Cholera carrier studies in Calcutta, 1968

Cholera carrier studies in Calcutta during 1966-67 established the prevalence of carriers even in the absence of any overt disease. The carriers excreted V. cholerae intermittently and usually only for short periods. Some, however, excreted intermittently over a long period and thus continued to be potential sources of infection. Intensive field and laboratory studies were carried out during 1968 to determine the incidence of cholera infection in households, in which a case of cholera occurred. An investigation of 492 persons in 23 households, exposed to cholera infection, showed that 96 (20%) persons in 19 households excreted vibrios. Within the first 10 days of the investigation, 86 carriers were detected and another 10 were detected during the next 14 days. Repeated isolations were obtained from 43 (45%) of the 96 carriers at intervals of 1-79 days.     

Serological studies on cholera patients and their household contacts in Calcutta in 1968

Vibriocidal and agglutination tests have been performed, using a microtechnique, on 170 pairs of sera obtained, at intervals of 13-26 days, from bacteriologically proven cholera patients and their contacts, carriers and vibrio-negative contacts. Of the carriers, 44%-46% of those with low initial vibriocidin titres (≤ 1:80) and 28%-37% of those having high initial titres (≤ 1:160) showed a 4-fold or greater rise in vibriocidal titres. Carriers and negative contacts exhibited almost similar pictures. With an increase in the number of carriers per household, a larger number of negative contacts developed significant titres in their second samples. In general, initial titres increased with age, but were highest in the 10-25-years age-group: however, 30% of children below 10 years of age had titres ≥ 1:640. The results indicated that individuals with high titres might become carriers but may not suffer from overt cholera.     

Randomized Controlled Trial of Hospital-Based Hygiene and Water Treatment Intervention (CHoBI7) to Reduce Cholera

The risk for cholera infection is >100 times higher for household contacts of cholera patients during the week after the index patient seeks hospital care than it is for the general population. To initiate a standard of care for this high-risk population, we developed Cholera-Hospital-Based-Intervention-for-7-Days (CHoBI7), which promotes hand washing with soap and treatment of water. To test CHoBI7, we conducted a randomized controlled trial among 219 intervention household contacts of 82 cholera patients and 220 control contacts of 83 cholera patients in Dhaka, Bangladesh, during 2013–2014. Intervention contacts had significantly fewer symptomatic Vibrio cholerae infections than did control contacts and 47% fewer overall V. cholerae infections. Intervention households had no stored drinking water with V. cholerae and 14 times higher odds of hand washing with soap at key events during structured observation on surveillance days 5, 6, or 7. CHoBI7 presents a promising approach for controlling cholera among highly susceptible household contacts of cholera patients.     

Diphtheria: a possible foodborne outbreak in Hodeida, Yemen Arab Republic

Between 29 August 1981 and 16 January 1982, an epidemic of diphtheria produced 149 cases in Hodeida, Yemen Arab Republic. The overall attack rate was 11.8 per 10 000; the most frequent victims were males under 5 years of age, with an attack rate of 55.7 per 10 000. Severity of the illness varied inversely with age and the number of previous doses of DPT. A case—control study showed that vaccination with DPT was protective (P = 0.03) with an efficacy of 87.3% (95% confidence interval, 32.2-99.5%) among those who had received 3 or more doses. Risk factors for the development of disease were previous contact with a case (P = 0.002), previous contact with a person having skin disease (P = 0.04), obtaining drinking-water from a wheeled carrier (P = 0.008), and consumption of factory-made yoghurt (P = 0.003). The secondary attack rate among household contacts under 15 years of age was at least 1.3%.     

