Doxycycline and rifampicin for mild scrub-typhus infections in northern Thailand: a randomised trial

BACKGROUND

Some strains of scrub typhus in northern Thailand are poorly responsive to standard antirickettsial drugs. We therefore did a masked, randomised trial to compare rifampicin with standard doxycycline therapy for patients with scrub typhus.

METHODS

Adult patients with strictly defined, mild scrub typhus were initially randomly assigned 1 week of daily oral treatment with 200 mg doxycycline (n=40), 600 mg rifampicin (n=38), or doxycycline with rifampicin (n=11). During the first year of treatment, the combined regimen was withdrawn because of lack of efficacy and the regimen was replaced with 900 mg rifampicin (n=37). Treatment outcome was assessed by fever clearance time (the time for oral temperature to fall below 37.3 degrees C).

FINDINGS

About 12,800 fever patients were screened during the 3-year study to recruit 126 patients with confirmed scrub typhus and no other infection, of whom 86 completed therapy. Eight individuals received the combined regimen that was discontinued after 1 year. The median duration of pyrexia was significantly shorter (p=0.01) in the 24 patients treated with 900 mg daily rifampicin (fever clearance time 22.5 h) and in the 26 patients who received 600 mg rifampicin (fever clearance time 27.5 h) than in the 28 patients given doxycycline monotherapy (fever clearance time 52 h). Fever resolved in a significantly higher proportion of patients within 48 h of starting rifampicin (900 mg=79% [19 of 24], 600 mg=77% [20 of 26]) than in patients treated with doxycycline (46% [13 of 28]; p=0.02). Severe gastrointestinal events warranted exclusion of two patients on doxycyline. There were two relapses after doxycycline therapy, but none after rifampicin therapy.

INTERPRETATION

Rifampicin is more effective than doxycycline against scrub-typhus infections acquired in northern Thailand, where strains with reduced susceptibility to antibiotics can occur.

[Impact of Streptococcus pneumoniae on pneumonia in Latin American children. SIREVA-Vigía Group]

Community-acquired pneumonia is one of the leading causes of infant morbidity and mortality. Studies conducted in developing countries indicate that the most serious symptoms of pneumonia are associated with bacterial causes, mainly Streptococcus pneumoniae, followed by Haemophilus influenzae type b. Managing those infections in children under two years of age is hindered by the lack of appropriate vaccines and by the decreased susceptibility of S. pneumoniae to penicillin and other antibiotics. In 1993, at the initiative of the Regional System for Vaccines of the Pan American Health Organization, and with funding from the Canadian International Development Agency, a study was designed to identify the S. pneumoniae capsular types that cause invasive disease in Latin American children under 5 years of age. The objective of the study was to determine the ideal composition of a conjugate vaccine that could be used in Latin America, and the penicillin susceptibility of the S. pneumoniae isolates. The initiative was undertaken in Argentina, Brazil, Chile, Colombia, Mexico, and Uruguay. This report analyzes the information that the participating countries generated on pneumococcal pneumonia. A total of 3,393 children were found with systemic S. pneumoniae infections, of which 1,578 corresponded to pneumonias. The analysis focused on 1,409 cases of pneumonia in Argentina, Brazil, Colombia, Mexico, and Uruguay. Of the children, 63.8% of them were under two years of age. Twelve prevalent capsular types were identified, of which serotypes 14, 5, and 1 were the three most common in the majority of the countries. At the beginning of the study the highest level of penicillin resistance was found in Mexico (47.0%), and the lowest in Colombia (12.1%). Over the 1993-1998 period, resistance to penicillin increased in the five countries. Penicillin resistance was associated with a small number of capsular serotypes, mainly 14 and 23F. The first of those serotypes was resistant to penicillin and to trimethoprim-sulfamethoxazole, and the second was multiresistant. The frequency of resistance to trimethoprim-sulfamethoxazole was high in all of the countries; Argentina had the highest level, 58.0%. A decrease in susceptibility to chloramphenicol was uncommon, except in Colombia, where there was a resistance level of 23.4%. Resistance to erythromycin was low in all the countries, and all the isolates were susceptible to vancomycin.

Improving the monitoring of immunization services in Kyrgyzstan

Following the disbanding of the Soviet Union in 1991, the government of Kyrgyzstan was unable to maintain the previous level of health services. To revitalize the health services, the Ministry of Health (MOH) first focused on improving their immunization services, including the immunization component of the Health Management Information System (HMIS). Secondly, to increase immunization coverage, the MOH set as a priority the elimination of prescribing false contraindications to immunization. To accomplish both goals, the MOH updated the national immunization policies and established a more effective structure for managing immunization services. To support the MOH, the US Agency for International Development (USAID) Resources for Child Health (REACH) and Basic Support for Institutionalizing Child Survival (BASICS) projects provided technical assistance through a resident coordinator and consultants, and by organizing an international seminar. The improvements extended beyond systems and forms, but, instead, emphasized monitoring by the frontline health worker and supervising the quality of health information. To accomplish their objectives, the MOH appointed a Working Group to define the problems, revise record-keeping procedures, and develop monitoring tools. This group, representing both national and local levels, was composed of MOH epidemiologists, paediatricians and a management information specialist. To reduce the burden of excessive record-keeping and reporting requirements, the Working Group identified four key indicators for the service delivery level: (1) DPT3 immunization coverage rates for children less than 1 year of age; (2) contraindication rates for DPT; (3) usage of DPT vaccine; and (4) daily refrigerator temperatures. Additional indicators were included at district and provincial levels. After a successful 1-year trial, the MOH implemented the revised HMIS nationally. Not only did the quality of the information system improve, but the new approach provided visible evidence, from facility to national levels, that the MOH was approaching their objective of reducing contraindication rates for DPT immunizations to 5% or less, and that vaccine wastage could be substantially reduced. The project demonstrated that giving health workers the basic epidemiologic skills to monitor their own work measurably improved the quality of the data, and by acquiring the new skills, the workers developed a sense of pride in their work.

