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WHAT'S NEW THIS THURSDAY

Wednesday, 8th of February 2012 Print
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  • ·         WHAT’S NEW THIS THURSDAY: CHOLERA IN AFRICA; ITN/MEASLES CAMPAIGN IN MADAGASCAR; IPTI IMPACT IN SOUTHERN TANZANIA

 

  • BOOK REVIEW: AFRICA IN THE TIME OF CHOLERA: A HISTORY OF PANDEMICS FROM 1817 TO THE PRESENT

 Also at www.cdc.gov/eid

Myron Echenberg

Cambridge University Press, New York, NY, USA, 2011 ISBN: 978-0521188203 Pages: 232; Price: US $27.99, UK £17.99

In contrast to the setting of Love in the Time of Cholera by Gabriel Garcia Márquez, we live in a time when no one should have to contract or die of cholera. Nonetheless, ≈100,000 persons in Africa contracted cholera in 2011 alone, and >2,500 died in what Mintz and Guerrant have referred to as an “unconscionable tragedy” (1).

In Africa in the Time of Cholera, Echenberg chronicles how, within a century, cholera has been transformed from an imported scourge to an African disease. Echenberg sets the stage with a concise historical overview, depicting the eventual triumph over cholera in most of the world as a technological conquest over the original technological advances that created pandemic cholera. The first part of the book, devoted to the first 6 pandemics, is a lucid account of cholera in Africa before the 1950s. It includes some lesser known facets of cholera history, such as James Christie’s excellent mid-19th century epidemiologic work in Zanzibar and the political consequences of that period’s cholera outbreaks in Tunisia.

The second part, which covers the current and 7th cholera pandemic, begins with an overview of medical advances that have yielded today’s intervention tools. The section unfortunately includes a smattering of scientific inaccuracies, mostly related to the cell biology of Vibrio cholerae, in an otherwise well-researched and accessible book. Drawing from biomedical as well as historical sources, Echenberg demonstrates how the failure to provide clean water and sanitation to most of Africa’s inhabitants has led to explosive human and fi nancial costs from cholera. He sketches portraits of these failures in countries with different histories andgovernance problems, illustrating infrastructural setbacks that have enabled cholera to erupt in present day Angola, South Africa, Senegal, and Zimbabwe.

The book highlights the success of oral rehydration therapy for cholera case management, and the futility of antimicrobial drug strategies because of drug resistance. Echenberg touches on the potential for vaccines, withappropriate caution, emphasizing that vaccination is no substitute for plumbing. Unfortunately, vaccines are often presented in a manner that entangles their weaknesses with those of antimicrobial drugs, underplaying the potential advantages that vaccines may have over drugs in dealing with outbreaks once they occur. It has taken cholera experts decades to advocate for vaccine use in high risk settings, culminating in World Health Assemblyresolution WHA64.15 in May 2011, which urges that all states “give consideration to the administration of vaccines, where appropriate, in conjunction with other recommended prevention and control methods andnot as a substitute for such methods.”

The most compelling arguments for vaccine use in conjunction with preventive interventions were published just as the book was being completed (2), and it is unfortunate that they were not included in this otherwise commendable analysis of intervention possibilities. However, Echenberg is to be commended for the strength of the key message of the book: that lack of potable water and sanitation, the factors that eliminated cholera from much of the world, is the principal reason why today’s cholera crisis (excluding complex emergencies, perhaps typifi ed by the ongoing epidemic in Haiti) is largely African.

The story of cholera in Africa is long overdue and timely. In his usual engaging and accessible style, Echenberg has written another book that infectious disease experts should read for historical and social perspectives on the diseases they investigate and treat.

Iruka N. Okeke

Author affiliation: Haverford College, Haverford, Pennsylvania, USA

DOI: http://dx.doi.org/10.3201/eid1802.111535

References

1. Mintz ED, Guerrant RL. A lion in our village: the unconscionable tragedy of cholera in Africa. N Engl J Med. 2009;360:1060–3. http://dx.doi.org/10.1056/NEJMp0810559

2. Bhattacharya S, Black R, Bourgeois L, Clemens J, Cravioto A, Deen JL, et al. Public health. The cholera crisis in Africa. Science. 2009;324:885. http://dx.doi.

Address for correspondence: Iruka N. Okeke, Department of Biology, Haverford College,370 Lancaster Ave, Haverford, PA 19041, USA;email: iokeke@haverford.edu

Are any readers aware of combined measles/LLIN campaigns done since the year 2010?