湖南省2002-2009年霍乱监测结果报告

目的及时发现人群中霍乱病例和被霍乱弧菌污染的水体及食物,尽早采取预防控制措施,防止疫情扩散。方法采取全省常规监测和疫点监测相结合的方法。结果湖南省2002-2009年共发生37起霍乱疫情,报告病例86例,死亡2例,病死率为2.44%;常规外环境监测样品320279份,检出霍乱弧菌阳性211份,均为海水产品;疫点检测人粪便样8655份,检出带菌者102例,阳性率为1.18%;检测外环境样1599份,阳性55份,阳性率为3.44%;来自病人、带菌者、甲鱼中分离的O139群霍乱弧菌高度同源。结论甲鱼等水产品被污染是湖南省发生霍乱的主要因素,应加强水产品的监测和卫生管理,并做好农村聚餐的卫生指导。     

Epidemiology of hepatitis B virus infection in South African Chinese

The authors determined the age-specific prevalence of hepatitis B virus markers in 1,408 Chinese who resided in South Africa in 1983-1985. The small South African Chinese community consists of original Chinese settlers, almost all of whom migrated from the hepatitis B virus endemic mainland China province of Guangdong, and their South African-born descendants. The Chinese live among the white South African community, which has a very low hepatitis B virus carrier rate. The overall hepatitis B virus carrier rate was 5.3%, and the carrier rate was highest in age group 30-39 years (11.9%) and significantly lower in children aged 1-9 and 10-19 years (2.4% and 2.0%, respectively). Overall infection rates increased progressively with increasing age, starting at about 10% in the children aged 1-19 years and reaching 50% in adults aged 60-69 years. Among carrier children, 89% had carrier mothers, and all of the latter were also hepatitis e antigen (HBeAg)-positive. The prevalence of hepatitis B virus carriers in South African Chinese women of child-bearing age was 6.1%, and 41.9% of these carriers were HBeAg-positive. The age-specific prevalence of hepatitis B virus markers among South African Chinese is appreciably lower than that of Chinese in southeastern China, who have carrier rates of 15-20% with a peak in childhood. The prevalence of hepatitis B virus infection appears to be decreasing in South African Chinese, probably because improved hygienic and socioeconomic circumstances, in comparison with those in Guangdong, have resulted in less horizontal transmission of the virus. A diminishing pool of carriers is maintained by perinatal maternal-infant infection.     

Clinical and bacteriological studies of El Tor cholera after ingestion of known inocula in Thai volunteers.

Twenty-six healthy adult Thai volunteers were recruited for clinical and bacteriological studies of cholera induced by oral inoculation with Vibrio cholerae El Tor Inaba strain N16961. Vibrio dosages of 0.3 x 10(4), 1.6 x 10(5) and 1.9 x 10(6) c.f.u. were given to three groups of five volunteers, and 2.0 x 10(7) c.f.u. to 11 volunteers. Diarrhoeal attack rates correlated positively with the size of the inocula (p less than 0.01). It was estimated that a diarrhoeal attack rate of 90% (ED90) would be achievable by inoculation of 1.3 x 10(7) c.f.u. of the organisms. There were no significant differences between the groups in the latent period to positive stool culture, maximum vibrio count per gram of stool and duration of stool positivity. The ED90 of V. cholerae obtained may be used as a challenge dose in subsequent studies on protective efficacy of cholera vaccines in Thai adult volunteers.     

Clinical studies of the use of bacteriophage in the treatment of cholera

This study reports the use of bacteriophage prepared in the USSR in the treatment of cholera. Patients with acute cholera were rehydrated with a standard intravenous solution and were then given a bacteriophage preparation in addition to maintenance intravenous therapy. The titre of the phage preparations was between 10⁸ and 10⁹ pfu/ml. Bacteriophage was given by mouth (25 ml for adults and 20 ml for children) for 3 days; in addition, some patients were also given an intramuscular injection (20 ml) of phage on the first day in hospital. For comparison, other groups of patients were given a standard tetracycline regimen or a placebo preparation. Daily vibrio and phage counts were made on stool samples from all patients and the vibrio strains isolated from each patient were tested for sensitivity to the phage preparation.     