Vaginal infections in pregnant women in Jamaica: prevalence and risk factors

Trichomoniasis, bacterial vaginosis (BV) and candidiasis are reproductive tract infections (RTIs) of the vagina. We conducted a cross-sectional study in 4 prenatal clinics in Kingston, Jamaica, to estimate the prevalence of these infections and the risk factors that may facilitate their transmission among pregnant women. Of the 269 women studied, 18.0% had culture-positive trichomoniasis, 44.1% had BV (Nugent score > or = 7) and 30.7% were positive for candidiasis by wet mount. A multiple logistic regression analysis showed that having a malodorous discharge was associated with trichomoniasis (odd ratios [OR]=3.9, confidence intervals [CI]=1.04-14.7) and BV (OR=3.4, CI=1.3-8.7). Women who took action to prevent HIV infection had lower BV prevalence (OR=0.34, CI=0.12-0.98). Women who were employed were less likely to have any of the infections (OR=0.61, CI=0.36-1.03). The strong association of a symptomatic presentation with trichomoniasis and BV suggests the merit of considering syndromic management of vaginitis in this population.

Geographical patterns of cholera in Mexico, 1991-1996

BACKGROUND

The seventh cholera pandemic has been ongoing in Mexico since 1991 and threatens to become endemic. This paper aims to determine the geographical pattern of cholera in Mexico to define areas at high risk of endemic cholera.

METHODS

Ecologic research was conducted based upon the cartography of disease incidence. The 32 Mexican states were grouped into five strata according to the value of the 1991-1996 cumulative incidence rate of cholera. Rate ratios were computed for strata of states classified by geographical situation, urbanization, and poverty level.

RESULTS

Cholera incidence was 2.47 times higher in coastal states than in the interior (95% CI : 2.42-2.52). The disease was negatively associated with urbanization. Incidence in the least urbanized stratum was four times as high as in the most urban stratum (95% CI : 3.9-4.12). The poorest stratum showed the most remarkable incidence, i.e. 5.9 times higher than the rate in the least poor stratum (95% CI : 5.73-6.04).

CONCLUSIONS

This ecologic research suggests that high poverty level, low urbanization, and southern location are the most important predictors of endemic cholera in Mexican states. It is hypothesized that the natural environment of the coastal plains in southern states may also play a significant role in cholera incidence. Poor communities residing in the southern, predominantly rural, coastal states should be prioritized when it comes to investing in safe water supply facilities, adequate excreta disposal systems and cholera surveillance.

John Snow: the first hired gun?

The 1854 English cholera outbreak led to reform of Victorian public health legislation, including the Nuisances Removal and Diseases Prevention Act. The reforms threatened the closure of many factories whose fumes were considered hazardous to the public's health. The second witness to appear before the Parliamentary committee considering the reforms was Dr. John Snow. Snow testified on behalf of the manufacturers threatened by the reforms. He stated that the fumes from such establishments were not hazardous. He contended that the workers in these factories did not become ill as a result of their exposures, and therefore these fumes could not be a hazard to the general public's health. Snow also presented data from the 1854 cholera outbreak as the basis for his belief that epidemic diseases were transmitted by water, not air. Although the data concerned cholera, Snow extended the inference to all epidemic diseases. When the committee's report was published, The Lancet chastised Snow in a stinging editorial. Parliament subsequently revised the bill in favor of the manufacturers and passed it into law. The implications of this particular episode in the history of epidemiology are discussed.

Amylase-resistant starch plus oral rehydration solution for cholera

BACKGROUND

Although standard glucose-based oral rehydration therapy corrects the dehydration caused by cholera, it does not reduce the diarrhea. Short-chain fatty acids, which are produced in the colon from nonabsorbed carbohydrates, enhance sodium absorption. We conducted a study to determine the effects of an orally administered, nonabsorbed starch (i.e., one resistant to digestion by amylase) on fecal fluid loss and the duration of diarrhea in patients with cholera.

METHODS

We randomly assigned 48 adolescents and adults with cholera to treatment with standard oral rehydration therapy (16 patients), standard therapy and 50 g of rice flour per liter of oral rehydration solution (16 patients), or standard therapy and 50 g of high-amylose maize starch, an amylase-resistant starch, per liter of oral rehydration solution (16 patients). The primary end points were fecal weight (for every 12-hour period during the first 48 hours after enrollment) and the length of time to the first formed stool.

