Incidence of Infectious Diseases One Month after the Bam Earthquake (2004)

The Impact of Earthquakes on Public Health: A Narrative Review of Infectious Diseases in the Post-Disaster Period Aiming to Disaster Risk Reduction

Earthquakes are among the most impressive natural phenomena with very high potential to set off a chain of effects that significantly affects public health through casualties and injuries. Related disasters are attributed not only to the strong ground motion and coseismic phenomena but also to secondary effects, comprising mainly landslides and tsunamis, among others. All these can create harsh conditions favorable for the emergence of infectious diseases that are capable of causing additional human and economic losses and disruption of the emergency and recovery process. The present study comprises an extensive narrative review of the existing literature on the earthquake-triggered infectious diseases recorded worldwide, along with their symptoms, causative pathogens, associated risk factors, most vulnerable population groups, and prevention strategies. Respiratory, gastrointestinal, and vector-borne diseases, as well as wound and skin infections, are mainly recorded among the earthquake-affected population. Measures for effectively preventing earthquake-triggered infectious diseases are also proposed. One of the widely proposed measures is the establishment of a proper disease surveillance system in order to immediately and effectively identify the pre- and post-disaster occurrence of infectious diseases. This approach significantly contributes to disease trends monitoring, validation of early warning, and support of the emergency response and recovery actions.

Incidence of infectious diseases after earthquakes: a systematic review and meta-analysis

OBJECTIVES

Evaluation of the incidence of infectious diseases after natural disasters can help develop healthcare policies. This study provides a global review of the most prevalent infectious diseases observed after earthquakes.

STUDY DESIGN

A systematic review and meta-analysis were performed.

METHODS

A systematic review was performed on electronic databases, including PubMed, Scopus and Web of Science, up to March 2020 (with no time limitations). Studies addressing earthquakes and infectious diseases were collected based on specified inclusion and exclusion criteria. Subsequently, the quality of the studies was assessed by the Newcastle-Ottawa scale (NOS). Data analyses were carried out on six subgroups under five different disease categories using comprehensive meta-analysis software.

RESULTS

In total, 24 studies qualified for the systematic review and 18 were included in the meta-analysis. The incidences of gastrointestinal infections, dermal infections, respiratory infections, central nervous system infections and other infectious diseases were as follows: odds ratio (OR) 163.4 (95% confidence interval [CI]: 31.0-858.1), OR 84.5 (95% CI: 27.1-262.8), OR 9.9 (95% CI: 3.5-27.7), OR 0.5 (95% CI: 0.2-1.1) and OR 4.4 (95% CI: 1.9-9.9) cases per 100,000 people, respectively. The association between the incidences of infectious diseases before and after earthquakes was significant, namely, 1.561 (95% CI: 1.244-1.957) with a P-value <0.001.

CONCLUSIONS

The results show an increase in the prevalence of infectious diseases after earthquakes. Governments should take essential measures to be better prepared for such unpredictable catastrophes.

Tularemia and plague survey in rodents in an earthquake zone in southeastern Iran

OBJECTIVES

Earthquakes are one the most common natural disasters that lead to increased mortality and morbidity from transmissible diseases, partially because the rodents displaced by an earthquake can lead to an increased rate of disease transmission. The aim of this study was to evaluate the prevalence of plague and tularemia in rodents in the earthquake zones in southeastern Iran.

METHODS

In April 2013, a research team was dispatched to explore the possible presence of diseases in rodents displaced by a recent earthquake magnitude 7.7 around the cities of Khash and Saravan in Sistan and Baluchestan Province. Rodents were trapped near and in the earthquake zone, in a location where an outbreak of tularemia was reported in 2007. Rodent serums were tested for a serological survey using an enzyme-linked immunosorbent assay.

RESULTS

In the 13 areas that were studied, nine rodents were caught over a total of 200 trap-days. Forty-eight fleas and 10 ticks were obtained from the rodents. The ticks were from the Hyalomma genus and the fleas were from the Xenopsylla genus. All the trapped rodents were Tatera indica. Serological results were negative for plague, but the serum agglutination test was positive for tularemia in one of the rodents. Tatera indica has never been previously documented to be involved in the transmission of tularemia.

CONCLUSIONS

No evidence of the plague cycle was found in the rodents of the area, but evidence was found of tularemia infection in rodents, as demonstrated by a positive serological test for tularemia in one rodent.

The burden of acute respiratory infections in crisis-affected populations: a systematic review

Crises due to armed conflict, forced displacement and natural disasters result in excess morbidity and mortality due to infectious diseases. Historically, acute respiratory infections (ARIs) have received relatively little attention in the humanitarian sector. We performed a systematic review to generate evidence on the burden of ARI in crises, and inform prioritisation of relief interventions. We identified 36 studies published since 1980 reporting data on the burden (incidence, prevalence, proportional morbidity or mortality, case-fatality, attributable mortality rate) of ARI, as defined by the International Classification of Diseases, version 10 and as diagnosed by a clinician, in populations who at the time of the study were affected by natural disasters, armed conflict, forced displacement, and nutritional emergencies. We described studies and stratified data by age group, but did not do pooled analyses due to heterogeneity in case definitions. The published evidence, mainly from refugee camps and surveillance or patient record review studies, suggests very high excess morbidity and mortality (20-35% proportional mortality) and case-fatality (up to 30-35%) due to ARI. However, ARI disease burden comparisons with non-crisis settings are difficult because of non-comparability of data. Better epidemiological studies with clearer case definitions are needed to provide the evidence base for priority setting and programme impact assessments. Humanitarian agencies should include ARI prevention and control among infants, children and adults as priority activities in crises. Improved data collection, case management and vaccine strategies will help to reduce disease burden.