Serology as an indicator of Taenia solium tapeworm infections in a rural community in Mexico

Serial stool examinations were carried out on a sample of 516 persons living in the town of El Salado (1993 inhabitants). In a group of 40 families (198 individuals), selected by random sampling, there were 2 cases of Taenia solium infection (1.2%); an additional group of 67 families (318 individuals), who volunteered for the study, had 4 cases (1.1%). 5 of the 6 T. solium cases were clustered in 4 neighbouring households. Serum antibodies to the larval stage of T. solium were detected by ELISA using bladder fluid as antigen. 22 members of the random sample group were positive (11%); 58 persons of the total sample of 478 were positive (12%). 43% of individuals living in the same household as a T. solium-infected person were positive, compared to 8.6% seropositive individuals among those not known to have been in daily contact with a T. solium carrier. Odds ratio analysis of the random and total samples showed that the risk of being seropositive when living in the same household as a tapeworm carrier was 9.05 and 6.85 respectively. The results showed a significant correlation between T. solium tapeworm clusters and higher seropositivity rates among contacts rather than among non-contacts. The immune response is a sensitive indicator of a tapeworm infection in a household or family, and is easier to determine than the traditional search for taeniid eggs in stool, a method which is difficult to apply in developing countries due to lack of trained personnel.(ABSTRACT TRUNCATED AT 250 WORDS)     

Vibrio cholerae O139 Bengal: a descriptive study

A prospective study was conducted to determine the clinical and laboratory characteristics and the clinical course of cholera due to Vibrio cholerae O139 Bengal. The study subjects included 22 adult males with stool culture-proven V. cholerae O139. On enrollment, mean +/- SD concentrations (mmol/L) of serum sodium, potassium, chloride, and bicarbonate were 134 +/- 3, 4 +/- 1, 102 +/- 4, and 13 +/- 4 respectively, and stool sodium, potassium, chloride, and bicarbonate concentrations were 120 +/- 24, 18 +/- 6, 93 +/- 16, and 37 +/- 9 respectively. Seventeen patients (7.8%) had faecal leukocytes ranging from 11 to 50 per high-power field. All V. cholerae O139 isolates (100%) were susceptible to tetracycline, erythromycin, and ciprofloxacin, 92% to furazolidine, and only 5% to trimethoprim-sulphamethaxazole. The median (interquartile) volume of liquid stool during the first 24 hours was 9 (5-12) litre. The median (interquartile) volume of liquid stool and the amounts of intravenous and oral rehydration fluids required during the entire study period were 16 (9-24) litre, 9 (6-18) litre, and 14 (9-20) litre respectively. The median (interquartile) duration of diarrhoea was 80 (48-104) hours. The median (interquartile) duration of excretion of V. cholerae O139 in stool was 5 (3-6) days. Clinical and laboratory features, and case management of cholera due to V. cholerae O139 are very similar to conventional cholera due to V. cholerae O1.     

Epidemiological relationships between Aeromonas strains isolated from symptomatic children and household environments as determined by ribotyping

Ribotyping was used to study the epidemiology of Aeromonasassociated gastro-enteritis in young children. Ribotyping patterns of 29 Aeromonasstrains (16 Aeromonas caviae, 8 Aeromonas hydrophila, 3 Aeromonas eucrenophila, 1 Aeromonas veronii, and 1 Aeromonas encheleia) isolated from primary stool cultures of sick children were compared using the GelCompare software with patterns of 104 strains (39 Aeromonas eucrenophila, 29 Aeromonas caviae, 11 Aeromonas encheleia, 10 Aeromonas hydrophila, 6 Aeromonas bestiarum, 3 Aeromonas veronii, 3 Aeromonas popoffiiand 3 Aeromonas media) isolated from their household environment in order to investigate the route of transmission of these bacteria. Fifteen strains (47%) isolated from stool cultures of patients showed the same riboprofile as strains found in contacts or environment. In particular, three strains isolated from patients shared the same riboprofile with strains found in their domestic environment. The wide diffusion of potentially pathogenic Aeromonasstrains in our household samples, and the high rate of asymptomatic carriers among family members, suggested that predisposing factors of the host could make children prone to an Aeromonas-related intestinal disease.     