RESULTS

The mean (+/-SD) fecal weights in the periods 12 to 24 hours, 24 to 36 hours, and 36 to 48 hours after enrollment were significantly lower in the resistant-starch group (2206+/-1158 g, 1810+/-1018 g, and 985+/-668 g) than in the standard-therapy group (3251+/-766 g, 2621+/-1149 g, and 2498+/-1080 g; P=0.01, P= 0.04, and P=0.001, respectively). From 36 to 48 hours after enrollment, fecal weight was also significantly lower with the resistant-starch therapy than with the rice-flour therapy (985+/-668 g vs. 1790+/-866 g, P=0.01). The mean duration of diarrhea was significantly shorter with the resistant-starch therapy (56.7+/-18.6 hours) than with standard therapy alone (90.9+/-29.8 hours, P=0.001) or the rice-flour therapy (70.8+/-20.2 hours, P=0.05). Fecal excretion of starch was higher with the resistant-starch therapy (32.6+/-30.4) than with the standard therapy (11.7+/-4.1 g, P=0.002) or the rice-flour therapy (15.1+/-8.4 g, P=0.01).

CONCLUSIONS

The addition of a resistant starch to oral rehydration solution reduces fecal fluid loss and shortens the duration of diarrhea in adolescents and adults with cholera.

Determination of drug susceptibility and DNA fingerprint patterns of clinical isolates of Mycobacterium tuberculosis from Kampala, Uganda

OBJECTIVE

To ascertain the rate of initial drug resistance and transmission patterns of Mycobacterium tuberculosis in Kampala, Uganda.

SETTING

National Tuberculosis (TB) Treatment Centre, Mulago Hospital, Kampala, Uganda and Case Western Reserve University, Cleveland, Ohio, USA and McClellan Memorial Veterans Hospital, Little Rock, Arkansas, USA.

METHODS

Using a radiometric BACTEC 460 TB system, susceptibility of 215 M. tuberculosis isolates from previously untreated patients from Kampala, Uganda (age range, 17-48 years, mean, 28 years; 56% males and 69% human immunodeficiency virus (HIV)-seropositive) was determined for isoniazid, rifampin, streptomycin and ethambutol. Isolates from 73 patients, selected on the basis of geographical location, were tested for strain diversity or relatedness using the IS6110 DNA fingerprinting technique.

RESULTS

Resistance rates were as follows: isoniazid, 7.9% streptomycin, 6.1% rifampin, 1.4% and ethambutol 0.9%. Twelve per cent of the strains were resistant to at least one of the first line drugs tested and 4.7% were multiply resistant. There were no significant differences in resistance rates between patients with and without HIV infection. Using the number and size of DNA fragments containing IS6110, only three clusters of isolates with identical RFLP patterns were found out of the 73 isolates tested (8.2%). Each cluster contained two isolates. Three (4.1%) isolates had less than seven copies of IS6110.

CONCLUSION

This study shows that in Uganda initial drug resistance rates to anti-tuberculosis agents are low and similar to other sub-Saharan African countries and that multiple strains of M. tuberculosis have been transmitted within the community.

Diphtheria in urban slums in north India

We recorded a reappearance of cases of microbiologically confirmed diphtheria in a tertiary care hospital in north India. Poor immunisation coverage, population migrations, and overcrowded urban slums may be contributory factors.

Elevated levels of maternal anti-tetanus toxin antibodies do not suppress the immune response to a Haemophilus influenzae type b polyribosylphosphate-tetanus toxoid conjugate vaccine

Reported are the effects of elevated levels of anti-tetanus antibodies on the safety and immune response to a Haemophilus influenzae type b polyribosylphosphate (PRP)-tetanus toxoid conjugate (PRP-T) vaccine. A group of Thai infants (n = 177) born to women immunized against tetanus during pregnancy were vaccinated with either a combined diphtheria-tetanus-pertussis (DTP) PRP-T vaccine or DTP and a PRP-conjugate vaccine using Neisseria meningitidis group B outer-membrane proteins as a carrier (PedVax HIB). Although most infants possessed high titres (> 1 IU/ml) of anti-tetanus antibodies, the DTP-PRP-T combined vaccine engendered an excellent antibody response to all vaccine components. In both vaccine groups > 98% of infants attained anti-PRP antibody titres > or = 0.15 microgram/ml. The geometric mean anti-PRP antibody titres were 5.41 micrograms/ml and 2.1 micrograms/ml for infants immunized with three doses of PRP-T versus two doses of PedVax HIB vaccines, respectively (P < 0.005). Similarly, the proportion of infants who achieved titres > or = 1 microgram/ml was higher in the PRP-T group (87.8%) than in the group immunized with PedVax HIB (74.2%) (P = 0.036). A subgroup analysis showed that there was no significant difference in the anti-PRP antibody response for infants exhibiting either < 1 IU of anti-tetanus antibody per millilitre or > or = 1 IU/ml at baseline. These finding indicate that pre-existing anti-carrier antibody does not diminish the immune response to the PRP moiety. All infants possessed protective levels of anti-D and anti-T antibody levels after immunization.

Neonatal tetanus associated with topical umbilical ghee: covert role of cow dung

BACKGROUND

Previous studies in Pakistan have shown that ghee (clarified butter) is commonly applied to umbilical wounds of neonates, and have documented that such applications are a risk factor for neonatal tetanus (NNT). In-use contamination of ghee with Clostridium tetani has been demonstrated, but mechanisms underlying the risk of ghee have been incompletely evaluated epidemiologically.

METHODS

Detailed information on ghee usage, including fuels used to heat it, was obtained from cases of NNT (n = 229) and their matched controls (n = 687) from a population-based study of NNT in Punjab Province, Pakistan. Design variables were created to evaluate the impact of different fuel sources on risk of ghee applications.