• IMPROVED EQUITY IN MEASLES VACCINATION FROM INTEGRATING INSECTICIDE-TREATED BEDNETS IN A VACCINATION CAMPAIGN, MADAGASCAR

James L. Goodson1, Manisha A. Kulkarni2, Jodi L. Vanden Eng1, Kathleen A. Wannemuehler1, Annett H. Cotte1, Rachelle E. Desrochers2, Bakolalao Randriamanalina3 and Elizabeth T. Luman1 1 Centers for Disease Control and Prevention, Atlanta, GA, USA 2 HealthBridge ⁄ University of Ottawa, Ottawa, Canada 3 Expanded Programme on Immunization, Ministry of Health, Madagascar

Abstract below; full text to subscribers. See also free full text of a previous article on this subject at http://www.ajtmh.org/content/82/3/420.long

Objective To evaluate the effect of integrating ITN distribution on measles vaccination campaign coverage in Madagascar. Methods Nationwide cross-sectional survey to estimate measles vaccination coverage, nationally, and in districts with and without ITN integration. To evaluate the effect of ITN integration, propensity score matching was used to create comparable samples in ITN and non-ITN districts. Relative risks (RR) and 95% confidence intervals (CI) were estimated via log-binomial models. Equity ratios, defined as the coverage ratio between the lowest and highest household wealth quintile (Q), were used to assess equity in measles vaccination coverage. results National measles vaccination coverage during the campaign was 66.9% (95% CI 63.0–70.7). Among the propensity score subset, vaccination campaign coverage was higher in ITN districts (70.8%) than non-ITN districts (59.1%) (RR = 1.3, 95% CI 1.1–1.6). Among children in the poorest wealth quintile, vaccination coverage was higher in ITN than in non-ITN districts (Q1; RR = 2.4, 95% CI 1.2–4.8) and equity for measles vaccination was greater in ITN districts (equity ratio = 1.0, 95% CI 0.8–1.3) than in non-ITN districts (equity ratio = 0.4, 95% CI 0.2–0.8).

Conclusion: Integration of ITN distribution with a vaccination campaign might improve measles vaccination coverage among the poor, thus providing protection for the most vulnerable and difficult to reach children.

 

Malar J. 2011 Dec 30;10:387.

  • CLUSTER-RANDOMIZED STUDY OF INTERMITTENT PREVENTIVE TREATMENT FOR MALARIA IN INFANTS (IPTI) IN SOUTHERN TANZANIA: EVALUATION OF IMPACT ON SURVIVAL.

‘The lack of evidence of an effect of IPTi on survival could be a false negative result due to a lack of power or imbalance of unmeasured confounders. Alternatively, there could be no mortality impact of IPTi due to low coverage, late administration, drug resistance, decreased malaria transmission or improvements in vector control and case management.’

The electronic version of this article is the complete one and can be found online at: http://www.malariajournal.com/content/10/1/387

* Corresponding author: Joanna RMA Schellenberg Joanna.schellenberg@lshtm.ac.uk

Malaria Journal 2011, 10:387 doi:10.1186/1475-2875-10-387

© 2011 Schellenberg et al; licensee BioMed Central Ltd.

This is an Open Acess article distributed under the terms of the Creative Common Attribution License (http://creativecommons.org/license/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Background

Intermittent Preventive Treatment for malaria control in infants (IPTi) consists of the administration of a treatment dose of an anti-malarial drug, usually sulphadoxine-pyrimethamine, at scheduled intervals, regardless of the presence of Plasmodium falciparum infection. A pooled analysis of individually randomized trials reported that IPTi reduced clinical episodes by 30%. This study evaluated the effect of IPTi on child survival in the context of a five-district implementation project in southern Tanzania. [Trial registration: clinical trials.gov NCT00152204].

Methods

After baseline household and health facility surveys in 2004, five districts comprising 24 divisions were randomly assigned either to receive IPTi (n = 12) or not (n = 12). Implementation started in March 2005, led by routine health services with support from the research team. In 2007, a large household survey was undertaken to assess the impact of IPTi on survival in infants aged two-11 months through birth history interviews with all women aged 13-49 years. The analysis is based on an "intention-to-treat" ecological design, with survival outcomes analysed according to the cluster in which the mothers lived.

Results

Survival in infants aged two-11 months was comparable in IPTi and comparison areas at baseline. In intervention areas in 2007, 48% of children aged 12-23 months had documented evidence of receiving three doses of IPTi, compared to 2% in comparison areas (P < 0.0001). Over the three years of the study there was a marked improvement in survival in both groups. Between 2001-4 and 2005-7, mortality rates in two-11 month olds fell from 34.1 to 23.6 per 1,000 person-years in intervention areas and from 32.3 to 20.7 in comparison areas. In 2007, divisions implementing IPTi had a 14% (95% CI -12%, 49%) higher mortality rate in two-11 month olds in comparison with non-implementing divisions (P = 0.31).

Conclusion

The lack of evidence of an effect of IPTi on survival could be a false negative result due to a lack of power or imbalance of unmeasured confounders. Alternatively, there could be no mortality impact of IPTi due to low coverage, late administration, drug resistance, decreased malaria transmission or improvements in vector control and case management. This study raises important questions for programme evaluation design.

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