Factors associated with seeking medical care and submitting a stool sample in estimating the burden of foodborne illness

Laboratory-based surveillance is a foundation for public health and is essential for determining the incidence of most foodborne diseases caused by bacterial pathogens; however, reported cases represent a subset of infections in the community. To identify the factors associated with seeking medical care and submitting a stool specimen among persons with acute diarrheal illness, we used multivariate logistic regression to analyze data from two 12- month population-based telephone surveys conducted in the Foodborne Diseases Active Surveillance Network (FoodNet) from 2000 to 2003. Of 31,082 persons interviewed, 5% reported an acute diarrheal illness in the four weeks prior to the interview; of these, 20% sought medical care. On multivariate analysis, among persons with an acute diarrheal illness, factors associated with seeking medical care included: male sex; age <5 or >or=65 years; household income <25,000 dollars; having health insurance; diarrhea duration >or=3 days; having bloody diarrhea, fever, vomiting, sore throat, or cough. Of those seeking medical care, 19% provided a stool sample. Bloody diarrhea (odds ratio [OR] 3.35; 95% confidence interval [CI] 1.18-9.51) and diarrhea duration >or=3 days (OR 3.81; 95% CI: 1.50-9.69) were the most important factors associated with submission of a stool specimen. Cases of acute diarrheal illness ascertained through laboratory-based public health surveillance are likely to differ systematically from unreported cases and likely over-represent those with bloody diarrhea and longer diarrhea duration.     

Effect of massive doses of bacteriophage on excretion of vibrios, duration of diarrhoea and output of stools in acute cases of cholera

Each member of a group of 8 patients with acute cholera was treated with a mixture of four cholera bacteriophage preparations containing over 2 × 10¹² phage particles/ml. These massive doses were intended to kill immediately all vibrios in the intestine by ”lysis from without”. The numbers of Vibrio cholerae were drastically reduced rapidly. In 4 patients, V. cholerae was completely eliminated from the stools early in the treatment; the total stool volume and after-treatment of diarrhoea were reduced in comparison with a control group but were higher than in a group of patients treated with tetracycline. In the other 4 patients treated with phage, vibrios disappeard more slowly from the stools and there was no apparent clinical effect of the phage. In all the patients treated with phage, the duration of diarrhoea was longer than in patients in a control group who excreted vibrios for a similar length of time although the stool output was similar. This was interpreted as being due to the persistence of vibrios in foci of infection in the upper intestine.     

Randomized placebo controlled human volunteer trial of a live oral cholera vaccine VA1.3 for safety and immune response

A live oral cholera vaccine developed from a non-toxigenic Vibrio cholerae O1 El Tor strain VA1.3 was tested in a double-blind randomized placebo controlled study for safety and immunogenicity in 304 men aged between 16 and 50 years from Kolkata, India. A dose of 5 × 10⁹ CFU (n = 186) or a placebo (n = 116) containing the diluent buffer was administered. The vaccine did not elicit adverse events except in two vaccine recipients with mild diarrhoea and vomiting. None excreted the vaccine strain. Vibriocidal antibody response developed in 105/186 (57%) and 5/116 (4%) in vaccine and placebo recipients, respectively. In a subgroup, anti-CT antibody rose (≥2-folds) in 23/30 (77%) and 6/19 (32%) in vaccine and placebo recipients, respectively. These studies demonstrate that VA1.3 at a dose of 5 × 10⁹ is safe and immunogenic in adults from a cholera endemic region.     

Anaphylaxis rates following mRNA COVID-19 vaccination in children and adolescents: Analysis of data reported to EudraVigilance