RESULTS

Nearly one-third of all infants had ghee applied, and it was nearly always heated before application to umbilical wounds of newborns. After controlling for all factors found to be significantly associated with NNT in conditional logistic regression, only ghee that had always been heated with dried cow dung fuel was significantly associated with NNT. Topical antimicrobials and ghee were never applied together.

CONCLUSIONS

Ghee applications to umbilical wounds, when heated with 'clean' fuels, appear to pose no increased risk of NNT, although handling practices undoubtedly result in hazardous microbial contamination. In contrast, ghee heated with dung fuel was significantly associated with NNT. The effective promotion of topical antimicrobials might help reduce ghee use, since the intended purpose of each is to enhance healing.

Rheumatic fever in children

Rheumatic fever (RF) and rheumatic heart disease (RHD) are major public health problems in developing countries. A prospective study carried out in a large general hospital showed that carditis was the predominant feature in first attack and also the recurrence of RF but that recurrence was associated with more severe manifestations. Echocardiography picked up cases of subclinical carditis. Presence of congestive cardiac failure in association with carditis always led to chronic RHD. Recurrence occurred only when patient defaulted penicillin prophylaxis. The overall recurrence rate was 0.026 per patient.

India embarks on vaccine-development scheme

Six diseases are the targets of the vaccine development program in India. The project involves 12 national research institutions and two private companies, Indian Immunologicals and Bharat Biotech, which are both based in Hyderabad, India. Targets of the program are AIDS, cholera, Japanese encephalitis, malaria, rabies, and tuberculosis. In a report in the journal Nature Medicine, K. S. Jayaraman notes that a single agency--the Department of Biotechnology (DBT)--will oversee the project. According to Jayaraman, DBT secretary Manju Sharma predicts the deployment of cholera and rabies vaccines by the year 2002. An oral recombinant cholera vaccine recently proved safe in Phase I trials at the Institute of Microbial Technology, Chandigart, and a promising DNA vaccine for rabies is in late preclinical development at the Indian Institute of Science, Bangalore. The AIDS vaccine initiative, underway at the All India Institute of Medical Sciences, New Delhi, will use a poxvirus construct expressing HIV-I subtype C, the strain most prevalent on the Indian subcontinent. N. K. Vinayak, head of the DBT medical division, told Jayaraman that the HIV vaccine would be ready for animal studies in a year. Funding for the program seems small by Western standards: $4 million over 3 years.

Mycobacterium ulcerans infection

After tuberculosis and leprosy, Buruli-ulcer disease (caused by infection with Mycobacterium ulcerans) is the third most common mycobacterial disease in immunocompetent people. Countries in which the disease is endemic have been identified, predominantly in areas of tropical rain forest; the emergence of Buruli-ulcer disease in West African countries over the past decade has been dramatic. Current evidence suggests that the infection is transmitted through abraded skin or mild traumatic injuries after contact with contaminated water, soil, or vegetation; there is one unconfirmed preliminary report on possible transmission by insects. The clinical picture ranges from a painless nodule to large, undermined ulcerative lesions that heal spontaneously but slowly. Most patients are children. The disease is accompanied by remarkably few systemic symptoms, but occasionally secondary infections resulting in sepsis or tetanus cause severe systemic disease and death. Extensive scarring can lead to contractures of the limbs, blindness, and other adverse sequelae, which impose a substantial health and economic burden. Treatment is still primarily surgical, and includes excision, skin grafting, or both. Although BCG has a mild but significant protective effect, new vaccine developments directed at the toxins produced by M. ulcerans are warranted. In West Africa, affected populations are underprivileged, and the economic burden imposed by Buruli-ulcer disease is daunting. Combined efforts to improve treatment, prevention, control, and research strategies (overseen by the WHO and funded by international relief agencies) are urgently needed.

Typhoid fever in children aged less than 5 years

BACKGROUND

Calculation of the incidence of typhoid fever during preschool years is important to define the optimum age of immunisation and the choice of vaccines for public-health programmes in developing countries. Hospital-based studies have suggested that children younger than 5 years do not need vaccination against typhoid fever, but this view needs to be re-examined in community-based longitudinal studies. We undertook a prospective follow-up study of residents of a low-income urban area of Delhi, India, with active surveillance for case detection.

METHODS

A baseline census was undertaken in 1995. Between Nov 1, 1995, and Oct 31, 1996, we visited 8172 residents of 1820 households in Kalkaji, Delhi, twice weekly to detect febrile cases. Blood samples were obtained from febrile patients, and those who tested positive for Salmonella typhi were treated with ciprofloxacin.

FINDINGS

63 culture-positive typhoid fever cases were detected. Of these, 28 (44%) were in children aged under 5 years. The incidence rate of typhoid per 1000 person-years was 27.3 at age under 5 years, 11.7 at 5-19 years, and 1.1 between 19 and 40 years. The difference in the incidence of typhoid fever between those under 5 years and those aged 5-19 years (15.6 per 1000 person-years [95% CI 4.7-26.5]), and those aged 19-40 years (26.2 [16.0-36.3]) was significant (p<0.001 for both). The difference between the incidence of typhoid at 5-19 years and the incidence at 19-40 years was also significant (10.6 [6.3-14.8], p<0.001). Morbidity in those under 5 and in older people was similar in terms of duration of fever, signs and symptoms, and need for hospital admission.

