message sources, culture of dependency and sentimental animal husbandry were barriers to the reception of public health messages.

Conclusion

Many participants had limited scientific knowledge about cholera etiology and transmission. The cultural practice of mountain burial seemed to explain the high cholera attack rate in the mountainous terrain compared to the floodplains. Cultural factors are likely to play important roles in the exposure to and spread of cholera. Understanding cultural context, individual and community perceptions of risk and disease may help public health agencies in response to outbreak prevention and control.

Which health research gets used and why? An empirical analysis of 30 cases

BACKGROUND

While health research is considered essential for improving health worldwide, it remains unclear how it is best organized to contribute to health. This study examined research that was part of a Ghanaian-Dutch research program that aimed to increase the likelihood that results would be used by funding research that focused on national research priorities and was led by local researchers. The aim of this study was to map the contribution of this research to action and examine which features of research and translation processes were associated with the use of the results.

METHODS

Using Contribution Mapping, we systematically examined how 30 studies evolved and how results were used to contribute to action. We combined interviews with 113 purposively selected key informants, document analysis and triangulation to map how research and translation processes evolved and contributions to action were realized. After each case was analysed separately, a cross-case analysis was conducted to identify patterns in the association between features of research processes and the use of research.

RESULTS

The results of 20 of the 30 studies were used to contribute to action within 12 months. The priority setting and proposal selection process led to the funding of studies which were from the outset closely aligned with health sector priorities. Research was most likely to be used when it was initiated and conducted by people who were in a position to use their results in their own work. The results of 17 out of 18 of these user-initiated studies were translated into action. Other features of research that appeared to contribute to its use were involving potential key users in formulating proposals and developing recommendations.

CONCLUSIONS

Our study underlines the importance of supporting research that meets locally-expressed needs and that is led by people embedded in the contexts in which results can be used. Supporting the involvement of health sector professionals in the design, conduct and interpretation of research appears to be an especially worthwhile investment.

Cholera outbreaks in Africa

During the current seventh cholera pandemic, Africa bore the major brunt of global disease burden. More than 40 years after its resurgence in Africa in 1970, cholera remains a grave public health problem, characterized by large disease burden, frequent outbreaks, persistent endemicity, and high CFRs, particularly in the region of the central African Great Lakes which might act as reservoirs for cholera. There, cases occur year round with a rise in incidence during the rainy season. Elsewhere in sub-Saharan Africa, cholera occurs mostly in outbreaks of varying size with a constant threat of widespread epidemics. Between 1970 and 2011, African countries reported 3,221,050 suspected cholera cases to the World Health Organization, representing 46 % of all cases reported globally. Excluding the Haitian epidemic, sub-Saharan Africa accounted for 86 % of reported cases and 99 % of deaths worldwide in 2011. The number of cholera cases is possibly much higher than what is reported to the WHO due to the variation in modalities, completeness, and case definition of national cholera data. One source on country specific incidence rates for Africa, adjusting for underreporting, estimates 1,341,080 cases and 160,930 deaths (52.6 % of 2,548,227 estimated cases and 79.6 % of 209,216 estimated deaths worldwide). Another estimates 1,411,453 cases and 53,632 deaths per year, respectively (50 % of 2,836,669 estimated cases and 58.6 % of 91,490 estimated deaths worldwide). Within Africa, half of all cases between 1970 and 2011 were notified from only seven countries: Angola, Democratic Republic of the Congo, Mozambique, Nigeria, Somalia, Tanzania, and South Africa. In contrast to a global trend of decreasing case fatality ratios (CFRs), CFRs have remained stable in Africa at approximately 2 %. Early propagation of cholera outbreaks depends largely on the extent of individual bacterial shedding, host and organism characteristics, the likelihood of people coming into contact with an infectious dose of Vibrio cholerae and on the virulence of the implicated strain. Cholera transmission can then be amplified by several factors including contamination of human water- or food sources; climate and extreme weather events; political and economic crises; high population density combined with poor quality informal housing and poor hygiene practices; spread beyond a local community through human travel and animals, e.g., water birds. At an individual level, cholera risk may increase with decreasing immunity and hypochlorhydria, such as that induced by Helicobacter pylori infection, which is endemic in much of Africa, and may increase individual susceptibility and cholera incidence. Since contaminated water is the main vehicle for the spread of cholera, the obvious long-term solution to eradicate the disease is the provision of safe water to all African populations. This requires considerable human and financial resources and time. In the short and medium term, vaccination may help to prevent and control the spread of cholera outbreaks. Regardless of the intervention, further understanding of cholera biology and epidemiology is essential to identify populations and areas at increased risk and thus ensure the most efficient use of scarce resources for the prevention and control of cholera.