AimThe present study aimed to estimate the anaphylaxis rates following mRNA COVID-19 vaccination in children and adolescents in Europe.MethodsWe retrieved data on 371 anaphylaxis cases following mRNA COVID-19 vaccination in children ≤ 17 years old notified to EudraVigilance as of October 8, 2022. Overall, 27,120,512 doses of BNT162b2 vaccine and 1,400,300 doses of mRNA-1273 vaccine have been delivered to children during the study period.ResultsThe overall mean anaphylaxis rate was 12.81 [95% confidence interval (CI): 11.49–14.12] per 10⁶ mRNA vaccine doses [12.14 (95% CI: 6.37–17.91) per 10⁶ doses for mRNA-1273 and 12.84 (95% CI: 11.49–14.19) per 10⁶ doses for BNT162b2]. Children 12–17 years old accounted for 317 anaphylaxis cases, followed by 48 cases in children 3–11 years old, and 6 cases in children 0–2 years old. Children 10–17 years old had a mean anaphylaxis rate of 13.52 (95% CI: 12.03–15.00) cases per 10⁶ mRNA vaccine doses and children 5–9 years old had a mean anaphylaxis rate of 9.51 (95% CI: 6.82–12.20) cases per 10⁶ mRNA vaccine doses. There were two fatalities, both in the 12–17 years age group. The fatal anaphylaxis rate was 0.07 cases per 10⁶ mRNA vaccine doses.ConclusionsAnaphylaxis is a rare adverse event after receiving an mRNA COVID-19 vaccine in children. Continuous surveillance of serious adverse events is needed to guide vaccination policies as we move towards SARS-CoV-2 endemicity. Larger real-world studies on COVID-19 vaccination in children, using clinical case confirmation, are imperative.     

Lipopolysaccharide-specific memory B cell responses to an attenuated live cholera vaccine are associated with protection against Vibrio cholerae infection

BackgroundThe single-dose live attenuated vaccine CVD 103-HgR protects against experimental Vibrio cholerae infection in cholera-naïve adults for at least 6 months after vaccination. While vaccine-induced vibriocidal seroconversion is associated with protection, vibriocidal titers decline rapidly from their peak 1–2 weeks after vaccination. Although vaccine-induced memory B cells (MBCs) might mediate sustained protection in individuals without detectable circulating antibodies, it is unknown whether oral cholera vaccination induces a MBC response.MethodsIn a study that enrolled North American adults, we measured lipopolysaccharide (LPS)- and cholera toxin (CtxB)-specific MBC responses to PXVX0200 (derived from the CVD 103-HgR strain) and assessed stool volumes following experimental Vibrio cholerae infection. We then evaluated the association between vaccine-induced MBC responses and protection against cholera.ResultsThere was a significant increase in % CT-specific IgG, % LPS-specific IgG, and % LPS-specific IgA MBCs which persisted 180 days after vaccination as well as a significant association between vaccine-induced increase in % LPS-specific IgA MBCs and lower post-challenge stool volume (r = −0.56, p < 0.001).DiscussionOral cholera vaccination induces antigen-specific MBC responses, and the anamnestic LPS-specific responses may contribute to long-term protection and provide correlates of the duration of vaccine-induced protection.Clinical trials registration: NCT01895855.     

Transmission of hepatitis B and hepatitis delta viruses in the households of chronic hepatitis B surface antigen carriers: a regression analysis of indicators of risk

To evaluate whether clinical and laboratory features of a hepatitis B surface antigen (HBsAg) carrier can predict risks of infection, its chronicity, and the development of liver disease among close contacts, the authors studied a cohort of 994 first degree relatives or cohabitants (household contacts) of 226 non-drug-addicted chronic HBsAg carriers (index cases), of whom 77% had liver disease and 26% were superinfected by hepatitis D virus (HDV). A logistic form of regression analysis was used to assess the role of each feature in the index case as predictor of hepatitis B virus (HBV)- and HDV-related outcomes among household contacts. Six models of risk, expressed as odds ratios, were assessed by multivariate step-down analysis, with the following results. 1) Infection with HBV in the household contact was independently predicted by the index case being son, sibling, spouse, female, or HBV-DNA positive. 2) Chronic HBsAg carriage in the adult household contact was associated with female sex of the index case and with being a sibling; among young subjects, household contacts were more likely to be chronic HBsAg carriers when the index case was the mother, a sibling, or an HBV-DNA-positive subject. 3) HBV-DNA positivity in the young contact was more likely when the index case was HBV-DNA positive and when she was the mother. 4) HBV-DNA positivity in the absence of hepatitis B e antigen (HBeAg) in serum in the index case was not related to a similar pattern of infection in HBsAg-positive contacts. 5) Super-infection with HDV of an HBsAg-positive household contact was significantly predicted by female sex of the index case and by anti-HDV positivity. 6) Chronic liver disease in a contact was predicted only by HDV superinfection of the index case. We conclude that horizontal, nonparenteral transmission of HBV among siblings plays a major role in the household of HBsAg carriers from an intermediate endemicity area.     