INTERPRETATION

Our findings challenge the common view that typhoid fever is a disorder of school-age children and of adults. Typhoid is a common and significant cause of morbidity between 1 and 5 years of age. The optimum age of typhoid immunisation and the choice of vaccines needs to be reassessed.

First do no harm: making oral rehydration solution safer in a cholera epidemic

Oral rehydration solution (ORS) is lifesaving therapy for cholera and pediatric diarrhea. During a cholera epidemic in Guinea-Bissau, we evaluated the microbiologic quality of ORS prepared at a hospital and tested a simple intervention using special vessels for disinfecting tap water with bleach and for preparing, storing, and dispensing ORS. Few coliform bacteria and Escherichia coli were recovered from tap water; however, pre-intervention ORS contained numerous bacteria including E. coli and toxigenic Vibrio cholerae O1. In contrast, ORS samples from intervention vessels had few or no coliform bacteria, no E. coli, and no V. cholerae. Mean pre-intervention counts of coliform bacteria (3.4 x 10(7) colony-forming units [cfu]/100 ml) and E. coli (6.2 x 10(3) cfu) decreased significantly during the intervention period to 3.6 x 10(2) cfu and 0 cfu, respectively (P < 0.001). This simple system using bleach disinfectant and special storage vessels prevents bacterial contamination of ORS and reduces the risk of nosocomial transmission of cholera and other enteric pathogens.

Enteropathogenic bacteria in faecal swabs of young children fed on lactic acid-fermented cereal gruels

The influence of consumption of a lactic acid-fermented cereal gruel togwa with pH < or = 4 on the presence of faecal enteric bacteria such as campylobacter, enterohaemorrhagic Escherichia coli (EHEC:O157), enterotoxigenic Escherichia coli (ETEC), salmonella and shigella was evaluated. Under 5 years old healthy children listed in an ascending order of age were alternatively assigned and given either a lactic-acid fermented cereal gruel togwa (test diet) or an unfermented cereal gruel uji (control diet) once a day for 13 consecutive days. The presence of the enteropathogens was examined in rectal swabs collected from the children at baseline (before feeding session started), on days 7 and 13, and additionally 14 days (follow-up day) after the feeding session had stopped. The swabs were cultured on to different optimal media for respective enteropathogen and confirmed by standard microbiological and serological methods. Campylobacter spp. dominated among the enteropathogens (62% out of total) followed by Salmonella spp., ETEC and Shigella spp. Children with isolated enteropathogens in the togwa group was significantly reduced (P < 0.001) from 27.6% at baseline to 7.8, 8.2 and 12.7% on days 7, 13 and follow-up day, respectively. The effect was more pronounced in those children taking togwa > 6 times during the study period. In the control group, there was a slight decrease from 16.7% at baseline to 11.4% on day 7 and 8.1% on day 13. On the follow-up day, enteropathogens were found in 22.6% of the children, which was significantly higher than in those children taking togwa > 6 times. We conclude, that regular consumption of togwa with pH < or = 4, once a day, three times a week may help to control intestinal colonization with potential diarrhoea-causing pathogens in young children.

Risk of diphtheria among schoolchildren in the Russian Federation in relation to time since last vaccination

BACKGROUND

Between 1990 and 1996, more than 110,000 cases and 2900 deaths from diphtheria were reported in the Russian Federation. In 1994, because disease rates were high among children aged 7-10 years, the age of administration of the second booster dose of diphtheria vaccine was lowered from 9 years to 6 years, the age of school entry. To assess the impact of this policy change, we did a matched case-control study in three Russian cities.

METHODS

Children aged 6-8 years who had diphtheria between September, 1994, and December, 1996, were each matched with five to seven children acting as controls who were within 3 months of age of the case and were from the same class at school. We did a matched analysis using conditional logistic regression.

FINDINGS

We analysed the immunisation records of 58 cases and 306 controls. All but one case and all controls had received at least three doses of diphtheria-toxoid vaccine. 19 (33%) cases and 144 (47%) controls had received a booster dose of diphtheria toxoid within the previous 2 years. Cases were more likely than were controls to have received only four doses rather than five (odds ratio 2.8 [95% CI 1.2-6.5]) and to have a time since the last dose of diphtheria toxoid of 3-4 years (3.1 [1.1-9.1]) or 5-7 years (15.0 [2.5-89.0]), compared with children for whom it was 2 years or less. On multivariate analysis only a time since the last dose of 5-7 years remained significantly associated with disease (matched odds ratio adjusted for total number of doses 10.9 [1.6-75.1]).

CONCLUSION

A booster dose of diphtheria-toxoid vaccine given to children in the Russian Federation at 6-8 years of age reduced the interval since the last dose of diphtheria toxoid and improved protection against diphtheria.

Mass vaccination with a two-dose oral cholera vaccine in a refugee camp

In refugee settings, the use of cholera vaccines is controversial since a mass vaccination campaign might disrupt other priority interventions. We therefore conducted a study to assess the feasibility of such a campaign using a two-dose oral cholera vaccine in a refugee camp. The campaign, using killed whole-cell/recombinant B-subunit cholera vaccine, was carried out in October 1997 among 44,000 south Sudanese refugees in Uganda. Outcome variables included the number of doses administered, the drop-out rate between the two rounds, the proportion of vaccine wasted, the speed of administration, the cost of the campaign, and the vaccine coverage. Overall, 63,220 doses of vaccine were administered. At best, 200 vaccine doses were administered per vaccination site and per hour. The direct cost of the campaign amounted to US$ 14,655, not including the vaccine itself. Vaccine coverage, based on vaccination cards, was 83.0% and 75.9% for the first and second rounds, respectively. Mass vaccination of a large refugee population with an oral cholera vaccine therefore proved to be feasible. A pre-emptive vaccination strategy could be considered in stable refugee settings and in urban slums in high-risk areas. However, the potential cost of the vaccine and the absence of quickly accessible stockpiles are major drawbacks for its large-scale use.