Effect of lime juice on Vibrio parahaemolyticus and Salmonella enterica inactivation during the preparation of the raw fish dish ceviche

Ceviche is a raw fish dish common in Peru and other Latin American counties. The most characteristic feature of ceviche is the use of lime juice for marinating or "cooking" the raw fish. Confirmed cases of cholera in Peru, New Jersey, and Florida have been associated with ceviche. Although the effect of organic acids on pathogenic bacteria has been well characterized, few data exist on the effect of these acids in seafood systems. The objective of the study was to evaluate the effects of lime juice marination on pathogens likely to be present in ceviche. Tilapia (Oreochromis niloticus) fillet pieces were inoculated with Vibrio parahaemolyticus and Salmonella enterica (>7 log CFU/g) and incubated at 25 and 4°C for 30 or 120 min in the presence of fresh lime juice at concentrations typical for the preparation of ceviche. Similar levels of cells were also inoculated into fresh lime juice without tilapia. Surviving cells were enumerated on selective (xylose lysine Tergitol 4 and thiosulfate-bile-citrate-sucrose) and nonselective (tryptic soy agar) media. V. parahaemolyticus levels were reduced to below detection limits (∼5-log reduction) under all conditions studied. Salmonella strains on tilapia were much more resistant to inactivation and were only slightly reduced (∼1- to 2-log reduction). Salmonella and V. parahaemolyticus inoculated directly into lime juice without tilapia were all reduced to below detection limits (∼5-log reduction). A typical ceviche recipe reduces V. parahaemolyticus risk significantly but is less effective for control of S. enterica.

Using limes and synthetic psoralens to enhance solar disinfection of water (SODIS): a laboratory evaluation with norovirus, Escherichia coli, and MS2

We investigated the use of psoralens and limes to enhance solar disinfection of water (SODIS) using an UV lamp and natural sunlight experiments. SODIS conditions were replicated using sunlight, 2 L polyethylene terephthalate (PET) bottles, and tap water with Escherichia coli, MS2 bacteriophage, and murine norovirus (MNV). Psoralens and lime acidity both interact synergistically with UV radiation to accelerate inactivation of microbes. Escherichia coli was ablated > 6.1 logs by SODIS + Lime Slurry and 5.6 logs by SODIS + Lime Juice in 30-minute solar exposures, compared with a 1.5 log reduction with SODIS alone (N = 3; P < 0.001). MS2 was inactivated > 3.9 logs by SODIS + Lime Slurry, 1.9 logs by SODIS + Lime Juice, and 1.4 logs by SODIS in 2.5-hour solar exposures (N = 3; P < 0.05). MNV was resistant to SODIS, with < 2 log reductions after 6 hours. Efficacy of SODIS against human norovirus should be investigated further.

The emergence and current performance of a health research system: lessons from Guinea Bissau

BACKGROUND

Little is known about how health research systems (HRS) in low-income countries emerge and evolve over time, and how this process relates to their performance. Understanding how HRSs emerge is important for the development of well functioning National Health Research Systems (NHRS). The aim of this study was to assess how the HRS in Guinea Bissau has emerged and evolved over time and how the present system functions.

METHODS

We used a qualitative case-study methodology to explore the emergence and current performance of the HRS, using the NHRS framework. We reviewed documents and carried out 39 in-depth interviews, ranging from health research to policy and practice stakeholders. Using an iterative approach, we undertook a thematic analysis of the data.