The patho-physiology of cholera

Studies conducted by US Navy Medical Research personnel in Cairo in 1947, and subsequently in Dacca, Bangkok, Hong Kong and Manila, have delineated, for the first time, the water and electrolyte losses in this disease, and have demonstrated that the cholera stool approximates an isotonic solution with a low (0.1 g%) protein content. The potassium content approximates 15 mEq/litre and the HCO₃^- ion approximates 45 mEq/litre; the sodium and chloride concentrations are proportionately lower than their plasma values. The low protein content and other studies refute the idea that the cholera stool is a transudate. The 1958 studies in Bangkok postulated that the diarrhoea resulted from an inhibition of the active transport of sodium ion from gut lumen to plasma. Subsequently, the presence of such an inhibitor was found in stools of patients with Asiatic cholera (Bangkok and Dacca) and with cholera El Tor (Hong Kong and Manila).     

A cholera outbreak among semi-nomadic pastoralists in northeastern Uganda: epidemiology and interventions

In sub-Saharan Africa, many nomadic pastoralists have begun to settle in permanent communities as a result of long-term water, food, and civil insecurity. Little is known about the epidemiology of cholera in these emerging semi-nomadic populations. We report the results of a case-control study conducted during a cholera outbreak among semi-nomadic pastoralists in the Karamoja sub-region of northeastern Uganda in 2010. Data from 99 cases and 99 controls were analysed. In multivariate analyses, risk factors identified were: residing in the same household as another cholera case [adjusted odds ratio (aOR) 6·67, 95% confidence interval (CI) 2·83-15·70], eating roadside food (aOR 2·91, 95% CI 1·24-6·81), not disposing of children's faeces in a latrine (aOR 15·76, 95% CI 1·54-161·25), not treating drinking water with chlorine (aOR 3·86, 95% CI 1·63-9·14), female gender (aOR 2·43, 95% CI 1·09-5·43), and childhood age (10-17 years) (aOR 7·14, 95% CI 1·97-25·83). This is the first epidemiological study of cholera reported from a setting of semi-nomadic pastoralism in sub-Saharan Africa. Public health interventions among semi-nomadic pastoralists should include a two-faceted approach to cholera prevention: intensive health education programmes to address behaviours inherited from insecure nomadic lifestyles, as well as improvements in water and sanitation infrastructure. The utilization of community-based village health teams provides an important method of implementing such activities.     

The Good Heart,Good Life survey: self-reported cardiovascular disease risk factors,health knowledge and attitudes among Greek-Australians in Sydney

Abstract: This survey aimed to assess the prevalence and knowledge of coronary risk factors and self-perceived coronary heart disease risk among Greek-Australians in the Marrickville area of inner Sydney. A random sample of 834 household addresses was selected from the 2 403 households having Greek-Australian surnames on the electoral roll. In each household, one individual aged 18 years or over was selected using a Kish grid, and a questionnaire was administered by a bilingual interviewer. Questions concerned knowledge of and self-reported risk factors for coronary heart disease, and ratings of perceived stress, social support and networks. There was a response rate of 81 per cent of actual Greek-Australian households, a total of 541 interviews (61 per cent women). Most of the sample (86 per cent) were born in Greece and 77 per cent of interviews were administered in Greek. The age-adjusted male prevalences of self-reported smoking, high blood pressure, high blood cholesterol and body mass index over 26 kg/m² were 44 per cent, 5 per cent, 14 per cent and 58 per cent, respectively. The age-adjusted female prevalences of self-reported smoking, high blood pressure, high blood cholesterol and body mass index over 26 kg/m² were 19 per cent, 8 per cent, 15 per cent and 40 per cent, respectively. Compared to the National Heart Foundation risk-factor prevalence survey, the prevalence of self-reported high blood pressure was lower, but obesity and, among males, smoking, were higher. Low levels of education and poor English-language skills among older Greek-Australians may be contributing to the problem. There is a need for linguistically and culturally appropriate health promotion programs for communities of non-English-speaking background.