Epidemiology of bacterial meningitis in Niamey, Niger, 1981-96

In the African meningitis belt the importance of endemic meningitis is not as well recognized as that of epidemics of meningococcal meningitis that occur from time to time. Using retrospective surveillance, we identified a total of 7078 cases of laboratory-diagnosed bacterial meningitis in Niamey, Niger, from 1981 to 1996. The majority (57.7%) were caused by Neisseria meningitidis, followed by Streptococcus pneumoniae (13.2%) and Haemophilus influenzae b (Hib) (9.5%). The mean annual incidence of bacterial meningitis was 101 per 100,000 population (70 per 100,000 during 11 non-epidemic years) and the average annual mortality rate was 17 deaths per 100,000. Over a 7-year period (including one major epidemic year) for which data were available, S. pneumoniae and Hib together caused more meningitis deaths than N. meningitidis. Meningitis cases were more common among males and occurred mostly during the dry season. Serogroup A caused 85.6% of meningococcal meningitis cases during the period investigated; three-quarters of these occurred among children aged < 15 years, and over 40% among under-5-year-olds. Both incidence and mortality rates were highest among infants aged < 1 year. In this age group, Hib was the leading cause of bacterial meningitis, followed by S. pneumoniae. The predominant cause of meningitis in persons aged 1-40 years was N. meningitidis. Use of the available vaccines against meningitis due to N. meningitidis, S. pneumoniae, and Hib could prevent substantial endemic illness and deaths in sub-Saharan Africa, and potentially prevent recurrent meningococcal epidemics.

Where do people go for treatment of sexually transmitted diseases?

CONTEXT

Major public health resources are devoted to the prevention of sexually transmitted diseases (STDs) through public STD clinics. However, little is known about where people actually receive treatment for STDs.

METHODS

As part of the National Health and Social Life Survey, household interviews were performed from February to September 1992 with 3,432 persons aged 18-59. Weighted population estimates and multinomial response methods were used to describe the prevalence of self-reported STDs and patterns of treatment utilization by persons who ever had a bacterial or viral STD.

RESULTS

An estimated two million STDs were self-reported in the previous year, and 22 million 18-59-year-olds self-reported lifetime STDs. Bacterial STDs (gonorrhea, chlamydia, nongonococcal urethritis, pelvic inflammatory disease and syphilis) were more common than viral STDs (genital herpes, genital warts, hepatitis and HIV). Genital warts were the most commonly reported STD in the past year, while gonorrhea was the most common ever-reported STD. Almost half of all respondents who had ever had an STD had gone to a private practice for treatment (49%); in comparison, only 5% of respondents had sought treatment at an STD clinic. Respondents with a bacterial STD were seven times more likely to report going to an STD clinic than were respondents with a viral STD--except for chlamydia, which was more likely to be treated at family planning clinics. Men were significantly more likely than women to go to an STD clinic. Young, poor or black respondents were all more likely to use a family planning clinic for STD treatment than older, relatively wealthy or white respondents. Age, sexual history and geographic location did not predict particular types of treatment-seeking.

CONCLUSIONS

The health care utilization patterns for STD treatment in the United States are complex. Specific disease diagnosis, gender, race and income status all affect where people will seek treatment. These factors need to be taken into account when STD prevention strategies are being developed.

Global burden of Shigella infections: implications for vaccine development and implementation of control strategies

Few studies provide data on the global morbidity and mortality caused by infection with Shigella spp.; such estimates are needed, however, to plan strategies of prevention and treatment. Here we report the results of a review of the literature published between 1966 and 1997 on Shigella infection. The data obtained permit calculation of the number of cases of Shigella infection and the associated mortality occurring worldwide each year, by age, and (as a proxy for disease severity) by clinical category, i.e. mild cases remaining at home, moderate cases requiring outpatient care, and severe cases demanding hospitalization. A sensitivity analysis was performed to estimate the high and low range of morbid and fatal cases in each category. Finally, the frequency distribution of Shigella infection, by serogroup and serotype and by region of the world, was determined. The annual number of Shigella episodes throughout the world was estimated to be 164.7 million, of which 163.2 million were in developing countries (with 1.1 million deaths) and 1.5 million in industrialized countries. A total of 69% of all episodes and 61% of all deaths attributable to shigellosis involved children under 5 years of age. The median percentages of isolates of S. flexneri, S. sonnei, S. boydii, and S. dysenteriae were, respectively, 60%, 15%, 6%, and 6% (30% of S. dysenteriae cases were type 1) in developing countries; and 16%, 77%, 2%, and 1% in industrialized countries. In developing countries, the predominant serotype of S. flexneri is 2a, followed by 1b, 3a, 4a, and 6. In industrialized countries, most isolates are S. flexneri 2a or other unspecified type 2 strains. Shigellosis, which continues to have an important global impact, cannot be adequately controlled with the existing prevention and treatment measures. Innovative strategies, including development of vaccines against the most common serotypes, could provide substantial benefits.