RESULTS

The research practices in Guinea Bissau led to the emergence of a HRS with both local and international links and strong dependencies on international partners and donors. The post-colonial, volatile and resource-dependent context, changes in donor policies, training of local researchers and nature of the research findings influenced how the HRS evolved. Research priorities have mostly been set by 'expatriate' researchers and focused on understanding and reducing child mortality. Research funding is almost exclusively provided by foreign donors and international agencies. The training of Guinean researchers started in the mid-nineties and has since reinforced the links with the health system, broadened the research agenda and enhanced local use of research. While some studies have made an important contribution to global health, the use of research within Guinea Bissau has been constrained by the weak and donor dependent health system, volatile government, top-down policies of international agencies, and the controversial nature of some of the research findings.

CONCLUSIONS

In Guinea Bissau a de facto 'system' of research has emerged through research practices and co-evolving national and international research and development dynamics. If the aim of research is to contribute to local decision making, it is essential to modulate the emerged system by setting national research priorities, aligning funding, building national research capacity and linking research to decision making processes. Donors and international agencies can contribute to this process by coordinating their efforts and aligning to national priorities.

Evaluation of the effect of lime fruit juice on the anticoagulant effect of warfarin

AIM

Citrus aurantifolia (Family Rutaceae) is commonly known as a familiar food and medicine, and s therapeutic effectiveness in a variety of diseases has been suggested in traditional medicine. Various complementary and alternative medicines (CAM) have been shown to interact with orthodox medicines. Hence, the aim of this study is to investigate such a phenomenon particularly the interaction of lime fruit juice with warfarin.

MATERIALS AND METHOD

Wistar strain albino rats of both sexes weighing between 190 and 230g were administered with oral doses of the respective drugs used depending on the groups of animals. Effects on the anticoagulant activity of warfarin were determined by standard laboratory methods.

RESULT

Lime fruit juice caused a reduction in the anticoagulant activity of warfarin.

CONCLUSION

This finding has shown that CAM can interact with orthodox medicines hence, warfarin prescribers need to be aware of the usage of CAM and monitor the international normalized ratio (INR) of their patients more frequently.

Field evaluation of crystal VC Rapid Dipstick test for cholera during a cholera outbreak in Guinea-Bissau

OBJECTIVES

To evaluate performance characteristics and ease of use of the new commercially available Crystal VC Rapid Dipstick (VC) test (Span Diagnostics, India) for Vibrio cholerae O1 and O139.

METHODS

Whole stool was collected from patients presenting to a hospital cholera ward during a 2008 epidemic in Guinea-Bissau. The VC test on stool samples was conducted on-site; samples were subsequently stored in Cary-Blair transport media and sent to the Centers for Disease Control and Prevention for diagnostic testing by culture and polymerase chain reaction (PCR). In addition, four local laboratory technicians who were unfamiliar with the test were provided with stool samples, the VC test kit, and simple written instructions and asked to perform the test and interpret results.

RESULTS

A total of 101 stool specimens were collected and tested. Compared with PCR, the test was 97% sensitive and 71-76% specific. Laboratory technicians in Bissau performed the test and interpreted results correctly using only simple written instructions.

CONCLUSIONS

The VC test may be useful for cholera diagnosis in outbreak situations where laboratory capacity is limited.

Inactivation of Escherichia coli O157:H7 in single-strength lemon and lime juices

Survival of a five-strain mixture of stationary phase (nonadapted) and acid-adapted Escherichia coli O157:H7 in single-strength lemon and lime juices was evaluated at room temperature (22 degrees C). The juices were reconstituted from concentrates that contained no preservatives and intrinsic pH values of 2.5 to 2.6 and titratable acidities of 4.51 to 4.53% (wt/vol, citric acid). A greater than 5-log reduction of stationary-phase cells was achieved in both lemon and lime juices after 72 h of incubation. Similar log reductions were obtained when the reconstituted juices were adjusted to pH 2.7, which is above the highest value normally observed in juice processing plants during the reconstitution of single-strength lemon or lime juice from concentrates. Lemon juice had a significantly higher inhibitory effect (P < 0.05) on E. coli O157:H7 than did lime juice. Validation tests with commercially produced shelf-stable lemon and lime juices confirmed that storage of the juices at room temperature (22 degrees C) for 3 days may be an alternative to heat treatment to ensure the 5-log reduction of vegetative pathogens of concern required for the products under the U.S. Food and Drug Administration juice hazard analysis and critical control point regulations.