HIV infection and disturbances of vaginal flora during pregnancy

Disturbances of vaginal flora are common among women of reproductive age. In areas of sub-Saharan Africa where the prevalence of HIV is high, the frequency of bacterial vaginosis (BV) is also high. In this study, we assessed the association of BV and other disturbances of vaginal flora with prevalent HIV infection in two cross-sectional studies among pregnant women in urban Malawi. The prevalence of HIV-1 was 23% in 1990 and 30% in 1993. Overall, 30% of the women had BV, 59% had mild or moderate disturbance of vaginal flora, and only 11% had normal vaginal flora. Increasing prevalence of HIV was significantly associated with increasing severity of disturbance of vaginal flora (p < .00001, chi2 trend test). This trend of increased prevalence persisted after controlling for concurrent sexually transmitted diseases (STDs), sexual activity, and socioeconomic factors. After multivariate adjustment for potential confounders, the odds ratio for the association of BV with prevalent HIV infection was 3.0 (95% confidence interval [CI], 2.4-3.8), that of moderate vaginal disturbance with HIV infection was 2.2 (95% CI, 1.7-2.8), and that of mild vaginal disturbance with HIV infection was 1.6 (95% CI, 1.3-2.1). Among women with BV, HIV infection was higher among younger women than older, implying more recent infection. Although these studies were cross-sectional, our data suggest that BV could be associated with increased susceptibility to HIV infection.

A prospective study of community-acquired bloodstream infections among febrile adults admitted to Mulago Hospital in Kampala, Uganda

Septicemia is a frequent cause of death in HIV-infected adults in developing countries. Additional prospective studies are needed to determine the etiology of bloodstream infections (BSI) in febrile HIV-infected adults and guide initial evaluation and treatment in this setting. We assessed the prevalence and etiology of community-acquired BSI among 299 consecutive febrile adult medical admissions to Mulago Hospital, Kampala, Uganda, over a 4-month period in 1997. The median age of our patients was 30 years, 159 (53%) were male, and 227 (76%) HIV-1-seropositive. Overall, prevalence of bacteremia or fungemia (1 patient) was 24%. Bacteremia was more frequent in HIV-infected than in uninfected patients (27% versus 15%, respectively; p = .04). Mycobacterium tuberculosis (n = 28), Streptococcus pneumoniae (n = 15) and Salmonella species (n = 13) were the most frequent isolates. All Salmonella and mycobacterial isolates were recovered from HIV-infected patients. Pneumococcal bacteremia was not associated with HIV seropositivity. M. avium complex and M. simiae were isolated from two HIV-infected patients. The rate of mycobacteremia among febrile HIV-infected adults presenting for hospitalization was 13%. Bacteremia and disseminated tuberculosis are frequent causes of morbidity in febrile HIV-infected Ugandan adults. Initial empiric antibiotic coverage in this setting should be targeted toward the pneumococcus and gram-negative enteric bacilli, especially nontyphi Salmonella species. All patients presenting with chronic cough should be evaluated for tuberculosis.

Molecular epidemiology and antifungal susceptibility of Cryptococcus neoformans isolates from Ugandan AIDS patients

Little is known of the antifungal susceptibility patterns and molecular epidemiology of Cryptococcus neoformans from tropical regions. We studied 164 clinical isolates of C. neofomans from 120 Ugandan AIDS patients with cryptococcal meningitis by analyzing their electrophoretic karyotypes and antifungal susceptibility profiles. Computer-assisted analysis of karyotype patterns was performed to generate dendrograms. MICs of fluconazole and flucytosine were determined by reference methods. A total of 43 distinguishable DNA types were identified among the 164 isolates. Only 30 patients (25%) were infected with their own unique strain of c. neoformans, whereas 75% of the patients shared their infecting strain with at least one other patient. Among 17 patients with more than one CSF isolate of C. neoformans, sequential isolates were identical or highly related in 12 (71%) and were different in five patients (29%). The isolates were susceptible to both fluconazole and flucytosine and there were no instances in which a stepwise increase in either fluconazole or flucytosine MICs was observed among serial isolates. These findings suggest that the epidemiology of cryptococcal disease in AIDS patients from tropical regions may be somewhat different from that observed in more temperate climates.

Cholera in Turkana

An outbreak of cholera which killed 17 people at Kalokol on the shores of Lake Turkana has been brought under control. Rift Valley provincial medical officer, Dr. Kenneth Chebet, said 369 cases had been attended to within 1 month but no new cases were now being seen. AMFEF airlifted medical supplies to augment government efforts in the affected areas. Chiefs meetings were held at which clinical officers advised residents on how to curb the spread of the disease.

A review of bacteriological culture of removed intrauterine contraceptive devices

A retrospective review of clinical and microbiological data was made, over an 18 month period, of intrauterine contraceptive devices removed and sent for examination. An association with symptoms at time of removal was found for Streptococcus agalactiae, Streptococcus milleri, enterobacteria and obligate anaerobes. Thirty four per cent of IUDs yielded one or more Actinomycesspecies spp but no correlation with symptoms was found. In the small group of symptomatic patients who were followed up, no difference in outcome was observed between those who were treated with antibiotics and those who were not.