Breast milk reduces the risk of illness in children of mothers with cholera: observations from an epidemic of cholera in Guinea-Bissau

BACKGROUND

A protective effect of breastfeeding against cholera has been demonstrated in areas endemic of cholera. To assess the protection offered by breast milk from mothers living in an area that had been free from cholera for 7 years, we investigated mothers with cholera and their children during an epidemic with Vibrio cholerae El Tor in the capital of Guinea-Bissau.

METHODS

Eighty mothers with clinical cholera and their children were identified, and interviewed. Blood samples for vibriocidal and antitoxin antibodies were collected from mother-and-child pairs. Breast milk samples were collected from lactating mothers. Cholera was defined as acute watery diarrhea during the epidemic and a vibriocidal reciprocal titer of 20 or above.

RESULTS

Three (7%) of 42 breastfed children had cholera as defined above compared with 9 (24%) of 38 nonbreastfed children (RR for breastfed children, 0.19; 95% CI, 0.04-0.91, adjusted for age). The 3 breastfed children who developed cholera received milk containing lower concentrations of anticholera toxin IgA/total IgA (median, 2.0 units/mL) than 14 children who had serologic signs of colonization but did not develop the disease (median, 17.4 units/mL).

CONCLUSIONS

The protective effect of breast milk against cholera is not confined to endemic areas. Lactating mothers with cholera should receive supportive care to continue breastfeeding.

Antibacterial Activity of Citrus Fruit Juices Against Vibrio Species

Lemon, lime and sudachi juices were tested for antibacterial activity against seven strains of Vibrio species. All juices were effective in inhibiting the growth of the Vibrio strains. Citric acid, the major organic acid in these juices, was found to be responsible for inhibiting the growth of Vibrio parahaemolyticus. Sauce prepared from sudachi juice showed a strong bactericidal activity against Vibrio parahaemolyticus, whereas the sauce adjusted to higher pH values had no bacterial activity. Diluted sudachi juice or citric acid solution also had antibacterial activity independently. These results suggest that citrus fruit juices are effective in preventing infection with Vibrio species.

Pharmacological properties of citrus and their ancient and medieval uses in the Mediterranean region

This paper reviews the pharmacological properties of Mediterranean-grown citrus species (Citrus L., Rutaceae), including citron (Citrus medica L.), lime (Citrus xauantiifolia [Christm.] Swingle), lemon (Citrus xlimon [L.] Osbeck), bitter orange (Citrus xaurantium L.) and pomelo (Citrus maxima [Burm.] Merr.), as referred to in ancient, medieval and 16th century sources. The virtues of the species reported in these texts were compared to those known to modern science. A much broader spectrum of pharmacological properties was recorded by these early writers than one might expect. The use of the citron and lemon as antidotes for 'poison and venom' is recorded in the very earliest material. According to modern scientific literature the citron and the bitter orange may possess anti-cancer activity, lime may have an immunomodulatory effect in humans, and the pomelo may be useful for treating circulatory problems. Lemons might even ease hangover symptoms. Research is required to confirm these properties.

An Outbreak of Vibrio cholerae O1 infections on Ebeye Island, Republic of the Marshall Islands, associated with use of an adequately chlorinated water source

In December 2000, physicians in the Republic of the Marshall Islands reported the first known outbreak of Vibrio cholerae O1 infection (biotype El Tor, serotype Ogawa) from this country. In a matched case-control study on Ebeye Island, patients with cholera (n=53) had greater odds than persons without cholera (n=104) to have drunk adequately chlorinated water collected from a US military installation on neighboring Kwajalein Island and transported back to Ebeye (matched odds ratio [MOR], 8.0; P=.01). Transporting or storing drinking water in a water cooler with a spout and a tight-fitting lid was associated with reduced odds of illness (MOR, 0.24; P<.01), as was drinking bottled water (MOR, 0.08; P<.01), boiled water (MOR, 0.47; P=.02), or water flavored with powdered drink mixes (MOR, 0.18; P<.01). No cases of cholera were reported among Kwajalein residents. This outbreak highlights the critical importance of handling and storing drinking water safely, especially during outbreaks of gastrointestinal illness.

Effects of Citrus aurantifolia concentrated extract on the spontaneous proliferation of MDA-MB-453 and RPMI-8866 tumor cell lines

The in vitro effects of concentrated lime juice (CLJ) extract on the spontaneous proliferation of a human breast carcinoma cell line (MDA-MB-453) and a human lymphoblastoid B cell line (RPMI-8866) were investigated. CLJ extract was prepared by freeze-drying fresh fruit juice and dialyzing the concentrated extract against phosphate buffered saline in order to deplete low molecular weight micronutrients such as flavonoids as well as adjusting the pH of the extract to the physiological range. The effects of different concentrations of the CLJ extract on the spontaneous proliferative responses of the cell lines were determined by 3H-thymidine incorporation after 24 hrs of incubation. CLJ extract had no significant effect on MDA-MB-453 cell line, however, using the concentrations of 125, 250, and 500 microg/ml of CLJ extract a significant inhibition of the spontaneous proliferation of RPMI-8866 cell line was detected (P < 0.05). Due to the protein nature of the biologically active macromolecules of the CLJ extract (Gharagozloo and Ghaderi, 2001), it is reasonable to assume that the protein components of the CLJ extract may have anti-proliferative effects on tumor cell lines.

Recent developments in cholera

Cholera continues to be an important public health problem among many poorer communities in Africa, Asia and South America, despite the bacteriology and epidemiology of the disease having been described over a century ago. Molecular techniques have enabled current researchers to gain new insights into pathogenicity, into the relationships between environmental and clinical strains, and into new strategies for vaccine development. The description of non-culturable 'dormant' strains in the environment and the effect of environmental factors on toxin gene regulation provide valuable clues to the ecology of the disease. Disease management continues to be based on urgent and appropriate rehydration, and recent community studies emphasize the need for effective local health services to provide this if case fatality rates are to remain low. While antimicrobial agents may play a role in case management and prophylaxis, the increasing prevalence of antimicrobial resistance must be addressed. New vaccine candidates, based on a molecular understanding of pathogenicity, provide scope for improved strategies for disease prevention, though the appropriate public health context for their use has not been determined. This review summarizes activities in these fields of cholera research and considers the continuing global problem of the disease.

Immunomodulatory effect of concentrated lime juice extract on activated human mononuclear cells

In this study, the in vitro immunomodulatory effect of concentrated juice of Citrus aurantifolia cv. swingle (Lime) was investigated. Clarified fresh lime juice was concentrated by freeze-drying. After dialysis against phosphate buffered saline and sterilization by a Millipore filter, it was used for further experiments. Immunogenic property of the CLJ extract was documented by production of specific polyclonal antibodies in rabbits. The immunomodulatory effect of the extract was tested in mitogen activated cultured mononuclear cells. The culture results indicated that proliferation of phytohemagglutinin (PHA) activated mononuclear cells were significantly inhibited by 250 and 500 microg/ml of CLJ extract, whereas only 500 microg/ml of the extract could inhibit proliferation of staphylococcal protein A (SPA) activated mononuclear cells (P<0.05). The abrogation of this inhibitory effect of the CLJ extract was noted by adding anti-CLJ antibody to the lymphocyte culture. Considering these data, it can be concluded that the CLJ extract possesses immunomodulatory principles, which may mainly be due to the protein components of the extract.