Effects of Cryptosporidium parvum infection in Peruvian children: growth faltering and subsequent catch-up growth

The authors conducted a 2-year (1989-1991) community-based longitudinal study in a shantytown in Lima, Peru, to examine the effect of Cryptosporidium parvum infection on child growth during the year following the onset of infection. A cohort of children, aged 0-3 months at recruitment, was followed monthly for anthropometrics, weekly for stool samples, and daily for diarrheal status. Data from 185 children in the cohort permitted a comparison of growth in C. parvum-infected and noninfected children. The analyses fitted smooth, flexible curves with a linear random-effects model to estimate growth differences between C. parvum-infected and noninfected children. Children infected with C. parvum experienced growth faltering, both in weight and in height, for several months after the onset of infection, followed by a period of catch-up growth. Younger children took longer to catch up in weight than did older children. Catch-up growth, however, did not occur in children infected between ages 0 and 5 months. These children did not catch up in height, and one year after infection they exhibited an average deficit of 0.95 cm (95% confidence interval (CI) 0.38-1.53) relative to noninfected children of similar age. Stunted children who became infected also did not catch up in either weight or height, and one year after infection they exhibited a height deficit of 1.05 cm (95% CI 0.46-1.66) relative to noninfected, stunted children of similar age. These results indicate that Cryptosporidium parvum has a lasting adverse effect on linear (height) growth, especially when acquired during infancy and when children are stunted before they become infected.

Sexually transmitted infections among sex workers in KwaZulu-Natal, South Africa

OBJECTIVE

The purpose of this study was to investigate the prevalence of sexually transmitted infections, including human immunodeficiency virus (HIV), among female sex workers operating at truckstops in the KwaZulu-Natal midlands of South Africa.

METHODS

A total of 145 sex workers were recruited from August 1996 to March 1997. A gynecologic examination, including a speculum examination, was performed. Investigations were performed to identify gonorrhea, syphilis, chlamydia (infection), candidiasis, trichomoniasis, bacterial vaginosis, and HIV infection.

RESULTS

A total of 50.3% of the sex workers were HIV positive. Infection with Trichomonas vaginalis was present in 41.3% of the women, Candida albicans in 40.6%, Neisseria gonorrheae in 14.3%, and Chlamydia trachomatis in 16.4%. Bacterial vaginosis was present in 71% and active syphilis in 42.1% of the women.

CONCLUSION

The high prevalence of sexually transmitted infections, including HIV, clearly highlights the urgent need for interventions. In addition to empowering women with methods they can use and control to reduce their risk of infection, an effective approach to control of sexually transmitted infections also needs to recognize the role of the clients, such as truck drivers, so that they also are targeted for interventions.

Protecting the world's children: the story of WHO's immunization programme

Systematic immunization on a worldwide scale was not officially recognized as a practical possibility until 1974, when WHO launched its Expanded Programme on Immunization. Today, 80% of the world's children receive this form of protection against childhood diseases during their first year of life. Coverage can reach 90% by the year 2000, the effectiveness of the vaccines used is improving, and vaccines against additional diseases are being added to the programme.

Endogenous Candida endophthalmitis after induced abortion

PURPOSE

To report two young healthy women who developed endogenous Candida endophthalmitis after undergoing surgically induced abortion.

METHOD

Case reports.

RESULTS

In two eyes of two patients, a diagnosis of Candida endophthalmitis was established by typical fundus appearance, positive vaginal culture, and, in one case, positive vitreous culture. After vitrectomy and intravitreal amphotericin B injection, one eye of one patient had a best-corrected visual acuity of 20/200, whereas one eye of one patient, who had systemic corticosteroid treatment before the correct diagnosis, developed recurrent retinal detachment and a best-corrected visual acuity of counting fingers.

CONCLUSIONS

Induced abortion may cause endogenous Candida endophthalmitis in young healthy pregnant women. Systemic corticosteroid treatment may increase the risk of endophthalmitis.

Estimation of vaccine efficacy in the presence of waning: application to cholera vaccines

The authors present a nonparametric method for estimating vaccine efficacy as a smooth function of time from vaccine trials. Use of the method requires a minimum of assumptions. Estimation is based on the smoothed case hazard rate ratio comparing the vaccinated with the unvaccinated. The estimation procedure allows investigators to assess time-varying changes in vaccine-induced protection, such as those produced by waning and boosting. The authors use the method to reanalyze data from a vaccine trial of two cholera vaccines in rural Bangladesh. This analysis reveals the differential protection and waning effects for the vaccines as a function of biotype and age.

Cholera reveals helminthiasis problem

Cholera has now lasted for about 6 months in our hilly region in Mwanza, Tanzania. The heavy rains coupled with the poor sanitary conditions and sewage disposal system have worsened the situation. The pit latrines used by the majority of low-income people are either not adequately and properly used for excreta disposal or they overflow. At our regional referral and consultancy hospital we were, for a period, receiving cholera cases which should have been managed in isolation at other centers. (This situation has now been rectified.) Some of the children with cholera either vomited or passed Ascaris lumbricoides in their rice water-like stools. Previously, these children were not being treated for ascariasis. Practical steps can be taken to reduce the transmission of fecal-borne infections. For more than 30 years we have failed to have a latrine for each family; we should aim for at least one for every 10 households. The provision of clean tap-water and facilities to deworm pre-school children would also be welcomed. In addition, medical officers should actively instruct the community in the science of hygiene.